1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1986, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright 2015, Joyent, Inc. All rights reserved.
  24  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  25  */
  26 
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T     */
  28 /*        All Rights Reserved   */
  29 
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39 
  40 /*
  41  * VM - shared or copy-on-write from a vnode/anonymous memory.
  42  */
  43 
  44 #include <sys/types.h>
  45 #include <sys/param.h>
  46 #include <sys/t_lock.h>
  47 #include <sys/errno.h>
  48 #include <sys/systm.h>
  49 #include <sys/mman.h>
  50 #include <sys/debug.h>
  51 #include <sys/cred.h>
  52 #include <sys/vmsystm.h>
  53 #include <sys/tuneable.h>
  54 #include <sys/bitmap.h>
  55 #include <sys/swap.h>
  56 #include <sys/kmem.h>
  57 #include <sys/sysmacros.h>
  58 #include <sys/vtrace.h>
  59 #include <sys/cmn_err.h>
  60 #include <sys/callb.h>
  61 #include <sys/vm.h>
  62 #include <sys/dumphdr.h>
  63 #include <sys/lgrp.h>
  64 
  65 #include <vm/hat.h>
  66 #include <vm/as.h>
  67 #include <vm/seg.h>
  68 #include <vm/seg_vn.h>
  69 #include <vm/pvn.h>
  70 #include <vm/anon.h>
  71 #include <vm/page.h>
  72 #include <vm/vpage.h>
  73 #include <sys/proc.h>
  74 #include <sys/task.h>
  75 #include <sys/project.h>
  76 #include <sys/zone.h>
  77 #include <sys/shm_impl.h>
  78 
  79 /*
  80  * segvn_fault needs a temporary page list array.  To avoid calling kmem all
  81  * the time, it creates a small (PVN_GETPAGE_NUM entry) array and uses it if
  82  * it can.  In the rare case when this page list is not large enough, it
  83  * goes and gets a large enough array from kmem.
  84  *
  85  * This small page list array covers either 8 pages or 64kB worth of pages -
  86  * whichever is smaller.
  87  */
  88 #define PVN_MAX_GETPAGE_SZ      0x10000
  89 #define PVN_MAX_GETPAGE_NUM     0x8
  90 
  91 #if PVN_MAX_GETPAGE_SZ > PVN_MAX_GETPAGE_NUM * PAGESIZE
  92 #define PVN_GETPAGE_SZ  ptob(PVN_MAX_GETPAGE_NUM)
  93 #define PVN_GETPAGE_NUM PVN_MAX_GETPAGE_NUM
  94 #else
  95 #define PVN_GETPAGE_SZ  PVN_MAX_GETPAGE_SZ
  96 #define PVN_GETPAGE_NUM btop(PVN_MAX_GETPAGE_SZ)
  97 #endif
  98 
  99 /*
 100  * Private seg op routines.
 101  */
 102 static int      segvn_dup(struct seg *seg, struct seg *newseg);
 103 static int      segvn_unmap(struct seg *seg, caddr_t addr, size_t len);
 104 static void     segvn_free(struct seg *seg);
 105 static faultcode_t segvn_fault(struct hat *hat, struct seg *seg,
 106                     caddr_t addr, size_t len, enum fault_type type,
 107                     enum seg_rw rw);
 108 static faultcode_t segvn_faulta(struct seg *seg, caddr_t addr);
 109 static int      segvn_setprot(struct seg *seg, caddr_t addr,
 110                     size_t len, uint_t prot);
 111 static int      segvn_checkprot(struct seg *seg, caddr_t addr,
 112                     size_t len, uint_t prot);
 113 static int      segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta);
 114 static size_t   segvn_swapout(struct seg *seg);
 115 static int      segvn_sync(struct seg *seg, caddr_t addr, size_t len,
 116                     int attr, uint_t flags);
 117 static size_t   segvn_incore(struct seg *seg, caddr_t addr, size_t len,
 118                     char *vec);
 119 static int      segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
 120                     int attr, int op, ulong_t *lockmap, size_t pos);
 121 static int      segvn_getprot(struct seg *seg, caddr_t addr, size_t len,
 122                     uint_t *protv);
 123 static u_offset_t       segvn_getoffset(struct seg *seg, caddr_t addr);
 124 static int      segvn_gettype(struct seg *seg, caddr_t addr);
 125 static int      segvn_getvp(struct seg *seg, caddr_t addr,
 126                     struct vnode **vpp);
 127 static int      segvn_advise(struct seg *seg, caddr_t addr, size_t len,
 128                     uint_t behav);
 129 static void     segvn_dump(struct seg *seg);
 130 static int      segvn_pagelock(struct seg *seg, caddr_t addr, size_t len,
 131                     struct page ***ppp, enum lock_type type, enum seg_rw rw);
 132 static int      segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len,
 133                     uint_t szc);
 134 static int      segvn_getmemid(struct seg *seg, caddr_t addr,
 135                     memid_t *memidp);
 136 static lgrp_mem_policy_info_t   *segvn_getpolicy(struct seg *, caddr_t);
 137 static int      segvn_capable(struct seg *seg, segcapability_t capable);
 138 static int      segvn_inherit(struct seg *, caddr_t, size_t, uint_t);
 139 
 140 struct  seg_ops segvn_ops = {
 141         segvn_dup,
 142         segvn_unmap,
 143         segvn_free,
 144         segvn_fault,
 145         segvn_faulta,
 146         segvn_setprot,
 147         segvn_checkprot,
 148         segvn_kluster,
 149         segvn_swapout,
 150         segvn_sync,
 151         segvn_incore,
 152         segvn_lockop,
 153         segvn_getprot,
 154         segvn_getoffset,
 155         segvn_gettype,
 156         segvn_getvp,
 157         segvn_advise,
 158         segvn_dump,
 159         segvn_pagelock,
 160         segvn_setpagesize,
 161         segvn_getmemid,
 162         segvn_getpolicy,
 163         segvn_capable,
 164         segvn_inherit
 165 };
 166 
 167 /*
 168  * Common zfod structures, provided as a shorthand for others to use.
 169  */
 170 static segvn_crargs_t zfod_segvn_crargs =
 171         SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
 172 static segvn_crargs_t kzfod_segvn_crargs =
 173         SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_USER,
 174         PROT_ALL & ~PROT_USER);
 175 static segvn_crargs_t stack_noexec_crargs =
 176         SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_EXEC, PROT_ALL);
 177 
 178 caddr_t zfod_argsp = (caddr_t)&zfod_segvn_crargs;   /* user zfod argsp */
 179 caddr_t kzfod_argsp = (caddr_t)&kzfod_segvn_crargs; /* kernel zfod argsp */
 180 caddr_t stack_exec_argsp = (caddr_t)&zfod_segvn_crargs;     /* executable stack */
 181 caddr_t stack_noexec_argsp = (caddr_t)&stack_noexec_crargs; /* noexec stack */
 182 
 183 #define vpgtob(n)       ((n) * sizeof (struct vpage))   /* For brevity */
 184 
 185 size_t  segvn_comb_thrshld = UINT_MAX;  /* patchable -- see 1196681 */
 186 
 187 size_t  segvn_pglock_comb_thrshld = (1UL << 16);  /* 64K */
 188 size_t  segvn_pglock_comb_balign = (1UL << 16);           /* 64K */
 189 uint_t  segvn_pglock_comb_bshift;
 190 size_t  segvn_pglock_comb_palign;
 191 
 192 static int      segvn_concat(struct seg *, struct seg *, int);
 193 static int      segvn_extend_prev(struct seg *, struct seg *,
 194                     struct segvn_crargs *, size_t);
 195 static int      segvn_extend_next(struct seg *, struct seg *,
 196                     struct segvn_crargs *, size_t);
 197 static void     segvn_softunlock(struct seg *, caddr_t, size_t, enum seg_rw);
 198 static void     segvn_pagelist_rele(page_t **);
 199 static void     segvn_setvnode_mpss(vnode_t *);
 200 static void     segvn_relocate_pages(page_t **, page_t *);
 201 static int      segvn_full_szcpages(page_t **, uint_t, int *, uint_t *);
 202 static int      segvn_fill_vp_pages(struct segvn_data *, vnode_t *, u_offset_t,
 203     uint_t, page_t **, page_t **, uint_t *, int *);
 204 static faultcode_t segvn_fault_vnodepages(struct hat *, struct seg *, caddr_t,
 205     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
 206 static faultcode_t segvn_fault_anonpages(struct hat *, struct seg *, caddr_t,
 207     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
 208 static faultcode_t segvn_faultpage(struct hat *, struct seg *, caddr_t,
 209     u_offset_t, struct vpage *, page_t **, uint_t,
 210     enum fault_type, enum seg_rw, int);
 211 static void     segvn_vpage(struct seg *);
 212 static size_t   segvn_count_swap_by_vpages(struct seg *);
 213 
 214 static void segvn_purge(struct seg *seg);
 215 static int segvn_reclaim(void *, caddr_t, size_t, struct page **,
 216     enum seg_rw, int);
 217 static int shamp_reclaim(void *, caddr_t, size_t, struct page **,
 218     enum seg_rw, int);
 219 
 220 static int sameprot(struct seg *, caddr_t, size_t);
 221 
 222 static int segvn_demote_range(struct seg *, caddr_t, size_t, int, uint_t);
 223 static int segvn_clrszc(struct seg *);
 224 static struct seg *segvn_split_seg(struct seg *, caddr_t);
 225 static int segvn_claim_pages(struct seg *, struct vpage *, u_offset_t,
 226     ulong_t, uint_t);
 227 
 228 static void segvn_hat_rgn_unload_callback(caddr_t, caddr_t, caddr_t,
 229     size_t, void *, u_offset_t);
 230 
 231 static struct kmem_cache *segvn_cache;
 232 static struct kmem_cache **segvn_szc_cache;
 233 
 234 #ifdef VM_STATS
 235 static struct segvnvmstats_str {
 236         ulong_t fill_vp_pages[31];
 237         ulong_t fltvnpages[49];
 238         ulong_t fullszcpages[10];
 239         ulong_t relocatepages[3];
 240         ulong_t fltanpages[17];
 241         ulong_t pagelock[2];
 242         ulong_t demoterange[3];
 243 } segvnvmstats;
 244 #endif /* VM_STATS */
 245 
 246 #define SDR_RANGE       1               /* demote entire range */
 247 #define SDR_END         2               /* demote non aligned ends only */
 248 
 249 #define CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr) {          \
 250                 if ((len) != 0) {                                             \
 251                         lpgaddr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);  \
 252                         ASSERT(lpgaddr >= (seg)->s_base);               \
 253                         lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)((addr) +    \
 254                             (len)), pgsz);                                    \
 255                         ASSERT(lpgeaddr > lpgaddr);                        \
 256                         ASSERT(lpgeaddr <= (seg)->s_base + (seg)->s_size);    \
 257                 } else {                                                      \
 258                         lpgeaddr = lpgaddr = (addr);                          \
 259                 }                                                             \
 260         }
 261 
 262 /*ARGSUSED*/
 263 static int
 264 segvn_cache_constructor(void *buf, void *cdrarg, int kmflags)
 265 {
 266         struct segvn_data *svd = buf;
 267 
 268         rw_init(&svd->lock, NULL, RW_DEFAULT, NULL);
 269         mutex_init(&svd->segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
 270         svd->svn_trnext = svd->svn_trprev = NULL;
 271         return (0);
 272 }
 273 
 274 /*ARGSUSED1*/
 275 static void
 276 segvn_cache_destructor(void *buf, void *cdrarg)
 277 {
 278         struct segvn_data *svd = buf;
 279 
 280         rw_destroy(&svd->lock);
 281         mutex_destroy(&svd->segfree_syncmtx);
 282 }
 283 
 284 /*ARGSUSED*/
 285 static int
 286 svntr_cache_constructor(void *buf, void *cdrarg, int kmflags)
 287 {
 288         bzero(buf, sizeof (svntr_t));
 289         return (0);
 290 }
 291 
 292 /*
 293  * Patching this variable to non-zero allows the system to run with
 294  * stacks marked as "not executable".  It's a bit of a kludge, but is
 295  * provided as a tweakable for platforms that export those ABIs
 296  * (e.g. sparc V8) that have executable stacks enabled by default.
 297  * There are also some restrictions for platforms that don't actually
 298  * implement 'noexec' protections.
 299  *
 300  * Once enabled, the system is (therefore) unable to provide a fully
 301  * ABI-compliant execution environment, though practically speaking,
 302  * most everything works.  The exceptions are generally some interpreters
 303  * and debuggers that create executable code on the stack and jump
 304  * into it (without explicitly mprotecting the address range to include
 305  * PROT_EXEC).
 306  *
 307  * One important class of applications that are disabled are those
 308  * that have been transformed into malicious agents using one of the
 309  * numerous "buffer overflow" attacks.  See 4007890.
 310  */
 311 int noexec_user_stack = 0;
 312 int noexec_user_stack_log = 1;
 313 
 314 int segvn_lpg_disable = 0;
 315 uint_t segvn_maxpgszc = 0;
 316 
 317 ulong_t segvn_vmpss_clrszc_cnt;
 318 ulong_t segvn_vmpss_clrszc_err;
 319 ulong_t segvn_fltvnpages_clrszc_cnt;
 320 ulong_t segvn_fltvnpages_clrszc_err;
 321 ulong_t segvn_setpgsz_align_err;
 322 ulong_t segvn_setpgsz_anon_align_err;
 323 ulong_t segvn_setpgsz_getattr_err;
 324 ulong_t segvn_setpgsz_eof_err;
 325 ulong_t segvn_faultvnmpss_align_err1;
 326 ulong_t segvn_faultvnmpss_align_err2;
 327 ulong_t segvn_faultvnmpss_align_err3;
 328 ulong_t segvn_faultvnmpss_align_err4;
 329 ulong_t segvn_faultvnmpss_align_err5;
 330 ulong_t segvn_vmpss_pageio_deadlk_err;
 331 
 332 int segvn_use_regions = 1;
 333 
 334 /*
 335  * Segvn supports text replication optimization for NUMA platforms. Text
 336  * replica's are represented by anon maps (amp). There's one amp per text file
 337  * region per lgroup. A process chooses the amp for each of its text mappings
 338  * based on the lgroup assignment of its main thread (t_tid = 1). All
 339  * processes that want a replica on a particular lgroup for the same text file
 340  * mapping share the same amp. amp's are looked up in svntr_hashtab hash table
 341  * with vp,off,size,szc used as a key. Text replication segments are read only
 342  * MAP_PRIVATE|MAP_TEXT segments that map vnode. Replication is achieved by
 343  * forcing COW faults from vnode to amp and mapping amp pages instead of vnode
 344  * pages. Replication amp is assigned to a segment when it gets its first
 345  * pagefault. To handle main thread lgroup rehoming segvn_trasync_thread
 346  * rechecks periodically if the process still maps an amp local to the main
 347  * thread. If not async thread forces process to remap to an amp in the new
 348  * home lgroup of the main thread. Current text replication implementation
 349  * only provides the benefit to workloads that do most of their work in the
 350  * main thread of a process or all the threads of a process run in the same
 351  * lgroup. To extend text replication benefit to different types of
 352  * multithreaded workloads further work would be needed in the hat layer to
 353  * allow the same virtual address in the same hat to simultaneously map
 354  * different physical addresses (i.e. page table replication would be needed
 355  * for x86).
 356  *
 357  * amp pages are used instead of vnode pages as long as segment has a very
 358  * simple life cycle.  It's created via segvn_create(), handles S_EXEC
 359  * (S_READ) pagefaults and is fully unmapped.  If anything more complicated
 360  * happens such as protection is changed, real COW fault happens, pagesize is
 361  * changed, MC_LOCK is requested or segment is partially unmapped we turn off
 362  * text replication by converting the segment back to vnode only segment
 363  * (unmap segment's address range and set svd->amp to NULL).
 364  *
 365  * The original file can be changed after amp is inserted into
 366  * svntr_hashtab. Processes that are launched after the file is already
 367  * changed can't use the replica's created prior to the file change. To
 368  * implement this functionality hash entries are timestamped. Replica's can
 369  * only be used if current file modification time is the same as the timestamp
 370  * saved when hash entry was created. However just timestamps alone are not
 371  * sufficient to detect file modification via mmap(MAP_SHARED) mappings. We
 372  * deal with file changes via MAP_SHARED mappings differently. When writable
 373  * MAP_SHARED mappings are created to vnodes marked as executable we mark all
 374  * existing replica's for this vnode as not usable for future text
 375  * mappings. And we don't create new replica's for files that currently have
 376  * potentially writable MAP_SHARED mappings (i.e. vn_is_mapped(V_WRITE) is
 377  * true).
 378  */
 379 
 380 #define SEGVN_TEXTREPL_MAXBYTES_FACTOR  (20)
 381 size_t  segvn_textrepl_max_bytes_factor = SEGVN_TEXTREPL_MAXBYTES_FACTOR;
 382 
 383 static ulong_t                  svntr_hashtab_sz = 512;
 384 static svntr_bucket_t           *svntr_hashtab = NULL;
 385 static struct kmem_cache        *svntr_cache;
 386 static svntr_stats_t            *segvn_textrepl_stats;
 387 static ksema_t                  segvn_trasync_sem;
 388 
 389 int                             segvn_disable_textrepl = 1;
 390 size_t                          textrepl_size_thresh = (size_t)-1;
 391 size_t                          segvn_textrepl_bytes = 0;
 392 size_t                          segvn_textrepl_max_bytes = 0;
 393 clock_t                         segvn_update_textrepl_interval = 0;
 394 int                             segvn_update_tr_time = 10;
 395 int                             segvn_disable_textrepl_update = 0;
 396 
 397 static void segvn_textrepl(struct seg *);
 398 static void segvn_textunrepl(struct seg *, int);
 399 static void segvn_inval_trcache(vnode_t *);
 400 static void segvn_trasync_thread(void);
 401 static void segvn_trupdate_wakeup(void *);
 402 static void segvn_trupdate(void);
 403 static void segvn_trupdate_seg(struct seg *, segvn_data_t *, svntr_t *,
 404     ulong_t);
 405 
 406 /*
 407  * Initialize segvn data structures
 408  */
 409 void
 410 segvn_init(void)
 411 {
 412         uint_t maxszc;
 413         uint_t szc;
 414         size_t pgsz;
 415 
 416         segvn_cache = kmem_cache_create("segvn_cache",
 417             sizeof (struct segvn_data), 0,
 418             segvn_cache_constructor, segvn_cache_destructor, NULL,
 419             NULL, NULL, 0);
 420 
 421         if (segvn_lpg_disable == 0) {
 422                 szc = maxszc = page_num_pagesizes() - 1;
 423                 if (szc == 0) {
 424                         segvn_lpg_disable = 1;
 425                 }
 426                 if (page_get_pagesize(0) != PAGESIZE) {
 427                         panic("segvn_init: bad szc 0");
 428                         /*NOTREACHED*/
 429                 }
 430                 while (szc != 0) {
 431                         pgsz = page_get_pagesize(szc);
 432                         if (pgsz <= PAGESIZE || !IS_P2ALIGNED(pgsz, pgsz)) {
 433                                 panic("segvn_init: bad szc %d", szc);
 434                                 /*NOTREACHED*/
 435                         }
 436                         szc--;
 437                 }
 438                 if (segvn_maxpgszc == 0 || segvn_maxpgszc > maxszc)
 439                         segvn_maxpgszc = maxszc;
 440         }
 441 
 442         if (segvn_maxpgszc) {
 443                 segvn_szc_cache = (struct kmem_cache **)kmem_alloc(
 444                     (segvn_maxpgszc + 1) * sizeof (struct kmem_cache *),
 445                     KM_SLEEP);
 446         }
 447 
 448         for (szc = 1; szc <= segvn_maxpgszc; szc++) {
 449                 char    str[32];
 450 
 451                 (void) sprintf(str, "segvn_szc_cache%d", szc);
 452                 segvn_szc_cache[szc] = kmem_cache_create(str,
 453                     page_get_pagecnt(szc) * sizeof (page_t *), 0,
 454                     NULL, NULL, NULL, NULL, NULL, KMC_NODEBUG);
 455         }
 456 
 457 
 458         if (segvn_use_regions && !hat_supported(HAT_SHARED_REGIONS, NULL))
 459                 segvn_use_regions = 0;
 460 
 461         /*
 462          * For now shared regions and text replication segvn support
 463          * are mutually exclusive. This is acceptable because
 464          * currently significant benefit from text replication was
 465          * only observed on AMD64 NUMA platforms (due to relatively
 466          * small L2$ size) and currently we don't support shared
 467          * regions on x86.
 468          */
 469         if (segvn_use_regions && !segvn_disable_textrepl) {
 470                 segvn_disable_textrepl = 1;
 471         }
 472 
 473 #if defined(_LP64)
 474         if (lgrp_optimizations() && textrepl_size_thresh != (size_t)-1 &&
 475             !segvn_disable_textrepl) {
 476                 ulong_t i;
 477                 size_t hsz = svntr_hashtab_sz * sizeof (svntr_bucket_t);
 478 
 479                 svntr_cache = kmem_cache_create("svntr_cache",
 480                     sizeof (svntr_t), 0, svntr_cache_constructor, NULL,
 481                     NULL, NULL, NULL, 0);
 482                 svntr_hashtab = kmem_zalloc(hsz, KM_SLEEP);
 483                 for (i = 0; i < svntr_hashtab_sz; i++) {
 484                         mutex_init(&svntr_hashtab[i].tr_lock,  NULL,
 485                             MUTEX_DEFAULT, NULL);
 486                 }
 487                 segvn_textrepl_max_bytes = ptob(physmem) /
 488                     segvn_textrepl_max_bytes_factor;
 489                 segvn_textrepl_stats = kmem_zalloc(NCPU *
 490                     sizeof (svntr_stats_t), KM_SLEEP);
 491                 sema_init(&segvn_trasync_sem, 0, NULL, SEMA_DEFAULT, NULL);
 492                 (void) thread_create(NULL, 0, segvn_trasync_thread,
 493                     NULL, 0, &p0, TS_RUN, minclsyspri);
 494         }
 495 #endif
 496 
 497         if (!ISP2(segvn_pglock_comb_balign) ||
 498             segvn_pglock_comb_balign < PAGESIZE) {
 499                 segvn_pglock_comb_balign = 1UL << 16; /* 64K */
 500         }
 501         segvn_pglock_comb_bshift = highbit(segvn_pglock_comb_balign) - 1;
 502         segvn_pglock_comb_palign = btop(segvn_pglock_comb_balign);
 503 }
 504 
 505 #define SEGVN_PAGEIO    ((void *)0x1)
 506 #define SEGVN_NOPAGEIO  ((void *)0x2)
 507 
 508 static void
 509 segvn_setvnode_mpss(vnode_t *vp)
 510 {
 511         int err;
 512 
 513         ASSERT(vp->v_mpssdata == NULL ||
 514             vp->v_mpssdata == SEGVN_PAGEIO ||
 515             vp->v_mpssdata == SEGVN_NOPAGEIO);
 516 
 517         if (vp->v_mpssdata == NULL) {
 518                 if (vn_vmpss_usepageio(vp)) {
 519                         err = VOP_PAGEIO(vp, (page_t *)NULL,
 520                             (u_offset_t)0, 0, 0, CRED(), NULL);
 521                 } else {
 522                         err = ENOSYS;
 523                 }
 524                 /*
 525                  * set v_mpssdata just once per vnode life
 526                  * so that it never changes.
 527                  */
 528                 mutex_enter(&vp->v_lock);
 529                 if (vp->v_mpssdata == NULL) {
 530                         if (err == EINVAL) {
 531                                 vp->v_mpssdata = SEGVN_PAGEIO;
 532                         } else {
 533                                 vp->v_mpssdata = SEGVN_NOPAGEIO;
 534                         }
 535                 }
 536                 mutex_exit(&vp->v_lock);
 537         }
 538 }
 539 
 540 int
 541 segvn_create(struct seg *seg, void *argsp)
 542 {
 543         struct segvn_crargs *a = (struct segvn_crargs *)argsp;
 544         struct segvn_data *svd;
 545         size_t swresv = 0;
 546         struct cred *cred;
 547         struct anon_map *amp;
 548         int error = 0;
 549         size_t pgsz;
 550         lgrp_mem_policy_t mpolicy = LGRP_MEM_POLICY_DEFAULT;
 551         int use_rgn = 0;
 552         int trok = 0;
 553 
 554         ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
 555 
 556         if (a->type != MAP_PRIVATE && a->type != MAP_SHARED) {
 557                 panic("segvn_create type");
 558                 /*NOTREACHED*/
 559         }
 560 
 561         /*
 562          * Check arguments.  If a shared anon structure is given then
 563          * it is illegal to also specify a vp.
 564          */
 565         if (a->amp != NULL && a->vp != NULL) {
 566                 panic("segvn_create anon_map");
 567                 /*NOTREACHED*/
 568         }
 569 
 570         if (a->type == MAP_PRIVATE && (a->flags & MAP_TEXT) &&
 571             a->vp != NULL && a->prot == (PROT_USER | PROT_READ | PROT_EXEC) &&
 572             segvn_use_regions) {
 573                 use_rgn = 1;
 574         }
 575 
 576         /* MAP_NORESERVE on a MAP_SHARED segment is meaningless. */
 577         if (a->type == MAP_SHARED)
 578                 a->flags &= ~MAP_NORESERVE;
 579 
 580         if (a->szc != 0) {
 581                 if (segvn_lpg_disable != 0 || (a->szc == AS_MAP_NO_LPOOB) ||
 582                     (a->amp != NULL && a->type == MAP_PRIVATE) ||
 583                     (a->flags & MAP_NORESERVE) || seg->s_as == &kas) {
 584                         a->szc = 0;
 585                 } else {
 586                         if (a->szc > segvn_maxpgszc)
 587                                 a->szc = segvn_maxpgszc;
 588                         pgsz = page_get_pagesize(a->szc);
 589                         if (!IS_P2ALIGNED(seg->s_base, pgsz) ||
 590                             !IS_P2ALIGNED(seg->s_size, pgsz)) {
 591                                 a->szc = 0;
 592                         } else if (a->vp != NULL) {
 593                                 if (IS_SWAPFSVP(a->vp) || VN_ISKAS(a->vp)) {
 594                                         /*
 595                                          * paranoid check.
 596                                          * hat_page_demote() is not supported
 597                                          * on swapfs pages.
 598                                          */
 599                                         a->szc = 0;
 600                                 } else if (map_addr_vacalign_check(seg->s_base,
 601                                     a->offset & PAGEMASK)) {
 602                                         a->szc = 0;
 603                                 }
 604                         } else if (a->amp != NULL) {
 605                                 pgcnt_t anum = btopr(a->offset);
 606                                 pgcnt_t pgcnt = page_get_pagecnt(a->szc);
 607                                 if (!IS_P2ALIGNED(anum, pgcnt)) {
 608                                         a->szc = 0;
 609                                 }
 610                         }
 611                 }
 612         }
 613 
 614         /*
 615          * If segment may need private pages, reserve them now.
 616          */
 617         if (!(a->flags & MAP_NORESERVE) && ((a->vp == NULL && a->amp == NULL) ||
 618             (a->type == MAP_PRIVATE && (a->prot & PROT_WRITE)))) {
 619                 if (anon_resv_zone(seg->s_size,
 620                     seg->s_as->a_proc->p_zone) == 0)
 621                         return (EAGAIN);
 622                 swresv = seg->s_size;
 623                 TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
 624                     seg, swresv, 1);
 625         }
 626 
 627         /*
 628          * Reserve any mapping structures that may be required.
 629          *
 630          * Don't do it for segments that may use regions. It's currently a
 631          * noop in the hat implementations anyway.
 632          */
 633         if (!use_rgn) {
 634                 hat_map(seg->s_as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
 635         }
 636 
 637         if (a->cred) {
 638                 cred = a->cred;
 639                 crhold(cred);
 640         } else {
 641                 crhold(cred = CRED());
 642         }
 643 
 644         /* Inform the vnode of the new mapping */
 645         if (a->vp != NULL) {
 646                 error = VOP_ADDMAP(a->vp, a->offset & PAGEMASK,
 647                     seg->s_as, seg->s_base, seg->s_size, a->prot,
 648                     a->maxprot, a->type, cred, NULL);
 649                 if (error) {
 650                         if (swresv != 0) {
 651                                 anon_unresv_zone(swresv,
 652                                     seg->s_as->a_proc->p_zone);
 653                                 TRACE_3(TR_FAC_VM, TR_ANON_PROC,
 654                                     "anon proc:%p %lu %u", seg, swresv, 0);
 655                         }
 656                         crfree(cred);
 657                         if (!use_rgn) {
 658                                 hat_unload(seg->s_as->a_hat, seg->s_base,
 659                                     seg->s_size, HAT_UNLOAD_UNMAP);
 660                         }
 661                         return (error);
 662                 }
 663                 /*
 664                  * svntr_hashtab will be NULL if we support shared regions.
 665                  */
 666                 trok = ((a->flags & MAP_TEXT) &&
 667                     (seg->s_size > textrepl_size_thresh ||
 668                     (a->flags & _MAP_TEXTREPL)) &&
 669                     lgrp_optimizations() && svntr_hashtab != NULL &&
 670                     a->type == MAP_PRIVATE && swresv == 0 &&
 671                     !(a->flags & MAP_NORESERVE) &&
 672                     seg->s_as != &kas && a->vp->v_type == VREG);
 673 
 674                 ASSERT(!trok || !use_rgn);
 675         }
 676 
 677         /*
 678          * MAP_NORESERVE mappings don't count towards the VSZ of a process
 679          * until we fault the pages in.
 680          */
 681         if ((a->vp == NULL || a->vp->v_type != VREG) &&
 682             a->flags & MAP_NORESERVE) {
 683                 seg->s_as->a_resvsize -= seg->s_size;
 684         }
 685 
 686         /*
 687          * If more than one segment in the address space, and they're adjacent
 688          * virtually, try to concatenate them.  Don't concatenate if an
 689          * explicit anon_map structure was supplied (e.g., SystemV shared
 690          * memory) or if we'll use text replication for this segment.
 691          */
 692         if (a->amp == NULL && !use_rgn && !trok) {
 693                 struct seg *pseg, *nseg;
 694                 struct segvn_data *psvd, *nsvd;
 695                 lgrp_mem_policy_t ppolicy, npolicy;
 696                 uint_t  lgrp_mem_policy_flags = 0;
 697                 extern lgrp_mem_policy_t lgrp_mem_default_policy;
 698 
 699                 /*
 700                  * Memory policy flags (lgrp_mem_policy_flags) is valid when
 701                  * extending stack/heap segments.
 702                  */
 703                 if ((a->vp == NULL) && (a->type == MAP_PRIVATE) &&
 704                     !(a->flags & MAP_NORESERVE) && (seg->s_as != &kas)) {
 705                         lgrp_mem_policy_flags = a->lgrp_mem_policy_flags;
 706                 } else {
 707                         /*
 708                          * Get policy when not extending it from another segment
 709                          */
 710                         mpolicy = lgrp_mem_policy_default(seg->s_size, a->type);
 711                 }
 712 
 713                 /*
 714                  * First, try to concatenate the previous and new segments
 715                  */
 716                 pseg = AS_SEGPREV(seg->s_as, seg);
 717                 if (pseg != NULL &&
 718                     pseg->s_base + pseg->s_size == seg->s_base &&
 719                     pseg->s_ops == &segvn_ops) {
 720                         /*
 721                          * Get memory allocation policy from previous segment.
 722                          * When extension is specified (e.g. for heap) apply
 723                          * this policy to the new segment regardless of the
 724                          * outcome of segment concatenation.  Extension occurs
 725                          * for non-default policy otherwise default policy is
 726                          * used and is based on extended segment size.
 727                          */
 728                         psvd = (struct segvn_data *)pseg->s_data;
 729                         ppolicy = psvd->policy_info.mem_policy;
 730                         if (lgrp_mem_policy_flags ==
 731                             LGRP_MP_FLAG_EXTEND_UP) {
 732                                 if (ppolicy != lgrp_mem_default_policy) {
 733                                         mpolicy = ppolicy;
 734                                 } else {
 735                                         mpolicy = lgrp_mem_policy_default(
 736                                             pseg->s_size + seg->s_size,
 737                                             a->type);
 738                                 }
 739                         }
 740 
 741                         if (mpolicy == ppolicy &&
 742                             (pseg->s_size + seg->s_size <=
 743                             segvn_comb_thrshld || psvd->amp == NULL) &&
 744                             segvn_extend_prev(pseg, seg, a, swresv) == 0) {
 745                                 /*
 746                                  * success! now try to concatenate
 747                                  * with following seg
 748                                  */
 749                                 crfree(cred);
 750                                 nseg = AS_SEGNEXT(pseg->s_as, pseg);
 751                                 if (nseg != NULL &&
 752                                     nseg != pseg &&
 753                                     nseg->s_ops == &segvn_ops &&
 754                                     pseg->s_base + pseg->s_size ==
 755                                     nseg->s_base)
 756                                         (void) segvn_concat(pseg, nseg, 0);
 757                                 ASSERT(pseg->s_szc == 0 ||
 758                                     (a->szc == pseg->s_szc &&
 759                                     IS_P2ALIGNED(pseg->s_base, pgsz) &&
 760                                     IS_P2ALIGNED(pseg->s_size, pgsz)));
 761                                 return (0);
 762                         }
 763                 }
 764 
 765                 /*
 766                  * Failed, so try to concatenate with following seg
 767                  */
 768                 nseg = AS_SEGNEXT(seg->s_as, seg);
 769                 if (nseg != NULL &&
 770                     seg->s_base + seg->s_size == nseg->s_base &&
 771                     nseg->s_ops == &segvn_ops) {
 772                         /*
 773                          * Get memory allocation policy from next segment.
 774                          * When extension is specified (e.g. for stack) apply
 775                          * this policy to the new segment regardless of the
 776                          * outcome of segment concatenation.  Extension occurs
 777                          * for non-default policy otherwise default policy is
 778                          * used and is based on extended segment size.
 779                          */
 780                         nsvd = (struct segvn_data *)nseg->s_data;
 781                         npolicy = nsvd->policy_info.mem_policy;
 782                         if (lgrp_mem_policy_flags ==
 783                             LGRP_MP_FLAG_EXTEND_DOWN) {
 784                                 if (npolicy != lgrp_mem_default_policy) {
 785                                         mpolicy = npolicy;
 786                                 } else {
 787                                         mpolicy = lgrp_mem_policy_default(
 788                                             nseg->s_size + seg->s_size,
 789                                             a->type);
 790                                 }
 791                         }
 792 
 793                         if (mpolicy == npolicy &&
 794                             segvn_extend_next(seg, nseg, a, swresv) == 0) {
 795                                 crfree(cred);
 796                                 ASSERT(nseg->s_szc == 0 ||
 797                                     (a->szc == nseg->s_szc &&
 798                                     IS_P2ALIGNED(nseg->s_base, pgsz) &&
 799                                     IS_P2ALIGNED(nseg->s_size, pgsz)));
 800                                 return (0);
 801                         }
 802                 }
 803         }
 804 
 805         if (a->vp != NULL) {
 806                 VN_HOLD(a->vp);
 807                 if (a->type == MAP_SHARED)
 808                         lgrp_shm_policy_init(NULL, a->vp);
 809         }
 810         svd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
 811 
 812         seg->s_ops = &segvn_ops;
 813         seg->s_data = (void *)svd;
 814         seg->s_szc = a->szc;
 815 
 816         svd->seg = seg;
 817         svd->vp = a->vp;
 818         /*
 819          * Anonymous mappings have no backing file so the offset is meaningless.
 820          */
 821         svd->offset = a->vp ? (a->offset & PAGEMASK) : 0;
 822         svd->prot = a->prot;
 823         svd->maxprot = a->maxprot;
 824         svd->pageprot = 0;
 825         svd->type = a->type;
 826         svd->vpage = NULL;
 827         svd->cred = cred;
 828         svd->advice = MADV_NORMAL;
 829         svd->pageadvice = 0;
 830         svd->flags = (ushort_t)a->flags;
 831         svd->softlockcnt = 0;
 832         svd->softlockcnt_sbase = 0;
 833         svd->softlockcnt_send = 0;
 834         svd->svn_inz = 0;
 835         svd->rcookie = HAT_INVALID_REGION_COOKIE;
 836         svd->pageswap = 0;
 837 
 838         if (a->szc != 0 && a->vp != NULL) {
 839                 segvn_setvnode_mpss(a->vp);
 840         }
 841         if (svd->type == MAP_SHARED && svd->vp != NULL &&
 842             (svd->vp->v_flag & VVMEXEC) && (svd->prot & PROT_WRITE)) {
 843                 ASSERT(vn_is_mapped(svd->vp, V_WRITE));
 844                 segvn_inval_trcache(svd->vp);
 845         }
 846 
 847         amp = a->amp;
 848         if ((svd->amp = amp) == NULL) {
 849                 svd->anon_index = 0;
 850                 if (svd->type == MAP_SHARED) {
 851                         svd->swresv = 0;
 852                         /*
 853                          * Shared mappings to a vp need no other setup.
 854                          * If we have a shared mapping to an anon_map object
 855                          * which hasn't been allocated yet,  allocate the
 856                          * struct now so that it will be properly shared
 857                          * by remembering the swap reservation there.
 858                          */
 859                         if (a->vp == NULL) {
 860                                 svd->amp = anonmap_alloc(seg->s_size, swresv,
 861                                     ANON_SLEEP);
 862                                 svd->amp->a_szc = seg->s_szc;
 863                         }
 864                 } else {
 865                         /*
 866                          * Private mapping (with or without a vp).
 867                          * Allocate anon_map when needed.
 868                          */
 869                         svd->swresv = swresv;
 870                 }
 871         } else {
 872                 pgcnt_t anon_num;
 873 
 874                 /*
 875                  * Mapping to an existing anon_map structure without a vp.
 876                  * For now we will insure that the segment size isn't larger
 877                  * than the size - offset gives us.  Later on we may wish to
 878                  * have the anon array dynamically allocated itself so that
 879                  * we don't always have to allocate all the anon pointer slots.
 880                  * This of course involves adding extra code to check that we
 881                  * aren't trying to use an anon pointer slot beyond the end
 882                  * of the currently allocated anon array.
 883                  */
 884                 if ((amp->size - a->offset) < seg->s_size) {
 885                         panic("segvn_create anon_map size");
 886                         /*NOTREACHED*/
 887                 }
 888 
 889                 anon_num = btopr(a->offset);
 890 
 891                 if (a->type == MAP_SHARED) {
 892                         /*
 893                          * SHARED mapping to a given anon_map.
 894                          */
 895                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
 896                         amp->refcnt++;
 897                         if (a->szc > amp->a_szc) {
 898                                 amp->a_szc = a->szc;
 899                         }
 900                         ANON_LOCK_EXIT(&amp->a_rwlock);
 901                         svd->anon_index = anon_num;
 902                         svd->swresv = 0;
 903                 } else {
 904                         /*
 905                          * PRIVATE mapping to a given anon_map.
 906                          * Make sure that all the needed anon
 907                          * structures are created (so that we will
 908                          * share the underlying pages if nothing
 909                          * is written by this mapping) and then
 910                          * duplicate the anon array as is done
 911                          * when a privately mapped segment is dup'ed.
 912                          */
 913                         struct anon *ap;
 914                         caddr_t addr;
 915                         caddr_t eaddr;
 916                         ulong_t anon_idx;
 917                         int hat_flag = HAT_LOAD;
 918 
 919                         if (svd->flags & MAP_TEXT) {
 920                                 hat_flag |= HAT_LOAD_TEXT;
 921                         }
 922 
 923                         svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
 924                         svd->amp->a_szc = seg->s_szc;
 925                         svd->anon_index = 0;
 926                         svd->swresv = swresv;
 927 
 928                         /*
 929                          * Prevent 2 threads from allocating anon
 930                          * slots simultaneously.
 931                          */
 932                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
 933                         eaddr = seg->s_base + seg->s_size;
 934 
 935                         for (anon_idx = anon_num, addr = seg->s_base;
 936                             addr < eaddr; addr += PAGESIZE, anon_idx++) {
 937                                 page_t *pp;
 938 
 939                                 if ((ap = anon_get_ptr(amp->ahp,
 940                                     anon_idx)) != NULL)
 941                                         continue;
 942 
 943                                 /*
 944                                  * Allocate the anon struct now.
 945                                  * Might as well load up translation
 946                                  * to the page while we're at it...
 947                                  */
 948                                 pp = anon_zero(seg, addr, &ap, cred);
 949                                 if (ap == NULL || pp == NULL) {
 950                                         panic("segvn_create anon_zero");
 951                                         /*NOTREACHED*/
 952                                 }
 953 
 954                                 /*
 955                                  * Re-acquire the anon_map lock and
 956                                  * initialize the anon array entry.
 957                                  */
 958                                 ASSERT(anon_get_ptr(amp->ahp,
 959                                     anon_idx) == NULL);
 960                                 (void) anon_set_ptr(amp->ahp, anon_idx, ap,
 961                                     ANON_SLEEP);
 962 
 963                                 ASSERT(seg->s_szc == 0);
 964                                 ASSERT(!IS_VMODSORT(pp->p_vnode));
 965 
 966                                 ASSERT(use_rgn == 0);
 967                                 hat_memload(seg->s_as->a_hat, addr, pp,
 968                                     svd->prot & ~PROT_WRITE, hat_flag);
 969 
 970                                 page_unlock(pp);
 971                         }
 972                         ASSERT(seg->s_szc == 0);
 973                         anon_dup(amp->ahp, anon_num, svd->amp->ahp,
 974                             0, seg->s_size);
 975                         ANON_LOCK_EXIT(&amp->a_rwlock);
 976                 }
 977         }
 978 
 979         /*
 980          * Set default memory allocation policy for segment
 981          *
 982          * Always set policy for private memory at least for initialization
 983          * even if this is a shared memory segment
 984          */
 985         (void) lgrp_privm_policy_set(mpolicy, &svd->policy_info, seg->s_size);
 986 
 987         if (svd->type == MAP_SHARED)
 988                 (void) lgrp_shm_policy_set(mpolicy, svd->amp, svd->anon_index,
 989                     svd->vp, svd->offset, seg->s_size);
 990 
 991         if (use_rgn) {
 992                 ASSERT(!trok);
 993                 ASSERT(svd->amp == NULL);
 994                 svd->rcookie = hat_join_region(seg->s_as->a_hat, seg->s_base,
 995                     seg->s_size, (void *)svd->vp, svd->offset, svd->prot,
 996                     (uchar_t)seg->s_szc, segvn_hat_rgn_unload_callback,
 997                     HAT_REGION_TEXT);
 998         }
 999 
1000         ASSERT(!trok || !(svd->prot & PROT_WRITE));
1001         svd->tr_state = trok ? SEGVN_TR_INIT : SEGVN_TR_OFF;
1002 
1003         return (0);
1004 }
1005 
1006 /*
1007  * Concatenate two existing segments, if possible.
1008  * Return 0 on success, -1 if two segments are not compatible
1009  * or -2 on memory allocation failure.
1010  * If amp_cat == 1 then try and concat segments with anon maps
1011  */
1012 static int
1013 segvn_concat(struct seg *seg1, struct seg *seg2, int amp_cat)
1014 {
1015         struct segvn_data *svd1 = seg1->s_data;
1016         struct segvn_data *svd2 = seg2->s_data;
1017         struct anon_map *amp1 = svd1->amp;
1018         struct anon_map *amp2 = svd2->amp;
1019         struct vpage *vpage1 = svd1->vpage;
1020         struct vpage *vpage2 = svd2->vpage, *nvpage = NULL;
1021         size_t size, nvpsize;
1022         pgcnt_t npages1, npages2;
1023 
1024         ASSERT(seg1->s_as && seg2->s_as && seg1->s_as == seg2->s_as);
1025         ASSERT(AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
1026         ASSERT(seg1->s_ops == seg2->s_ops);
1027 
1028         if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie) ||
1029             HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
1030                 return (-1);
1031         }
1032 
1033         /* both segments exist, try to merge them */
1034 #define incompat(x)     (svd1->x != svd2->x)
1035         if (incompat(vp) || incompat(maxprot) ||
1036             (!svd1->pageadvice && !svd2->pageadvice && incompat(advice)) ||
1037             (!svd1->pageprot && !svd2->pageprot && incompat(prot)) ||
1038             incompat(type) || incompat(cred) || incompat(flags) ||
1039             seg1->s_szc != seg2->s_szc || incompat(policy_info.mem_policy) ||
1040             (svd2->softlockcnt > 0) || svd1->softlockcnt_send > 0)
1041                 return (-1);
1042 #undef incompat
1043 
1044         /*
1045          * vp == NULL implies zfod, offset doesn't matter
1046          */
1047         if (svd1->vp != NULL &&
1048             svd1->offset + seg1->s_size != svd2->offset) {
1049                 return (-1);
1050         }
1051 
1052         /*
1053          * Don't concatenate if either segment uses text replication.
1054          */
1055         if (svd1->tr_state != SEGVN_TR_OFF || svd2->tr_state != SEGVN_TR_OFF) {
1056                 return (-1);
1057         }
1058 
1059         /*
1060          * Fail early if we're not supposed to concatenate
1061          * segments with non NULL amp.
1062          */
1063         if (amp_cat == 0 && (amp1 != NULL || amp2 != NULL)) {
1064                 return (-1);
1065         }
1066 
1067         if (svd1->vp == NULL && svd1->type == MAP_SHARED) {
1068                 if (amp1 != amp2) {
1069                         return (-1);
1070                 }
1071                 if (amp1 != NULL && svd1->anon_index + btop(seg1->s_size) !=
1072                     svd2->anon_index) {
1073                         return (-1);
1074                 }
1075                 ASSERT(amp1 == NULL || amp1->refcnt >= 2);
1076         }
1077 
1078         /*
1079          * If either seg has vpages, create a new merged vpage array.
1080          */
1081         if (vpage1 != NULL || vpage2 != NULL) {
1082                 struct vpage *vp, *evp;
1083 
1084                 npages1 = seg_pages(seg1);
1085                 npages2 = seg_pages(seg2);
1086                 nvpsize = vpgtob(npages1 + npages2);
1087 
1088                 if ((nvpage = kmem_zalloc(nvpsize, KM_NOSLEEP)) == NULL) {
1089                         return (-2);
1090                 }
1091 
1092                 if (vpage1 != NULL) {
1093                         bcopy(vpage1, nvpage, vpgtob(npages1));
1094                 } else {
1095                         evp = nvpage + npages1;
1096                         for (vp = nvpage; vp < evp; vp++) {
1097                                 VPP_SETPROT(vp, svd1->prot);
1098                                 VPP_SETADVICE(vp, svd1->advice);
1099                         }
1100                 }
1101 
1102                 if (vpage2 != NULL) {
1103                         bcopy(vpage2, nvpage + npages1, vpgtob(npages2));
1104                 } else {
1105                         evp = nvpage + npages1 + npages2;
1106                         for (vp = nvpage + npages1; vp < evp; vp++) {
1107                                 VPP_SETPROT(vp, svd2->prot);
1108                                 VPP_SETADVICE(vp, svd2->advice);
1109                         }
1110                 }
1111 
1112                 if (svd2->pageswap && (!svd1->pageswap && svd1->swresv)) {
1113                         ASSERT(svd1->swresv == seg1->s_size);
1114                         ASSERT(!(svd1->flags & MAP_NORESERVE));
1115                         ASSERT(!(svd2->flags & MAP_NORESERVE));
1116                         evp = nvpage + npages1;
1117                         for (vp = nvpage; vp < evp; vp++) {
1118                                 VPP_SETSWAPRES(vp);
1119                         }
1120                 }
1121 
1122                 if (svd1->pageswap && (!svd2->pageswap && svd2->swresv)) {
1123                         ASSERT(svd2->swresv == seg2->s_size);
1124                         ASSERT(!(svd1->flags & MAP_NORESERVE));
1125                         ASSERT(!(svd2->flags & MAP_NORESERVE));
1126                         vp = nvpage + npages1;
1127                         evp = vp + npages2;
1128                         for (; vp < evp; vp++) {
1129                                 VPP_SETSWAPRES(vp);
1130                         }
1131                 }
1132         }
1133         ASSERT((vpage1 != NULL || vpage2 != NULL) ||
1134             (svd1->pageswap == 0 && svd2->pageswap == 0));
1135 
1136         /*
1137          * If either segment has private pages, create a new merged anon
1138          * array. If mergeing shared anon segments just decrement anon map's
1139          * refcnt.
1140          */
1141         if (amp1 != NULL && svd1->type == MAP_SHARED) {
1142                 ASSERT(amp1 == amp2 && svd1->vp == NULL);
1143                 ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1144                 ASSERT(amp1->refcnt >= 2);
1145                 amp1->refcnt--;
1146                 ANON_LOCK_EXIT(&amp1->a_rwlock);
1147                 svd2->amp = NULL;
1148         } else if (amp1 != NULL || amp2 != NULL) {
1149                 struct anon_hdr *nahp;
1150                 struct anon_map *namp = NULL;
1151                 size_t asize;
1152 
1153                 ASSERT(svd1->type == MAP_PRIVATE);
1154 
1155                 asize = seg1->s_size + seg2->s_size;
1156                 if ((nahp = anon_create(btop(asize), ANON_NOSLEEP)) == NULL) {
1157                         if (nvpage != NULL) {
1158                                 kmem_free(nvpage, nvpsize);
1159                         }
1160                         return (-2);
1161                 }
1162                 if (amp1 != NULL) {
1163                         /*
1164                          * XXX anon rwlock is not really needed because
1165                          * this is a private segment and we are writers.
1166                          */
1167                         ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1168                         ASSERT(amp1->refcnt == 1);
1169                         if (anon_copy_ptr(amp1->ahp, svd1->anon_index,
1170                             nahp, 0, btop(seg1->s_size), ANON_NOSLEEP)) {
1171                                 anon_release(nahp, btop(asize));
1172                                 ANON_LOCK_EXIT(&amp1->a_rwlock);
1173                                 if (nvpage != NULL) {
1174                                         kmem_free(nvpage, nvpsize);
1175                                 }
1176                                 return (-2);
1177                         }
1178                 }
1179                 if (amp2 != NULL) {
1180                         ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1181                         ASSERT(amp2->refcnt == 1);
1182                         if (anon_copy_ptr(amp2->ahp, svd2->anon_index,
1183                             nahp, btop(seg1->s_size), btop(seg2->s_size),
1184                             ANON_NOSLEEP)) {
1185                                 anon_release(nahp, btop(asize));
1186                                 ANON_LOCK_EXIT(&amp2->a_rwlock);
1187                                 if (amp1 != NULL) {
1188                                         ANON_LOCK_EXIT(&amp1->a_rwlock);
1189                                 }
1190                                 if (nvpage != NULL) {
1191                                         kmem_free(nvpage, nvpsize);
1192                                 }
1193                                 return (-2);
1194                         }
1195                 }
1196                 if (amp1 != NULL) {
1197                         namp = amp1;
1198                         anon_release(amp1->ahp, btop(amp1->size));
1199                 }
1200                 if (amp2 != NULL) {
1201                         if (namp == NULL) {
1202                                 ASSERT(amp1 == NULL);
1203                                 namp = amp2;
1204                                 anon_release(amp2->ahp, btop(amp2->size));
1205                         } else {
1206                                 amp2->refcnt--;
1207                                 ANON_LOCK_EXIT(&amp2->a_rwlock);
1208                                 anonmap_free(amp2);
1209                         }
1210                         svd2->amp = NULL; /* needed for seg_free */
1211                 }
1212                 namp->ahp = nahp;
1213                 namp->size = asize;
1214                 svd1->amp = namp;
1215                 svd1->anon_index = 0;
1216                 ANON_LOCK_EXIT(&namp->a_rwlock);
1217         }
1218         /*
1219          * Now free the old vpage structures.
1220          */
1221         if (nvpage != NULL) {
1222                 if (vpage1 != NULL) {
1223                         kmem_free(vpage1, vpgtob(npages1));
1224                 }
1225                 if (vpage2 != NULL) {
1226                         svd2->vpage = NULL;
1227                         kmem_free(vpage2, vpgtob(npages2));
1228                 }
1229                 if (svd2->pageprot) {
1230                         svd1->pageprot = 1;
1231                 }
1232                 if (svd2->pageadvice) {
1233                         svd1->pageadvice = 1;
1234                 }
1235                 if (svd2->pageswap) {
1236                         svd1->pageswap = 1;
1237                 }
1238                 svd1->vpage = nvpage;
1239         }
1240 
1241         /* all looks ok, merge segments */
1242         svd1->swresv += svd2->swresv;
1243         svd2->swresv = 0;  /* so seg_free doesn't release swap space */
1244         size = seg2->s_size;
1245         seg_free(seg2);
1246         seg1->s_size += size;
1247         return (0);
1248 }
1249 
1250 /*
1251  * Extend the previous segment (seg1) to include the
1252  * new segment (seg2 + a), if possible.
1253  * Return 0 on success.
1254  */
1255 static int
1256 segvn_extend_prev(seg1, seg2, a, swresv)
1257         struct seg *seg1, *seg2;
1258         struct segvn_crargs *a;
1259         size_t swresv;
1260 {
1261         struct segvn_data *svd1 = (struct segvn_data *)seg1->s_data;
1262         size_t size;
1263         struct anon_map *amp1;
1264         struct vpage *new_vpage;
1265 
1266         /*
1267          * We don't need any segment level locks for "segvn" data
1268          * since the address space is "write" locked.
1269          */
1270         ASSERT(seg1->s_as && AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
1271 
1272         if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie)) {
1273                 return (-1);
1274         }
1275 
1276         /* second segment is new, try to extend first */
1277         /* XXX - should also check cred */
1278         if (svd1->vp != a->vp || svd1->maxprot != a->maxprot ||
1279             (!svd1->pageprot && (svd1->prot != a->prot)) ||
1280             svd1->type != a->type || svd1->flags != a->flags ||
1281             seg1->s_szc != a->szc || svd1->softlockcnt_send > 0)
1282                 return (-1);
1283 
1284         /* vp == NULL implies zfod, offset doesn't matter */
1285         if (svd1->vp != NULL &&
1286             svd1->offset + seg1->s_size != (a->offset & PAGEMASK))
1287                 return (-1);
1288 
1289         if (svd1->tr_state != SEGVN_TR_OFF) {
1290                 return (-1);
1291         }
1292 
1293         amp1 = svd1->amp;
1294         if (amp1) {
1295                 pgcnt_t newpgs;
1296 
1297                 /*
1298                  * Segment has private pages, can data structures
1299                  * be expanded?
1300                  *
1301                  * Acquire the anon_map lock to prevent it from changing,
1302                  * if it is shared.  This ensures that the anon_map
1303                  * will not change while a thread which has a read/write
1304                  * lock on an address space references it.
1305                  * XXX - Don't need the anon_map lock at all if "refcnt"
1306                  * is 1.
1307                  *
1308                  * Can't grow a MAP_SHARED segment with an anonmap because
1309                  * there may be existing anon slots where we want to extend
1310                  * the segment and we wouldn't know what to do with them
1311                  * (e.g., for tmpfs right thing is to just leave them there,
1312                  * for /dev/zero they should be cleared out).
1313                  */
1314                 if (svd1->type == MAP_SHARED)
1315                         return (-1);
1316 
1317                 ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1318                 if (amp1->refcnt > 1) {
1319                         ANON_LOCK_EXIT(&amp1->a_rwlock);
1320                         return (-1);
1321                 }
1322                 newpgs = anon_grow(amp1->ahp, &svd1->anon_index,
1323                     btop(seg1->s_size), btop(seg2->s_size), ANON_NOSLEEP);
1324 
1325                 if (newpgs == 0) {
1326                         ANON_LOCK_EXIT(&amp1->a_rwlock);
1327                         return (-1);
1328                 }
1329                 amp1->size = ptob(newpgs);
1330                 ANON_LOCK_EXIT(&amp1->a_rwlock);
1331         }
1332         if (svd1->vpage != NULL) {
1333                 struct vpage *vp, *evp;
1334                 new_vpage =
1335                     kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1336                         KM_NOSLEEP);
1337                 if (new_vpage == NULL)
1338                         return (-1);
1339                 bcopy(svd1->vpage, new_vpage, vpgtob(seg_pages(seg1)));
1340                 kmem_free(svd1->vpage, vpgtob(seg_pages(seg1)));
1341                 svd1->vpage = new_vpage;
1342 
1343                 vp = new_vpage + seg_pages(seg1);
1344                 evp = vp + seg_pages(seg2);
1345                 for (; vp < evp; vp++)
1346                         VPP_SETPROT(vp, a->prot);
1347                 if (svd1->pageswap && swresv) {
1348                         ASSERT(!(svd1->flags & MAP_NORESERVE));
1349                         ASSERT(swresv == seg2->s_size);
1350                         vp = new_vpage + seg_pages(seg1);
1351                         for (; vp < evp; vp++) {
1352                                 VPP_SETSWAPRES(vp);
1353                         }
1354                 }
1355         }
1356         ASSERT(svd1->vpage != NULL || svd1->pageswap == 0);
1357         size = seg2->s_size;
1358         seg_free(seg2);
1359         seg1->s_size += size;
1360         svd1->swresv += swresv;
1361         if (svd1->pageprot && (a->prot & PROT_WRITE) &&
1362             svd1->type == MAP_SHARED && svd1->vp != NULL &&
1363             (svd1->vp->v_flag & VVMEXEC)) {
1364                 ASSERT(vn_is_mapped(svd1->vp, V_WRITE));
1365                 segvn_inval_trcache(svd1->vp);
1366         }
1367         return (0);
1368 }
1369 
1370 /*
1371  * Extend the next segment (seg2) to include the
1372  * new segment (seg1 + a), if possible.
1373  * Return 0 on success.
1374  */
1375 static int
1376 segvn_extend_next(
1377         struct seg *seg1,
1378         struct seg *seg2,
1379         struct segvn_crargs *a,
1380         size_t swresv)
1381 {
1382         struct segvn_data *svd2 = (struct segvn_data *)seg2->s_data;
1383         size_t size;
1384         struct anon_map *amp2;
1385         struct vpage *new_vpage;
1386 
1387         /*
1388          * We don't need any segment level locks for "segvn" data
1389          * since the address space is "write" locked.
1390          */
1391         ASSERT(seg2->s_as && AS_WRITE_HELD(seg2->s_as, &seg2->s_as->a_lock));
1392 
1393         if (HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
1394                 return (-1);
1395         }
1396 
1397         /* first segment is new, try to extend second */
1398         /* XXX - should also check cred */
1399         if (svd2->vp != a->vp || svd2->maxprot != a->maxprot ||
1400             (!svd2->pageprot && (svd2->prot != a->prot)) ||
1401             svd2->type != a->type || svd2->flags != a->flags ||
1402             seg2->s_szc != a->szc || svd2->softlockcnt_sbase > 0)
1403                 return (-1);
1404         /* vp == NULL implies zfod, offset doesn't matter */
1405         if (svd2->vp != NULL &&
1406             (a->offset & PAGEMASK) + seg1->s_size != svd2->offset)
1407                 return (-1);
1408 
1409         if (svd2->tr_state != SEGVN_TR_OFF) {
1410                 return (-1);
1411         }
1412 
1413         amp2 = svd2->amp;
1414         if (amp2) {
1415                 pgcnt_t newpgs;
1416 
1417                 /*
1418                  * Segment has private pages, can data structures
1419                  * be expanded?
1420                  *
1421                  * Acquire the anon_map lock to prevent it from changing,
1422                  * if it is shared.  This ensures that the anon_map
1423                  * will not change while a thread which has a read/write
1424                  * lock on an address space references it.
1425                  *
1426                  * XXX - Don't need the anon_map lock at all if "refcnt"
1427                  * is 1.
1428                  */
1429                 if (svd2->type == MAP_SHARED)
1430                         return (-1);
1431 
1432                 ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1433                 if (amp2->refcnt > 1) {
1434                         ANON_LOCK_EXIT(&amp2->a_rwlock);
1435                         return (-1);
1436                 }
1437                 newpgs = anon_grow(amp2->ahp, &svd2->anon_index,
1438                     btop(seg2->s_size), btop(seg1->s_size),
1439                     ANON_NOSLEEP | ANON_GROWDOWN);
1440 
1441                 if (newpgs == 0) {
1442                         ANON_LOCK_EXIT(&amp2->a_rwlock);
1443                         return (-1);
1444                 }
1445                 amp2->size = ptob(newpgs);
1446                 ANON_LOCK_EXIT(&amp2->a_rwlock);
1447         }
1448         if (svd2->vpage != NULL) {
1449                 struct vpage *vp, *evp;
1450                 new_vpage =
1451                     kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1452                     KM_NOSLEEP);
1453                 if (new_vpage == NULL) {
1454                         /* Not merging segments so adjust anon_index back */
1455                         if (amp2)
1456                                 svd2->anon_index += seg_pages(seg1);
1457                         return (-1);
1458                 }
1459                 bcopy(svd2->vpage, new_vpage + seg_pages(seg1),
1460                     vpgtob(seg_pages(seg2)));
1461                 kmem_free(svd2->vpage, vpgtob(seg_pages(seg2)));
1462                 svd2->vpage = new_vpage;
1463 
1464                 vp = new_vpage;
1465                 evp = vp + seg_pages(seg1);
1466                 for (; vp < evp; vp++)
1467                         VPP_SETPROT(vp, a->prot);
1468                 if (svd2->pageswap && swresv) {
1469                         ASSERT(!(svd2->flags & MAP_NORESERVE));
1470                         ASSERT(swresv == seg1->s_size);
1471                         vp = new_vpage;
1472                         for (; vp < evp; vp++) {
1473                                 VPP_SETSWAPRES(vp);
1474                         }
1475                 }
1476         }
1477         ASSERT(svd2->vpage != NULL || svd2->pageswap == 0);
1478         size = seg1->s_size;
1479         seg_free(seg1);
1480         seg2->s_size += size;
1481         seg2->s_base -= size;
1482         svd2->offset -= size;
1483         svd2->swresv += swresv;
1484         if (svd2->pageprot && (a->prot & PROT_WRITE) &&
1485             svd2->type == MAP_SHARED && svd2->vp != NULL &&
1486             (svd2->vp->v_flag & VVMEXEC)) {
1487                 ASSERT(vn_is_mapped(svd2->vp, V_WRITE));
1488                 segvn_inval_trcache(svd2->vp);
1489         }
1490         return (0);
1491 }
1492 
1493 /*
1494  * Duplicate all the pages in the segment. This may break COW sharing for a
1495  * given page. If the page is marked with inherit zero set, then instead of
1496  * duplicating the page, we zero the page.
1497  */
1498 static int
1499 segvn_dup_pages(struct seg *seg, struct seg *newseg)
1500 {
1501         int error;
1502         uint_t prot;
1503         page_t *pp;
1504         struct anon *ap, *newap;
1505         size_t i;
1506         caddr_t addr;
1507 
1508         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1509         struct segvn_data *newsvd = (struct segvn_data *)newseg->s_data;
1510         ulong_t old_idx = svd->anon_index;
1511         ulong_t new_idx = 0;
1512 
1513         i = btopr(seg->s_size);
1514         addr = seg->s_base;
1515 
1516         /*
1517          * XXX break cow sharing using PAGESIZE
1518          * pages. They will be relocated into larger
1519          * pages at fault time.
1520          */
1521         while (i-- > 0) {
1522                 if ((ap = anon_get_ptr(svd->amp->ahp, old_idx)) != NULL) {
1523                         struct vpage *vpp;
1524 
1525                         vpp = &svd->vpage[seg_page(seg, addr)];
1526 
1527                         /*
1528                          * prot need not be computed below 'cause anon_private
1529                          * is going to ignore it anyway as child doesn't inherit
1530                          * pagelock from parent.
1531                          */
1532                         prot = svd->pageprot ? VPP_PROT(vpp) : svd->prot;
1533 
1534                         /*
1535                          * Check whether we should zero this or dup it.
1536                          */
1537                         if (svd->svn_inz == SEGVN_INZ_ALL ||
1538                             (svd->svn_inz == SEGVN_INZ_VPP &&
1539                             VPP_ISINHZERO(vpp))) {
1540                                 pp = anon_zero(newseg, addr, &newap,
1541                                     newsvd->cred);
1542                         } else {
1543                                 page_t *anon_pl[1+1];
1544                                 uint_t vpprot;
1545                                 error = anon_getpage(&ap, &vpprot, anon_pl,
1546                                     PAGESIZE, seg, addr, S_READ, svd->cred);
1547                                 if (error != 0)
1548                                         return (error);
1549 
1550                                 pp = anon_private(&newap, newseg, addr, prot,
1551                                     anon_pl[0], 0, newsvd->cred);
1552                         }
1553                         if (pp == NULL) {
1554                                 return (ENOMEM);
1555                         }
1556                         (void) anon_set_ptr(newsvd->amp->ahp, new_idx, newap,
1557                             ANON_SLEEP);
1558                         page_unlock(pp);
1559                 }
1560                 addr += PAGESIZE;
1561                 old_idx++;
1562                 new_idx++;
1563         }
1564 
1565         return (0);
1566 }
1567 
1568 static int
1569 segvn_dup(struct seg *seg, struct seg *newseg)
1570 {
1571         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1572         struct segvn_data *newsvd;
1573         pgcnt_t npages = seg_pages(seg);
1574         int error = 0;
1575         size_t len;
1576         struct anon_map *amp;
1577 
1578         ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1579         ASSERT(newseg->s_as->a_proc->p_parent == curproc);
1580 
1581         /*
1582          * If segment has anon reserved, reserve more for the new seg.
1583          * For a MAP_NORESERVE segment swresv will be a count of all the
1584          * allocated anon slots; thus we reserve for the child as many slots
1585          * as the parent has allocated. This semantic prevents the child or
1586          * parent from dieing during a copy-on-write fault caused by trying
1587          * to write a shared pre-existing anon page.
1588          */
1589         if ((len = svd->swresv) != 0) {
1590                 if (anon_resv(svd->swresv) == 0)
1591                         return (ENOMEM);
1592 
1593                 TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
1594                     seg, len, 0);
1595         }
1596 
1597         newsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
1598 
1599         newseg->s_ops = &segvn_ops;
1600         newseg->s_data = (void *)newsvd;
1601         newseg->s_szc = seg->s_szc;
1602 
1603         newsvd->seg = newseg;
1604         if ((newsvd->vp = svd->vp) != NULL) {
1605                 VN_HOLD(svd->vp);
1606                 if (svd->type == MAP_SHARED)
1607                         lgrp_shm_policy_init(NULL, svd->vp);
1608         }
1609         newsvd->offset = svd->offset;
1610         newsvd->prot = svd->prot;
1611         newsvd->maxprot = svd->maxprot;
1612         newsvd->pageprot = svd->pageprot;
1613         newsvd->type = svd->type;
1614         newsvd->cred = svd->cred;
1615         crhold(newsvd->cred);
1616         newsvd->advice = svd->advice;
1617         newsvd->pageadvice = svd->pageadvice;
1618         newsvd->svn_inz = svd->svn_inz;
1619         newsvd->swresv = svd->swresv;
1620         newsvd->pageswap = svd->pageswap;
1621         newsvd->flags = svd->flags;
1622         newsvd->softlockcnt = 0;
1623         newsvd->softlockcnt_sbase = 0;
1624         newsvd->softlockcnt_send = 0;
1625         newsvd->policy_info = svd->policy_info;
1626         newsvd->rcookie = HAT_INVALID_REGION_COOKIE;
1627 
1628         if ((amp = svd->amp) == NULL || svd->tr_state == SEGVN_TR_ON) {
1629                 /*
1630                  * Not attaching to a shared anon object.
1631                  */
1632                 ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie) ||
1633                     svd->tr_state == SEGVN_TR_OFF);
1634                 if (svd->tr_state == SEGVN_TR_ON) {
1635                         ASSERT(newsvd->vp != NULL && amp != NULL);
1636                         newsvd->tr_state = SEGVN_TR_INIT;
1637                 } else {
1638                         newsvd->tr_state = svd->tr_state;
1639                 }
1640                 newsvd->amp = NULL;
1641                 newsvd->anon_index = 0;
1642         } else {
1643                 /* regions for now are only used on pure vnode segments */
1644                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
1645                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
1646                 newsvd->tr_state = SEGVN_TR_OFF;
1647                 if (svd->type == MAP_SHARED) {
1648                         ASSERT(svd->svn_inz == SEGVN_INZ_NONE);
1649                         newsvd->amp = amp;
1650                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1651                         amp->refcnt++;
1652                         ANON_LOCK_EXIT(&amp->a_rwlock);
1653                         newsvd->anon_index = svd->anon_index;
1654                 } else {
1655                         int reclaim = 1;
1656 
1657                         /*
1658                          * Allocate and initialize new anon_map structure.
1659                          */
1660                         newsvd->amp = anonmap_alloc(newseg->s_size, 0,
1661                             ANON_SLEEP);
1662                         newsvd->amp->a_szc = newseg->s_szc;
1663                         newsvd->anon_index = 0;
1664                         ASSERT(svd->svn_inz == SEGVN_INZ_NONE ||
1665                             svd->svn_inz == SEGVN_INZ_ALL ||
1666                             svd->svn_inz == SEGVN_INZ_VPP);
1667 
1668                         /*
1669                          * We don't have to acquire the anon_map lock
1670                          * for the new segment (since it belongs to an
1671                          * address space that is still not associated
1672                          * with any process), or the segment in the old
1673                          * address space (since all threads in it
1674                          * are stopped while duplicating the address space).
1675                          */
1676 
1677                         /*
1678                          * The goal of the following code is to make sure that
1679                          * softlocked pages do not end up as copy on write
1680                          * pages.  This would cause problems where one
1681                          * thread writes to a page that is COW and a different
1682                          * thread in the same process has softlocked it.  The
1683                          * softlock lock would move away from this process
1684                          * because the write would cause this process to get
1685                          * a copy (without the softlock).
1686                          *
1687                          * The strategy here is to just break the
1688                          * sharing on pages that could possibly be
1689                          * softlocked.
1690                          *
1691                          * In addition, if any pages have been marked that they
1692                          * should be inherited as zero, then we immediately go
1693                          * ahead and break COW and zero them. In the case of a
1694                          * softlocked page that should be inherited zero, we
1695                          * break COW and just get a zero page.
1696                          */
1697 retry:
1698                         if (svd->softlockcnt ||
1699                             svd->svn_inz != SEGVN_INZ_NONE) {
1700                                 /*
1701                                  * The softlock count might be non zero
1702                                  * because some pages are still stuck in the
1703                                  * cache for lazy reclaim. Flush the cache
1704                                  * now. This should drop the count to zero.
1705                                  * [or there is really I/O going on to these
1706                                  * pages]. Note, we have the writers lock so
1707                                  * nothing gets inserted during the flush.
1708                                  */
1709                                 if (svd->softlockcnt && reclaim == 1) {
1710                                         segvn_purge(seg);
1711                                         reclaim = 0;
1712                                         goto retry;
1713                                 }
1714 
1715                                 error = segvn_dup_pages(seg, newseg);
1716                                 if (error != 0) {
1717                                         newsvd->vpage = NULL;
1718                                         goto out;
1719                                 }
1720                         } else {        /* common case */
1721                                 if (seg->s_szc != 0) {
1722                                         /*
1723                                          * If at least one of anon slots of a
1724                                          * large page exists then make sure
1725                                          * all anon slots of a large page
1726                                          * exist to avoid partial cow sharing
1727                                          * of a large page in the future.
1728                                          */
1729                                         anon_dup_fill_holes(amp->ahp,
1730                                             svd->anon_index, newsvd->amp->ahp,
1731                                             0, seg->s_size, seg->s_szc,
1732                                             svd->vp != NULL);
1733                                 } else {
1734                                         anon_dup(amp->ahp, svd->anon_index,
1735                                             newsvd->amp->ahp, 0, seg->s_size);
1736                                 }
1737 
1738                                 hat_clrattr(seg->s_as->a_hat, seg->s_base,
1739                                     seg->s_size, PROT_WRITE);
1740                         }
1741                 }
1742         }
1743         /*
1744          * If necessary, create a vpage structure for the new segment.
1745          * Do not copy any page lock indications.
1746          */
1747         if (svd->vpage != NULL) {
1748                 uint_t i;
1749                 struct vpage *ovp = svd->vpage;
1750                 struct vpage *nvp;
1751 
1752                 nvp = newsvd->vpage =
1753                     kmem_alloc(vpgtob(npages), KM_SLEEP);
1754                 for (i = 0; i < npages; i++) {
1755                         *nvp = *ovp++;
1756                         VPP_CLRPPLOCK(nvp++);
1757                 }
1758         } else
1759                 newsvd->vpage = NULL;
1760 
1761         /* Inform the vnode of the new mapping */
1762         if (newsvd->vp != NULL) {
1763                 error = VOP_ADDMAP(newsvd->vp, (offset_t)newsvd->offset,
1764                     newseg->s_as, newseg->s_base, newseg->s_size, newsvd->prot,
1765                     newsvd->maxprot, newsvd->type, newsvd->cred, NULL);
1766         }
1767 out:
1768         if (error == 0 && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1769                 ASSERT(newsvd->amp == NULL);
1770                 ASSERT(newsvd->tr_state == SEGVN_TR_OFF);
1771                 newsvd->rcookie = svd->rcookie;
1772                 hat_dup_region(newseg->s_as->a_hat, newsvd->rcookie);
1773         }
1774         return (error);
1775 }
1776 
1777 
1778 /*
1779  * callback function to invoke free_vp_pages() for only those pages actually
1780  * processed by the HAT when a shared region is destroyed.
1781  */
1782 extern int free_pages;
1783 
1784 static void
1785 segvn_hat_rgn_unload_callback(caddr_t saddr, caddr_t eaddr, caddr_t r_saddr,
1786     size_t r_size, void *r_obj, u_offset_t r_objoff)
1787 {
1788         u_offset_t off;
1789         size_t len;
1790         vnode_t *vp = (vnode_t *)r_obj;
1791 
1792         ASSERT(eaddr > saddr);
1793         ASSERT(saddr >= r_saddr);
1794         ASSERT(saddr < r_saddr + r_size);
1795         ASSERT(eaddr > r_saddr);
1796         ASSERT(eaddr <= r_saddr + r_size);
1797         ASSERT(vp != NULL);
1798 
1799         if (!free_pages) {
1800                 return;
1801         }
1802 
1803         len = eaddr - saddr;
1804         off = (saddr - r_saddr) + r_objoff;
1805         free_vp_pages(vp, off, len);
1806 }
1807 
1808 /*
1809  * callback function used by segvn_unmap to invoke free_vp_pages() for only
1810  * those pages actually processed by the HAT
1811  */
1812 static void
1813 segvn_hat_unload_callback(hat_callback_t *cb)
1814 {
1815         struct seg              *seg = cb->hcb_data;
1816         struct segvn_data       *svd = (struct segvn_data *)seg->s_data;
1817         size_t                  len;
1818         u_offset_t              off;
1819 
1820         ASSERT(svd->vp != NULL);
1821         ASSERT(cb->hcb_end_addr > cb->hcb_start_addr);
1822         ASSERT(cb->hcb_start_addr >= seg->s_base);
1823 
1824         len = cb->hcb_end_addr - cb->hcb_start_addr;
1825         off = cb->hcb_start_addr - seg->s_base;
1826         free_vp_pages(svd->vp, svd->offset + off, len);
1827 }
1828 
1829 /*
1830  * This function determines the number of bytes of swap reserved by
1831  * a segment for which per-page accounting is present. It is used to
1832  * calculate the correct value of a segvn_data's swresv.
1833  */
1834 static size_t
1835 segvn_count_swap_by_vpages(struct seg *seg)
1836 {
1837         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1838         struct vpage *vp, *evp;
1839         size_t nswappages = 0;
1840 
1841         ASSERT(svd->pageswap);
1842         ASSERT(svd->vpage != NULL);
1843 
1844         evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
1845 
1846         for (vp = svd->vpage; vp < evp; vp++) {
1847                 if (VPP_ISSWAPRES(vp))
1848                         nswappages++;
1849         }
1850 
1851         return (nswappages << PAGESHIFT);
1852 }
1853 
1854 static int
1855 segvn_unmap(struct seg *seg, caddr_t addr, size_t len)
1856 {
1857         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1858         struct segvn_data *nsvd;
1859         struct seg *nseg;
1860         struct anon_map *amp;
1861         pgcnt_t opages;         /* old segment size in pages */
1862         pgcnt_t npages;         /* new segment size in pages */
1863         pgcnt_t dpages;         /* pages being deleted (unmapped) */
1864         hat_callback_t callback;        /* used for free_vp_pages() */
1865         hat_callback_t *cbp = NULL;
1866         caddr_t nbase;
1867         size_t nsize;
1868         size_t oswresv;
1869         int reclaim = 1;
1870 
1871         /*
1872          * We don't need any segment level locks for "segvn" data
1873          * since the address space is "write" locked.
1874          */
1875         ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1876 
1877         /*
1878          * Fail the unmap if pages are SOFTLOCKed through this mapping.
1879          * softlockcnt is protected from change by the as write lock.
1880          */
1881 retry:
1882         if (svd->softlockcnt > 0) {
1883                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
1884 
1885                 /*
1886                  * If this is shared segment non 0 softlockcnt
1887                  * means locked pages are still in use.
1888                  */
1889                 if (svd->type == MAP_SHARED) {
1890                         return (EAGAIN);
1891                 }
1892 
1893                 /*
1894                  * since we do have the writers lock nobody can fill
1895                  * the cache during the purge. The flush either succeeds
1896                  * or we still have pending I/Os.
1897                  */
1898                 if (reclaim == 1) {
1899                         segvn_purge(seg);
1900                         reclaim = 0;
1901                         goto retry;
1902                 }
1903                 return (EAGAIN);
1904         }
1905 
1906         /*
1907          * Check for bad sizes
1908          */
1909         if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
1910             (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
1911                 panic("segvn_unmap");
1912                 /*NOTREACHED*/
1913         }
1914 
1915         if (seg->s_szc != 0) {
1916                 size_t pgsz = page_get_pagesize(seg->s_szc);
1917                 int err;
1918                 if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
1919                         ASSERT(seg->s_base != addr || seg->s_size != len);
1920                         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1921                                 ASSERT(svd->amp == NULL);
1922                                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
1923                                 hat_leave_region(seg->s_as->a_hat,
1924                                     svd->rcookie, HAT_REGION_TEXT);
1925                                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
1926                                 /*
1927                                  * could pass a flag to segvn_demote_range()
1928                                  * below to tell it not to do any unloads but
1929                                  * this case is rare enough to not bother for
1930                                  * now.
1931                                  */
1932                         } else if (svd->tr_state == SEGVN_TR_INIT) {
1933                                 svd->tr_state = SEGVN_TR_OFF;
1934                         } else if (svd->tr_state == SEGVN_TR_ON) {
1935                                 ASSERT(svd->amp != NULL);
1936                                 segvn_textunrepl(seg, 1);
1937                                 ASSERT(svd->amp == NULL);
1938                                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
1939                         }
1940                         VM_STAT_ADD(segvnvmstats.demoterange[0]);
1941                         err = segvn_demote_range(seg, addr, len, SDR_END, 0);
1942                         if (err == 0) {
1943                                 return (IE_RETRY);
1944                         }
1945                         return (err);
1946                 }
1947         }
1948 
1949         /* Inform the vnode of the unmapping. */
1950         if (svd->vp) {
1951                 int error;
1952 
1953                 error = VOP_DELMAP(svd->vp,
1954                     (offset_t)svd->offset + (uintptr_t)(addr - seg->s_base),
1955                     seg->s_as, addr, len, svd->prot, svd->maxprot,
1956                     svd->type, svd->cred, NULL);
1957 
1958                 if (error == EAGAIN)
1959                         return (error);
1960         }
1961 
1962         /*
1963          * Remove any page locks set through this mapping.
1964          * If text replication is not off no page locks could have been
1965          * established via this mapping.
1966          */
1967         if (svd->tr_state == SEGVN_TR_OFF) {
1968                 (void) segvn_lockop(seg, addr, len, 0, MC_UNLOCK, NULL, 0);
1969         }
1970 
1971         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1972                 ASSERT(svd->amp == NULL);
1973                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
1974                 ASSERT(svd->type == MAP_PRIVATE);
1975                 hat_leave_region(seg->s_as->a_hat, svd->rcookie,
1976                     HAT_REGION_TEXT);
1977                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
1978         } else if (svd->tr_state == SEGVN_TR_ON) {
1979                 ASSERT(svd->amp != NULL);
1980                 ASSERT(svd->pageprot == 0 && !(svd->prot & PROT_WRITE));
1981                 segvn_textunrepl(seg, 1);
1982                 ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
1983         } else {
1984                 if (svd->tr_state != SEGVN_TR_OFF) {
1985                         ASSERT(svd->tr_state == SEGVN_TR_INIT);
1986                         svd->tr_state = SEGVN_TR_OFF;
1987                 }
1988                 /*
1989                  * Unload any hardware translations in the range to be taken
1990                  * out. Use a callback to invoke free_vp_pages() effectively.
1991                  */
1992                 if (svd->vp != NULL && free_pages != 0) {
1993                         callback.hcb_data = seg;
1994                         callback.hcb_function = segvn_hat_unload_callback;
1995                         cbp = &callback;
1996                 }
1997                 hat_unload_callback(seg->s_as->a_hat, addr, len,
1998                     HAT_UNLOAD_UNMAP, cbp);
1999 
2000                 if (svd->type == MAP_SHARED && svd->vp != NULL &&
2001                     (svd->vp->v_flag & VVMEXEC) &&
2002                     ((svd->prot & PROT_WRITE) || svd->pageprot)) {
2003                         segvn_inval_trcache(svd->vp);
2004                 }
2005         }
2006 
2007         /*
2008          * Check for entire segment
2009          */
2010         if (addr == seg->s_base && len == seg->s_size) {
2011                 seg_free(seg);
2012                 return (0);
2013         }
2014 
2015         opages = seg_pages(seg);
2016         dpages = btop(len);
2017         npages = opages - dpages;
2018         amp = svd->amp;
2019         ASSERT(amp == NULL || amp->a_szc >= seg->s_szc);
2020 
2021         /*
2022          * Check for beginning of segment
2023          */
2024         if (addr == seg->s_base) {
2025                 if (svd->vpage != NULL) {
2026                         size_t nbytes;
2027                         struct vpage *ovpage;
2028 
2029                         ovpage = svd->vpage; /* keep pointer to vpage */
2030 
2031                         nbytes = vpgtob(npages);
2032                         svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2033                         bcopy(&ovpage[dpages], svd->vpage, nbytes);
2034 
2035                         /* free up old vpage */
2036                         kmem_free(ovpage, vpgtob(opages));
2037                 }
2038                 if (amp != NULL) {
2039                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2040                         if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2041                                 /*
2042                                  * Shared anon map is no longer in use. Before
2043                                  * freeing its pages purge all entries from
2044                                  * pcache that belong to this amp.
2045                                  */
2046                                 if (svd->type == MAP_SHARED) {
2047                                         ASSERT(amp->refcnt == 1);
2048                                         ASSERT(svd->softlockcnt == 0);
2049                                         anonmap_purge(amp);
2050                                 }
2051                                 /*
2052                                  * Free up now unused parts of anon_map array.
2053                                  */
2054                                 if (amp->a_szc == seg->s_szc) {
2055                                         if (seg->s_szc != 0) {
2056                                                 anon_free_pages(amp->ahp,
2057                                                     svd->anon_index, len,
2058                                                     seg->s_szc);
2059                                         } else {
2060                                                 anon_free(amp->ahp,
2061                                                     svd->anon_index,
2062                                                     len);
2063                                         }
2064                                 } else {
2065                                         ASSERT(svd->type == MAP_SHARED);
2066                                         ASSERT(amp->a_szc > seg->s_szc);
2067                                         anon_shmap_free_pages(amp,
2068                                             svd->anon_index, len);
2069                                 }
2070 
2071                                 /*
2072                                  * Unreserve swap space for the
2073                                  * unmapped chunk of this segment in
2074                                  * case it's MAP_SHARED
2075                                  */
2076                                 if (svd->type == MAP_SHARED) {
2077                                         anon_unresv_zone(len,
2078                                             seg->s_as->a_proc->p_zone);
2079                                         amp->swresv -= len;
2080                                 }
2081                         }
2082                         ANON_LOCK_EXIT(&amp->a_rwlock);
2083                         svd->anon_index += dpages;
2084                 }
2085                 if (svd->vp != NULL)
2086                         svd->offset += len;
2087 
2088                 seg->s_base += len;
2089                 seg->s_size -= len;
2090 
2091                 if (svd->swresv) {
2092                         if (svd->flags & MAP_NORESERVE) {
2093                                 ASSERT(amp);
2094                                 oswresv = svd->swresv;
2095 
2096                                 svd->swresv = ptob(anon_pages(amp->ahp,
2097                                     svd->anon_index, npages));
2098                                 anon_unresv_zone(oswresv - svd->swresv,
2099                                     seg->s_as->a_proc->p_zone);
2100                                 if (SEG_IS_PARTIAL_RESV(seg))
2101                                         seg->s_as->a_resvsize -= oswresv -
2102                                             svd->swresv;
2103                         } else {
2104                                 size_t unlen;
2105 
2106                                 if (svd->pageswap) {
2107                                         oswresv = svd->swresv;
2108                                         svd->swresv =
2109                                             segvn_count_swap_by_vpages(seg);
2110                                         ASSERT(oswresv >= svd->swresv);
2111                                         unlen = oswresv - svd->swresv;
2112                                 } else {
2113                                         svd->swresv -= len;
2114                                         ASSERT(svd->swresv == seg->s_size);
2115                                         unlen = len;
2116                                 }
2117                                 anon_unresv_zone(unlen,
2118                                     seg->s_as->a_proc->p_zone);
2119                         }
2120                         TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2121                             seg, len, 0);
2122                 }
2123 
2124                 return (0);
2125         }
2126 
2127         /*
2128          * Check for end of segment
2129          */
2130         if (addr + len == seg->s_base + seg->s_size) {
2131                 if (svd->vpage != NULL) {
2132                         size_t nbytes;
2133                         struct vpage *ovpage;
2134 
2135                         ovpage = svd->vpage; /* keep pointer to vpage */
2136 
2137                         nbytes = vpgtob(npages);
2138                         svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2139                         bcopy(ovpage, svd->vpage, nbytes);
2140 
2141                         /* free up old vpage */
2142                         kmem_free(ovpage, vpgtob(opages));
2143 
2144                 }
2145                 if (amp != NULL) {
2146                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2147                         if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2148                                 /*
2149                                  * Free up now unused parts of anon_map array.
2150                                  */
2151                                 ulong_t an_idx = svd->anon_index + npages;
2152 
2153                                 /*
2154                                  * Shared anon map is no longer in use. Before
2155                                  * freeing its pages purge all entries from
2156                                  * pcache that belong to this amp.
2157                                  */
2158                                 if (svd->type == MAP_SHARED) {
2159                                         ASSERT(amp->refcnt == 1);
2160                                         ASSERT(svd->softlockcnt == 0);
2161                                         anonmap_purge(amp);
2162                                 }
2163 
2164                                 if (amp->a_szc == seg->s_szc) {
2165                                         if (seg->s_szc != 0) {
2166                                                 anon_free_pages(amp->ahp,
2167                                                     an_idx, len,
2168                                                     seg->s_szc);
2169                                         } else {
2170                                                 anon_free(amp->ahp, an_idx,
2171                                                     len);
2172                                         }
2173                                 } else {
2174                                         ASSERT(svd->type == MAP_SHARED);
2175                                         ASSERT(amp->a_szc > seg->s_szc);
2176                                         anon_shmap_free_pages(amp,
2177                                             an_idx, len);
2178                                 }
2179 
2180                                 /*
2181                                  * Unreserve swap space for the
2182                                  * unmapped chunk of this segment in
2183                                  * case it's MAP_SHARED
2184                                  */
2185                                 if (svd->type == MAP_SHARED) {
2186                                         anon_unresv_zone(len,
2187                                             seg->s_as->a_proc->p_zone);
2188                                         amp->swresv -= len;
2189                                 }
2190                         }
2191                         ANON_LOCK_EXIT(&amp->a_rwlock);
2192                 }
2193 
2194                 seg->s_size -= len;
2195 
2196                 if (svd->swresv) {
2197                         if (svd->flags & MAP_NORESERVE) {
2198                                 ASSERT(amp);
2199                                 oswresv = svd->swresv;
2200                                 svd->swresv = ptob(anon_pages(amp->ahp,
2201                                     svd->anon_index, npages));
2202                                 anon_unresv_zone(oswresv - svd->swresv,
2203                                     seg->s_as->a_proc->p_zone);
2204                                 if (SEG_IS_PARTIAL_RESV(seg))
2205                                         seg->s_as->a_resvsize -= oswresv -
2206                                             svd->swresv;
2207                         } else {
2208                                 size_t unlen;
2209 
2210                                 if (svd->pageswap) {
2211                                         oswresv = svd->swresv;
2212                                         svd->swresv =
2213                                             segvn_count_swap_by_vpages(seg);
2214                                         ASSERT(oswresv >= svd->swresv);
2215                                         unlen = oswresv - svd->swresv;
2216                                 } else {
2217                                         svd->swresv -= len;
2218                                         ASSERT(svd->swresv == seg->s_size);
2219                                         unlen = len;
2220                                 }
2221                                 anon_unresv_zone(unlen,
2222                                     seg->s_as->a_proc->p_zone);
2223                         }
2224                         TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2225                             "anon proc:%p %lu %u", seg, len, 0);
2226                 }
2227 
2228                 return (0);
2229         }
2230 
2231         /*
2232          * The section to go is in the middle of the segment,
2233          * have to make it into two segments.  nseg is made for
2234          * the high end while seg is cut down at the low end.
2235          */
2236         nbase = addr + len;                             /* new seg base */
2237         nsize = (seg->s_base + seg->s_size) - nbase;      /* new seg size */
2238         seg->s_size = addr - seg->s_base;         /* shrink old seg */
2239         nseg = seg_alloc(seg->s_as, nbase, nsize);
2240         if (nseg == NULL) {
2241                 panic("segvn_unmap seg_alloc");
2242                 /*NOTREACHED*/
2243         }
2244         nseg->s_ops = seg->s_ops;
2245         nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
2246         nseg->s_data = (void *)nsvd;
2247         nseg->s_szc = seg->s_szc;
2248         *nsvd = *svd;
2249         nsvd->seg = nseg;
2250         nsvd->offset = svd->offset + (uintptr_t)(nseg->s_base - seg->s_base);
2251         nsvd->swresv = 0;
2252         nsvd->softlockcnt = 0;
2253         nsvd->softlockcnt_sbase = 0;
2254         nsvd->softlockcnt_send = 0;
2255         nsvd->svn_inz = svd->svn_inz;
2256         ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
2257 
2258         if (svd->vp != NULL) {
2259                 VN_HOLD(nsvd->vp);
2260                 if (nsvd->type == MAP_SHARED)
2261                         lgrp_shm_policy_init(NULL, nsvd->vp);
2262         }
2263         crhold(svd->cred);
2264 
2265         if (svd->vpage == NULL) {
2266                 nsvd->vpage = NULL;
2267         } else {
2268                 /* need to split vpage into two arrays */
2269                 size_t nbytes;
2270                 struct vpage *ovpage;
2271 
2272                 ovpage = svd->vpage;         /* keep pointer to vpage */
2273 
2274                 npages = seg_pages(seg);        /* seg has shrunk */
2275                 nbytes = vpgtob(npages);
2276                 svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2277 
2278                 bcopy(ovpage, svd->vpage, nbytes);
2279 
2280                 npages = seg_pages(nseg);
2281                 nbytes = vpgtob(npages);
2282                 nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2283 
2284                 bcopy(&ovpage[opages - npages], nsvd->vpage, nbytes);
2285 
2286                 /* free up old vpage */
2287                 kmem_free(ovpage, vpgtob(opages));
2288         }
2289 
2290         if (amp == NULL) {
2291                 nsvd->amp = NULL;
2292                 nsvd->anon_index = 0;
2293         } else {
2294                 /*
2295                  * Need to create a new anon map for the new segment.
2296                  * We'll also allocate a new smaller array for the old
2297                  * smaller segment to save space.
2298                  */
2299                 opages = btop((uintptr_t)(addr - seg->s_base));
2300                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2301                 if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2302                         /*
2303                          * Free up now unused parts of anon_map array.
2304                          */
2305                         ulong_t an_idx = svd->anon_index + opages;
2306 
2307                         /*
2308                          * Shared anon map is no longer in use. Before
2309                          * freeing its pages purge all entries from
2310                          * pcache that belong to this amp.
2311                          */
2312                         if (svd->type == MAP_SHARED) {
2313                                 ASSERT(amp->refcnt == 1);
2314                                 ASSERT(svd->softlockcnt == 0);
2315                                 anonmap_purge(amp);
2316                         }
2317 
2318                         if (amp->a_szc == seg->s_szc) {
2319                                 if (seg->s_szc != 0) {
2320                                         anon_free_pages(amp->ahp, an_idx, len,
2321                                             seg->s_szc);
2322                                 } else {
2323                                         anon_free(amp->ahp, an_idx,
2324                                             len);
2325                                 }
2326                         } else {
2327                                 ASSERT(svd->type == MAP_SHARED);
2328                                 ASSERT(amp->a_szc > seg->s_szc);
2329                                 anon_shmap_free_pages(amp, an_idx, len);
2330                         }
2331 
2332                         /*
2333                          * Unreserve swap space for the
2334                          * unmapped chunk of this segment in
2335                          * case it's MAP_SHARED
2336                          */
2337                         if (svd->type == MAP_SHARED) {
2338                                 anon_unresv_zone(len,
2339                                     seg->s_as->a_proc->p_zone);
2340                                 amp->swresv -= len;
2341                         }
2342                 }
2343                 nsvd->anon_index = svd->anon_index +
2344                     btop((uintptr_t)(nseg->s_base - seg->s_base));
2345                 if (svd->type == MAP_SHARED) {
2346                         amp->refcnt++;
2347                         nsvd->amp = amp;
2348                 } else {
2349                         struct anon_map *namp;
2350                         struct anon_hdr *nahp;
2351 
2352                         ASSERT(svd->type == MAP_PRIVATE);
2353                         nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
2354                         namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
2355                         namp->a_szc = seg->s_szc;
2356                         (void) anon_copy_ptr(amp->ahp, svd->anon_index, nahp,
2357                             0, btop(seg->s_size), ANON_SLEEP);
2358                         (void) anon_copy_ptr(amp->ahp, nsvd->anon_index,
2359                             namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
2360                         anon_release(amp->ahp, btop(amp->size));
2361                         svd->anon_index = 0;
2362                         nsvd->anon_index = 0;
2363                         amp->ahp = nahp;
2364                         amp->size = seg->s_size;
2365                         nsvd->amp = namp;
2366                 }
2367                 ANON_LOCK_EXIT(&amp->a_rwlock);
2368         }
2369         if (svd->swresv) {
2370                 if (svd->flags & MAP_NORESERVE) {
2371                         ASSERT(amp);
2372                         oswresv = svd->swresv;
2373                         svd->swresv = ptob(anon_pages(amp->ahp,
2374                             svd->anon_index, btop(seg->s_size)));
2375                         nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
2376                             nsvd->anon_index, btop(nseg->s_size)));
2377                         ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2378                         anon_unresv_zone(oswresv - (svd->swresv + nsvd->swresv),
2379                             seg->s_as->a_proc->p_zone);
2380                         if (SEG_IS_PARTIAL_RESV(seg))
2381                                 seg->s_as->a_resvsize -= oswresv -
2382                                     (svd->swresv + nsvd->swresv);
2383                 } else {
2384                         size_t unlen;
2385 
2386                         if (svd->pageswap) {
2387                                 oswresv = svd->swresv;
2388                                 svd->swresv = segvn_count_swap_by_vpages(seg);
2389                                 nsvd->swresv = segvn_count_swap_by_vpages(nseg);
2390                                 ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2391                                 unlen = oswresv - (svd->swresv + nsvd->swresv);
2392                         } else {
2393                                 if (seg->s_size + nseg->s_size + len !=
2394                                     svd->swresv) {
2395                                         panic("segvn_unmap: cannot split "
2396                                             "swap reservation");
2397                                         /*NOTREACHED*/
2398                                 }
2399                                 svd->swresv = seg->s_size;
2400                                 nsvd->swresv = nseg->s_size;
2401                                 unlen = len;
2402                         }
2403                         anon_unresv_zone(unlen,
2404                             seg->s_as->a_proc->p_zone);
2405                 }
2406                 TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2407                     seg, len, 0);
2408         }
2409 
2410         return (0);                     /* I'm glad that's all over with! */
2411 }
2412 
2413 static void
2414 segvn_free(struct seg *seg)
2415 {
2416         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2417         pgcnt_t npages = seg_pages(seg);
2418         struct anon_map *amp;
2419         size_t len;
2420 
2421         /*
2422          * We don't need any segment level locks for "segvn" data
2423          * since the address space is "write" locked.
2424          */
2425         ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2426         ASSERT(svd->tr_state == SEGVN_TR_OFF);
2427 
2428         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2429 
2430         /*
2431          * Be sure to unlock pages. XXX Why do things get free'ed instead
2432          * of unmapped? XXX
2433          */
2434         (void) segvn_lockop(seg, seg->s_base, seg->s_size,
2435             0, MC_UNLOCK, NULL, 0);
2436 
2437         /*
2438          * Deallocate the vpage and anon pointers if necessary and possible.
2439          */
2440         if (svd->vpage != NULL) {
2441                 kmem_free(svd->vpage, vpgtob(npages));
2442                 svd->vpage = NULL;
2443         }
2444         if ((amp = svd->amp) != NULL) {
2445                 /*
2446                  * If there are no more references to this anon_map
2447                  * structure, then deallocate the structure after freeing
2448                  * up all the anon slot pointers that we can.
2449                  */
2450                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2451                 ASSERT(amp->a_szc >= seg->s_szc);
2452                 if (--amp->refcnt == 0) {
2453                         if (svd->type == MAP_PRIVATE) {
2454                                 /*
2455                                  * Private - we only need to anon_free
2456                                  * the part that this segment refers to.
2457                                  */
2458                                 if (seg->s_szc != 0) {
2459                                         anon_free_pages(amp->ahp,
2460                                             svd->anon_index, seg->s_size,
2461                                             seg->s_szc);
2462                                 } else {
2463                                         anon_free(amp->ahp, svd->anon_index,
2464                                             seg->s_size);
2465                                 }
2466                         } else {
2467 
2468                                 /*
2469                                  * Shared anon map is no longer in use. Before
2470                                  * freeing its pages purge all entries from
2471                                  * pcache that belong to this amp.
2472                                  */
2473                                 ASSERT(svd->softlockcnt == 0);
2474                                 anonmap_purge(amp);
2475 
2476                                 /*
2477                                  * Shared - anon_free the entire
2478                                  * anon_map's worth of stuff and
2479                                  * release any swap reservation.
2480                                  */
2481                                 if (amp->a_szc != 0) {
2482                                         anon_shmap_free_pages(amp, 0,
2483                                             amp->size);
2484                                 } else {
2485                                         anon_free(amp->ahp, 0, amp->size);
2486                                 }
2487                                 if ((len = amp->swresv) != 0) {
2488                                         anon_unresv_zone(len,
2489                                             seg->s_as->a_proc->p_zone);
2490                                         TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2491                                             "anon proc:%p %lu %u", seg, len, 0);
2492                                 }
2493                         }
2494                         svd->amp = NULL;
2495                         ANON_LOCK_EXIT(&amp->a_rwlock);
2496                         anonmap_free(amp);
2497                 } else if (svd->type == MAP_PRIVATE) {
2498                         /*
2499                          * We had a private mapping which still has
2500                          * a held anon_map so just free up all the
2501                          * anon slot pointers that we were using.
2502                          */
2503                         if (seg->s_szc != 0) {
2504                                 anon_free_pages(amp->ahp, svd->anon_index,
2505                                     seg->s_size, seg->s_szc);
2506                         } else {
2507                                 anon_free(amp->ahp, svd->anon_index,
2508                                     seg->s_size);
2509                         }
2510                         ANON_LOCK_EXIT(&amp->a_rwlock);
2511                 } else {
2512                         ANON_LOCK_EXIT(&amp->a_rwlock);
2513                 }
2514         }
2515 
2516         /*
2517          * Release swap reservation.
2518          */
2519         if ((len = svd->swresv) != 0) {
2520                 anon_unresv_zone(svd->swresv,
2521                     seg->s_as->a_proc->p_zone);
2522                 TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2523                     seg, len, 0);
2524                 if (SEG_IS_PARTIAL_RESV(seg))
2525                         seg->s_as->a_resvsize -= svd->swresv;
2526                 svd->swresv = 0;
2527         }
2528         /*
2529          * Release claim on vnode, credentials, and finally free the
2530          * private data.
2531          */
2532         if (svd->vp != NULL) {
2533                 if (svd->type == MAP_SHARED)
2534                         lgrp_shm_policy_fini(NULL, svd->vp);
2535                 VN_RELE(svd->vp);
2536                 svd->vp = NULL;
2537         }
2538         crfree(svd->cred);
2539         svd->pageprot = 0;
2540         svd->pageadvice = 0;
2541         svd->pageswap = 0;
2542         svd->cred = NULL;
2543 
2544         /*
2545          * Take segfree_syncmtx lock to let segvn_reclaim() finish if it's
2546          * still working with this segment without holding as lock (in case
2547          * it's called by pcache async thread).
2548          */
2549         ASSERT(svd->softlockcnt == 0);
2550         mutex_enter(&svd->segfree_syncmtx);
2551         mutex_exit(&svd->segfree_syncmtx);
2552 
2553         seg->s_data = NULL;
2554         kmem_cache_free(segvn_cache, svd);
2555 }
2556 
2557 /*
2558  * Do a F_SOFTUNLOCK call over the range requested.  The range must have
2559  * already been F_SOFTLOCK'ed.
2560  * Caller must always match addr and len of a softunlock with a previous
2561  * softlock with exactly the same addr and len.
2562  */
2563 static void
2564 segvn_softunlock(struct seg *seg, caddr_t addr, size_t len, enum seg_rw rw)
2565 {
2566         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2567         page_t *pp;
2568         caddr_t adr;
2569         struct vnode *vp;
2570         u_offset_t offset;
2571         ulong_t anon_index;
2572         struct anon_map *amp;
2573         struct anon *ap = NULL;
2574 
2575         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2576         ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
2577 
2578         if ((amp = svd->amp) != NULL)
2579                 anon_index = svd->anon_index + seg_page(seg, addr);
2580 
2581         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
2582                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
2583                 hat_unlock_region(seg->s_as->a_hat, addr, len, svd->rcookie);
2584         } else {
2585                 hat_unlock(seg->s_as->a_hat, addr, len);
2586         }
2587         for (adr = addr; adr < addr + len; adr += PAGESIZE) {
2588                 if (amp != NULL) {
2589                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2590                         if ((ap = anon_get_ptr(amp->ahp, anon_index++))
2591                             != NULL) {
2592                                 swap_xlate(ap, &vp, &offset);
2593                         } else {
2594                                 vp = svd->vp;
2595                                 offset = svd->offset +
2596                                     (uintptr_t)(adr - seg->s_base);
2597                         }
2598                         ANON_LOCK_EXIT(&amp->a_rwlock);
2599                 } else {
2600                         vp = svd->vp;
2601                         offset = svd->offset +
2602                             (uintptr_t)(adr - seg->s_base);
2603                 }
2604 
2605                 /*
2606                  * Use page_find() instead of page_lookup() to
2607                  * find the page since we know that it is locked.
2608                  */
2609                 pp = page_find(vp, offset);
2610                 if (pp == NULL) {
2611                         panic(
2612                             "segvn_softunlock: addr %p, ap %p, vp %p, off %llx",
2613                             (void *)adr, (void *)ap, (void *)vp, offset);
2614                         /*NOTREACHED*/
2615                 }
2616 
2617                 if (rw == S_WRITE) {
2618                         hat_setrefmod(pp);
2619                         if (seg->s_as->a_vbits)
2620                                 hat_setstat(seg->s_as, adr, PAGESIZE,
2621                                     P_REF | P_MOD);
2622                 } else if (rw != S_OTHER) {
2623                         hat_setref(pp);
2624                         if (seg->s_as->a_vbits)
2625                                 hat_setstat(seg->s_as, adr, PAGESIZE, P_REF);
2626                 }
2627                 TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2628                     "segvn_fault:pp %p vp %p offset %llx", pp, vp, offset);
2629                 page_unlock(pp);
2630         }
2631         ASSERT(svd->softlockcnt >= btop(len));
2632         if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -btop(len))) {
2633                 /*
2634                  * All SOFTLOCKS are gone. Wakeup any waiting
2635                  * unmappers so they can try again to unmap.
2636                  * Check for waiters first without the mutex
2637                  * held so we don't always grab the mutex on
2638                  * softunlocks.
2639                  */
2640                 if (AS_ISUNMAPWAIT(seg->s_as)) {
2641                         mutex_enter(&seg->s_as->a_contents);
2642                         if (AS_ISUNMAPWAIT(seg->s_as)) {
2643                                 AS_CLRUNMAPWAIT(seg->s_as);
2644                                 cv_broadcast(&seg->s_as->a_cv);
2645                         }
2646                         mutex_exit(&seg->s_as->a_contents);
2647                 }
2648         }
2649 }
2650 
2651 #define PAGE_HANDLED    ((page_t *)-1)
2652 
2653 /*
2654  * Release all the pages in the NULL terminated ppp list
2655  * which haven't already been converted to PAGE_HANDLED.
2656  */
2657 static void
2658 segvn_pagelist_rele(page_t **ppp)
2659 {
2660         for (; *ppp != NULL; ppp++) {
2661                 if (*ppp != PAGE_HANDLED)
2662                         page_unlock(*ppp);
2663         }
2664 }
2665 
2666 static int stealcow = 1;
2667 
2668 /*
2669  * Workaround for viking chip bug.  See bug id 1220902.
2670  * To fix this down in pagefault() would require importing so
2671  * much as and segvn code as to be unmaintainable.
2672  */
2673 int enable_mbit_wa = 0;
2674 
2675 /*
2676  * Handles all the dirty work of getting the right
2677  * anonymous pages and loading up the translations.
2678  * This routine is called only from segvn_fault()
2679  * when looping over the range of addresses requested.
2680  *
2681  * The basic algorithm here is:
2682  *      If this is an anon_zero case
2683  *              Call anon_zero to allocate page
2684  *              Load up translation
2685  *              Return
2686  *      endif
2687  *      If this is an anon page
2688  *              Use anon_getpage to get the page
2689  *      else
2690  *              Find page in pl[] list passed in
2691  *      endif
2692  *      If not a cow
2693  *              Load up the translation to the page
2694  *              return
2695  *      endif
2696  *      Call anon_private to handle cow
2697  *      Load up (writable) translation to new page
2698  */
2699 static faultcode_t
2700 segvn_faultpage(
2701         struct hat *hat,                /* the hat to use for mapping */
2702         struct seg *seg,                /* seg_vn of interest */
2703         caddr_t addr,                   /* address in as */
2704         u_offset_t off,                 /* offset in vp */
2705         struct vpage *vpage,            /* pointer to vpage for vp, off */
2706         page_t *pl[],                   /* object source page pointer */
2707         uint_t vpprot,                  /* access allowed to object pages */
2708         enum fault_type type,           /* type of fault */
2709         enum seg_rw rw,                 /* type of access at fault */
2710         int brkcow)                     /* we may need to break cow */
2711 {
2712         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2713         page_t *pp, **ppp;
2714         uint_t pageflags = 0;
2715         page_t *anon_pl[1 + 1];
2716         page_t *opp = NULL;             /* original page */
2717         uint_t prot;
2718         int err;
2719         int cow;
2720         int claim;
2721         int steal = 0;
2722         ulong_t anon_index;
2723         struct anon *ap, *oldap;
2724         struct anon_map *amp;
2725         int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
2726         int anon_lock = 0;
2727         anon_sync_obj_t cookie;
2728 
2729         if (svd->flags & MAP_TEXT) {
2730                 hat_flag |= HAT_LOAD_TEXT;
2731         }
2732 
2733         ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
2734         ASSERT(seg->s_szc == 0);
2735         ASSERT(svd->tr_state != SEGVN_TR_INIT);
2736 
2737         /*
2738          * Initialize protection value for this page.
2739          * If we have per page protection values check it now.
2740          */
2741         if (svd->pageprot) {
2742                 uint_t protchk;
2743 
2744                 switch (rw) {
2745                 case S_READ:
2746                         protchk = PROT_READ;
2747                         break;
2748                 case S_WRITE:
2749                         protchk = PROT_WRITE;
2750                         break;
2751                 case S_EXEC:
2752                         protchk = PROT_EXEC;
2753                         break;
2754                 case S_OTHER:
2755                 default:
2756                         protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
2757                         break;
2758                 }
2759 
2760                 prot = VPP_PROT(vpage);
2761                 if ((prot & protchk) == 0)
2762                         return (FC_PROT);       /* illegal access type */
2763         } else {
2764                 prot = svd->prot;
2765         }
2766 
2767         if (type == F_SOFTLOCK) {
2768                 atomic_inc_ulong((ulong_t *)&svd->softlockcnt);
2769         }
2770 
2771         /*
2772          * Always acquire the anon array lock to prevent 2 threads from
2773          * allocating separate anon slots for the same "addr".
2774          */
2775 
2776         if ((amp = svd->amp) != NULL) {
2777                 ASSERT(RW_READ_HELD(&amp->a_rwlock));
2778                 anon_index = svd->anon_index + seg_page(seg, addr);
2779                 anon_array_enter(amp, anon_index, &cookie);
2780                 anon_lock = 1;
2781         }
2782 
2783         if (svd->vp == NULL && amp != NULL) {
2784                 if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL) {
2785                         /*
2786                          * Allocate a (normally) writable anonymous page of
2787                          * zeroes. If no advance reservations, reserve now.
2788                          */
2789                         if (svd->flags & MAP_NORESERVE) {
2790                                 if (anon_resv_zone(ptob(1),
2791                                     seg->s_as->a_proc->p_zone)) {
2792                                         atomic_add_long(&svd->swresv, ptob(1));
2793                                         atomic_add_long(&seg->s_as->a_resvsize,
2794                                             ptob(1));
2795                                 } else {
2796                                         err = ENOMEM;
2797                                         goto out;
2798                                 }
2799                         }
2800                         if ((pp = anon_zero(seg, addr, &ap,
2801                             svd->cred)) == NULL) {
2802                                 err = ENOMEM;
2803                                 goto out;       /* out of swap space */
2804                         }
2805                         /*
2806                          * Re-acquire the anon_map lock and
2807                          * initialize the anon array entry.
2808                          */
2809                         (void) anon_set_ptr(amp->ahp, anon_index, ap,
2810                             ANON_SLEEP);
2811 
2812                         ASSERT(pp->p_szc == 0);
2813 
2814                         /*
2815                          * Handle pages that have been marked for migration
2816                          */
2817                         if (lgrp_optimizations())
2818                                 page_migrate(seg, addr, &pp, 1);
2819 
2820                         if (enable_mbit_wa) {
2821                                 if (rw == S_WRITE)
2822                                         hat_setmod(pp);
2823                                 else if (!hat_ismod(pp))
2824                                         prot &= ~PROT_WRITE;
2825                         }
2826                         /*
2827                          * If AS_PAGLCK is set in a_flags (via memcntl(2)
2828                          * with MC_LOCKAS, MCL_FUTURE) and this is a
2829                          * MAP_NORESERVE segment, we may need to
2830                          * permanently lock the page as it is being faulted
2831                          * for the first time. The following text applies
2832                          * only to MAP_NORESERVE segments:
2833                          *
2834                          * As per memcntl(2), if this segment was created
2835                          * after MCL_FUTURE was applied (a "future"
2836                          * segment), its pages must be locked.  If this
2837                          * segment existed at MCL_FUTURE application (a
2838                          * "past" segment), the interface is unclear.
2839                          *
2840                          * We decide to lock only if vpage is present:
2841                          *
2842                          * - "future" segments will have a vpage array (see
2843                          *    as_map), and so will be locked as required
2844                          *
2845                          * - "past" segments may not have a vpage array,
2846                          *    depending on whether events (such as
2847                          *    mprotect) have occurred. Locking if vpage
2848                          *    exists will preserve legacy behavior.  Not
2849                          *    locking if vpage is absent, will not break
2850                          *    the interface or legacy behavior.  Note that
2851                          *    allocating vpage here if it's absent requires
2852                          *    upgrading the segvn reader lock, the cost of
2853                          *    which does not seem worthwhile.
2854                          *
2855                          * Usually testing and setting VPP_ISPPLOCK and
2856                          * VPP_SETPPLOCK requires holding the segvn lock as
2857                          * writer, but in this case all readers are
2858                          * serializing on the anon array lock.
2859                          */
2860                         if (AS_ISPGLCK(seg->s_as) && vpage != NULL &&
2861                             (svd->flags & MAP_NORESERVE) &&
2862                             !VPP_ISPPLOCK(vpage)) {
2863                                 proc_t *p = seg->s_as->a_proc;
2864                                 ASSERT(svd->type == MAP_PRIVATE);
2865                                 mutex_enter(&p->p_lock);
2866                                 if (rctl_incr_locked_mem(p, NULL, PAGESIZE,
2867                                     1) == 0) {
2868                                         claim = VPP_PROT(vpage) & PROT_WRITE;
2869                                         if (page_pp_lock(pp, claim, 0)) {
2870                                                 VPP_SETPPLOCK(vpage);
2871                                         } else {
2872                                                 rctl_decr_locked_mem(p, NULL,
2873                                                     PAGESIZE, 1);
2874                                         }
2875                                 }
2876                                 mutex_exit(&p->p_lock);
2877                         }
2878 
2879                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2880                         hat_memload(hat, addr, pp, prot, hat_flag);
2881 
2882                         if (!(hat_flag & HAT_LOAD_LOCK))
2883                                 page_unlock(pp);
2884 
2885                         anon_array_exit(&cookie);
2886                         return (0);
2887                 }
2888         }
2889 
2890         /*
2891          * Obtain the page structure via anon_getpage() if it is
2892          * a private copy of an object (the result of a previous
2893          * copy-on-write).
2894          */
2895         if (amp != NULL) {
2896                 if ((ap = anon_get_ptr(amp->ahp, anon_index)) != NULL) {
2897                         err = anon_getpage(&ap, &vpprot, anon_pl, PAGESIZE,
2898                             seg, addr, rw, svd->cred);
2899                         if (err)
2900                                 goto out;
2901 
2902                         if (svd->type == MAP_SHARED) {
2903                                 /*
2904                                  * If this is a shared mapping to an
2905                                  * anon_map, then ignore the write
2906                                  * permissions returned by anon_getpage().
2907                                  * They apply to the private mappings
2908                                  * of this anon_map.
2909                                  */
2910                                 vpprot |= PROT_WRITE;
2911                         }
2912                         opp = anon_pl[0];
2913                 }
2914         }
2915 
2916         /*
2917          * Search the pl[] list passed in if it is from the
2918          * original object (i.e., not a private copy).
2919          */
2920         if (opp == NULL) {
2921                 /*
2922                  * Find original page.  We must be bringing it in
2923                  * from the list in pl[].
2924                  */
2925                 for (ppp = pl; (opp = *ppp) != NULL; ppp++) {
2926                         if (opp == PAGE_HANDLED)
2927                                 continue;
2928                         ASSERT(opp->p_vnode == svd->vp); /* XXX */
2929                         if (opp->p_offset == off)
2930                                 break;
2931                 }
2932                 if (opp == NULL) {
2933                         panic("segvn_faultpage not found");
2934                         /*NOTREACHED*/
2935                 }
2936                 *ppp = PAGE_HANDLED;
2937 
2938         }
2939 
2940         ASSERT(PAGE_LOCKED(opp));
2941 
2942         TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2943             "segvn_fault:pp %p vp %p offset %llx", opp, NULL, 0);
2944 
2945         /*
2946          * The fault is treated as a copy-on-write fault if a
2947          * write occurs on a private segment and the object
2948          * page (i.e., mapping) is write protected.  We assume
2949          * that fatal protection checks have already been made.
2950          */
2951 
2952         if (brkcow) {
2953                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
2954                 cow = !(vpprot & PROT_WRITE);
2955         } else if (svd->tr_state == SEGVN_TR_ON) {
2956                 /*
2957                  * If we are doing text replication COW on first touch.
2958                  */
2959                 ASSERT(amp != NULL);
2960                 ASSERT(svd->vp != NULL);
2961                 ASSERT(rw != S_WRITE);
2962                 cow = (ap == NULL);
2963         } else {
2964                 cow = 0;
2965         }
2966 
2967         /*
2968          * If not a copy-on-write case load the translation
2969          * and return.
2970          */
2971         if (cow == 0) {
2972 
2973                 /*
2974                  * Handle pages that have been marked for migration
2975                  */
2976                 if (lgrp_optimizations())
2977                         page_migrate(seg, addr, &opp, 1);
2978 
2979                 if (IS_VMODSORT(opp->p_vnode) || enable_mbit_wa) {
2980                         if (rw == S_WRITE)
2981                                 hat_setmod(opp);
2982                         else if (rw != S_OTHER && !hat_ismod(opp))
2983                                 prot &= ~PROT_WRITE;
2984                 }
2985 
2986                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
2987                     (!svd->pageprot && svd->prot == (prot & vpprot)));
2988                 ASSERT(amp == NULL ||
2989                     svd->rcookie == HAT_INVALID_REGION_COOKIE);
2990                 hat_memload_region(hat, addr, opp, prot & vpprot, hat_flag,
2991                     svd->rcookie);
2992 
2993                 if (!(hat_flag & HAT_LOAD_LOCK))
2994                         page_unlock(opp);
2995 
2996                 if (anon_lock) {
2997                         anon_array_exit(&cookie);
2998                 }
2999                 return (0);
3000         }
3001 
3002         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3003 
3004         hat_setref(opp);
3005 
3006         ASSERT(amp != NULL && anon_lock);
3007 
3008         /*
3009          * Steal the page only if it isn't a private page
3010          * since stealing a private page is not worth the effort.
3011          */
3012         if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL)
3013                 steal = 1;
3014 
3015         /*
3016          * Steal the original page if the following conditions are true:
3017          *
3018          * We are low on memory, the page is not private, page is not large,
3019          * not shared, not modified, not `locked' or if we have it `locked'
3020          * (i.e., p_cowcnt == 1 and p_lckcnt == 0, which also implies
3021          * that the page is not shared) and if it doesn't have any
3022          * translations. page_struct_lock isn't needed to look at p_cowcnt
3023          * and p_lckcnt because we first get exclusive lock on page.
3024          */
3025         (void) hat_pagesync(opp, HAT_SYNC_DONTZERO | HAT_SYNC_STOPON_MOD);
3026 
3027         if (stealcow && freemem < minfree && steal && opp->p_szc == 0 &&
3028             page_tryupgrade(opp) && !hat_ismod(opp) &&
3029             ((opp->p_lckcnt == 0 && opp->p_cowcnt == 0) ||
3030             (opp->p_lckcnt == 0 && opp->p_cowcnt == 1 &&
3031             vpage != NULL && VPP_ISPPLOCK(vpage)))) {
3032                 /*
3033                  * Check if this page has other translations
3034                  * after unloading our translation.
3035                  */
3036                 if (hat_page_is_mapped(opp)) {
3037                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3038                         hat_unload(seg->s_as->a_hat, addr, PAGESIZE,
3039                             HAT_UNLOAD);
3040                 }
3041 
3042                 /*
3043                  * hat_unload() might sync back someone else's recent
3044                  * modification, so check again.
3045                  */
3046                 if (!hat_ismod(opp) && !hat_page_is_mapped(opp))
3047                         pageflags |= STEAL_PAGE;
3048         }
3049 
3050         /*
3051          * If we have a vpage pointer, see if it indicates that we have
3052          * ``locked'' the page we map -- if so, tell anon_private to
3053          * transfer the locking resource to the new page.
3054          *
3055          * See Statement at the beginning of segvn_lockop regarding
3056          * the way lockcnts/cowcnts are handled during COW.
3057          *
3058          */
3059         if (vpage != NULL && VPP_ISPPLOCK(vpage))
3060                 pageflags |= LOCK_PAGE;
3061 
3062         /*
3063          * Allocate a private page and perform the copy.
3064          * For MAP_NORESERVE reserve swap space now, unless this
3065          * is a cow fault on an existing anon page in which case
3066          * MAP_NORESERVE will have made advance reservations.
3067          */
3068         if ((svd->flags & MAP_NORESERVE) && (ap == NULL)) {
3069                 if (anon_resv_zone(ptob(1), seg->s_as->a_proc->p_zone)) {
3070                         atomic_add_long(&svd->swresv, ptob(1));
3071                         atomic_add_long(&seg->s_as->a_resvsize, ptob(1));
3072                 } else {
3073                         page_unlock(opp);
3074                         err = ENOMEM;
3075                         goto out;
3076                 }
3077         }
3078         oldap = ap;
3079         pp = anon_private(&ap, seg, addr, prot, opp, pageflags, svd->cred);
3080         if (pp == NULL) {
3081                 err = ENOMEM;   /* out of swap space */
3082                 goto out;
3083         }
3084 
3085         /*
3086          * If we copied away from an anonymous page, then
3087          * we are one step closer to freeing up an anon slot.
3088          *
3089          * NOTE:  The original anon slot must be released while
3090          * holding the "anon_map" lock.  This is necessary to prevent
3091          * other threads from obtaining a pointer to the anon slot
3092          * which may be freed if its "refcnt" is 1.
3093          */
3094         if (oldap != NULL)
3095                 anon_decref(oldap);
3096 
3097         (void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3098 
3099         /*
3100          * Handle pages that have been marked for migration
3101          */
3102         if (lgrp_optimizations())
3103                 page_migrate(seg, addr, &pp, 1);
3104 
3105         ASSERT(pp->p_szc == 0);
3106 
3107         ASSERT(!IS_VMODSORT(pp->p_vnode));
3108         if (enable_mbit_wa) {
3109                 if (rw == S_WRITE)
3110                         hat_setmod(pp);
3111                 else if (!hat_ismod(pp))
3112                         prot &= ~PROT_WRITE;
3113         }
3114 
3115         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3116         hat_memload(hat, addr, pp, prot, hat_flag);
3117 
3118         if (!(hat_flag & HAT_LOAD_LOCK))
3119                 page_unlock(pp);
3120 
3121         ASSERT(anon_lock);
3122         anon_array_exit(&cookie);
3123         return (0);
3124 out:
3125         if (anon_lock)
3126                 anon_array_exit(&cookie);
3127 
3128         if (type == F_SOFTLOCK) {
3129                 atomic_dec_ulong((ulong_t *)&svd->softlockcnt);
3130         }
3131         return (FC_MAKE_ERR(err));
3132 }
3133 
3134 /*
3135  * relocate a bunch of smaller targ pages into one large repl page. all targ
3136  * pages must be complete pages smaller than replacement pages.
3137  * it's assumed that no page's szc can change since they are all PAGESIZE or
3138  * complete large pages locked SHARED.
3139  */
3140 static void
3141 segvn_relocate_pages(page_t **targ, page_t *replacement)
3142 {
3143         page_t *pp;
3144         pgcnt_t repl_npgs, curnpgs;
3145         pgcnt_t i;
3146         uint_t repl_szc = replacement->p_szc;
3147         page_t *first_repl = replacement;
3148         page_t *repl;
3149         spgcnt_t npgs;
3150 
3151         VM_STAT_ADD(segvnvmstats.relocatepages[0]);
3152 
3153         ASSERT(repl_szc != 0);
3154         npgs = repl_npgs = page_get_pagecnt(repl_szc);
3155 
3156         i = 0;
3157         while (repl_npgs) {
3158                 spgcnt_t nreloc;
3159                 int err;
3160                 ASSERT(replacement != NULL);
3161                 pp = targ[i];
3162                 ASSERT(pp->p_szc < repl_szc);
3163                 ASSERT(PAGE_EXCL(pp));
3164                 ASSERT(!PP_ISFREE(pp));
3165                 curnpgs = page_get_pagecnt(pp->p_szc);
3166                 if (curnpgs == 1) {
3167                         VM_STAT_ADD(segvnvmstats.relocatepages[1]);
3168                         repl = replacement;
3169                         page_sub(&replacement, repl);
3170                         ASSERT(PAGE_EXCL(repl));
3171                         ASSERT(!PP_ISFREE(repl));
3172                         ASSERT(repl->p_szc == repl_szc);
3173                 } else {
3174                         page_t *repl_savepp;
3175                         int j;
3176                         VM_STAT_ADD(segvnvmstats.relocatepages[2]);
3177                         repl_savepp = replacement;
3178                         for (j = 0; j < curnpgs; j++) {
3179                                 repl = replacement;
3180                                 page_sub(&replacement, repl);
3181                                 ASSERT(PAGE_EXCL(repl));
3182                                 ASSERT(!PP_ISFREE(repl));
3183                                 ASSERT(repl->p_szc == repl_szc);
3184                                 ASSERT(page_pptonum(targ[i + j]) ==
3185                                     page_pptonum(targ[i]) + j);
3186                         }
3187                         repl = repl_savepp;
3188                         ASSERT(IS_P2ALIGNED(page_pptonum(repl), curnpgs));
3189                 }
3190                 err = page_relocate(&pp, &repl, 0, 1, &nreloc, NULL);
3191                 if (err || nreloc != curnpgs) {
3192                         panic("segvn_relocate_pages: "
3193                             "page_relocate failed err=%d curnpgs=%ld "
3194                             "nreloc=%ld", err, curnpgs, nreloc);
3195                 }
3196                 ASSERT(curnpgs <= repl_npgs);
3197                 repl_npgs -= curnpgs;
3198                 i += curnpgs;
3199         }
3200         ASSERT(replacement == NULL);
3201 
3202         repl = first_repl;
3203         repl_npgs = npgs;
3204         for (i = 0; i < repl_npgs; i++) {
3205                 ASSERT(PAGE_EXCL(repl));
3206                 ASSERT(!PP_ISFREE(repl));
3207                 targ[i] = repl;
3208                 page_downgrade(targ[i]);
3209                 repl++;
3210         }
3211 }
3212 
3213 /*
3214  * Check if all pages in ppa array are complete smaller than szc pages and
3215  * their roots will still be aligned relative to their current size if the
3216  * entire ppa array is relocated into one szc page. If these conditions are
3217  * not met return 0.
3218  *
3219  * If all pages are properly aligned attempt to upgrade their locks
3220  * to exclusive mode. If it fails set *upgrdfail to 1 and return 0.
3221  * upgrdfail was set to 0 by caller.
3222  *
3223  * Return 1 if all pages are aligned and locked exclusively.
3224  *
3225  * If all pages in ppa array happen to be physically contiguous to make one
3226  * szc page and all exclusive locks are successfully obtained promote the page
3227  * size to szc and set *pszc to szc. Return 1 with pages locked shared.
3228  */
3229 static int
3230 segvn_full_szcpages(page_t **ppa, uint_t szc, int *upgrdfail, uint_t *pszc)
3231 {
3232         page_t *pp;
3233         pfn_t pfn;
3234         pgcnt_t totnpgs = page_get_pagecnt(szc);
3235         pfn_t first_pfn;
3236         int contig = 1;
3237         pgcnt_t i;
3238         pgcnt_t j;
3239         uint_t curszc;
3240         pgcnt_t curnpgs;
3241         int root = 0;
3242 
3243         ASSERT(szc > 0);
3244 
3245         VM_STAT_ADD(segvnvmstats.fullszcpages[0]);
3246 
3247         for (i = 0; i < totnpgs; i++) {
3248                 pp = ppa[i];
3249                 ASSERT(PAGE_SHARED(pp));
3250                 ASSERT(!PP_ISFREE(pp));
3251                 pfn = page_pptonum(pp);
3252                 if (i == 0) {
3253                         if (!IS_P2ALIGNED(pfn, totnpgs)) {
3254                                 contig = 0;
3255                         } else {
3256                                 first_pfn = pfn;
3257                         }
3258                 } else if (contig && pfn != first_pfn + i) {
3259                         contig = 0;
3260                 }
3261                 if (pp->p_szc == 0) {
3262                         if (root) {
3263                                 VM_STAT_ADD(segvnvmstats.fullszcpages[1]);
3264                                 return (0);
3265                         }
3266                 } else if (!root) {
3267                         if ((curszc = pp->p_szc) >= szc) {
3268                                 VM_STAT_ADD(segvnvmstats.fullszcpages[2]);
3269                                 return (0);
3270                         }
3271                         if (curszc == 0) {
3272                                 /*
3273                                  * p_szc changed means we don't have all pages
3274                                  * locked. return failure.
3275                                  */
3276                                 VM_STAT_ADD(segvnvmstats.fullszcpages[3]);
3277                                 return (0);
3278                         }
3279                         curnpgs = page_get_pagecnt(curszc);
3280                         if (!IS_P2ALIGNED(pfn, curnpgs) ||
3281                             !IS_P2ALIGNED(i, curnpgs)) {
3282                                 VM_STAT_ADD(segvnvmstats.fullszcpages[4]);
3283                                 return (0);
3284                         }
3285                         root = 1;
3286                 } else {
3287                         ASSERT(i > 0);
3288                         VM_STAT_ADD(segvnvmstats.fullszcpages[5]);
3289                         if (pp->p_szc != curszc) {
3290                                 VM_STAT_ADD(segvnvmstats.fullszcpages[6]);
3291                                 return (0);
3292                         }
3293                         if (pfn - 1 != page_pptonum(ppa[i - 1])) {
3294                                 panic("segvn_full_szcpages: "
3295                                     "large page not physically contiguous");
3296                         }
3297                         if (P2PHASE(pfn, curnpgs) == curnpgs - 1) {
3298                                 root = 0;
3299                         }
3300                 }
3301         }
3302 
3303         for (i = 0; i < totnpgs; i++) {
3304                 ASSERT(ppa[i]->p_szc < szc);
3305                 if (!page_tryupgrade(ppa[i])) {
3306                         for (j = 0; j < i; j++) {
3307                                 page_downgrade(ppa[j]);
3308                         }
3309                         *pszc = ppa[i]->p_szc;
3310                         *upgrdfail = 1;
3311                         VM_STAT_ADD(segvnvmstats.fullszcpages[7]);
3312                         return (0);
3313                 }
3314         }
3315 
3316         /*
3317          * When a page is put a free cachelist its szc is set to 0.  if file
3318          * system reclaimed pages from cachelist targ pages will be physically
3319          * contiguous with 0 p_szc.  in this case just upgrade szc of targ
3320          * pages without any relocations.
3321          * To avoid any hat issues with previous small mappings
3322          * hat_pageunload() the target pages first.
3323          */
3324         if (contig) {
3325                 VM_STAT_ADD(segvnvmstats.fullszcpages[8]);
3326                 for (i = 0; i < totnpgs; i++) {
3327                         (void) hat_pageunload(ppa[i], HAT_FORCE_PGUNLOAD);
3328                 }
3329                 for (i = 0; i < totnpgs; i++) {
3330                         ppa[i]->p_szc = szc;
3331                 }
3332                 for (i = 0; i < totnpgs; i++) {
3333                         ASSERT(PAGE_EXCL(ppa[i]));
3334                         page_downgrade(ppa[i]);
3335                 }
3336                 if (pszc != NULL) {
3337                         *pszc = szc;
3338                 }
3339         }
3340         VM_STAT_ADD(segvnvmstats.fullszcpages[9]);
3341         return (1);
3342 }
3343 
3344 /*
3345  * Create physically contiguous pages for [vp, off] - [vp, off +
3346  * page_size(szc)) range and for private segment return them in ppa array.
3347  * Pages are created either via IO or relocations.
3348  *
3349  * Return 1 on success and 0 on failure.
3350  *
3351  * If physically contiguous pages already exist for this range return 1 without
3352  * filling ppa array. Caller initializes ppa[0] as NULL to detect that ppa
3353  * array wasn't filled. In this case caller fills ppa array via VOP_GETPAGE().
3354  */
3355 
3356 static int
3357 segvn_fill_vp_pages(struct segvn_data *svd, vnode_t *vp, u_offset_t off,
3358     uint_t szc, page_t **ppa, page_t **ppplist, uint_t *ret_pszc,
3359     int *downsize)
3360 
3361 {
3362         page_t *pplist = *ppplist;
3363         size_t pgsz = page_get_pagesize(szc);
3364         pgcnt_t pages = btop(pgsz);
3365         ulong_t start_off = off;
3366         u_offset_t eoff = off + pgsz;
3367         spgcnt_t nreloc;
3368         u_offset_t io_off = off;
3369         size_t io_len;
3370         page_t *io_pplist = NULL;
3371         page_t *done_pplist = NULL;
3372         pgcnt_t pgidx = 0;
3373         page_t *pp;
3374         page_t *newpp;
3375         page_t *targpp;
3376         int io_err = 0;
3377         int i;
3378         pfn_t pfn;
3379         ulong_t ppages;
3380         page_t *targ_pplist = NULL;
3381         page_t *repl_pplist = NULL;
3382         page_t *tmp_pplist;
3383         int nios = 0;
3384         uint_t pszc;
3385         struct vattr va;
3386 
3387         VM_STAT_ADD(segvnvmstats.fill_vp_pages[0]);
3388 
3389         ASSERT(szc != 0);
3390         ASSERT(pplist->p_szc == szc);
3391 
3392         /*
3393          * downsize will be set to 1 only if we fail to lock pages. this will
3394          * allow subsequent faults to try to relocate the page again. If we
3395          * fail due to misalignment don't downsize and let the caller map the
3396          * whole region with small mappings to avoid more faults into the area
3397          * where we can't get large pages anyway.
3398          */
3399         *downsize = 0;
3400 
3401         while (off < eoff) {
3402                 newpp = pplist;
3403                 ASSERT(newpp != NULL);
3404                 ASSERT(PAGE_EXCL(newpp));
3405                 ASSERT(!PP_ISFREE(newpp));
3406                 /*
3407                  * we pass NULL for nrelocp to page_lookup_create()
3408                  * so that it doesn't relocate. We relocate here
3409                  * later only after we make sure we can lock all
3410                  * pages in the range we handle and they are all
3411                  * aligned.
3412                  */
3413                 pp = page_lookup_create(vp, off, SE_SHARED, newpp, NULL, 0);
3414                 ASSERT(pp != NULL);
3415                 ASSERT(!PP_ISFREE(pp));
3416                 ASSERT(pp->p_vnode == vp);
3417                 ASSERT(pp->p_offset == off);
3418                 if (pp == newpp) {
3419                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[1]);
3420                         page_sub(&pplist, pp);
3421                         ASSERT(PAGE_EXCL(pp));
3422                         ASSERT(page_iolock_assert(pp));
3423                         page_list_concat(&io_pplist, &pp);
3424                         off += PAGESIZE;
3425                         continue;
3426                 }
3427                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[2]);
3428                 pfn = page_pptonum(pp);
3429                 pszc = pp->p_szc;
3430                 if (pszc >= szc && targ_pplist == NULL && io_pplist == NULL &&
3431                     IS_P2ALIGNED(pfn, pages)) {
3432                         ASSERT(repl_pplist == NULL);
3433                         ASSERT(done_pplist == NULL);
3434                         ASSERT(pplist == *ppplist);
3435                         page_unlock(pp);
3436                         page_free_replacement_page(pplist);
3437                         page_create_putback(pages);
3438                         *ppplist = NULL;
3439                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[3]);
3440                         return (1);
3441                 }
3442                 if (pszc >= szc) {
3443                         page_unlock(pp);
3444                         segvn_faultvnmpss_align_err1++;
3445                         goto out;
3446                 }
3447                 ppages = page_get_pagecnt(pszc);
3448                 if (!IS_P2ALIGNED(pfn, ppages)) {
3449                         ASSERT(pszc > 0);
3450                         /*
3451                          * sizing down to pszc won't help.
3452                          */
3453                         page_unlock(pp);
3454                         segvn_faultvnmpss_align_err2++;
3455                         goto out;
3456                 }
3457                 pfn = page_pptonum(newpp);
3458                 if (!IS_P2ALIGNED(pfn, ppages)) {
3459                         ASSERT(pszc > 0);
3460                         /*
3461                          * sizing down to pszc won't help.
3462                          */
3463                         page_unlock(pp);
3464                         segvn_faultvnmpss_align_err3++;
3465                         goto out;
3466                 }
3467                 if (!PAGE_EXCL(pp)) {
3468                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[4]);
3469                         page_unlock(pp);
3470                         *downsize = 1;
3471                         *ret_pszc = pp->p_szc;
3472                         goto out;
3473                 }
3474                 targpp = pp;
3475                 if (io_pplist != NULL) {
3476                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[5]);
3477                         io_len = off - io_off;
3478                         /*
3479                          * Some file systems like NFS don't check EOF
3480                          * conditions in VOP_PAGEIO(). Check it here
3481                          * now that pages are locked SE_EXCL. Any file
3482                          * truncation will wait until the pages are
3483                          * unlocked so no need to worry that file will
3484                          * be truncated after we check its size here.
3485                          * XXX fix NFS to remove this check.
3486                          */
3487                         va.va_mask = AT_SIZE;
3488                         if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL)) {
3489                                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[6]);
3490                                 page_unlock(targpp);
3491                                 goto out;
3492                         }
3493                         if (btopr(va.va_size) < btopr(io_off + io_len)) {
3494                                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[7]);
3495                                 *downsize = 1;
3496                                 *ret_pszc = 0;
3497                                 page_unlock(targpp);
3498                                 goto out;
3499                         }
3500                         io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3501                                 B_READ, svd->cred, NULL);
3502                         if (io_err) {
3503                                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[8]);
3504                                 page_unlock(targpp);
3505                                 if (io_err == EDEADLK) {
3506                                         segvn_vmpss_pageio_deadlk_err++;
3507                                 }
3508                                 goto out;
3509                         }
3510                         nios++;
3511                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[9]);
3512                         while (io_pplist != NULL) {
3513                                 pp = io_pplist;
3514                                 page_sub(&io_pplist, pp);
3515                                 ASSERT(page_iolock_assert(pp));
3516                                 page_io_unlock(pp);
3517                                 pgidx = (pp->p_offset - start_off) >>
3518                                     PAGESHIFT;
3519                                 ASSERT(pgidx < pages);
3520                                 ppa[pgidx] = pp;
3521                                 page_list_concat(&done_pplist, &pp);
3522                         }
3523                 }
3524                 pp = targpp;
3525                 ASSERT(PAGE_EXCL(pp));
3526                 ASSERT(pp->p_szc <= pszc);
3527                 if (pszc != 0 && !group_page_trylock(pp, SE_EXCL)) {
3528                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[10]);
3529                         page_unlock(pp);
3530                         *downsize = 1;
3531                         *ret_pszc = pp->p_szc;
3532                         goto out;
3533                 }
3534                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[11]);
3535                 /*
3536                  * page szc chould have changed before the entire group was
3537                  * locked. reread page szc.
3538                  */
3539                 pszc = pp->p_szc;
3540                 ppages = page_get_pagecnt(pszc);
3541 
3542                 /* link just the roots */
3543                 page_list_concat(&targ_pplist, &pp);
3544                 page_sub(&pplist, newpp);
3545                 page_list_concat(&repl_pplist, &newpp);
3546                 off += PAGESIZE;
3547                 while (--ppages != 0) {
3548                         newpp = pplist;
3549                         page_sub(&pplist, newpp);
3550                         off += PAGESIZE;
3551                 }
3552                 io_off = off;
3553         }
3554         if (io_pplist != NULL) {
3555                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[12]);
3556                 io_len = eoff - io_off;
3557                 va.va_mask = AT_SIZE;
3558                 if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL) != 0) {
3559                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[13]);
3560                         goto out;
3561                 }
3562                 if (btopr(va.va_size) < btopr(io_off + io_len)) {
3563                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[14]);
3564                         *downsize = 1;
3565                         *ret_pszc = 0;
3566                         goto out;
3567                 }
3568                 io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3569                     B_READ, svd->cred, NULL);
3570                 if (io_err) {
3571                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[15]);
3572                         if (io_err == EDEADLK) {
3573                                 segvn_vmpss_pageio_deadlk_err++;
3574                         }
3575                         goto out;
3576                 }
3577                 nios++;
3578                 while (io_pplist != NULL) {
3579                         pp = io_pplist;
3580                         page_sub(&io_pplist, pp);
3581                         ASSERT(page_iolock_assert(pp));
3582                         page_io_unlock(pp);
3583                         pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3584                         ASSERT(pgidx < pages);
3585                         ppa[pgidx] = pp;
3586                 }
3587         }
3588         /*
3589          * we're now bound to succeed or panic.
3590          * remove pages from done_pplist. it's not needed anymore.
3591          */
3592         while (done_pplist != NULL) {
3593                 pp = done_pplist;
3594                 page_sub(&done_pplist, pp);
3595         }
3596         VM_STAT_ADD(segvnvmstats.fill_vp_pages[16]);
3597         ASSERT(pplist == NULL);
3598         *ppplist = NULL;
3599         while (targ_pplist != NULL) {
3600                 int ret;
3601                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[17]);
3602                 ASSERT(repl_pplist);
3603                 pp = targ_pplist;
3604                 page_sub(&targ_pplist, pp);
3605                 pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3606                 newpp = repl_pplist;
3607                 page_sub(&repl_pplist, newpp);
3608 #ifdef DEBUG
3609                 pfn = page_pptonum(pp);
3610                 pszc = pp->p_szc;
3611                 ppages = page_get_pagecnt(pszc);
3612                 ASSERT(IS_P2ALIGNED(pfn, ppages));
3613                 pfn = page_pptonum(newpp);
3614                 ASSERT(IS_P2ALIGNED(pfn, ppages));
3615                 ASSERT(P2PHASE(pfn, pages) == pgidx);
3616 #endif
3617                 nreloc = 0;
3618                 ret = page_relocate(&pp, &newpp, 0, 1, &nreloc, NULL);
3619                 if (ret != 0 || nreloc == 0) {
3620                         panic("segvn_fill_vp_pages: "
3621                             "page_relocate failed");
3622                 }
3623                 pp = newpp;
3624                 while (nreloc-- != 0) {
3625                         ASSERT(PAGE_EXCL(pp));
3626                         ASSERT(pp->p_vnode == vp);
3627                         ASSERT(pgidx ==
3628                             ((pp->p_offset - start_off) >> PAGESHIFT));
3629                         ppa[pgidx++] = pp;
3630                         pp++;
3631                 }
3632         }
3633 
3634         if (svd->type == MAP_PRIVATE) {
3635                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[18]);
3636                 for (i = 0; i < pages; i++) {
3637                         ASSERT(ppa[i] != NULL);
3638                         ASSERT(PAGE_EXCL(ppa[i]));
3639                         ASSERT(ppa[i]->p_vnode == vp);
3640                         ASSERT(ppa[i]->p_offset ==
3641                             start_off + (i << PAGESHIFT));
3642                         page_downgrade(ppa[i]);
3643                 }
3644                 ppa[pages] = NULL;
3645         } else {
3646                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[19]);
3647                 /*
3648                  * the caller will still call VOP_GETPAGE() for shared segments
3649                  * to check FS write permissions. For private segments we map
3650                  * file read only anyway.  so no VOP_GETPAGE is needed.
3651                  */
3652                 for (i = 0; i < pages; i++) {
3653                         ASSERT(ppa[i] != NULL);
3654                         ASSERT(PAGE_EXCL(ppa[i]));
3655                         ASSERT(ppa[i]->p_vnode == vp);
3656                         ASSERT(ppa[i]->p_offset ==
3657                             start_off + (i << PAGESHIFT));
3658                         page_unlock(ppa[i]);
3659                 }
3660                 ppa[0] = NULL;
3661         }
3662 
3663         return (1);
3664 out:
3665         /*
3666          * Do the cleanup. Unlock target pages we didn't relocate. They are
3667          * linked on targ_pplist by root pages. reassemble unused replacement
3668          * and io pages back to pplist.
3669          */
3670         if (io_pplist != NULL) {
3671                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[20]);
3672                 pp = io_pplist;
3673                 do {
3674                         ASSERT(pp->p_vnode == vp);
3675                         ASSERT(pp->p_offset == io_off);
3676                         ASSERT(page_iolock_assert(pp));
3677                         page_io_unlock(pp);
3678                         page_hashout(pp, NULL);
3679                         io_off += PAGESIZE;
3680                 } while ((pp = pp->p_next) != io_pplist);
3681                 page_list_concat(&io_pplist, &pplist);
3682                 pplist = io_pplist;
3683         }
3684         tmp_pplist = NULL;
3685         while (targ_pplist != NULL) {
3686                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[21]);
3687                 pp = targ_pplist;
3688                 ASSERT(PAGE_EXCL(pp));
3689                 page_sub(&targ_pplist, pp);
3690 
3691                 pszc = pp->p_szc;
3692                 ppages = page_get_pagecnt(pszc);
3693                 ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3694 
3695                 if (pszc != 0) {
3696                         group_page_unlock(pp);
3697                 }
3698                 page_unlock(pp);
3699 
3700                 pp = repl_pplist;
3701                 ASSERT(pp != NULL);
3702                 ASSERT(PAGE_EXCL(pp));
3703                 ASSERT(pp->p_szc == szc);
3704                 page_sub(&repl_pplist, pp);
3705 
3706                 ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3707 
3708                 /* relink replacement page */
3709                 page_list_concat(&tmp_pplist, &pp);
3710                 while (--ppages != 0) {
3711                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[22]);
3712                         pp++;
3713                         ASSERT(PAGE_EXCL(pp));
3714                         ASSERT(pp->p_szc == szc);
3715                         page_list_concat(&tmp_pplist, &pp);
3716                 }
3717         }
3718         if (tmp_pplist != NULL) {
3719                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[23]);
3720                 page_list_concat(&tmp_pplist, &pplist);
3721                 pplist = tmp_pplist;
3722         }
3723         /*
3724          * at this point all pages are either on done_pplist or
3725          * pplist. They can't be all on done_pplist otherwise
3726          * we'd've been done.
3727          */
3728         ASSERT(pplist != NULL);
3729         if (nios != 0) {
3730                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[24]);
3731                 pp = pplist;
3732                 do {
3733                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[25]);
3734                         ASSERT(pp->p_szc == szc);
3735                         ASSERT(PAGE_EXCL(pp));
3736                         ASSERT(pp->p_vnode != vp);
3737                         pp->p_szc = 0;
3738                 } while ((pp = pp->p_next) != pplist);
3739 
3740                 pp = done_pplist;
3741                 do {
3742                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[26]);
3743                         ASSERT(pp->p_szc == szc);
3744                         ASSERT(PAGE_EXCL(pp));
3745                         ASSERT(pp->p_vnode == vp);
3746                         pp->p_szc = 0;
3747                 } while ((pp = pp->p_next) != done_pplist);
3748 
3749                 while (pplist != NULL) {
3750                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[27]);
3751                         pp = pplist;
3752                         page_sub(&pplist, pp);
3753                         page_free(pp, 0);
3754                 }
3755 
3756                 while (done_pplist != NULL) {
3757                         VM_STAT_ADD(segvnvmstats.fill_vp_pages[28]);
3758                         pp = done_pplist;
3759                         page_sub(&done_pplist, pp);
3760                         page_unlock(pp);
3761                 }
3762                 *ppplist = NULL;
3763                 return (0);
3764         }
3765         ASSERT(pplist == *ppplist);
3766         if (io_err) {
3767                 VM_STAT_ADD(segvnvmstats.fill_vp_pages[29]);
3768                 /*
3769                  * don't downsize on io error.
3770                  * see if vop_getpage succeeds.
3771                  * pplist may still be used in this case
3772                  * for relocations.
3773                  */
3774                 return (0);
3775         }
3776         VM_STAT_ADD(segvnvmstats.fill_vp_pages[30]);
3777         page_free_replacement_page(pplist);
3778         page_create_putback(pages);
3779         *ppplist = NULL;
3780         return (0);
3781 }
3782 
3783 int segvn_anypgsz = 0;
3784 
3785 #define SEGVN_RESTORE_SOFTLOCK_VP(type, pages)                          \
3786                 if ((type) == F_SOFTLOCK) {                             \
3787                         atomic_add_long((ulong_t *)&(svd)->softlockcnt, \
3788                             -(pages));                                  \
3789                 }
3790 
3791 #define SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot)              \
3792                 if (IS_VMODSORT((ppa)[0]->p_vnode)) {                        \
3793                         if ((rw) == S_WRITE) {                          \
3794                                 for (i = 0; i < (pages); i++) {              \
3795                                         ASSERT((ppa)[i]->p_vnode ==  \
3796                                             (ppa)[0]->p_vnode);              \
3797                                         hat_setmod((ppa)[i]);           \
3798                                 }                                       \
3799                         } else if ((rw) != S_OTHER &&                   \
3800                             ((prot) & (vpprot) & PROT_WRITE)) {         \
3801                                 for (i = 0; i < (pages); i++) {              \
3802                                         ASSERT((ppa)[i]->p_vnode ==  \
3803                                             (ppa)[0]->p_vnode);              \
3804                                         if (!hat_ismod((ppa)[i])) {     \
3805                                                 prot &= ~PROT_WRITE;        \
3806                                                 break;                  \
3807                                         }                               \
3808                                 }                                       \
3809                         }                                               \
3810                 }
3811 
3812 #ifdef  VM_STATS
3813 
3814 #define SEGVN_VMSTAT_FLTVNPAGES(idx)                                    \
3815                 VM_STAT_ADD(segvnvmstats.fltvnpages[(idx)]);
3816 
3817 #else /* VM_STATS */
3818 
3819 #define SEGVN_VMSTAT_FLTVNPAGES(idx)
3820 
3821 #endif
3822 
3823 static faultcode_t
3824 segvn_fault_vnodepages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
3825     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
3826     caddr_t eaddr, int brkcow)
3827 {
3828         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
3829         struct anon_map *amp = svd->amp;
3830         uchar_t segtype = svd->type;
3831         uint_t szc = seg->s_szc;
3832         size_t pgsz = page_get_pagesize(szc);
3833         size_t maxpgsz = pgsz;
3834         pgcnt_t pages = btop(pgsz);
3835         pgcnt_t maxpages = pages;
3836         size_t ppasize = (pages + 1) * sizeof (page_t *);
3837         caddr_t a = lpgaddr;
3838         caddr_t maxlpgeaddr = lpgeaddr;
3839         u_offset_t off = svd->offset + (uintptr_t)(a - seg->s_base);
3840         ulong_t aindx = svd->anon_index + seg_page(seg, a);
3841         struct vpage *vpage = (svd->vpage != NULL) ?
3842             &svd->vpage[seg_page(seg, a)] : NULL;
3843         vnode_t *vp = svd->vp;
3844         page_t **ppa;
3845         uint_t  pszc;
3846         size_t  ppgsz;
3847         pgcnt_t ppages;
3848         faultcode_t err = 0;
3849         int ierr;
3850         int vop_size_err = 0;
3851         uint_t protchk, prot, vpprot;
3852         ulong_t i;
3853         int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
3854         anon_sync_obj_t an_cookie;
3855         enum seg_rw arw;
3856         int alloc_failed = 0;
3857         int adjszc_chk;
3858         struct vattr va;
3859         page_t *pplist;
3860         pfn_t pfn;
3861         int physcontig;
3862         int upgrdfail;
3863         int segvn_anypgsz_vnode = 0; /* for now map vnode with 2 page sizes */
3864         int tron = (svd->tr_state == SEGVN_TR_ON);
3865 
3866         ASSERT(szc != 0);
3867         ASSERT(vp != NULL);
3868         ASSERT(brkcow == 0 || amp != NULL);
3869         ASSERT(tron == 0 || amp != NULL);
3870         ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
3871         ASSERT(!(svd->flags & MAP_NORESERVE));
3872         ASSERT(type != F_SOFTUNLOCK);
3873         ASSERT(IS_P2ALIGNED(a, maxpgsz));
3874         ASSERT(amp == NULL || IS_P2ALIGNED(aindx, maxpages));
3875         ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
3876         ASSERT(seg->s_szc < NBBY * sizeof (int));
3877         ASSERT(type != F_SOFTLOCK || lpgeaddr - a == maxpgsz);
3878         ASSERT(svd->tr_state != SEGVN_TR_INIT);
3879 
3880         VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltvnpages[0]);
3881         VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltvnpages[1]);
3882 
3883         if (svd->flags & MAP_TEXT) {
3884                 hat_flag |= HAT_LOAD_TEXT;
3885         }
3886 
3887         if (svd->pageprot) {
3888                 switch (rw) {
3889                 case S_READ:
3890                         protchk = PROT_READ;
3891                         break;
3892                 case S_WRITE:
3893                         protchk = PROT_WRITE;
3894                         break;
3895                 case S_EXEC:
3896                         protchk = PROT_EXEC;
3897                         break;
3898                 case S_OTHER:
3899                 default:
3900                         protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
3901                         break;
3902                 }
3903         } else {
3904                 prot = svd->prot;
3905                 /* caller has already done segment level protection check. */
3906         }
3907 
3908         if (rw == S_WRITE && segtype == MAP_PRIVATE) {
3909                 SEGVN_VMSTAT_FLTVNPAGES(2);
3910                 arw = S_READ;
3911         } else {
3912                 arw = rw;
3913         }
3914 
3915         ppa = kmem_alloc(ppasize, KM_SLEEP);
3916 
3917         VM_STAT_COND_ADD(amp != NULL, segvnvmstats.fltvnpages[3]);
3918 
3919         for (;;) {
3920                 adjszc_chk = 0;
3921                 for (; a < lpgeaddr; a += pgsz, off += pgsz, aindx += pages) {
3922                         if (adjszc_chk) {
3923                                 while (szc < seg->s_szc) {
3924                                         uintptr_t e;
3925                                         uint_t tszc;
3926                                         tszc = segvn_anypgsz_vnode ? szc + 1 :
3927                                             seg->s_szc;
3928                                         ppgsz = page_get_pagesize(tszc);
3929                                         if (!IS_P2ALIGNED(a, ppgsz) ||
3930                                             ((alloc_failed >> tszc) & 0x1)) {
3931                                                 break;
3932                                         }
3933                                         SEGVN_VMSTAT_FLTVNPAGES(4);
3934                                         szc = tszc;
3935                                         pgsz = ppgsz;
3936                                         pages = btop(pgsz);
3937                                         e = P2ROUNDUP((uintptr_t)eaddr, pgsz);
3938                                         lpgeaddr = (caddr_t)e;
3939                                 }
3940                         }
3941 
3942                 again:
3943                         if (IS_P2ALIGNED(a, maxpgsz) && amp != NULL) {
3944                                 ASSERT(IS_P2ALIGNED(aindx, maxpages));
3945                                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3946                                 anon_array_enter(amp, aindx, &an_cookie);
3947                                 if (anon_get_ptr(amp->ahp, aindx) != NULL) {
3948                                         SEGVN_VMSTAT_FLTVNPAGES(5);
3949                                         ASSERT(anon_pages(amp->ahp, aindx,
3950                                             maxpages) == maxpages);
3951                                         anon_array_exit(&an_cookie);
3952                                         ANON_LOCK_EXIT(&amp->a_rwlock);
3953                                         err = segvn_fault_anonpages(hat, seg,
3954                                             a, a + maxpgsz, type, rw,
3955                                             MAX(a, addr),
3956                                             MIN(a + maxpgsz, eaddr), brkcow);
3957                                         if (err != 0) {
3958                                                 SEGVN_VMSTAT_FLTVNPAGES(6);
3959                                                 goto out;
3960                                         }
3961                                         if (szc < seg->s_szc) {
3962                                                 szc = seg->s_szc;
3963                                                 pgsz = maxpgsz;
3964                                                 pages = maxpages;
3965                                                 lpgeaddr = maxlpgeaddr;
3966                                         }
3967                                         goto next;
3968                                 } else {
3969                                         ASSERT(anon_pages(amp->ahp, aindx,
3970                                             maxpages) == 0);
3971                                         SEGVN_VMSTAT_FLTVNPAGES(7);
3972                                         anon_array_exit(&an_cookie);
3973                                         ANON_LOCK_EXIT(&amp->a_rwlock);
3974                                 }
3975                         }
3976                         ASSERT(!brkcow || IS_P2ALIGNED(a, maxpgsz));
3977                         ASSERT(!tron || IS_P2ALIGNED(a, maxpgsz));
3978 
3979                         if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
3980                                 ASSERT(vpage != NULL);
3981                                 prot = VPP_PROT(vpage);
3982                                 ASSERT(sameprot(seg, a, maxpgsz));
3983                                 if ((prot & protchk) == 0) {
3984                                         SEGVN_VMSTAT_FLTVNPAGES(8);
3985                                         err = FC_PROT;
3986                                         goto out;
3987                                 }
3988                         }
3989                         if (type == F_SOFTLOCK) {
3990                                 atomic_add_long((ulong_t *)&svd->softlockcnt,
3991                                     pages);
3992                         }
3993 
3994                         pplist = NULL;
3995                         physcontig = 0;
3996                         ppa[0] = NULL;
3997                         if (!brkcow && !tron && szc &&
3998                             !page_exists_physcontig(vp, off, szc,
3999                             segtype == MAP_PRIVATE ? ppa : NULL)) {
4000                                 SEGVN_VMSTAT_FLTVNPAGES(9);
4001                                 if (page_alloc_pages(vp, seg, a, &pplist, NULL,
4002                                     szc, 0, 0) && type != F_SOFTLOCK) {
4003                                         SEGVN_VMSTAT_FLTVNPAGES(10);
4004                                         pszc = 0;
4005                                         ierr = -1;
4006                                         alloc_failed |= (1 << szc);
4007                                         break;
4008                                 }
4009                                 if (pplist != NULL &&
4010                                     vp->v_mpssdata == SEGVN_PAGEIO) {
4011                                         int downsize;
4012                                         SEGVN_VMSTAT_FLTVNPAGES(11);
4013                                         physcontig = segvn_fill_vp_pages(svd,
4014                                             vp, off, szc, ppa, &pplist,
4015                                             &pszc, &downsize);
4016                                         ASSERT(!physcontig || pplist == NULL);
4017                                         if (!physcontig && downsize &&
4018                                             type != F_SOFTLOCK) {
4019                                                 ASSERT(pplist == NULL);
4020                                                 SEGVN_VMSTAT_FLTVNPAGES(12);
4021                                                 ierr = -1;
4022                                                 break;
4023                                         }
4024                                         ASSERT(!physcontig ||
4025                                             segtype == MAP_PRIVATE ||
4026                                             ppa[0] == NULL);
4027                                         if (physcontig && ppa[0] == NULL) {
4028                                                 physcontig = 0;
4029                                         }
4030                                 }
4031                         } else if (!brkcow && !tron && szc && ppa[0] != NULL) {
4032                                 SEGVN_VMSTAT_FLTVNPAGES(13);
4033                                 ASSERT(segtype == MAP_PRIVATE);
4034                                 physcontig = 1;
4035                         }
4036 
4037                         if (!physcontig) {
4038                                 SEGVN_VMSTAT_FLTVNPAGES(14);
4039                                 ppa[0] = NULL;
4040                                 ierr = VOP_GETPAGE(vp, (offset_t)off, pgsz,
4041                                     &vpprot, ppa, pgsz, seg, a, arw,
4042                                     svd->cred, NULL);
4043 #ifdef DEBUG
4044                                 if (ierr == 0) {
4045                                         for (i = 0; i < pages; i++) {
4046                                                 ASSERT(PAGE_LOCKED(ppa[i]));
4047                                                 ASSERT(!PP_ISFREE(ppa[i]));
4048                                                 ASSERT(ppa[i]->p_vnode == vp);
4049                                                 ASSERT(ppa[i]->p_offset ==
4050                                                     off + (i << PAGESHIFT));
4051                                         }
4052                                 }
4053 #endif /* DEBUG */
4054                                 if (segtype == MAP_PRIVATE) {
4055                                         SEGVN_VMSTAT_FLTVNPAGES(15);
4056                                         vpprot &= ~PROT_WRITE;
4057                                 }
4058                         } else {
4059                                 ASSERT(segtype == MAP_PRIVATE);
4060                                 SEGVN_VMSTAT_FLTVNPAGES(16);
4061                                 vpprot = PROT_ALL & ~PROT_WRITE;
4062                                 ierr = 0;
4063                         }
4064 
4065                         if (ierr != 0) {
4066                                 SEGVN_VMSTAT_FLTVNPAGES(17);
4067                                 if (pplist != NULL) {
4068                                         SEGVN_VMSTAT_FLTVNPAGES(18);
4069                                         page_free_replacement_page(pplist);
4070                                         page_create_putback(pages);
4071                                 }
4072                                 SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4073                                 if (a + pgsz <= eaddr) {
4074                                         SEGVN_VMSTAT_FLTVNPAGES(19);
4075                                         err = FC_MAKE_ERR(ierr);
4076                                         goto out;
4077                                 }
4078                                 va.va_mask = AT_SIZE;
4079                                 if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL)) {
4080                                         SEGVN_VMSTAT_FLTVNPAGES(20);
4081                                         err = FC_MAKE_ERR(EIO);
4082                                         goto out;
4083                                 }
4084                                 if (btopr(va.va_size) >= btopr(off + pgsz)) {
4085                                         SEGVN_VMSTAT_FLTVNPAGES(21);
4086                                         err = FC_MAKE_ERR(ierr);
4087                                         goto out;
4088                                 }
4089                                 if (btopr(va.va_size) <
4090                                     btopr(off + (eaddr - a))) {
4091                                         SEGVN_VMSTAT_FLTVNPAGES(22);
4092                                         err = FC_MAKE_ERR(ierr);
4093                                         goto out;
4094                                 }
4095                                 if (brkcow || tron || type == F_SOFTLOCK) {
4096                                         /* can't reduce map area */
4097                                         SEGVN_VMSTAT_FLTVNPAGES(23);
4098                                         vop_size_err = 1;
4099                                         goto out;
4100                                 }
4101                                 SEGVN_VMSTAT_FLTVNPAGES(24);
4102                                 ASSERT(szc != 0);
4103                                 pszc = 0;
4104                                 ierr = -1;
4105                                 break;
4106                         }
4107 
4108                         if (amp != NULL) {
4109                                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4110                                 anon_array_enter(amp, aindx, &an_cookie);
4111                         }
4112                         if (amp != NULL &&
4113                             anon_get_ptr(amp->ahp, aindx) != NULL) {
4114                                 ulong_t taindx = P2ALIGN(aindx, maxpages);
4115 
4116                                 SEGVN_VMSTAT_FLTVNPAGES(25);
4117                                 ASSERT(anon_pages(amp->ahp, taindx,
4118                                     maxpages) == maxpages);
4119                                 for (i = 0; i < pages; i++) {
4120                                         page_unlock(ppa[i]);
4121                                 }
4122                                 anon_array_exit(&an_cookie);
4123                                 ANON_LOCK_EXIT(&amp->a_rwlock);
4124                                 if (pplist != NULL) {
4125                                         page_free_replacement_page(pplist);
4126                                         page_create_putback(pages);
4127                                 }
4128                                 SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4129                                 if (szc < seg->s_szc) {
4130                                         SEGVN_VMSTAT_FLTVNPAGES(26);
4131                                         /*
4132                                          * For private segments SOFTLOCK
4133                                          * either always breaks cow (any rw
4134                                          * type except S_READ_NOCOW) or
4135                                          * address space is locked as writer
4136                                          * (S_READ_NOCOW case) and anon slots
4137                                          * can't show up on second check.
4138                                          * Therefore if we are here for
4139                                          * SOFTLOCK case it must be a cow
4140                                          * break but cow break never reduces
4141                                          * szc. text replication (tron) in
4142                                          * this case works as cow break.
4143                                          * Thus the assert below.
4144                                          */
4145                                         ASSERT(!brkcow && !tron &&
4146                                             type != F_SOFTLOCK);
4147                                         pszc = seg->s_szc;
4148                                         ierr = -2;
4149                                         break;
4150                                 }
4151                                 ASSERT(IS_P2ALIGNED(a, maxpgsz));
4152                                 goto again;
4153                         }
4154 #ifdef DEBUG
4155                         if (amp != NULL) {
4156                                 ulong_t taindx = P2ALIGN(aindx, maxpages);
4157                                 ASSERT(!anon_pages(amp->ahp, taindx, maxpages));
4158                         }
4159 #endif /* DEBUG */
4160 
4161                         if (brkcow || tron) {
4162                                 ASSERT(amp != NULL);
4163                                 ASSERT(pplist == NULL);
4164                                 ASSERT(szc == seg->s_szc);
4165                                 ASSERT(IS_P2ALIGNED(a, maxpgsz));
4166                                 ASSERT(IS_P2ALIGNED(aindx, maxpages));
4167                                 SEGVN_VMSTAT_FLTVNPAGES(27);
4168                                 ierr = anon_map_privatepages(amp, aindx, szc,
4169                                     seg, a, prot, ppa, vpage, segvn_anypgsz,
4170                                     tron ? PG_LOCAL : 0, svd->cred);
4171                                 if (ierr != 0) {
4172                                         SEGVN_VMSTAT_FLTVNPAGES(28);
4173                                         anon_array_exit(&an_cookie);
4174                                         ANON_LOCK_EXIT(&amp->a_rwlock);
4175                                         SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4176                                         err = FC_MAKE_ERR(ierr);
4177                                         goto out;
4178                                 }
4179 
4180                                 ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4181                                 /*
4182                                  * p_szc can't be changed for locked
4183                                  * swapfs pages.
4184                                  */
4185                                 ASSERT(svd->rcookie ==
4186                                     HAT_INVALID_REGION_COOKIE);
4187                                 hat_memload_array(hat, a, pgsz, ppa, prot,
4188                                     hat_flag);
4189 
4190                                 if (!(hat_flag & HAT_LOAD_LOCK)) {
4191                                         SEGVN_VMSTAT_FLTVNPAGES(29);
4192                                         for (i = 0; i < pages; i++) {
4193                                                 page_unlock(ppa[i]);
4194                                         }
4195                                 }
4196                                 anon_array_exit(&an_cookie);
4197                                 ANON_LOCK_EXIT(&amp->a_rwlock);
4198                                 goto next;
4199                         }
4200 
4201                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
4202                             (!svd->pageprot && svd->prot == (prot & vpprot)));
4203 
4204                         pfn = page_pptonum(ppa[0]);
4205                         /*
4206                          * hat_page_demote() needs an SE_EXCL lock on one of
4207                          * constituent page_t's and it decreases root's p_szc
4208                          * last. This means if root's p_szc is equal szc and
4209                          * all its constituent pages are locked
4210                          * hat_page_demote() that could have changed p_szc to
4211                          * szc is already done and no new have page_demote()
4212                          * can start for this large page.
4213                          */
4214 
4215                         /*
4216                          * we need to make sure same mapping size is used for
4217                          * the same address range if there's a possibility the
4218                          * adddress is already mapped because hat layer panics
4219                          * when translation is loaded for the range already
4220                          * mapped with a different page size.  We achieve it
4221                          * by always using largest page size possible subject
4222                          * to the constraints of page size, segment page size
4223                          * and page alignment.  Since mappings are invalidated
4224                          * when those constraints change and make it
4225                          * impossible to use previously used mapping size no
4226                          * mapping size conflicts should happen.
4227                          */
4228 
4229                 chkszc:
4230                         if ((pszc = ppa[0]->p_szc) == szc &&
4231                             IS_P2ALIGNED(pfn, pages)) {
4232 
4233                                 SEGVN_VMSTAT_FLTVNPAGES(30);
4234 #ifdef DEBUG
4235                                 for (i = 0; i < pages; i++) {
4236                                         ASSERT(PAGE_LOCKED(ppa[i]));
4237                                         ASSERT(!PP_ISFREE(ppa[i]));
4238                                         ASSERT(page_pptonum(ppa[i]) ==
4239                                             pfn + i);
4240                                         ASSERT(ppa[i]->p_szc == szc);
4241                                         ASSERT(ppa[i]->p_vnode == vp);
4242                                         ASSERT(ppa[i]->p_offset ==
4243                                             off + (i << PAGESHIFT));
4244                                 }
4245 #endif /* DEBUG */
4246                                 /*
4247                                  * All pages are of szc we need and they are
4248                                  * all locked so they can't change szc. load
4249                                  * translations.
4250                                  *
4251                                  * if page got promoted since last check
4252                                  * we don't need pplist.
4253                                  */
4254                                 if (pplist != NULL) {
4255                                         page_free_replacement_page(pplist);
4256                                         page_create_putback(pages);
4257                                 }
4258                                 if (PP_ISMIGRATE(ppa[0])) {
4259                                         page_migrate(seg, a, ppa, pages);
4260                                 }
4261                                 SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4262                                     prot, vpprot);
4263                                 hat_memload_array_region(hat, a, pgsz,
4264                                     ppa, prot & vpprot, hat_flag,
4265                                     svd->rcookie);
4266 
4267                                 if (!(hat_flag & HAT_LOAD_LOCK)) {
4268                                         for (i = 0; i < pages; i++) {
4269                                                 page_unlock(ppa[i]);
4270                                         }
4271                                 }
4272                                 if (amp != NULL) {
4273                                         anon_array_exit(&an_cookie);
4274                                         ANON_LOCK_EXIT(&amp->a_rwlock);
4275                                 }
4276                                 goto next;
4277                         }
4278 
4279                         /*
4280                          * See if upsize is possible.
4281                          */
4282                         if (pszc > szc && szc < seg->s_szc &&
4283                             (segvn_anypgsz_vnode || pszc >= seg->s_szc)) {
4284                                 pgcnt_t aphase;
4285                                 uint_t pszc1 = MIN(pszc, seg->s_szc);
4286                                 ppgsz = page_get_pagesize(pszc1);
4287                                 ppages = btop(ppgsz);
4288                                 aphase = btop(P2PHASE((uintptr_t)a, ppgsz));
4289 
4290                                 ASSERT(type != F_SOFTLOCK);
4291 
4292                                 SEGVN_VMSTAT_FLTVNPAGES(31);
4293                                 if (aphase != P2PHASE(pfn, ppages)) {
4294                                         segvn_faultvnmpss_align_err4++;
4295                                 } else {
4296                                         SEGVN_VMSTAT_FLTVNPAGES(32);
4297                                         if (pplist != NULL) {
4298                                                 page_t *pl = pplist;
4299                                                 page_free_replacement_page(pl);
4300                                                 page_create_putback(pages);
4301                                         }
4302                                         for (i = 0; i < pages; i++) {
4303                                                 page_unlock(ppa[i]);
4304                                         }
4305                                         if (amp != NULL) {
4306                                                 anon_array_exit(&an_cookie);
4307                                                 ANON_LOCK_EXIT(&amp->a_rwlock);
4308                                         }
4309                                         pszc = pszc1;
4310                                         ierr = -2;
4311                                         break;
4312                                 }
4313                         }
4314 
4315                         /*
4316                          * check if we should use smallest mapping size.
4317                          */
4318                         upgrdfail = 0;
4319                         if (szc == 0 ||
4320                             (pszc >= szc &&
4321                             !IS_P2ALIGNED(pfn, pages)) ||
4322                             (pszc < szc &&
4323                             !segvn_full_szcpages(ppa, szc, &upgrdfail,
4324                             &pszc))) {
4325 
4326                                 if (upgrdfail && type != F_SOFTLOCK) {
4327                                         /*
4328                                          * segvn_full_szcpages failed to lock
4329                                          * all pages EXCL. Size down.
4330                                          */
4331                                         ASSERT(pszc < szc);
4332 
4333                                         SEGVN_VMSTAT_FLTVNPAGES(33);
4334 
4335                                         if (pplist != NULL) {
4336                                                 page_t *pl = pplist;
4337                                                 page_free_replacement_page(pl);
4338                                                 page_create_putback(pages);
4339                                         }
4340 
4341                                         for (i = 0; i < pages; i++) {
4342                                                 page_unlock(ppa[i]);
4343                                         }
4344                                         if (amp != NULL) {
4345                                                 anon_array_exit(&an_cookie);
4346                                                 ANON_LOCK_EXIT(&amp->a_rwlock);
4347                                         }
4348                                         ierr = -1;
4349                                         break;
4350                                 }
4351                                 if (szc != 0 && !upgrdfail) {
4352                                         segvn_faultvnmpss_align_err5++;
4353                                 }
4354                                 SEGVN_VMSTAT_FLTVNPAGES(34);
4355                                 if (pplist != NULL) {
4356                                         page_free_replacement_page(pplist);
4357                                         page_create_putback(pages);
4358                                 }
4359                                 SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4360                                     prot, vpprot);
4361                                 if (upgrdfail && segvn_anypgsz_vnode) {
4362                                         /* SOFTLOCK case */
4363                                         hat_memload_array_region(hat, a, pgsz,
4364                                             ppa, prot & vpprot, hat_flag,
4365                                             svd->rcookie);
4366                                 } else {
4367                                         for (i = 0; i < pages; i++) {
4368                                                 hat_memload_region(hat,
4369                                                     a + (i << PAGESHIFT),
4370                                                     ppa[i], prot & vpprot,
4371                                                     hat_flag, svd->rcookie);
4372                                         }
4373                                 }
4374                                 if (!(hat_flag & HAT_LOAD_LOCK)) {
4375                                         for (i = 0; i < pages; i++) {
4376                                                 page_unlock(ppa[i]);
4377                                         }
4378                                 }
4379                                 if (amp != NULL) {
4380                                         anon_array_exit(&an_cookie);
4381                                         ANON_LOCK_EXIT(&amp->a_rwlock);
4382                                 }
4383                                 goto next;
4384                         }
4385 
4386                         if (pszc == szc) {
4387                                 /*
4388                                  * segvn_full_szcpages() upgraded pages szc.
4389                                  */
4390                                 ASSERT(pszc == ppa[0]->p_szc);
4391                                 ASSERT(IS_P2ALIGNED(pfn, pages));
4392                                 goto chkszc;
4393                         }
4394 
4395                         if (pszc > szc) {
4396                                 kmutex_t *szcmtx;
4397                                 SEGVN_VMSTAT_FLTVNPAGES(35);
4398                                 /*
4399                                  * p_szc of ppa[0] can change since we haven't
4400                                  * locked all constituent pages. Call
4401                                  * page_lock_szc() to prevent szc changes.
4402                                  * This should be a rare case that happens when
4403                                  * multiple segments use a different page size
4404                                  * to map the same file offsets.
4405                                  */
4406                                 szcmtx = page_szc_lock(ppa[0]);
4407                                 pszc = ppa[0]->p_szc;
4408                                 ASSERT(szcmtx != NULL || pszc == 0);
4409                                 ASSERT(ppa[0]->p_szc <= pszc);
4410                                 if (pszc <= szc) {
4411                                         SEGVN_VMSTAT_FLTVNPAGES(36);
4412                                         if (szcmtx != NULL) {
4413                                                 mutex_exit(szcmtx);
4414                                         }
4415                                         goto chkszc;
4416                                 }
4417                                 if (pplist != NULL) {
4418                                         /*
4419                                          * page got promoted since last check.
4420                                          * we don't need preaalocated large
4421                                          * page.
4422                                          */
4423                                         SEGVN_VMSTAT_FLTVNPAGES(37);
4424                                         page_free_replacement_page(pplist);
4425                                         page_create_putback(pages);
4426                                 }
4427                                 SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4428                                     prot, vpprot);
4429                                 hat_memload_array_region(hat, a, pgsz, ppa,
4430                                     prot & vpprot, hat_flag, svd->rcookie);
4431                                 mutex_exit(szcmtx);
4432                                 if (!(hat_flag & HAT_LOAD_LOCK)) {
4433                                         for (i = 0; i < pages; i++) {
4434                                                 page_unlock(ppa[i]);
4435                                         }
4436                                 }
4437                                 if (amp != NULL) {
4438                                         anon_array_exit(&an_cookie);
4439                                         ANON_LOCK_EXIT(&amp->a_rwlock);
4440                                 }
4441                                 goto next;
4442                         }
4443 
4444                         /*
4445                          * if page got demoted since last check
4446                          * we could have not allocated larger page.
4447                          * allocate now.
4448                          */
4449                         if (pplist == NULL &&
4450                             page_alloc_pages(vp, seg, a, &pplist, NULL,
4451                             szc, 0, 0) && type != F_SOFTLOCK) {
4452                                 SEGVN_VMSTAT_FLTVNPAGES(38);
4453                                 for (i = 0; i < pages; i++) {
4454                                         page_unlock(ppa[i]);
4455                                 }
4456                                 if (amp != NULL) {
4457                                         anon_array_exit(&an_cookie);
4458                                         ANON_LOCK_EXIT(&amp->a_rwlock);
4459                                 }
4460                                 ierr = -1;
4461                                 alloc_failed |= (1 << szc);
4462                                 break;
4463                         }
4464 
4465                         SEGVN_VMSTAT_FLTVNPAGES(39);
4466 
4467                         if (pplist != NULL) {
4468                                 segvn_relocate_pages(ppa, pplist);
4469 #ifdef DEBUG
4470                         } else {
4471                                 ASSERT(type == F_SOFTLOCK);
4472                                 SEGVN_VMSTAT_FLTVNPAGES(40);
4473 #endif /* DEBUG */
4474                         }
4475 
4476                         SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot);
4477 
4478                         if (pplist == NULL && segvn_anypgsz_vnode == 0) {
4479                                 ASSERT(type == F_SOFTLOCK);
4480                                 for (i = 0; i < pages; i++) {
4481                                         ASSERT(ppa[i]->p_szc < szc);
4482                                         hat_memload_region(hat,
4483                                             a + (i << PAGESHIFT),
4484                                             ppa[i], prot & vpprot, hat_flag,
4485                                             svd->rcookie);
4486                                 }
4487                         } else {
4488                                 ASSERT(pplist != NULL || type == F_SOFTLOCK);
4489                                 hat_memload_array_region(hat, a, pgsz, ppa,
4490                                     prot & vpprot, hat_flag, svd->rcookie);
4491                         }
4492                         if (!(hat_flag & HAT_LOAD_LOCK)) {
4493                                 for (i = 0; i < pages; i++) {
4494                                         ASSERT(PAGE_SHARED(ppa[i]));
4495                                         page_unlock(ppa[i]);
4496                                 }
4497                         }
4498                         if (amp != NULL) {
4499                                 anon_array_exit(&an_cookie);
4500                                 ANON_LOCK_EXIT(&amp->a_rwlock);
4501                         }
4502 
4503                 next:
4504                         if (vpage != NULL) {
4505                                 vpage += pages;
4506                         }
4507                         adjszc_chk = 1;
4508                 }
4509                 if (a == lpgeaddr)
4510                         break;
4511                 ASSERT(a < lpgeaddr);
4512 
4513                 ASSERT(!brkcow && !tron && type != F_SOFTLOCK);
4514 
4515                 /*
4516                  * ierr == -1 means we failed to map with a large page.
4517                  * (either due to allocation/relocation failures or
4518                  * misalignment with other mappings to this file.
4519                  *
4520                  * ierr == -2 means some other thread allocated a large page
4521                  * after we gave up tp map with a large page.  retry with
4522                  * larger mapping.
4523                  */
4524                 ASSERT(ierr == -1 || ierr == -2);
4525                 ASSERT(ierr == -2 || szc != 0);
4526                 ASSERT(ierr == -1 || szc < seg->s_szc);
4527                 if (ierr == -2) {
4528                         SEGVN_VMSTAT_FLTVNPAGES(41);
4529                         ASSERT(pszc > szc && pszc <= seg->s_szc);
4530                         szc = pszc;
4531                 } else if (segvn_anypgsz_vnode) {
4532                         SEGVN_VMSTAT_FLTVNPAGES(42);
4533                         szc--;
4534                 } else {
4535                         SEGVN_VMSTAT_FLTVNPAGES(43);
4536                         ASSERT(pszc < szc);
4537                         /*
4538                          * other process created pszc large page.
4539                          * but we still have to drop to 0 szc.
4540                          */
4541                         szc = 0;
4542                 }
4543 
4544                 pgsz = page_get_pagesize(szc);
4545                 pages = btop(pgsz);
4546                 if (ierr == -2) {
4547                         /*
4548                          * Size up case. Note lpgaddr may only be needed for
4549                          * softlock case so we don't adjust it here.
4550                          */
4551                         a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4552                         ASSERT(a >= lpgaddr);
4553                         lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4554                         off = svd->offset + (uintptr_t)(a - seg->s_base);
4555                         aindx = svd->anon_index + seg_page(seg, a);
4556                         vpage = (svd->vpage != NULL) ?
4557                             &svd->vpage[seg_page(seg, a)] : NULL;
4558                 } else {
4559                         /*
4560                          * Size down case. Note lpgaddr may only be needed for
4561                          * softlock case so we don't adjust it here.
4562                          */
4563                         ASSERT(IS_P2ALIGNED(a, pgsz));
4564                         ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4565                         lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4566                         ASSERT(a < lpgeaddr);
4567                         if (a < addr) {
4568                                 SEGVN_VMSTAT_FLTVNPAGES(44);
4569                                 /*
4570                                  * The beginning of the large page region can
4571                                  * be pulled to the right to make a smaller
4572                                  * region. We haven't yet faulted a single
4573                                  * page.
4574                                  */
4575                                 a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4576                                 ASSERT(a >= lpgaddr);
4577                                 off = svd->offset +
4578                                     (uintptr_t)(a - seg->s_base);
4579                                 aindx = svd->anon_index + seg_page(seg, a);
4580                                 vpage = (svd->vpage != NULL) ?
4581                                     &svd->vpage[seg_page(seg, a)] : NULL;
4582                         }
4583                 }
4584         }
4585 out:
4586         kmem_free(ppa, ppasize);
4587         if (!err && !vop_size_err) {
4588                 SEGVN_VMSTAT_FLTVNPAGES(45);
4589                 return (0);
4590         }
4591         if (type == F_SOFTLOCK && a > lpgaddr) {
4592                 SEGVN_VMSTAT_FLTVNPAGES(46);
4593                 segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4594         }
4595         if (!vop_size_err) {
4596                 SEGVN_VMSTAT_FLTVNPAGES(47);
4597                 return (err);
4598         }
4599         ASSERT(brkcow || tron || type == F_SOFTLOCK);
4600         /*
4601          * Large page end is mapped beyond the end of file and it's a cow
4602          * fault (can be a text replication induced cow) or softlock so we can't
4603          * reduce the map area.  For now just demote the segment. This should
4604          * really only happen if the end of the file changed after the mapping
4605          * was established since when large page segments are created we make
4606          * sure they don't extend beyond the end of the file.
4607          */
4608         SEGVN_VMSTAT_FLTVNPAGES(48);
4609 
4610         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4611         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4612         err = 0;
4613         if (seg->s_szc != 0) {
4614                 segvn_fltvnpages_clrszc_cnt++;
4615                 ASSERT(svd->softlockcnt == 0);
4616                 err = segvn_clrszc(seg);
4617                 if (err != 0) {
4618                         segvn_fltvnpages_clrszc_err++;
4619                 }
4620         }
4621         ASSERT(err || seg->s_szc == 0);
4622         SEGVN_LOCK_DOWNGRADE(seg->s_as, &svd->lock);
4623         /* segvn_fault will do its job as if szc had been zero to begin with */
4624         return (err == 0 ? IE_RETRY : FC_MAKE_ERR(err));
4625 }
4626 
4627 /*
4628  * This routine will attempt to fault in one large page.
4629  * it will use smaller pages if that fails.
4630  * It should only be called for pure anonymous segments.
4631  */
4632 static faultcode_t
4633 segvn_fault_anonpages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
4634     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
4635     caddr_t eaddr, int brkcow)
4636 {
4637         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4638         struct anon_map *amp = svd->amp;
4639         uchar_t segtype = svd->type;
4640         uint_t szc = seg->s_szc;
4641         size_t pgsz = page_get_pagesize(szc);
4642         size_t maxpgsz = pgsz;
4643         pgcnt_t pages = btop(pgsz);
4644         uint_t ppaszc = szc;
4645         caddr_t a = lpgaddr;
4646         ulong_t aindx = svd->anon_index + seg_page(seg, a);
4647         struct vpage *vpage = (svd->vpage != NULL) ?
4648             &svd->vpage[seg_page(seg, a)] : NULL;
4649         page_t **ppa;
4650         uint_t  ppa_szc;
4651         faultcode_t err;
4652         int ierr;
4653         uint_t protchk, prot, vpprot;
4654         ulong_t i;
4655         int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
4656         anon_sync_obj_t cookie;
4657         int adjszc_chk;
4658         int pgflags = (svd->tr_state == SEGVN_TR_ON) ? PG_LOCAL : 0;
4659 
4660         ASSERT(szc != 0);
4661         ASSERT(amp != NULL);
4662         ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
4663         ASSERT(!(svd->flags & MAP_NORESERVE));
4664         ASSERT(type != F_SOFTUNLOCK);
4665         ASSERT(IS_P2ALIGNED(a, maxpgsz));
4666         ASSERT(!brkcow || svd->tr_state == SEGVN_TR_OFF);
4667         ASSERT(svd->tr_state != SEGVN_TR_INIT);
4668 
4669         ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
4670 
4671         VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltanpages[0]);
4672         VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltanpages[1]);
4673 
4674         if (svd->flags & MAP_TEXT) {
4675                 hat_flag |= HAT_LOAD_TEXT;
4676         }
4677 
4678         if (svd->pageprot) {
4679                 switch (rw) {
4680                 case S_READ:
4681                         protchk = PROT_READ;
4682                         break;
4683                 case S_WRITE:
4684                         protchk = PROT_WRITE;
4685                         break;
4686                 case S_EXEC:
4687                         protchk = PROT_EXEC;
4688                         break;
4689                 case S_OTHER:
4690                 default:
4691                         protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4692                         break;
4693                 }
4694                 VM_STAT_ADD(segvnvmstats.fltanpages[2]);
4695         } else {
4696                 prot = svd->prot;
4697                 /* caller has already done segment level protection check. */
4698         }
4699 
4700         ppa = kmem_cache_alloc(segvn_szc_cache[ppaszc], KM_SLEEP);
4701         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4702         for (;;) {
4703                 adjszc_chk = 0;
4704                 for (; a < lpgeaddr; a += pgsz, aindx += pages) {
4705                         if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
4706                                 VM_STAT_ADD(segvnvmstats.fltanpages[3]);
4707                                 ASSERT(vpage != NULL);
4708                                 prot = VPP_PROT(vpage);
4709                                 ASSERT(sameprot(seg, a, maxpgsz));
4710                                 if ((prot & protchk) == 0) {
4711                                         err = FC_PROT;
4712                                         goto error;
4713                                 }
4714                         }
4715                         if (adjszc_chk && IS_P2ALIGNED(a, maxpgsz) &&
4716                             pgsz < maxpgsz) {
4717                                 ASSERT(a > lpgaddr);
4718                                 szc = seg->s_szc;
4719                                 pgsz = maxpgsz;
4720                                 pages = btop(pgsz);
4721                                 ASSERT(IS_P2ALIGNED(aindx, pages));
4722                                 lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr,
4723                                     pgsz);
4724                         }
4725                         if (type == F_SOFTLOCK) {
4726                                 atomic_add_long((ulong_t *)&svd->softlockcnt,
4727                                     pages);
4728                         }
4729                         anon_array_enter(amp, aindx, &cookie);
4730                         ppa_szc = (uint_t)-1;
4731                         ierr = anon_map_getpages(amp, aindx, szc, seg, a,
4732                             prot, &vpprot, ppa, &ppa_szc, vpage, rw, brkcow,
4733                             segvn_anypgsz, pgflags, svd->cred);
4734                         if (ierr != 0) {
4735                                 anon_array_exit(&cookie);
4736                                 VM_STAT_ADD(segvnvmstats.fltanpages[4]);
4737                                 if (type == F_SOFTLOCK) {
4738                                         atomic_add_long(
4739                                             (ulong_t *)&svd->softlockcnt,
4740                                             -pages);
4741                                 }
4742                                 if (ierr > 0) {
4743                                         VM_STAT_ADD(segvnvmstats.fltanpages[6]);
4744                                         err = FC_MAKE_ERR(ierr);
4745                                         goto error;
4746                                 }
4747                                 break;
4748                         }
4749 
4750                         ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4751 
4752                         ASSERT(segtype == MAP_SHARED ||
4753                             ppa[0]->p_szc <= szc);
4754                         ASSERT(segtype == MAP_PRIVATE ||
4755                             ppa[0]->p_szc >= szc);
4756 
4757                         /*
4758                          * Handle pages that have been marked for migration
4759                          */
4760                         if (lgrp_optimizations())
4761                                 page_migrate(seg, a, ppa, pages);
4762 
4763                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
4764 
4765                         if (segtype == MAP_SHARED) {
4766                                 vpprot |= PROT_WRITE;
4767                         }
4768 
4769                         hat_memload_array(hat, a, pgsz, ppa,
4770                             prot & vpprot, hat_flag);
4771 
4772                         if (hat_flag & HAT_LOAD_LOCK) {
4773                                 VM_STAT_ADD(segvnvmstats.fltanpages[7]);
4774                         } else {
4775                                 VM_STAT_ADD(segvnvmstats.fltanpages[8]);
4776                                 for (i = 0; i < pages; i++)
4777                                         page_unlock(ppa[i]);
4778                         }
4779                         if (vpage != NULL)
4780                                 vpage += pages;
4781 
4782                         anon_array_exit(&cookie);
4783                         adjszc_chk = 1;
4784                 }
4785                 if (a == lpgeaddr)
4786                         break;
4787                 ASSERT(a < lpgeaddr);
4788                 /*
4789                  * ierr == -1 means we failed to allocate a large page.
4790                  * so do a size down operation.
4791                  *
4792                  * ierr == -2 means some other process that privately shares
4793                  * pages with this process has allocated a larger page and we
4794                  * need to retry with larger pages. So do a size up
4795                  * operation. This relies on the fact that large pages are
4796                  * never partially shared i.e. if we share any constituent
4797                  * page of a large page with another process we must share the
4798                  * entire large page. Note this cannot happen for SOFTLOCK
4799                  * case, unless current address (a) is at the beginning of the
4800                  * next page size boundary because the other process couldn't
4801                  * have relocated locked pages.
4802                  */
4803                 ASSERT(ierr == -1 || ierr == -2);
4804 
4805                 if (segvn_anypgsz) {
4806                         ASSERT(ierr == -2 || szc != 0);
4807                         ASSERT(ierr == -1 || szc < seg->s_szc);
4808                         szc = (ierr == -1) ? szc - 1 : szc + 1;
4809                 } else {
4810                         /*
4811                          * For non COW faults and segvn_anypgsz == 0
4812                          * we need to be careful not to loop forever
4813                          * if existing page is found with szc other
4814                          * than 0 or seg->s_szc. This could be due
4815                          * to page relocations on behalf of DR or
4816                          * more likely large page creation. For this
4817                          * case simply re-size to existing page's szc
4818                          * if returned by anon_map_getpages().
4819                          */
4820                         if (ppa_szc == (uint_t)-1) {
4821                                 szc = (ierr == -1) ? 0 : seg->s_szc;
4822                         } else {
4823                                 ASSERT(ppa_szc <= seg->s_szc);
4824                                 ASSERT(ierr == -2 || ppa_szc < szc);
4825                                 ASSERT(ierr == -1 || ppa_szc > szc);
4826                                 szc = ppa_szc;
4827                         }
4828                 }
4829 
4830                 pgsz = page_get_pagesize(szc);
4831                 pages = btop(pgsz);
4832                 ASSERT(type != F_SOFTLOCK || ierr == -1 ||
4833                     (IS_P2ALIGNED(a, pgsz) && IS_P2ALIGNED(lpgeaddr, pgsz)));
4834                 if (type == F_SOFTLOCK) {
4835                         /*
4836                          * For softlocks we cannot reduce the fault area
4837                          * (calculated based on the largest page size for this
4838                          * segment) for size down and a is already next
4839                          * page size aligned as assertted above for size
4840                          * ups. Therefore just continue in case of softlock.
4841                          */
4842                         VM_STAT_ADD(segvnvmstats.fltanpages[9]);
4843                         continue; /* keep lint happy */
4844                 } else if (ierr == -2) {
4845 
4846                         /*
4847                          * Size up case. Note lpgaddr may only be needed for
4848                          * softlock case so we don't adjust it here.
4849                          */
4850                         VM_STAT_ADD(segvnvmstats.fltanpages[10]);
4851                         a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4852                         ASSERT(a >= lpgaddr);
4853                         lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4854                         aindx = svd->anon_index + seg_page(seg, a);
4855                         vpage = (svd->vpage != NULL) ?
4856                             &svd->vpage[seg_page(seg, a)] : NULL;
4857                 } else {
4858                         /*
4859                          * Size down case. Note lpgaddr may only be needed for
4860                          * softlock case so we don't adjust it here.
4861                          */
4862                         VM_STAT_ADD(segvnvmstats.fltanpages[11]);
4863                         ASSERT(IS_P2ALIGNED(a, pgsz));
4864                         ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4865                         lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4866                         ASSERT(a < lpgeaddr);
4867                         if (a < addr) {
4868                                 /*
4869                                  * The beginning of the large page region can
4870                                  * be pulled to the right to make a smaller
4871                                  * region. We haven't yet faulted a single
4872                                  * page.
4873                                  */
4874                                 VM_STAT_ADD(segvnvmstats.fltanpages[12]);
4875                                 a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4876                                 ASSERT(a >= lpgaddr);
4877                                 aindx = svd->anon_index + seg_page(seg, a);
4878                                 vpage = (svd->vpage != NULL) ?
4879                                     &svd->vpage[seg_page(seg, a)] : NULL;
4880                         }
4881                 }
4882         }
4883         VM_STAT_ADD(segvnvmstats.fltanpages[13]);
4884         ANON_LOCK_EXIT(&amp->a_rwlock);
4885         kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4886         return (0);
4887 error:
4888         VM_STAT_ADD(segvnvmstats.fltanpages[14]);
4889         ANON_LOCK_EXIT(&amp->a_rwlock);
4890         kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4891         if (type == F_SOFTLOCK && a > lpgaddr) {
4892                 VM_STAT_ADD(segvnvmstats.fltanpages[15]);
4893                 segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4894         }
4895         return (err);
4896 }
4897 
4898 int fltadvice = 1;      /* set to free behind pages for sequential access */
4899 
4900 /*
4901  * This routine is called via a machine specific fault handling routine.
4902  * It is also called by software routines wishing to lock or unlock
4903  * a range of addresses.
4904  *
4905  * Here is the basic algorithm:
4906  *      If unlocking
4907  *              Call segvn_softunlock
4908  *              Return
4909  *      endif
4910  *      Checking and set up work
4911  *      If we will need some non-anonymous pages
4912  *              Call VOP_GETPAGE over the range of non-anonymous pages
4913  *      endif
4914  *      Loop over all addresses requested
4915  *              Call segvn_faultpage passing in page list
4916  *                  to load up translations and handle anonymous pages
4917  *      endloop
4918  *      Load up translation to any additional pages in page list not
4919  *          already handled that fit into this segment
4920  */
4921 static faultcode_t
4922 segvn_fault(struct hat *hat, struct seg *seg, caddr_t addr, size_t len,
4923     enum fault_type type, enum seg_rw rw)
4924 {
4925         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4926         page_t **plp, **ppp, *pp;
4927         u_offset_t off;
4928         caddr_t a;
4929         struct vpage *vpage;
4930         uint_t vpprot, prot;
4931         int err;
4932         page_t *pl[PVN_GETPAGE_NUM + 1];
4933         size_t plsz, pl_alloc_sz;
4934         size_t page;
4935         ulong_t anon_index;
4936         struct anon_map *amp;
4937         int dogetpage = 0;
4938         caddr_t lpgaddr, lpgeaddr;
4939         size_t pgsz;
4940         anon_sync_obj_t cookie;
4941         int brkcow = BREAK_COW_SHARE(rw, type, svd->type);
4942 
4943         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
4944         ASSERT(svd->amp == NULL || svd->rcookie == HAT_INVALID_REGION_COOKIE);
4945 
4946         /*
4947          * First handle the easy stuff
4948          */
4949         if (type == F_SOFTUNLOCK) {
4950                 if (rw == S_READ_NOCOW) {
4951                         rw = S_READ;
4952                         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
4953                 }
4954                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4955                 pgsz = (seg->s_szc == 0) ? PAGESIZE :
4956                     page_get_pagesize(seg->s_szc);
4957                 VM_STAT_COND_ADD(pgsz > PAGESIZE, segvnvmstats.fltanpages[16]);
4958                 CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
4959                 segvn_softunlock(seg, lpgaddr, lpgeaddr - lpgaddr, rw);
4960                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4961                 return (0);
4962         }
4963 
4964         ASSERT(svd->tr_state == SEGVN_TR_OFF ||
4965             !HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
4966         if (brkcow == 0) {
4967                 if (svd->tr_state == SEGVN_TR_INIT) {
4968                         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4969                         if (svd->tr_state == SEGVN_TR_INIT) {
4970                                 ASSERT(svd->vp != NULL && svd->amp == NULL);
4971                                 ASSERT(svd->flags & MAP_TEXT);
4972                                 ASSERT(svd->type == MAP_PRIVATE);
4973                                 segvn_textrepl(seg);
4974                                 ASSERT(svd->tr_state != SEGVN_TR_INIT);
4975                                 ASSERT(svd->tr_state != SEGVN_TR_ON ||
4976                                     svd->amp != NULL);
4977                         }
4978                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4979                 }
4980         } else if (svd->tr_state != SEGVN_TR_OFF) {
4981                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4982 
4983                 if (rw == S_WRITE && svd->tr_state != SEGVN_TR_OFF) {
4984                         ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
4985                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4986                         return (FC_PROT);
4987                 }
4988 
4989                 if (svd->tr_state == SEGVN_TR_ON) {
4990                         ASSERT(svd->vp != NULL && svd->amp != NULL);
4991                         segvn_textunrepl(seg, 0);
4992                         ASSERT(svd->amp == NULL &&
4993                             svd->tr_state == SEGVN_TR_OFF);
4994                 } else if (svd->tr_state != SEGVN_TR_OFF) {
4995                         svd->tr_state = SEGVN_TR_OFF;
4996                 }
4997                 ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
4998                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4999         }
5000 
5001 top:
5002         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
5003 
5004         /*
5005          * If we have the same protections for the entire segment,
5006          * insure that the access being attempted is legitimate.
5007          */
5008 
5009         if (svd->pageprot == 0) {
5010                 uint_t protchk;
5011 
5012                 switch (rw) {
5013                 case S_READ:
5014                 case S_READ_NOCOW:
5015                         protchk = PROT_READ;
5016                         break;
5017                 case S_WRITE:
5018                         protchk = PROT_WRITE;
5019                         break;
5020                 case S_EXEC:
5021                         protchk = PROT_EXEC;
5022                         break;
5023                 case S_OTHER:
5024                 default:
5025                         protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
5026                         break;
5027                 }
5028 
5029                 if ((svd->prot & protchk) == 0) {
5030                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5031                         return (FC_PROT);       /* illegal access type */
5032                 }
5033         }
5034 
5035         if (brkcow && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5036                 /* this must be SOFTLOCK S_READ fault */
5037                 ASSERT(svd->amp == NULL);
5038                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
5039                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5040                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5041                 if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5042                         /*
5043                          * this must be the first ever non S_READ_NOCOW
5044                          * softlock for this segment.
5045                          */
5046                         ASSERT(svd->softlockcnt == 0);
5047                         hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5048                             HAT_REGION_TEXT);
5049                         svd->rcookie = HAT_INVALID_REGION_COOKIE;
5050                 }
5051                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5052                 goto top;
5053         }
5054 
5055         /*
5056          * We can't allow the long term use of softlocks for vmpss segments,
5057          * because in some file truncation cases we should be able to demote
5058          * the segment, which requires that there are no softlocks.  The
5059          * only case where it's ok to allow a SOFTLOCK fault against a vmpss
5060          * segment is S_READ_NOCOW, where the caller holds the address space
5061          * locked as writer and calls softunlock before dropping the as lock.
5062          * S_READ_NOCOW is used by /proc to read memory from another user.
5063          *
5064          * Another deadlock between SOFTLOCK and file truncation can happen
5065          * because segvn_fault_vnodepages() calls the FS one pagesize at
5066          * a time. A second VOP_GETPAGE() call by segvn_fault_vnodepages()
5067          * can cause a deadlock because the first set of page_t's remain
5068          * locked SE_SHARED.  To avoid this, we demote segments on a first
5069          * SOFTLOCK if they have a length greater than the segment's
5070          * page size.
5071          *
5072          * So for now, we only avoid demoting a segment on a SOFTLOCK when
5073          * the access type is S_READ_NOCOW and the fault length is less than
5074          * or equal to the segment's page size. While this is quite restrictive,
5075          * it should be the most common case of SOFTLOCK against a vmpss
5076          * segment.
5077          *
5078          * For S_READ_NOCOW, it's safe not to do a copy on write because the
5079          * caller makes sure no COW will be caused by another thread for a
5080          * softlocked page.
5081          */
5082         if (type == F_SOFTLOCK && svd->vp != NULL && seg->s_szc != 0) {
5083                 int demote = 0;
5084 
5085                 if (rw != S_READ_NOCOW) {
5086                         demote = 1;
5087                 }
5088                 if (!demote && len > PAGESIZE) {
5089                         pgsz = page_get_pagesize(seg->s_szc);
5090                         CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr,
5091                             lpgeaddr);
5092                         if (lpgeaddr - lpgaddr > pgsz) {
5093                                 demote = 1;
5094                         }
5095                 }
5096 
5097                 ASSERT(demote || AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5098 
5099                 if (demote) {
5100                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5101                         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5102                         if (seg->s_szc != 0) {
5103                                 segvn_vmpss_clrszc_cnt++;
5104                                 ASSERT(svd->softlockcnt == 0);
5105                                 err = segvn_clrszc(seg);
5106                                 if (err) {
5107                                         segvn_vmpss_clrszc_err++;
5108                                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5109                                         return (FC_MAKE_ERR(err));
5110                                 }
5111                         }
5112                         ASSERT(seg->s_szc == 0);
5113                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5114                         goto top;
5115                 }
5116         }
5117 
5118         /*
5119          * Check to see if we need to allocate an anon_map structure.
5120          */
5121         if (svd->amp == NULL && (svd->vp == NULL || brkcow)) {
5122                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5123                 /*
5124                  * Drop the "read" lock on the segment and acquire
5125                  * the "write" version since we have to allocate the
5126                  * anon_map.
5127                  */
5128                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5129                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5130 
5131                 if (svd->amp == NULL) {
5132                         svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
5133                         svd->amp->a_szc = seg->s_szc;
5134                 }
5135                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5136 
5137                 /*
5138                  * Start all over again since segment protections
5139                  * may have changed after we dropped the "read" lock.
5140                  */
5141                 goto top;
5142         }
5143 
5144         /*
5145          * S_READ_NOCOW vs S_READ distinction was
5146          * only needed for the code above. After
5147          * that we treat it as S_READ.
5148          */
5149         if (rw == S_READ_NOCOW) {
5150                 ASSERT(type == F_SOFTLOCK);
5151                 ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5152                 rw = S_READ;
5153         }
5154 
5155         amp = svd->amp;
5156 
5157         /*
5158          * MADV_SEQUENTIAL work is ignored for large page segments.
5159          */
5160         if (seg->s_szc != 0) {
5161                 pgsz = page_get_pagesize(seg->s_szc);
5162                 ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
5163                 CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
5164                 if (svd->vp == NULL) {
5165                         err = segvn_fault_anonpages(hat, seg, lpgaddr,
5166                             lpgeaddr, type, rw, addr, addr + len, brkcow);
5167                 } else {
5168                         err = segvn_fault_vnodepages(hat, seg, lpgaddr,
5169                             lpgeaddr, type, rw, addr, addr + len, brkcow);
5170                         if (err == IE_RETRY) {
5171                                 ASSERT(seg->s_szc == 0);
5172                                 ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
5173                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5174                                 goto top;
5175                         }
5176                 }
5177                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5178                 return (err);
5179         }
5180 
5181         page = seg_page(seg, addr);
5182         if (amp != NULL) {
5183                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5184                 anon_index = svd->anon_index + page;
5185 
5186                 if (type == F_PROT && rw == S_READ &&
5187                     svd->tr_state == SEGVN_TR_OFF &&
5188                     svd->type == MAP_PRIVATE && svd->pageprot == 0) {
5189                         size_t index = anon_index;
5190                         struct anon *ap;
5191 
5192                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5193                         /*
5194                          * The fast path could apply to S_WRITE also, except
5195                          * that the protection fault could be caused by lazy
5196                          * tlb flush when ro->rw. In this case, the pte is
5197                          * RW already. But RO in the other cpu's tlb causes
5198                          * the fault. Since hat_chgprot won't do anything if
5199                          * pte doesn't change, we may end up faulting
5200                          * indefinitely until the RO tlb entry gets replaced.
5201                          */
5202                         for (a = addr; a < addr + len; a += PAGESIZE, index++) {
5203                                 anon_array_enter(amp, index, &cookie);
5204                                 ap = anon_get_ptr(amp->ahp, index);
5205                                 anon_array_exit(&cookie);
5206                                 if ((ap == NULL) || (ap->an_refcnt != 1)) {
5207                                         ANON_LOCK_EXIT(&amp->a_rwlock);
5208                                         goto slow;
5209                                 }
5210                         }
5211                         hat_chgprot(seg->s_as->a_hat, addr, len, svd->prot);
5212                         ANON_LOCK_EXIT(&amp->a_rwlock);
5213                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5214                         return (0);
5215                 }
5216         }
5217 slow:
5218 
5219         if (svd->vpage == NULL)
5220                 vpage = NULL;
5221         else
5222                 vpage = &svd->vpage[page];
5223 
5224         off = svd->offset + (uintptr_t)(addr - seg->s_base);
5225 
5226         /*
5227          * If MADV_SEQUENTIAL has been set for the particular page we
5228          * are faulting on, free behind all pages in the segment and put
5229          * them on the free list.
5230          */
5231 
5232         if ((page != 0) && fltadvice && svd->tr_state != SEGVN_TR_ON) {
5233                 struct vpage *vpp;
5234                 ulong_t fanon_index;
5235                 size_t fpage;
5236                 u_offset_t pgoff, fpgoff;
5237                 struct vnode *fvp;
5238                 struct anon *fap = NULL;
5239 
5240                 if (svd->advice == MADV_SEQUENTIAL ||
5241                     (svd->pageadvice &&
5242                     VPP_ADVICE(vpage) == MADV_SEQUENTIAL)) {
5243                         pgoff = off - PAGESIZE;
5244                         fpage = page - 1;
5245                         if (vpage != NULL)
5246                                 vpp = &svd->vpage[fpage];
5247                         if (amp != NULL)
5248                                 fanon_index = svd->anon_index + fpage;
5249 
5250                         while (pgoff > svd->offset) {
5251                                 if (svd->advice != MADV_SEQUENTIAL &&
5252                                     (!svd->pageadvice || (vpage &&
5253                                     VPP_ADVICE(vpp) != MADV_SEQUENTIAL)))
5254                                         break;
5255 
5256                                 /*
5257                                  * If this is an anon page, we must find the
5258                                  * correct <vp, offset> for it
5259                                  */
5260                                 fap = NULL;
5261                                 if (amp != NULL) {
5262                                         ANON_LOCK_ENTER(&amp->a_rwlock,
5263                                             RW_READER);
5264                                         anon_array_enter(amp, fanon_index,
5265                                             &cookie);
5266                                         fap = anon_get_ptr(amp->ahp,
5267                                             fanon_index);
5268                                         if (fap != NULL) {
5269                                                 swap_xlate(fap, &fvp, &fpgoff);
5270                                         } else {
5271                                                 fpgoff = pgoff;
5272                                                 fvp = svd->vp;
5273                                         }
5274                                         anon_array_exit(&cookie);
5275                                         ANON_LOCK_EXIT(&amp->a_rwlock);
5276                                 } else {
5277                                         fpgoff = pgoff;
5278                                         fvp = svd->vp;
5279                                 }
5280                                 if (fvp == NULL)
5281                                         break;  /* XXX */
5282                                 /*
5283                                  * Skip pages that are free or have an
5284                                  * "exclusive" lock.
5285                                  */
5286                                 pp = page_lookup_nowait(fvp, fpgoff, SE_SHARED);
5287                                 if (pp == NULL)
5288                                         break;
5289                                 /*
5290                                  * We don't need the page_struct_lock to test
5291                                  * as this is only advisory; even if we
5292                                  * acquire it someone might race in and lock
5293                                  * the page after we unlock and before the
5294                                  * PUTPAGE, then VOP_PUTPAGE will do nothing.
5295                                  */
5296                                 if (pp->p_lckcnt == 0 && pp->p_cowcnt == 0) {
5297                                         /*
5298                                          * Hold the vnode before releasing
5299                                          * the page lock to prevent it from
5300                                          * being freed and re-used by some
5301                                          * other thread.
5302                                          */
5303                                         VN_HOLD(fvp);
5304                                         page_unlock(pp);
5305                                         /*
5306                                          * We should build a page list
5307                                          * to kluster putpages XXX
5308                                          */
5309                                         (void) VOP_PUTPAGE(fvp,
5310                                             (offset_t)fpgoff, PAGESIZE,
5311                                             (B_DONTNEED|B_FREE|B_ASYNC),
5312                                             svd->cred, NULL);
5313                                         VN_RELE(fvp);
5314                                 } else {
5315                                         /*
5316                                          * XXX - Should the loop terminate if
5317                                          * the page is `locked'?
5318                                          */
5319                                         page_unlock(pp);
5320                                 }
5321                                 --vpp;
5322                                 --fanon_index;
5323                                 pgoff -= PAGESIZE;
5324                         }
5325                 }
5326         }
5327 
5328         plp = pl;
5329         *plp = NULL;
5330         pl_alloc_sz = 0;
5331 
5332         /*
5333          * See if we need to call VOP_GETPAGE for
5334          * *any* of the range being faulted on.
5335          * We can skip all of this work if there
5336          * was no original vnode.
5337          */
5338         if (svd->vp != NULL) {
5339                 u_offset_t vp_off;
5340                 size_t vp_len;
5341                 struct anon *ap;
5342                 vnode_t *vp;
5343 
5344                 vp_off = off;
5345                 vp_len = len;
5346 
5347                 if (amp == NULL)
5348                         dogetpage = 1;
5349                 else {
5350                         /*
5351                          * Only acquire reader lock to prevent amp->ahp
5352                          * from being changed.  It's ok to miss pages,
5353                          * hence we don't do anon_array_enter
5354                          */
5355                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5356                         ap = anon_get_ptr(amp->ahp, anon_index);
5357 
5358                         if (len <= PAGESIZE)
5359                                 /* inline non_anon() */
5360                                 dogetpage = (ap == NULL);
5361                         else
5362                                 dogetpage = non_anon(amp->ahp, anon_index,
5363                                     &vp_off, &vp_len);
5364                         ANON_LOCK_EXIT(&amp->a_rwlock);
5365                 }
5366 
5367                 if (dogetpage) {
5368                         enum seg_rw arw;
5369                         struct as *as = seg->s_as;
5370 
5371                         if (len > ptob((sizeof (pl) / sizeof (pl[0])) - 1)) {
5372                                 /*
5373                                  * Page list won't fit in local array,
5374                                  * allocate one of the needed size.
5375                                  */
5376                                 pl_alloc_sz =
5377                                     (btop(len) + 1) * sizeof (page_t *);
5378                                 plp = kmem_alloc(pl_alloc_sz, KM_SLEEP);
5379                                 plp[0] = NULL;
5380                                 plsz = len;
5381                         } else if (rw == S_WRITE && svd->type == MAP_PRIVATE ||
5382                             svd->tr_state == SEGVN_TR_ON || rw == S_OTHER ||
5383                             (((size_t)(addr + PAGESIZE) <
5384                             (size_t)(seg->s_base + seg->s_size)) &&
5385                             hat_probe(as->a_hat, addr + PAGESIZE))) {
5386                                 /*
5387                                  * Ask VOP_GETPAGE to return the exact number
5388                                  * of pages if
5389                                  * (a) this is a COW fault, or
5390                                  * (b) this is a software fault, or
5391                                  * (c) next page is already mapped.
5392                                  */
5393                                 plsz = len;
5394                         } else {
5395                                 /*
5396                                  * Ask VOP_GETPAGE to return adjacent pages
5397                                  * within the segment.
5398                                  */
5399                                 plsz = MIN((size_t)PVN_GETPAGE_SZ, (size_t)
5400                                     ((seg->s_base + seg->s_size) - addr));
5401                                 ASSERT((addr + plsz) <=
5402                                     (seg->s_base + seg->s_size));
5403                         }
5404 
5405                         /*
5406                          * Need to get some non-anonymous pages.
5407                          * We need to make only one call to GETPAGE to do
5408                          * this to prevent certain deadlocking conditions
5409                          * when we are doing locking.  In this case
5410                          * non_anon() should have picked up the smallest
5411                          * range which includes all the non-anonymous
5412                          * pages in the requested range.  We have to
5413                          * be careful regarding which rw flag to pass in
5414                          * because on a private mapping, the underlying
5415                          * object is never allowed to be written.
5416                          */
5417                         if (rw == S_WRITE && svd->type == MAP_PRIVATE) {
5418                                 arw = S_READ;
5419                         } else {
5420                                 arw = rw;
5421                         }
5422                         vp = svd->vp;
5423                         TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5424                             "segvn_getpage:seg %p addr %p vp %p",
5425                             seg, addr, vp);
5426                         err = VOP_GETPAGE(vp, (offset_t)vp_off, vp_len,
5427                             &vpprot, plp, plsz, seg, addr + (vp_off - off), arw,
5428                             svd->cred, NULL);
5429                         if (err) {
5430                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5431                                 segvn_pagelist_rele(plp);
5432                                 if (pl_alloc_sz)
5433                                         kmem_free(plp, pl_alloc_sz);
5434                                 return (FC_MAKE_ERR(err));
5435                         }
5436                         if (svd->type == MAP_PRIVATE)
5437                                 vpprot &= ~PROT_WRITE;
5438                 }
5439         }
5440 
5441         /*
5442          * N.B. at this time the plp array has all the needed non-anon
5443          * pages in addition to (possibly) having some adjacent pages.
5444          */
5445 
5446         /*
5447          * Always acquire the anon_array_lock to prevent
5448          * 2 threads from allocating separate anon slots for
5449          * the same "addr".
5450          *
5451          * If this is a copy-on-write fault and we don't already
5452          * have the anon_array_lock, acquire it to prevent the
5453          * fault routine from handling multiple copy-on-write faults
5454          * on the same "addr" in the same address space.
5455          *
5456          * Only one thread should deal with the fault since after
5457          * it is handled, the other threads can acquire a translation
5458          * to the newly created private page.  This prevents two or
5459          * more threads from creating different private pages for the
5460          * same fault.
5461          *
5462          * We grab "serialization" lock here if this is a MAP_PRIVATE segment
5463          * to prevent deadlock between this thread and another thread
5464          * which has soft-locked this page and wants to acquire serial_lock.
5465          * ( bug 4026339 )
5466          *
5467          * The fix for bug 4026339 becomes unnecessary when using the
5468          * locking scheme with per amp rwlock and a global set of hash
5469          * lock, anon_array_lock.  If we steal a vnode page when low
5470          * on memory and upgrad the page lock through page_rename,
5471          * then the page is PAGE_HANDLED, nothing needs to be done
5472          * for this page after returning from segvn_faultpage.
5473          *
5474          * But really, the page lock should be downgraded after
5475          * the stolen page is page_rename'd.
5476          */
5477 
5478         if (amp != NULL)
5479                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5480 
5481         /*
5482          * Ok, now loop over the address range and handle faults
5483          */
5484         for (a = addr; a < addr + len; a += PAGESIZE, off += PAGESIZE) {
5485                 err = segvn_faultpage(hat, seg, a, off, vpage, plp, vpprot,
5486                     type, rw, brkcow);
5487                 if (err) {
5488                         if (amp != NULL)
5489                                 ANON_LOCK_EXIT(&amp->a_rwlock);
5490                         if (type == F_SOFTLOCK && a > addr) {
5491                                 segvn_softunlock(seg, addr, (a - addr),
5492                                     S_OTHER);
5493                         }
5494                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5495                         segvn_pagelist_rele(plp);
5496                         if (pl_alloc_sz)
5497                                 kmem_free(plp, pl_alloc_sz);
5498                         return (err);
5499                 }
5500                 if (vpage) {
5501                         vpage++;
5502                 } else if (svd->vpage) {
5503                         page = seg_page(seg, addr);
5504                         vpage = &svd->vpage[++page];
5505                 }
5506         }
5507 
5508         /* Didn't get pages from the underlying fs so we're done */
5509         if (!dogetpage)
5510                 goto done;
5511 
5512         /*
5513          * Now handle any other pages in the list returned.
5514          * If the page can be used, load up the translations now.
5515          * Note that the for loop will only be entered if "plp"
5516          * is pointing to a non-NULL page pointer which means that
5517          * VOP_GETPAGE() was called and vpprot has been initialized.
5518          */
5519         if (svd->pageprot == 0)
5520                 prot = svd->prot & vpprot;
5521 
5522 
5523         /*
5524          * Large Files: diff should be unsigned value because we started
5525          * supporting > 2GB segment sizes from 2.5.1 and when a
5526          * large file of size > 2GB gets mapped to address space
5527          * the diff value can be > 2GB.
5528          */
5529 
5530         for (ppp = plp; (pp = *ppp) != NULL; ppp++) {
5531                 size_t diff;
5532                 struct anon *ap;
5533                 int anon_index;
5534                 anon_sync_obj_t cookie;
5535                 int hat_flag = HAT_LOAD_ADV;
5536 
5537                 if (svd->flags & MAP_TEXT) {
5538                         hat_flag |= HAT_LOAD_TEXT;
5539                 }
5540 
5541                 if (pp == PAGE_HANDLED)
5542                         continue;
5543 
5544                 if (svd->tr_state != SEGVN_TR_ON &&
5545                     pp->p_offset >=  svd->offset &&
5546                     pp->p_offset < svd->offset + seg->s_size) {
5547 
5548                         diff = pp->p_offset - svd->offset;
5549 
5550                         /*
5551                          * Large Files: Following is the assertion
5552                          * validating the above cast.
5553                          */
5554                         ASSERT(svd->vp == pp->p_vnode);
5555 
5556                         page = btop(diff);
5557                         if (svd->pageprot)
5558                                 prot = VPP_PROT(&svd->vpage[page]) & vpprot;
5559 
5560                         /*
5561                          * Prevent other threads in the address space from
5562                          * creating private pages (i.e., allocating anon slots)
5563                          * while we are in the process of loading translations
5564                          * to additional pages returned by the underlying
5565                          * object.
5566                          */
5567                         if (amp != NULL) {
5568                                 anon_index = svd->anon_index + page;
5569                                 anon_array_enter(amp, anon_index, &cookie);
5570                                 ap = anon_get_ptr(amp->ahp, anon_index);
5571                         }
5572                         if ((amp == NULL) || (ap == NULL)) {
5573                                 if (IS_VMODSORT(pp->p_vnode) ||
5574                                     enable_mbit_wa) {
5575                                         if (rw == S_WRITE)
5576                                                 hat_setmod(pp);
5577                                         else if (rw != S_OTHER &&
5578                                             !hat_ismod(pp))
5579                                                 prot &= ~PROT_WRITE;
5580                                 }
5581                                 /*
5582                                  * Skip mapping read ahead pages marked
5583                                  * for migration, so they will get migrated
5584                                  * properly on fault
5585                                  */
5586                                 ASSERT(amp == NULL ||
5587                                     svd->rcookie == HAT_INVALID_REGION_COOKIE);
5588                                 if ((prot & PROT_READ) && !PP_ISMIGRATE(pp)) {
5589                                         hat_memload_region(hat,
5590                                             seg->s_base + diff,
5591                                             pp, prot, hat_flag,
5592                                             svd->rcookie);
5593                                 }
5594                         }
5595                         if (amp != NULL)
5596                                 anon_array_exit(&cookie);
5597                 }
5598                 page_unlock(pp);
5599         }
5600 done:
5601         if (amp != NULL)
5602                 ANON_LOCK_EXIT(&amp->a_rwlock);
5603         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5604         if (pl_alloc_sz)
5605                 kmem_free(plp, pl_alloc_sz);
5606         return (0);
5607 }
5608 
5609 /*
5610  * This routine is used to start I/O on pages asynchronously.  XXX it will
5611  * only create PAGESIZE pages. At fault time they will be relocated into
5612  * larger pages.
5613  */
5614 static faultcode_t
5615 segvn_faulta(struct seg *seg, caddr_t addr)
5616 {
5617         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5618         int err;
5619         struct anon_map *amp;
5620         vnode_t *vp;
5621 
5622         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5623 
5624         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
5625         if ((amp = svd->amp) != NULL) {
5626                 struct anon *ap;
5627 
5628                 /*
5629                  * Reader lock to prevent amp->ahp from being changed.
5630                  * This is advisory, it's ok to miss a page, so
5631                  * we don't do anon_array_enter lock.
5632                  */
5633                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5634                 if ((ap = anon_get_ptr(amp->ahp,
5635                     svd->anon_index + seg_page(seg, addr))) != NULL) {
5636 
5637                         err = anon_getpage(&ap, NULL, NULL,
5638                             0, seg, addr, S_READ, svd->cred);
5639 
5640                         ANON_LOCK_EXIT(&amp->a_rwlock);
5641                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5642                         if (err)
5643                                 return (FC_MAKE_ERR(err));
5644                         return (0);
5645                 }
5646                 ANON_LOCK_EXIT(&amp->a_rwlock);
5647         }
5648 
5649         if (svd->vp == NULL) {
5650                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5651                 return (0);                     /* zfod page - do nothing now */
5652         }
5653 
5654         vp = svd->vp;
5655         TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5656             "segvn_getpage:seg %p addr %p vp %p", seg, addr, vp);
5657         err = VOP_GETPAGE(vp,
5658             (offset_t)(svd->offset + (uintptr_t)(addr - seg->s_base)),
5659             PAGESIZE, NULL, NULL, 0, seg, addr,
5660             S_OTHER, svd->cred, NULL);
5661 
5662         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5663         if (err)
5664                 return (FC_MAKE_ERR(err));
5665         return (0);
5666 }
5667 
5668 static int
5669 segvn_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
5670 {
5671         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5672         struct vpage *cvp, *svp, *evp;
5673         struct vnode *vp;
5674         size_t pgsz;
5675         pgcnt_t pgcnt;
5676         anon_sync_obj_t cookie;
5677         int unload_done = 0;
5678 
5679         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5680 
5681         if ((svd->maxprot & prot) != prot)
5682                 return (EACCES);                        /* violated maxprot */
5683 
5684         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5685 
5686         /* return if prot is the same */
5687         if (!svd->pageprot && svd->prot == prot) {
5688                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5689                 return (0);
5690         }
5691 
5692         /*
5693          * Since we change protections we first have to flush the cache.
5694          * This makes sure all the pagelock calls have to recheck
5695          * protections.
5696          */
5697         if (svd->softlockcnt > 0) {
5698                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
5699 
5700                 /*
5701                  * If this is shared segment non 0 softlockcnt
5702                  * means locked pages are still in use.
5703                  */
5704                 if (svd->type == MAP_SHARED) {
5705                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5706                         return (EAGAIN);
5707                 }
5708 
5709                 /*
5710                  * Since we do have the segvn writers lock nobody can fill
5711                  * the cache with entries belonging to this seg during
5712                  * the purge. The flush either succeeds or we still have
5713                  * pending I/Os.
5714                  */
5715                 segvn_purge(seg);
5716                 if (svd->softlockcnt > 0) {
5717                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5718                         return (EAGAIN);
5719                 }
5720         }
5721 
5722         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5723                 ASSERT(svd->amp == NULL);
5724                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
5725                 hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5726                     HAT_REGION_TEXT);
5727                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
5728                 unload_done = 1;
5729         } else if (svd->tr_state == SEGVN_TR_INIT) {
5730                 svd->tr_state = SEGVN_TR_OFF;
5731         } else if (svd->tr_state == SEGVN_TR_ON) {
5732                 ASSERT(svd->amp != NULL);
5733                 segvn_textunrepl(seg, 0);
5734                 ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
5735                 unload_done = 1;
5736         }
5737 
5738         if ((prot & PROT_WRITE) && svd->type == MAP_SHARED &&
5739             svd->vp != NULL && (svd->vp->v_flag & VVMEXEC)) {
5740                 ASSERT(vn_is_mapped(svd->vp, V_WRITE));
5741                 segvn_inval_trcache(svd->vp);
5742         }
5743         if (seg->s_szc != 0) {
5744                 int err;
5745                 pgsz = page_get_pagesize(seg->s_szc);
5746                 pgcnt = pgsz >> PAGESHIFT;
5747                 ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
5748                 if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
5749                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5750                         ASSERT(seg->s_base != addr || seg->s_size != len);
5751                         /*
5752                          * If we are holding the as lock as a reader then
5753                          * we need to return IE_RETRY and let the as
5754                          * layer drop and re-acquire the lock as a writer.
5755                          */
5756                         if (AS_READ_HELD(seg->s_as, &seg->s_as->a_lock))
5757                                 return (IE_RETRY);
5758                         VM_STAT_ADD(segvnvmstats.demoterange[1]);
5759                         if (svd->type == MAP_PRIVATE || svd->vp != NULL) {
5760                                 err = segvn_demote_range(seg, addr, len,
5761                                     SDR_END, 0);
5762                         } else {
5763                                 uint_t szcvec = map_pgszcvec(seg->s_base,
5764                                     pgsz, (uintptr_t)seg->s_base,
5765                                     (svd->flags & MAP_TEXT), MAPPGSZC_SHM, 0);
5766                                 err = segvn_demote_range(seg, addr, len,
5767                                     SDR_END, szcvec);
5768                         }
5769                         if (err == 0)
5770                                 return (IE_RETRY);
5771                         if (err == ENOMEM)
5772                                 return (IE_NOMEM);
5773                         return (err);
5774                 }
5775         }
5776 
5777 
5778         /*
5779          * If it's a private mapping and we're making it writable then we
5780          * may have to reserve the additional swap space now. If we are
5781          * making writable only a part of the segment then we use its vpage
5782          * array to keep a record of the pages for which we have reserved
5783          * swap. In this case we set the pageswap field in the segment's
5784          * segvn structure to record this.
5785          *
5786          * If it's a private mapping to a file (i.e., vp != NULL) and we're
5787          * removing write permission on the entire segment and we haven't
5788          * modified any pages, we can release the swap space.
5789          */
5790         if (svd->type == MAP_PRIVATE) {
5791                 if (prot & PROT_WRITE) {
5792                         if (!(svd->flags & MAP_NORESERVE) &&
5793                             !(svd->swresv && svd->pageswap == 0)) {
5794                                 size_t sz = 0;
5795 
5796                                 /*
5797                                  * Start by determining how much swap
5798                                  * space is required.
5799                                  */
5800                                 if (addr == seg->s_base &&
5801                                     len == seg->s_size &&
5802                                     svd->pageswap == 0) {
5803                                         /* The whole segment */
5804                                         sz = seg->s_size;
5805                                 } else {
5806                                         /*
5807                                          * Make sure that the vpage array
5808                                          * exists, and make a note of the
5809                                          * range of elements corresponding
5810                                          * to len.
5811                                          */
5812                                         segvn_vpage(seg);
5813                                         if (svd->vpage == NULL) {
5814                                                 SEGVN_LOCK_EXIT(seg->s_as,
5815                                                     &svd->lock);
5816                                                 return (ENOMEM);
5817                                         }
5818                                         svp = &svd->vpage[seg_page(seg, addr)];
5819                                         evp = &svd->vpage[seg_page(seg,
5820                                             addr + len)];
5821 
5822                                         if (svd->pageswap == 0) {
5823                                                 /*
5824                                                  * This is the first time we've
5825                                                  * asked for a part of this
5826                                                  * segment, so we need to
5827                                                  * reserve everything we've
5828                                                  * been asked for.
5829                                                  */
5830                                                 sz = len;
5831                                         } else {
5832                                                 /*
5833                                                  * We have to count the number
5834                                                  * of pages required.
5835                                                  */
5836                                                 for (cvp = svp;  cvp < evp;
5837                                                     cvp++) {
5838                                                         if (!VPP_ISSWAPRES(cvp))
5839                                                                 sz++;
5840                                                 }
5841                                                 sz <<= PAGESHIFT;
5842                                         }
5843                                 }
5844 
5845                                 /* Try to reserve the necessary swap. */
5846                                 if (anon_resv_zone(sz,
5847                                     seg->s_as->a_proc->p_zone) == 0) {
5848                                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5849                                         return (IE_NOMEM);
5850                                 }
5851 
5852                                 /*
5853                                  * Make a note of how much swap space
5854                                  * we've reserved.
5855                                  */
5856                                 if (svd->pageswap == 0 && sz == seg->s_size) {
5857                                         svd->swresv = sz;
5858                                 } else {
5859                                         ASSERT(svd->vpage != NULL);
5860                                         svd->swresv += sz;
5861                                         svd->pageswap = 1;
5862                                         for (cvp = svp; cvp < evp; cvp++) {
5863                                                 if (!VPP_ISSWAPRES(cvp))
5864                                                         VPP_SETSWAPRES(cvp);
5865                                         }
5866                                 }
5867                         }
5868                 } else {
5869                         /*
5870                          * Swap space is released only if this segment
5871                          * does not map anonymous memory, since read faults
5872                          * on such segments still need an anon slot to read
5873                          * in the data.
5874                          */
5875                         if (svd->swresv != 0 && svd->vp != NULL &&
5876                             svd->amp == NULL && addr == seg->s_base &&
5877                             len == seg->s_size && svd->pageprot == 0) {
5878                                 ASSERT(svd->pageswap == 0);
5879                                 anon_unresv_zone(svd->swresv,
5880                                     seg->s_as->a_proc->p_zone);
5881                                 svd->swresv = 0;
5882                                 TRACE_3(TR_FAC_VM, TR_ANON_PROC,
5883                                     "anon proc:%p %lu %u", seg, 0, 0);
5884                         }
5885                 }
5886         }
5887 
5888         if (addr == seg->s_base && len == seg->s_size && svd->vpage == NULL) {
5889                 if (svd->prot == prot) {
5890                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5891                         return (0);                     /* all done */
5892                 }
5893                 svd->prot = (uchar_t)prot;
5894         } else if (svd->type == MAP_PRIVATE) {
5895                 struct anon *ap = NULL;
5896                 page_t *pp;
5897                 u_offset_t offset, off;
5898                 struct anon_map *amp;
5899                 ulong_t anon_idx = 0;
5900 
5901                 /*
5902                  * A vpage structure exists or else the change does not
5903                  * involve the entire segment.  Establish a vpage structure
5904                  * if none is there.  Then, for each page in the range,
5905                  * adjust its individual permissions.  Note that write-
5906                  * enabling a MAP_PRIVATE page can affect the claims for
5907                  * locked down memory.  Overcommitting memory terminates
5908                  * the operation.
5909                  */
5910                 segvn_vpage(seg);
5911                 if (svd->vpage == NULL) {
5912                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5913                         return (ENOMEM);
5914                 }
5915                 svd->pageprot = 1;
5916                 if ((amp = svd->amp) != NULL) {
5917                         anon_idx = svd->anon_index + seg_page(seg, addr);
5918                         ASSERT(seg->s_szc == 0 ||
5919                             IS_P2ALIGNED(anon_idx, pgcnt));
5920                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5921                 }
5922 
5923                 offset = svd->offset + (uintptr_t)(addr - seg->s_base);
5924                 evp = &svd->vpage[seg_page(seg, addr + len)];
5925 
5926                 /*
5927                  * See Statement at the beginning of segvn_lockop regarding
5928                  * the way cowcnts and lckcnts are handled.
5929                  */
5930                 for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5931 
5932                         if (seg->s_szc != 0) {
5933                                 if (amp != NULL) {
5934                                         anon_array_enter(amp, anon_idx,
5935                                             &cookie);
5936                                 }
5937                                 if (IS_P2ALIGNED(anon_idx, pgcnt) &&
5938                                     !segvn_claim_pages(seg, svp, offset,
5939                                     anon_idx, prot)) {
5940                                         if (amp != NULL) {
5941                                                 anon_array_exit(&cookie);
5942                                         }
5943                                         break;
5944                                 }
5945                                 if (amp != NULL) {
5946                                         anon_array_exit(&cookie);
5947                                 }
5948                                 anon_idx++;
5949                         } else {
5950                                 if (amp != NULL) {
5951                                         anon_array_enter(amp, anon_idx,
5952                                             &cookie);
5953                                         ap = anon_get_ptr(amp->ahp, anon_idx++);
5954                                 }
5955 
5956                                 if (VPP_ISPPLOCK(svp) &&
5957                                     VPP_PROT(svp) != prot) {
5958 
5959                                         if (amp == NULL || ap == NULL) {
5960                                                 vp = svd->vp;
5961                                                 off = offset;
5962                                         } else
5963                                                 swap_xlate(ap, &vp, &off);
5964                                         if (amp != NULL)
5965                                                 anon_array_exit(&cookie);
5966 
5967                                         if ((pp = page_lookup(vp, off,
5968                                             SE_SHARED)) == NULL) {
5969                                                 panic("segvn_setprot: no page");
5970                                                 /*NOTREACHED*/
5971                                         }
5972                                         ASSERT(seg->s_szc == 0);
5973                                         if ((VPP_PROT(svp) ^ prot) &
5974                                             PROT_WRITE) {
5975                                                 if (prot & PROT_WRITE) {
5976                                                         if (!page_addclaim(
5977                                                             pp)) {
5978                                                                 page_unlock(pp);
5979                                                                 break;
5980                                                         }
5981                                                 } else {
5982                                                         if (!page_subclaim(
5983                                                             pp)) {
5984                                                                 page_unlock(pp);
5985                                                                 break;
5986                                                         }
5987                                                 }
5988                                         }
5989                                         page_unlock(pp);
5990                                 } else if (amp != NULL)
5991                                         anon_array_exit(&cookie);
5992                         }
5993                         VPP_SETPROT(svp, prot);
5994                         offset += PAGESIZE;
5995                 }
5996                 if (amp != NULL)
5997                         ANON_LOCK_EXIT(&amp->a_rwlock);
5998 
5999                 /*
6000                  * Did we terminate prematurely?  If so, simply unload
6001                  * the translations to the things we've updated so far.
6002                  */
6003                 if (svp != evp) {
6004                         if (unload_done) {
6005                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6006                                 return (IE_NOMEM);
6007                         }
6008                         len = (svp - &svd->vpage[seg_page(seg, addr)]) *
6009                             PAGESIZE;
6010                         ASSERT(seg->s_szc == 0 || IS_P2ALIGNED(len, pgsz));
6011                         if (len != 0)
6012                                 hat_unload(seg->s_as->a_hat, addr,
6013                                     len, HAT_UNLOAD);
6014                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6015                         return (IE_NOMEM);
6016                 }
6017         } else {
6018                 segvn_vpage(seg);
6019                 if (svd->vpage == NULL) {
6020                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6021                         return (ENOMEM);
6022                 }
6023                 svd->pageprot = 1;
6024                 evp = &svd->vpage[seg_page(seg, addr + len)];
6025                 for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
6026                         VPP_SETPROT(svp, prot);
6027                 }
6028         }
6029 
6030         if (unload_done) {
6031                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6032                 return (0);
6033         }
6034 
6035         if (((prot & PROT_WRITE) != 0 &&
6036             (svd->vp != NULL || svd->type == MAP_PRIVATE)) ||
6037             (prot & ~PROT_USER) == PROT_NONE) {
6038                 /*
6039                  * Either private or shared data with write access (in
6040                  * which case we need to throw out all former translations
6041                  * so that we get the right translations set up on fault
6042                  * and we don't allow write access to any copy-on-write pages
6043                  * that might be around or to prevent write access to pages
6044                  * representing holes in a file), or we don't have permission
6045                  * to access the memory at all (in which case we have to
6046                  * unload any current translations that might exist).
6047                  */
6048                 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
6049         } else {
6050                 /*
6051                  * A shared mapping or a private mapping in which write
6052                  * protection is going to be denied - just change all the
6053                  * protections over the range of addresses in question.
6054                  * segvn does not support any other attributes other
6055                  * than prot so we can use hat_chgattr.
6056                  */
6057                 hat_chgattr(seg->s_as->a_hat, addr, len, prot);
6058         }
6059 
6060         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6061 
6062         return (0);
6063 }
6064 
6065 /*
6066  * segvn_setpagesize is called via SEGOP_SETPAGESIZE from as_setpagesize,
6067  * to determine if the seg is capable of mapping the requested szc.
6068  */
6069 static int
6070 segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
6071 {
6072         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6073         struct segvn_data *nsvd;
6074         struct anon_map *amp = svd->amp;
6075         struct seg *nseg;
6076         caddr_t eaddr = addr + len, a;
6077         size_t pgsz = page_get_pagesize(szc);
6078         pgcnt_t pgcnt = page_get_pagecnt(szc);
6079         int err;
6080         u_offset_t off = svd->offset + (uintptr_t)(addr - seg->s_base);
6081 
6082         ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6083         ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6084 
6085         if (seg->s_szc == szc || segvn_lpg_disable != 0) {
6086                 return (0);
6087         }
6088 
6089         /*
6090          * addr should always be pgsz aligned but eaddr may be misaligned if
6091          * it's at the end of the segment.
6092          *
6093          * XXX we should assert this condition since as_setpagesize() logic
6094          * guarantees it.
6095          */
6096         if (!IS_P2ALIGNED(addr, pgsz) ||
6097             (!IS_P2ALIGNED(eaddr, pgsz) &&
6098             eaddr != seg->s_base + seg->s_size)) {
6099 
6100                 segvn_setpgsz_align_err++;
6101                 return (EINVAL);
6102         }
6103 
6104         if (amp != NULL && svd->type == MAP_SHARED) {
6105                 ulong_t an_idx = svd->anon_index + seg_page(seg, addr);
6106                 if (!IS_P2ALIGNED(an_idx, pgcnt)) {
6107 
6108                         segvn_setpgsz_anon_align_err++;
6109                         return (EINVAL);
6110                 }
6111         }
6112 
6113         if ((svd->flags & MAP_NORESERVE) || seg->s_as == &kas ||
6114             szc > segvn_maxpgszc) {
6115                 return (EINVAL);
6116         }
6117 
6118         /* paranoid check */
6119         if (svd->vp != NULL &&
6120             (IS_SWAPFSVP(svd->vp) || VN_ISKAS(svd->vp))) {
6121                 return (EINVAL);
6122         }
6123 
6124         if (seg->s_szc == 0 && svd->vp != NULL &&
6125             map_addr_vacalign_check(addr, off)) {
6126                 return (EINVAL);
6127         }
6128 
6129         /*
6130          * Check that protections are the same within new page
6131          * size boundaries.
6132          */
6133         if (svd->pageprot) {
6134                 for (a = addr; a < eaddr; a += pgsz) {
6135                         if ((a + pgsz) > eaddr) {
6136                                 if (!sameprot(seg, a, eaddr - a)) {
6137                                         return (EINVAL);
6138                                 }
6139                         } else {
6140                                 if (!sameprot(seg, a, pgsz)) {
6141                                         return (EINVAL);
6142                                 }
6143                         }
6144                 }
6145         }
6146 
6147         /*
6148          * Since we are changing page size we first have to flush
6149          * the cache. This makes sure all the pagelock calls have
6150          * to recheck protections.
6151          */
6152         if (svd->softlockcnt > 0) {
6153                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
6154 
6155                 /*
6156                  * If this is shared segment non 0 softlockcnt
6157                  * means locked pages are still in use.
6158                  */
6159                 if (svd->type == MAP_SHARED) {
6160                         return (EAGAIN);
6161                 }
6162 
6163                 /*
6164                  * Since we do have the segvn writers lock nobody can fill
6165                  * the cache with entries belonging to this seg during
6166                  * the purge. The flush either succeeds or we still have
6167                  * pending I/Os.
6168                  */
6169                 segvn_purge(seg);
6170                 if (svd->softlockcnt > 0) {
6171                         return (EAGAIN);
6172                 }
6173         }
6174 
6175         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6176                 ASSERT(svd->amp == NULL);
6177                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
6178                 hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6179                     HAT_REGION_TEXT);
6180                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
6181         } else if (svd->tr_state == SEGVN_TR_INIT) {
6182                 svd->tr_state = SEGVN_TR_OFF;
6183         } else if (svd->tr_state == SEGVN_TR_ON) {
6184                 ASSERT(svd->amp != NULL);
6185                 segvn_textunrepl(seg, 1);
6186                 ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6187                 amp = NULL;
6188         }
6189 
6190         /*
6191          * Operation for sub range of existing segment.
6192          */
6193         if (addr != seg->s_base || eaddr != (seg->s_base + seg->s_size)) {
6194                 if (szc < seg->s_szc) {
6195                         VM_STAT_ADD(segvnvmstats.demoterange[2]);
6196                         err = segvn_demote_range(seg, addr, len, SDR_RANGE, 0);
6197                         if (err == 0) {
6198                                 return (IE_RETRY);
6199                         }
6200                         if (err == ENOMEM) {
6201                                 return (IE_NOMEM);
6202                         }
6203                         return (err);
6204                 }
6205                 if (addr != seg->s_base) {
6206                         nseg = segvn_split_seg(seg, addr);
6207                         if (eaddr != (nseg->s_base + nseg->s_size)) {
6208                                 /* eaddr is szc aligned */
6209                                 (void) segvn_split_seg(nseg, eaddr);
6210                         }
6211                         return (IE_RETRY);
6212                 }
6213                 if (eaddr != (seg->s_base + seg->s_size)) {
6214                         /* eaddr is szc aligned */
6215                         (void) segvn_split_seg(seg, eaddr);
6216                 }
6217                 return (IE_RETRY);
6218         }
6219 
6220         /*
6221          * Break any low level sharing and reset seg->s_szc to 0.
6222          */
6223         if ((err = segvn_clrszc(seg)) != 0) {
6224                 if (err == ENOMEM) {
6225                         err = IE_NOMEM;
6226                 }
6227                 return (err);
6228         }
6229         ASSERT(seg->s_szc == 0);
6230 
6231         /*
6232          * If the end of the current segment is not pgsz aligned
6233          * then attempt to concatenate with the next segment.
6234          */
6235         if (!IS_P2ALIGNED(eaddr, pgsz)) {
6236                 nseg = AS_SEGNEXT(seg->s_as, seg);
6237                 if (nseg == NULL || nseg == seg || eaddr != nseg->s_base) {
6238                         return (ENOMEM);
6239                 }
6240                 if (nseg->s_ops != &segvn_ops) {
6241                         return (EINVAL);
6242                 }
6243                 nsvd = (struct segvn_data *)nseg->s_data;
6244                 if (nsvd->softlockcnt > 0) {
6245                         /*
6246                          * If this is shared segment non 0 softlockcnt
6247                          * means locked pages are still in use.
6248                          */
6249                         if (nsvd->type == MAP_SHARED) {
6250                                 return (EAGAIN);
6251                         }
6252                         segvn_purge(nseg);
6253                         if (nsvd->softlockcnt > 0) {
6254                                 return (EAGAIN);
6255                         }
6256                 }
6257                 err = segvn_clrszc(nseg);
6258                 if (err == ENOMEM) {
6259                         err = IE_NOMEM;
6260                 }
6261                 if (err != 0) {
6262                         return (err);
6263                 }
6264                 ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6265                 err = segvn_concat(seg, nseg, 1);
6266                 if (err == -1) {
6267                         return (EINVAL);
6268                 }
6269                 if (err == -2) {
6270                         return (IE_NOMEM);
6271                 }
6272                 return (IE_RETRY);
6273         }
6274 
6275         /*
6276          * May need to re-align anon array to
6277          * new szc.
6278          */
6279         if (amp != NULL) {
6280                 if (!IS_P2ALIGNED(svd->anon_index, pgcnt)) {
6281                         struct anon_hdr *nahp;
6282 
6283                         ASSERT(svd->type == MAP_PRIVATE);
6284 
6285                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6286                         ASSERT(amp->refcnt == 1);
6287                         nahp = anon_create(btop(amp->size), ANON_NOSLEEP);
6288                         if (nahp == NULL) {
6289                                 ANON_LOCK_EXIT(&amp->a_rwlock);
6290                                 return (IE_NOMEM);
6291                         }
6292                         if (anon_copy_ptr(amp->ahp, svd->anon_index,
6293                             nahp, 0, btop(seg->s_size), ANON_NOSLEEP)) {
6294                                 anon_release(nahp, btop(amp->size));
6295                                 ANON_LOCK_EXIT(&amp->a_rwlock);
6296                                 return (IE_NOMEM);
6297                         }
6298                         anon_release(amp->ahp, btop(amp->size));
6299                         amp->ahp = nahp;
6300                         svd->anon_index = 0;
6301                         ANON_LOCK_EXIT(&amp->a_rwlock);
6302                 }
6303         }
6304         if (svd->vp != NULL && szc != 0) {
6305                 struct vattr va;
6306                 u_offset_t eoffpage = svd->offset;
6307                 va.va_mask = AT_SIZE;
6308                 eoffpage += seg->s_size;
6309                 eoffpage = btopr(eoffpage);
6310                 if (VOP_GETATTR(svd->vp, &va, 0, svd->cred, NULL) != 0) {
6311                         segvn_setpgsz_getattr_err++;
6312                         return (EINVAL);
6313                 }
6314                 if (btopr(va.va_size) < eoffpage) {
6315                         segvn_setpgsz_eof_err++;
6316                         return (EINVAL);
6317                 }
6318                 if (amp != NULL) {
6319                         /*
6320                          * anon_fill_cow_holes() may call VOP_GETPAGE().
6321                          * don't take anon map lock here to avoid holding it
6322                          * across VOP_GETPAGE() calls that may call back into
6323                          * segvn for klsutering checks. We don't really need
6324                          * anon map lock here since it's a private segment and
6325                          * we hold as level lock as writers.
6326                          */
6327                         if ((err = anon_fill_cow_holes(seg, seg->s_base,
6328                             amp->ahp, svd->anon_index, svd->vp, svd->offset,
6329                             seg->s_size, szc, svd->prot, svd->vpage,
6330                             svd->cred)) != 0) {
6331                                 return (EINVAL);
6332                         }
6333                 }
6334                 segvn_setvnode_mpss(svd->vp);
6335         }
6336 
6337         if (amp != NULL) {
6338                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6339                 if (svd->type == MAP_PRIVATE) {
6340                         amp->a_szc = szc;
6341                 } else if (szc > amp->a_szc) {
6342                         amp->a_szc = szc;
6343                 }
6344                 ANON_LOCK_EXIT(&amp->a_rwlock);
6345         }
6346 
6347         seg->s_szc = szc;
6348 
6349         return (0);
6350 }
6351 
6352 static int
6353 segvn_clrszc(struct seg *seg)
6354 {
6355         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6356         struct anon_map *amp = svd->amp;
6357         size_t pgsz;
6358         pgcnt_t pages;
6359         int err = 0;
6360         caddr_t a = seg->s_base;
6361         caddr_t ea = a + seg->s_size;
6362         ulong_t an_idx = svd->anon_index;
6363         vnode_t *vp = svd->vp;
6364         struct vpage *vpage = svd->vpage;
6365         page_t *anon_pl[1 + 1], *pp;
6366         struct anon *ap, *oldap;
6367         uint_t prot = svd->prot, vpprot;
6368         int pageflag = 0;
6369 
6370         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6371             SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
6372         ASSERT(svd->softlockcnt == 0);
6373 
6374         if (vp == NULL && amp == NULL) {
6375                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6376                 seg->s_szc = 0;
6377                 return (0);
6378         }
6379 
6380         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6381                 ASSERT(svd->amp == NULL);
6382                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
6383                 hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6384                     HAT_REGION_TEXT);
6385                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
6386         } else if (svd->tr_state == SEGVN_TR_ON) {
6387                 ASSERT(svd->amp != NULL);
6388                 segvn_textunrepl(seg, 1);
6389                 ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6390                 amp = NULL;
6391         } else {
6392                 if (svd->tr_state != SEGVN_TR_OFF) {
6393                         ASSERT(svd->tr_state == SEGVN_TR_INIT);
6394                         svd->tr_state = SEGVN_TR_OFF;
6395                 }
6396 
6397                 /*
6398                  * do HAT_UNLOAD_UNMAP since we are changing the pagesize.
6399                  * unload argument is 0 when we are freeing the segment
6400                  * and unload was already done.
6401                  */
6402                 hat_unload(seg->s_as->a_hat, seg->s_base, seg->s_size,
6403                     HAT_UNLOAD_UNMAP);
6404         }
6405 
6406         if (amp == NULL || svd->type == MAP_SHARED) {
6407                 seg->s_szc = 0;
6408                 return (0);
6409         }
6410 
6411         pgsz = page_get_pagesize(seg->s_szc);
6412         pages = btop(pgsz);
6413 
6414         /*
6415          * XXX anon rwlock is not really needed because this is a
6416          * private segment and we are writers.
6417          */
6418         ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6419 
6420         for (; a < ea; a += pgsz, an_idx += pages) {
6421                 if ((oldap = anon_get_ptr(amp->ahp, an_idx)) != NULL) {
6422                         ASSERT(vpage != NULL || svd->pageprot == 0);
6423                         if (vpage != NULL) {
6424                                 ASSERT(sameprot(seg, a, pgsz));
6425                                 prot = VPP_PROT(vpage);
6426                                 pageflag = VPP_ISPPLOCK(vpage) ? LOCK_PAGE : 0;
6427                         }
6428                         if (seg->s_szc != 0) {
6429                                 ASSERT(vp == NULL || anon_pages(amp->ahp,
6430                                     an_idx, pages) == pages);
6431                                 if ((err = anon_map_demotepages(amp, an_idx,
6432                                     seg, a, prot, vpage, svd->cred)) != 0) {
6433                                         goto out;
6434                                 }
6435                         } else {
6436                                 if (oldap->an_refcnt == 1) {
6437                                         continue;
6438                                 }
6439                                 if ((err = anon_getpage(&oldap, &vpprot,
6440                                     anon_pl, PAGESIZE, seg, a, S_READ,
6441                                     svd->cred))) {
6442                                         goto out;
6443                                 }
6444                                 if ((pp = anon_private(&ap, seg, a, prot,
6445                                     anon_pl[0], pageflag, svd->cred)) == NULL) {
6446                                         err = ENOMEM;
6447                                         goto out;
6448                                 }
6449                                 anon_decref(oldap);
6450                                 (void) anon_set_ptr(amp->ahp, an_idx, ap,
6451                                     ANON_SLEEP);
6452                                 page_unlock(pp);
6453                         }
6454                 }
6455                 vpage = (vpage == NULL) ? NULL : vpage + pages;
6456         }
6457 
6458         amp->a_szc = 0;
6459         seg->s_szc = 0;
6460 out:
6461         ANON_LOCK_EXIT(&amp->a_rwlock);
6462         return (err);
6463 }
6464 
6465 static int
6466 segvn_claim_pages(
6467         struct seg *seg,
6468         struct vpage *svp,
6469         u_offset_t off,
6470         ulong_t anon_idx,
6471         uint_t prot)
6472 {
6473         pgcnt_t pgcnt = page_get_pagecnt(seg->s_szc);
6474         size_t ppasize = (pgcnt + 1) * sizeof (page_t *);
6475         page_t  **ppa;
6476         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6477         struct anon_map *amp = svd->amp;
6478         struct vpage *evp = svp + pgcnt;
6479         caddr_t addr = ((uintptr_t)(svp - svd->vpage) << PAGESHIFT)
6480             + seg->s_base;
6481         struct anon *ap;
6482         struct vnode *vp = svd->vp;
6483         page_t *pp;
6484         pgcnt_t pg_idx, i;
6485         int err = 0;
6486         anoff_t aoff;
6487         int anon = (amp != NULL) ? 1 : 0;
6488 
6489         ASSERT(svd->type == MAP_PRIVATE);
6490         ASSERT(svd->vpage != NULL);
6491         ASSERT(seg->s_szc != 0);
6492         ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
6493         ASSERT(amp == NULL || IS_P2ALIGNED(anon_idx, pgcnt));
6494         ASSERT(sameprot(seg, addr, pgcnt << PAGESHIFT));
6495 
6496         if (VPP_PROT(svp) == prot)
6497                 return (1);
6498         if (!((VPP_PROT(svp) ^ prot) & PROT_WRITE))
6499                 return (1);
6500 
6501         ppa = kmem_alloc(ppasize, KM_SLEEP);
6502         if (anon && vp != NULL) {
6503                 if (anon_get_ptr(amp->ahp, anon_idx) == NULL) {
6504                         anon = 0;
6505                         ASSERT(!anon_pages(amp->ahp, anon_idx, pgcnt));
6506                 }
6507                 ASSERT(!anon ||
6508                     anon_pages(amp->ahp, anon_idx, pgcnt) == pgcnt);
6509         }
6510 
6511         for (*ppa = NULL, pg_idx = 0; svp < evp; svp++, anon_idx++) {
6512                 if (!VPP_ISPPLOCK(svp))
6513                         continue;
6514                 if (anon) {
6515                         ap = anon_get_ptr(amp->ahp, anon_idx);
6516                         if (ap == NULL) {
6517                                 panic("segvn_claim_pages: no anon slot");
6518                         }
6519                         swap_xlate(ap, &vp, &aoff);
6520                         off = (u_offset_t)aoff;
6521                 }
6522                 ASSERT(vp != NULL);
6523                 if ((pp = page_lookup(vp,
6524                     (u_offset_t)off, SE_SHARED)) == NULL) {
6525                         panic("segvn_claim_pages: no page");
6526                 }
6527                 ppa[pg_idx++] = pp;
6528                 off += PAGESIZE;
6529         }
6530 
6531         if (ppa[0] == NULL) {
6532                 kmem_free(ppa, ppasize);
6533                 return (1);
6534         }
6535 
6536         ASSERT(pg_idx <= pgcnt);
6537         ppa[pg_idx] = NULL;
6538 
6539 
6540         /* Find each large page within ppa, and adjust its claim */
6541 
6542         /* Does ppa cover a single large page? */
6543         if (ppa[0]->p_szc == seg->s_szc) {
6544                 if (prot & PROT_WRITE)
6545                         err = page_addclaim_pages(ppa);
6546                 else
6547                         err = page_subclaim_pages(ppa);
6548         } else {
6549                 for (i = 0; ppa[i]; i += pgcnt) {
6550                         ASSERT(IS_P2ALIGNED(page_pptonum(ppa[i]), pgcnt));
6551                         if (prot & PROT_WRITE)
6552                                 err = page_addclaim_pages(&ppa[i]);
6553                         else
6554                                 err = page_subclaim_pages(&ppa[i]);
6555                         if (err == 0)
6556                                 break;
6557                 }
6558         }
6559 
6560         for (i = 0; i < pg_idx; i++) {
6561                 ASSERT(ppa[i] != NULL);
6562                 page_unlock(ppa[i]);
6563         }
6564 
6565         kmem_free(ppa, ppasize);
6566         return (err);
6567 }
6568 
6569 /*
6570  * Returns right (upper address) segment if split occurred.
6571  * If the address is equal to the beginning or end of its segment it returns
6572  * the current segment.
6573  */
6574 static struct seg *
6575 segvn_split_seg(struct seg *seg, caddr_t addr)
6576 {
6577         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6578         struct seg *nseg;
6579         size_t nsize;
6580         struct segvn_data *nsvd;
6581 
6582         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6583         ASSERT(svd->tr_state == SEGVN_TR_OFF);
6584 
6585         ASSERT(addr >= seg->s_base);
6586         ASSERT(addr <= seg->s_base + seg->s_size);
6587         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6588 
6589         if (addr == seg->s_base || addr == seg->s_base + seg->s_size)
6590                 return (seg);
6591 
6592         nsize = seg->s_base + seg->s_size - addr;
6593         seg->s_size = addr - seg->s_base;
6594         nseg = seg_alloc(seg->s_as, addr, nsize);
6595         ASSERT(nseg != NULL);
6596         nseg->s_ops = seg->s_ops;
6597         nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
6598         nseg->s_data = (void *)nsvd;
6599         nseg->s_szc = seg->s_szc;
6600         *nsvd = *svd;
6601         ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6602         nsvd->seg = nseg;
6603         rw_init(&nsvd->lock, NULL, RW_DEFAULT, NULL);
6604 
6605         if (nsvd->vp != NULL) {
6606                 VN_HOLD(nsvd->vp);
6607                 nsvd->offset = svd->offset +
6608                     (uintptr_t)(nseg->s_base - seg->s_base);
6609                 if (nsvd->type == MAP_SHARED)
6610                         lgrp_shm_policy_init(NULL, nsvd->vp);
6611         } else {
6612                 /*
6613                  * The offset for an anonymous segment has no signifigance in
6614                  * terms of an offset into a file. If we were to use the above
6615                  * calculation instead, the structures read out of
6616                  * /proc/<pid>/xmap would be more difficult to decipher since
6617                  * it would be unclear whether two seemingly contiguous
6618                  * prxmap_t structures represented different segments or a
6619                  * single segment that had been split up into multiple prxmap_t
6620                  * structures (e.g. if some part of the segment had not yet
6621                  * been faulted in).
6622                  */
6623                 nsvd->offset = 0;
6624         }
6625 
6626         ASSERT(svd->softlockcnt == 0);
6627         ASSERT(svd->softlockcnt_sbase == 0);
6628         ASSERT(svd->softlockcnt_send == 0);
6629         crhold(svd->cred);
6630 
6631         if (svd->vpage != NULL) {
6632                 size_t bytes = vpgtob(seg_pages(seg));
6633                 size_t nbytes = vpgtob(seg_pages(nseg));
6634                 struct vpage *ovpage = svd->vpage;
6635 
6636                 svd->vpage = kmem_alloc(bytes, KM_SLEEP);
6637                 bcopy(ovpage, svd->vpage, bytes);
6638                 nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
6639                 bcopy(ovpage + seg_pages(seg), nsvd->vpage, nbytes);
6640                 kmem_free(ovpage, bytes + nbytes);
6641         }
6642         if (svd->amp != NULL && svd->type == MAP_PRIVATE) {
6643                 struct anon_map *oamp = svd->amp, *namp;
6644                 struct anon_hdr *nahp;
6645 
6646                 ANON_LOCK_ENTER(&oamp->a_rwlock, RW_WRITER);
6647                 ASSERT(oamp->refcnt == 1);
6648                 nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
6649                 (void) anon_copy_ptr(oamp->ahp, svd->anon_index,
6650                     nahp, 0, btop(seg->s_size), ANON_SLEEP);
6651 
6652                 namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
6653                 namp->a_szc = nseg->s_szc;
6654                 (void) anon_copy_ptr(oamp->ahp,
6655                     svd->anon_index + btop(seg->s_size),
6656                     namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
6657                 anon_release(oamp->ahp, btop(oamp->size));
6658                 oamp->ahp = nahp;
6659                 oamp->size = seg->s_size;
6660                 svd->anon_index = 0;
6661                 nsvd->amp = namp;
6662                 nsvd->anon_index = 0;
6663                 ANON_LOCK_EXIT(&oamp->a_rwlock);
6664         } else if (svd->amp != NULL) {
6665                 pgcnt_t pgcnt = page_get_pagecnt(seg->s_szc);
6666                 ASSERT(svd->amp == nsvd->amp);
6667                 ASSERT(seg->s_szc <= svd->amp->a_szc);
6668                 nsvd->anon_index = svd->anon_index + seg_pages(seg);
6669                 ASSERT(IS_P2ALIGNED(nsvd->anon_index, pgcnt));
6670                 ANON_LOCK_ENTER(&svd->amp->a_rwlock, RW_WRITER);
6671                 svd->amp->refcnt++;
6672                 ANON_LOCK_EXIT(&svd->amp->a_rwlock);
6673         }
6674 
6675         /*
6676          * Split the amount of swap reserved.
6677          */
6678         if (svd->swresv) {
6679                 /*
6680                  * For MAP_NORESERVE, only allocate swap reserve for pages
6681                  * being used.  Other segments get enough to cover whole
6682                  * segment.
6683                  */
6684                 if (svd->flags & MAP_NORESERVE) {
6685                         size_t  oswresv;
6686 
6687                         ASSERT(svd->amp);
6688                         oswresv = svd->swresv;
6689                         svd->swresv = ptob(anon_pages(svd->amp->ahp,
6690                             svd->anon_index, btop(seg->s_size)));
6691                         nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
6692                             nsvd->anon_index, btop(nseg->s_size)));
6693                         ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
6694                 } else {
6695                         if (svd->pageswap) {
6696                                 svd->swresv = segvn_count_swap_by_vpages(seg);
6697                                 ASSERT(nsvd->swresv >= svd->swresv);
6698                                 nsvd->swresv -= svd->swresv;
6699                         } else {
6700                                 ASSERT(svd->swresv == seg->s_size +
6701                                     nseg->s_size);
6702                                 svd->swresv = seg->s_size;
6703                                 nsvd->swresv = nseg->s_size;
6704                         }
6705                 }
6706         }
6707 
6708         return (nseg);
6709 }
6710 
6711 /*
6712  * called on memory operations (unmap, setprot, setpagesize) for a subset
6713  * of a large page segment to either demote the memory range (SDR_RANGE)
6714  * or the ends (SDR_END) by addr/len.
6715  *
6716  * returns 0 on success. returns errno, including ENOMEM, on failure.
6717  */
6718 static int
6719 segvn_demote_range(
6720         struct seg *seg,
6721         caddr_t addr,
6722         size_t len,
6723         int flag,
6724         uint_t szcvec)
6725 {
6726         caddr_t eaddr = addr + len;
6727         caddr_t lpgaddr, lpgeaddr;
6728         struct seg *nseg;
6729         struct seg *badseg1 = NULL;
6730         struct seg *badseg2 = NULL;
6731         size_t pgsz;
6732         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6733         int err;
6734         uint_t szc = seg->s_szc;
6735         uint_t tszcvec;
6736 
6737         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6738         ASSERT(svd->tr_state == SEGVN_TR_OFF);
6739         ASSERT(szc != 0);
6740         pgsz = page_get_pagesize(szc);
6741         ASSERT(seg->s_base != addr || seg->s_size != len);
6742         ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6743         ASSERT(svd->softlockcnt == 0);
6744         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6745         ASSERT(szcvec == 0 || (flag == SDR_END && svd->type == MAP_SHARED));
6746 
6747         CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
6748         ASSERT(flag == SDR_RANGE || eaddr < lpgeaddr || addr > lpgaddr);
6749         if (flag == SDR_RANGE) {
6750                 /* demote entire range */
6751                 badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6752                 (void) segvn_split_seg(nseg, lpgeaddr);
6753                 ASSERT(badseg1->s_base == lpgaddr);
6754                 ASSERT(badseg1->s_size == lpgeaddr - lpgaddr);
6755         } else if (addr != lpgaddr) {
6756                 ASSERT(flag == SDR_END);
6757                 badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6758                 if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz &&
6759                     eaddr < lpgaddr + 2 * pgsz) {
6760                         (void) segvn_split_seg(nseg, lpgeaddr);
6761                         ASSERT(badseg1->s_base == lpgaddr);
6762                         ASSERT(badseg1->s_size == 2 * pgsz);
6763                 } else {
6764                         nseg = segvn_split_seg(nseg, lpgaddr + pgsz);
6765                         ASSERT(badseg1->s_base == lpgaddr);
6766                         ASSERT(badseg1->s_size == pgsz);
6767                         if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz) {
6768                                 ASSERT(lpgeaddr - lpgaddr > 2 * pgsz);
6769                                 nseg = segvn_split_seg(nseg, lpgeaddr - pgsz);
6770                                 badseg2 = nseg;
6771                                 (void) segvn_split_seg(nseg, lpgeaddr);
6772                                 ASSERT(badseg2->s_base == lpgeaddr - pgsz);
6773                                 ASSERT(badseg2->s_size == pgsz);
6774                         }
6775                 }
6776         } else {
6777                 ASSERT(flag == SDR_END);
6778                 ASSERT(eaddr < lpgeaddr);
6779                 badseg1 = nseg = segvn_split_seg(seg, lpgeaddr - pgsz);
6780                 (void) segvn_split_seg(nseg, lpgeaddr);
6781                 ASSERT(badseg1->s_base == lpgeaddr - pgsz);
6782                 ASSERT(badseg1->s_size == pgsz);
6783         }
6784 
6785         ASSERT(badseg1 != NULL);
6786         ASSERT(badseg1->s_szc == szc);
6787         ASSERT(flag == SDR_RANGE || badseg1->s_size == pgsz ||
6788             badseg1->s_size == 2 * pgsz);
6789         ASSERT(sameprot(badseg1, badseg1->s_base, pgsz));
6790         ASSERT(badseg1->s_size == pgsz ||
6791             sameprot(badseg1, badseg1->s_base + pgsz, pgsz));
6792         if (err = segvn_clrszc(badseg1)) {
6793                 return (err);
6794         }
6795         ASSERT(badseg1->s_szc == 0);
6796 
6797         if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6798                 uint_t tszc = highbit(tszcvec) - 1;
6799                 caddr_t ta = MAX(addr, badseg1->s_base);
6800                 caddr_t te;
6801                 size_t tpgsz = page_get_pagesize(tszc);
6802 
6803                 ASSERT(svd->type == MAP_SHARED);
6804                 ASSERT(flag == SDR_END);
6805                 ASSERT(tszc < szc && tszc > 0);
6806 
6807                 if (eaddr > badseg1->s_base + badseg1->s_size) {
6808                         te = badseg1->s_base + badseg1->s_size;
6809                 } else {
6810                         te = eaddr;
6811                 }
6812 
6813                 ASSERT(ta <= te);
6814                 badseg1->s_szc = tszc;
6815                 if (!IS_P2ALIGNED(ta, tpgsz) || !IS_P2ALIGNED(te, tpgsz)) {
6816                         if (badseg2 != NULL) {
6817                                 err = segvn_demote_range(badseg1, ta, te - ta,
6818                                     SDR_END, tszcvec);
6819                                 if (err != 0) {
6820                                         return (err);
6821                                 }
6822                         } else {
6823                                 return (segvn_demote_range(badseg1, ta,
6824                                     te - ta, SDR_END, tszcvec));
6825                         }
6826                 }
6827         }
6828 
6829         if (badseg2 == NULL)
6830                 return (0);
6831         ASSERT(badseg2->s_szc == szc);
6832         ASSERT(badseg2->s_size == pgsz);
6833         ASSERT(sameprot(badseg2, badseg2->s_base, badseg2->s_size));
6834         if (err = segvn_clrszc(badseg2)) {
6835                 return (err);
6836         }
6837         ASSERT(badseg2->s_szc == 0);
6838 
6839         if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6840                 uint_t tszc = highbit(tszcvec) - 1;
6841                 size_t tpgsz = page_get_pagesize(tszc);
6842 
6843                 ASSERT(svd->type == MAP_SHARED);
6844                 ASSERT(flag == SDR_END);
6845                 ASSERT(tszc < szc && tszc > 0);
6846                 ASSERT(badseg2->s_base > addr);
6847                 ASSERT(eaddr > badseg2->s_base);
6848                 ASSERT(eaddr < badseg2->s_base + badseg2->s_size);
6849 
6850                 badseg2->s_szc = tszc;
6851                 if (!IS_P2ALIGNED(eaddr, tpgsz)) {
6852                         return (segvn_demote_range(badseg2, badseg2->s_base,
6853                             eaddr - badseg2->s_base, SDR_END, tszcvec));
6854                 }
6855         }
6856 
6857         return (0);
6858 }
6859 
6860 static int
6861 segvn_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
6862 {
6863         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6864         struct vpage *vp, *evp;
6865 
6866         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6867 
6868         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6869         /*
6870          * If segment protection can be used, simply check against them.
6871          */
6872         if (svd->pageprot == 0) {
6873                 int err;
6874 
6875                 err = ((svd->prot & prot) != prot) ? EACCES : 0;
6876                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6877                 return (err);
6878         }
6879 
6880         /*
6881          * Have to check down to the vpage level.
6882          */
6883         evp = &svd->vpage[seg_page(seg, addr + len)];
6884         for (vp = &svd->vpage[seg_page(seg, addr)]; vp < evp; vp++) {
6885                 if ((VPP_PROT(vp) & prot) != prot) {
6886                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6887                         return (EACCES);
6888                 }
6889         }
6890         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6891         return (0);
6892 }
6893 
6894 static int
6895 segvn_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
6896 {
6897         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6898         size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
6899 
6900         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6901 
6902         if (pgno != 0) {
6903                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6904                 if (svd->pageprot == 0) {
6905                         do {
6906                                 protv[--pgno] = svd->prot;
6907                         } while (pgno != 0);
6908                 } else {
6909                         size_t pgoff = seg_page(seg, addr);
6910 
6911                         do {
6912                                 pgno--;
6913                                 protv[pgno] = VPP_PROT(&svd->vpage[pgno+pgoff]);
6914                         } while (pgno != 0);
6915                 }
6916                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6917         }
6918         return (0);
6919 }
6920 
6921 static u_offset_t
6922 segvn_getoffset(struct seg *seg, caddr_t addr)
6923 {
6924         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6925 
6926         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6927 
6928         return (svd->offset + (uintptr_t)(addr - seg->s_base));
6929 }
6930 
6931 /*ARGSUSED*/
6932 static int
6933 segvn_gettype(struct seg *seg, caddr_t addr)
6934 {
6935         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6936 
6937         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6938 
6939         return (svd->type | (svd->flags & (MAP_NORESERVE | MAP_TEXT |
6940             MAP_INITDATA)));
6941 }
6942 
6943 /*ARGSUSED*/
6944 static int
6945 segvn_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
6946 {
6947         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6948 
6949         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6950 
6951         *vpp = svd->vp;
6952         return (0);
6953 }
6954 
6955 /*
6956  * Check to see if it makes sense to do kluster/read ahead to
6957  * addr + delta relative to the mapping at addr.  We assume here
6958  * that delta is a signed PAGESIZE'd multiple (which can be negative).
6959  *
6960  * For segvn, we currently "approve" of the action if we are
6961  * still in the segment and it maps from the same vp/off,
6962  * or if the advice stored in segvn_data or vpages allows it.
6963  * Currently, klustering is not allowed only if MADV_RANDOM is set.
6964  */
6965 static int
6966 segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta)
6967 {
6968         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6969         struct anon *oap, *ap;
6970         ssize_t pd;
6971         size_t page;
6972         struct vnode *vp1, *vp2;
6973         u_offset_t off1, off2;
6974         struct anon_map *amp;
6975 
6976         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6977         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6978             SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
6979 
6980         if (addr + delta < seg->s_base ||
6981             addr + delta >= (seg->s_base + seg->s_size))
6982                 return (-1);            /* exceeded segment bounds */
6983 
6984         pd = delta / (ssize_t)PAGESIZE; /* divide to preserve sign bit */
6985         page = seg_page(seg, addr);
6986 
6987         /*
6988          * Check to see if either of the pages addr or addr + delta
6989          * have advice set that prevents klustering (if MADV_RANDOM advice
6990          * is set for entire segment, or MADV_SEQUENTIAL is set and delta
6991          * is negative).
6992          */
6993         if (svd->advice == MADV_RANDOM ||
6994             svd->advice == MADV_SEQUENTIAL && delta < 0)
6995                 return (-1);
6996         else if (svd->pageadvice && svd->vpage) {
6997                 struct vpage *bvpp, *evpp;
6998 
6999                 bvpp = &svd->vpage[page];
7000                 evpp = &svd->vpage[page + pd];
7001                 if (VPP_ADVICE(bvpp) == MADV_RANDOM ||
7002                     VPP_ADVICE(evpp) == MADV_SEQUENTIAL && delta < 0)
7003                         return (-1);
7004                 if (VPP_ADVICE(bvpp) != VPP_ADVICE(evpp) &&
7005                     VPP_ADVICE(evpp) == MADV_RANDOM)
7006                         return (-1);
7007         }
7008 
7009         if (svd->type == MAP_SHARED)
7010                 return (0);             /* shared mapping - all ok */
7011 
7012         if ((amp = svd->amp) == NULL)
7013                 return (0);             /* off original vnode */
7014 
7015         page += svd->anon_index;
7016 
7017         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7018 
7019         oap = anon_get_ptr(amp->ahp, page);
7020         ap = anon_get_ptr(amp->ahp, page + pd);
7021 
7022         ANON_LOCK_EXIT(&amp->a_rwlock);
7023 
7024         if ((oap == NULL && ap != NULL) || (oap != NULL && ap == NULL)) {
7025                 return (-1);            /* one with and one without an anon */
7026         }
7027 
7028         if (oap == NULL) {              /* implies that ap == NULL */
7029                 return (0);             /* off original vnode */
7030         }
7031 
7032         /*
7033          * Now we know we have two anon pointers - check to
7034          * see if they happen to be properly allocated.
7035          */
7036 
7037         /*
7038          * XXX We cheat here and don't lock the anon slots. We can't because
7039          * we may have been called from the anon layer which might already
7040          * have locked them. We are holding a refcnt on the slots so they
7041          * can't disappear. The worst that will happen is we'll get the wrong
7042          * names (vp, off) for the slots and make a poor klustering decision.
7043          */
7044         swap_xlate(ap, &vp1, &off1);
7045         swap_xlate(oap, &vp2, &off2);
7046 
7047 
7048         if (!VOP_CMP(vp1, vp2, NULL) || off1 - off2 != delta)
7049                 return (-1);
7050         return (0);
7051 }
7052 
7053 /*
7054  * Swap the pages of seg out to secondary storage, returning the
7055  * number of bytes of storage freed.
7056  *
7057  * The basic idea is first to unload all translations and then to call
7058  * VOP_PUTPAGE() for all newly-unmapped pages, to push them out to the
7059  * swap device.  Pages to which other segments have mappings will remain
7060  * mapped and won't be swapped.  Our caller (as_swapout) has already
7061  * performed the unloading step.
7062  *
7063  * The value returned is intended to correlate well with the process's
7064  * memory requirements.  However, there are some caveats:
7065  * 1)   When given a shared segment as argument, this routine will
7066  *      only succeed in swapping out pages for the last sharer of the
7067  *      segment.  (Previous callers will only have decremented mapping
7068  *      reference counts.)
7069  * 2)   We assume that the hat layer maintains a large enough translation
7070  *      cache to capture process reference patterns.
7071  */
7072 static size_t
7073 segvn_swapout(struct seg *seg)
7074 {
7075         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7076         struct anon_map *amp;
7077         pgcnt_t pgcnt = 0;
7078         pgcnt_t npages;
7079         pgcnt_t page;
7080         ulong_t anon_index;
7081 
7082         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7083 
7084         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7085         /*
7086          * Find pages unmapped by our caller and force them
7087          * out to the virtual swap device.
7088          */
7089         if ((amp = svd->amp) != NULL)
7090                 anon_index = svd->anon_index;
7091         npages = seg->s_size >> PAGESHIFT;
7092         for (page = 0; page < npages; page++) {
7093                 page_t *pp;
7094                 struct anon *ap;
7095                 struct vnode *vp;
7096                 u_offset_t off;
7097                 anon_sync_obj_t cookie;
7098 
7099                 /*
7100                  * Obtain <vp, off> pair for the page, then look it up.
7101                  *
7102                  * Note that this code is willing to consider regular
7103                  * pages as well as anon pages.  Is this appropriate here?
7104                  */
7105                 ap = NULL;
7106                 if (amp != NULL) {
7107                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7108                         if (anon_array_try_enter(amp, anon_index + page,
7109                             &cookie)) {
7110                                 ANON_LOCK_EXIT(&amp->a_rwlock);
7111                                 continue;
7112                         }
7113                         ap = anon_get_ptr(amp->ahp, anon_index + page);
7114                         if (ap != NULL) {
7115                                 swap_xlate(ap, &vp, &off);
7116                         } else {
7117                                 vp = svd->vp;
7118                                 off = svd->offset + ptob(page);
7119                         }
7120                         anon_array_exit(&cookie);
7121                         ANON_LOCK_EXIT(&amp->a_rwlock);
7122                 } else {
7123                         vp = svd->vp;
7124                         off = svd->offset + ptob(page);
7125                 }
7126                 if (vp == NULL) {               /* untouched zfod page */
7127                         ASSERT(ap == NULL);
7128                         continue;
7129                 }
7130 
7131                 pp = page_lookup_nowait(vp, off, SE_SHARED);
7132                 if (pp == NULL)
7133                         continue;
7134 
7135 
7136                 /*
7137                  * Examine the page to see whether it can be tossed out,
7138                  * keeping track of how many we've found.
7139                  */
7140                 if (!page_tryupgrade(pp)) {
7141                         /*
7142                          * If the page has an i/o lock and no mappings,
7143                          * it's very likely that the page is being
7144                          * written out as a result of klustering.
7145                          * Assume this is so and take credit for it here.
7146                          */
7147                         if (!page_io_trylock(pp)) {
7148                                 if (!hat_page_is_mapped(pp))
7149                                         pgcnt++;
7150                         } else {
7151                                 page_io_unlock(pp);
7152                         }
7153                         page_unlock(pp);
7154                         continue;
7155                 }
7156                 ASSERT(!page_iolock_assert(pp));
7157 
7158 
7159                 /*
7160                  * Skip if page is locked or has mappings.
7161                  * We don't need the page_struct_lock to look at lckcnt
7162                  * and cowcnt because the page is exclusive locked.
7163                  */
7164                 if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0 ||
7165                     hat_page_is_mapped(pp)) {
7166                         page_unlock(pp);
7167                         continue;
7168                 }
7169 
7170                 /*
7171                  * dispose skips large pages so try to demote first.
7172                  */
7173                 if (pp->p_szc != 0 && !page_try_demote_pages(pp)) {
7174                         page_unlock(pp);
7175                         /*
7176                          * XXX should skip the remaining page_t's of this
7177                          * large page.
7178                          */
7179                         continue;
7180                 }
7181 
7182                 ASSERT(pp->p_szc == 0);
7183 
7184                 /*
7185                  * No longer mapped -- we can toss it out.  How
7186                  * we do so depends on whether or not it's dirty.
7187                  */
7188                 if (hat_ismod(pp) && pp->p_vnode) {
7189                         /*
7190                          * We must clean the page before it can be
7191                          * freed.  Setting B_FREE will cause pvn_done
7192                          * to free the page when the i/o completes.
7193                          * XXX: This also causes it to be accounted
7194                          *      as a pageout instead of a swap: need
7195                          *      B_SWAPOUT bit to use instead of B_FREE.
7196                          *
7197                          * Hold the vnode before releasing the page lock
7198                          * to prevent it from being freed and re-used by
7199                          * some other thread.
7200                          */
7201                         VN_HOLD(vp);
7202                         page_unlock(pp);
7203 
7204                         /*
7205                          * Queue all i/o requests for the pageout thread
7206                          * to avoid saturating the pageout devices.
7207                          */
7208                         if (!queue_io_request(vp, off))
7209                                 VN_RELE(vp);
7210                 } else {
7211                         /*
7212                          * The page was clean, free it.
7213                          *
7214                          * XXX: Can we ever encounter modified pages
7215                          *      with no associated vnode here?
7216                          */
7217                         ASSERT(pp->p_vnode != NULL);
7218                         /*LINTED: constant in conditional context*/
7219                         VN_DISPOSE(pp, B_FREE, 0, kcred);
7220                 }
7221 
7222                 /*
7223                  * Credit now even if i/o is in progress.
7224                  */
7225                 pgcnt++;
7226         }
7227         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7228 
7229         /*
7230          * Wakeup pageout to initiate i/o on all queued requests.
7231          */
7232         cv_signal_pageout();
7233         return (ptob(pgcnt));
7234 }
7235 
7236 /*
7237  * Synchronize primary storage cache with real object in virtual memory.
7238  *
7239  * XXX - Anonymous pages should not be sync'ed out at all.
7240  */
7241 static int
7242 segvn_sync(struct seg *seg, caddr_t addr, size_t len, int attr, uint_t flags)
7243 {
7244         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7245         struct vpage *vpp;
7246         page_t *pp;
7247         u_offset_t offset;
7248         struct vnode *vp;
7249         u_offset_t off;
7250         caddr_t eaddr;
7251         int bflags;
7252         int err = 0;
7253         int segtype;
7254         int pageprot;
7255         int prot;
7256         ulong_t anon_index;
7257         struct anon_map *amp;
7258         struct anon *ap;
7259         anon_sync_obj_t cookie;
7260 
7261         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7262 
7263         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7264 
7265         if (svd->softlockcnt > 0) {
7266                 /*
7267                  * If this is shared segment non 0 softlockcnt
7268                  * means locked pages are still in use.
7269                  */
7270                 if (svd->type == MAP_SHARED) {
7271                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7272                         return (EAGAIN);
7273                 }
7274 
7275                 /*
7276                  * flush all pages from seg cache
7277                  * otherwise we may deadlock in swap_putpage
7278                  * for B_INVAL page (4175402).
7279                  *
7280                  * Even if we grab segvn WRITER's lock
7281                  * here, there might be another thread which could've
7282                  * successfully performed lookup/insert just before
7283                  * we acquired the lock here.  So, grabbing either
7284                  * lock here is of not much use.  Until we devise
7285                  * a strategy at upper layers to solve the
7286                  * synchronization issues completely, we expect
7287                  * applications to handle this appropriately.
7288                  */
7289                 segvn_purge(seg);
7290                 if (svd->softlockcnt > 0) {
7291                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7292                         return (EAGAIN);
7293                 }
7294         } else if (svd->type == MAP_SHARED && svd->amp != NULL &&
7295             svd->amp->a_softlockcnt > 0) {
7296                 /*
7297                  * Try to purge this amp's entries from pcache. It will
7298                  * succeed only if other segments that share the amp have no
7299                  * outstanding softlock's.
7300                  */
7301                 segvn_purge(seg);
7302                 if (svd->amp->a_softlockcnt > 0 || svd->softlockcnt > 0) {
7303                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7304                         return (EAGAIN);
7305                 }
7306         }
7307 
7308         vpp = svd->vpage;
7309         offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7310         bflags = ((flags & MS_ASYNC) ? B_ASYNC : 0) |
7311             ((flags & MS_INVALIDATE) ? B_INVAL : 0);
7312 
7313         if (attr) {
7314                 pageprot = attr & ~(SHARED|PRIVATE);
7315                 segtype = (attr & SHARED) ? MAP_SHARED : MAP_PRIVATE;
7316 
7317                 /*
7318                  * We are done if the segment types don't match
7319                  * or if we have segment level protections and
7320                  * they don't match.
7321                  */
7322                 if (svd->type != segtype) {
7323                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7324                         return (0);
7325                 }
7326                 if (vpp == NULL) {
7327                         if (svd->prot != pageprot) {
7328                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7329                                 return (0);
7330                         }
7331                         prot = svd->prot;
7332                 } else
7333                         vpp = &svd->vpage[seg_page(seg, addr)];
7334 
7335         } else if (svd->vp && svd->amp == NULL &&
7336             (flags & MS_INVALIDATE) == 0) {
7337 
7338                 /*
7339                  * No attributes, no anonymous pages and MS_INVALIDATE flag
7340                  * is not on, just use one big request.
7341                  */
7342                 err = VOP_PUTPAGE(svd->vp, (offset_t)offset, len,
7343                     bflags, svd->cred, NULL);
7344                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7345                 return (err);
7346         }
7347 
7348         if ((amp = svd->amp) != NULL)
7349                 anon_index = svd->anon_index + seg_page(seg, addr);
7350 
7351         for (eaddr = addr + len; addr < eaddr; addr += PAGESIZE) {
7352                 ap = NULL;
7353                 if (amp != NULL) {
7354                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7355                         anon_array_enter(amp, anon_index, &cookie);
7356                         ap = anon_get_ptr(amp->ahp, anon_index++);
7357                         if (ap != NULL) {
7358                                 swap_xlate(ap, &vp, &off);
7359                         } else {
7360                                 vp = svd->vp;
7361                                 off = offset;
7362                         }
7363                         anon_array_exit(&cookie);
7364                         ANON_LOCK_EXIT(&amp->a_rwlock);
7365                 } else {
7366                         vp = svd->vp;
7367                         off = offset;
7368                 }
7369                 offset += PAGESIZE;
7370 
7371                 if (vp == NULL)         /* untouched zfod page */
7372                         continue;
7373 
7374                 if (attr) {
7375                         if (vpp) {
7376                                 prot = VPP_PROT(vpp);
7377                                 vpp++;
7378                         }
7379                         if (prot != pageprot) {
7380                                 continue;
7381                         }
7382                 }
7383 
7384                 /*
7385                  * See if any of these pages are locked --  if so, then we
7386                  * will have to truncate an invalidate request at the first
7387                  * locked one. We don't need the page_struct_lock to test
7388                  * as this is only advisory; even if we acquire it someone
7389                  * might race in and lock the page after we unlock and before
7390                  * we do the PUTPAGE, then PUTPAGE simply does nothing.
7391                  */
7392                 if (flags & MS_INVALIDATE) {
7393                         if ((pp = page_lookup(vp, off, SE_SHARED)) != NULL) {
7394                                 if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0) {
7395                                         page_unlock(pp);
7396                                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7397                                         return (EBUSY);
7398                                 }
7399                                 if (ap != NULL && pp->p_szc != 0 &&
7400                                     page_tryupgrade(pp)) {
7401                                         if (pp->p_lckcnt == 0 &&
7402                                             pp->p_cowcnt == 0) {
7403                                                 /*
7404                                                  * swapfs VN_DISPOSE() won't
7405                                                  * invalidate large pages.
7406                                                  * Attempt to demote.
7407                                                  * XXX can't help it if it
7408                                                  * fails. But for swapfs
7409                                                  * pages it is no big deal.
7410                                                  */
7411                                                 (void) page_try_demote_pages(
7412                                                     pp);
7413                                         }
7414                                 }
7415                                 page_unlock(pp);
7416                         }
7417                 } else if (svd->type == MAP_SHARED && amp != NULL) {
7418                         /*
7419                          * Avoid writing out to disk ISM's large pages
7420                          * because segspt_free_pages() relies on NULL an_pvp
7421                          * of anon slots of such pages.
7422                          */
7423 
7424                         ASSERT(svd->vp == NULL);
7425                         /*
7426                          * swapfs uses page_lookup_nowait if not freeing or
7427                          * invalidating and skips a page if
7428                          * page_lookup_nowait returns NULL.
7429                          */
7430                         pp = page_lookup_nowait(vp, off, SE_SHARED);
7431                         if (pp == NULL) {
7432                                 continue;
7433                         }
7434                         if (pp->p_szc != 0) {
7435                                 page_unlock(pp);
7436                                 continue;
7437                         }
7438 
7439                         /*
7440                          * Note ISM pages are created large so (vp, off)'s
7441                          * page cannot suddenly become large after we unlock
7442                          * pp.
7443                          */
7444                         page_unlock(pp);
7445                 }
7446                 /*
7447                  * XXX - Should ultimately try to kluster
7448                  * calls to VOP_PUTPAGE() for performance.
7449                  */
7450                 VN_HOLD(vp);
7451                 err = VOP_PUTPAGE(vp, (offset_t)off, PAGESIZE,
7452                     (bflags | (IS_SWAPFSVP(vp) ? B_PAGE_NOWAIT : 0)),
7453                     svd->cred, NULL);
7454 
7455                 VN_RELE(vp);
7456                 if (err)
7457                         break;
7458         }
7459         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7460         return (err);
7461 }
7462 
7463 /*
7464  * Determine if we have data corresponding to pages in the
7465  * primary storage virtual memory cache (i.e., "in core").
7466  */
7467 static size_t
7468 segvn_incore(struct seg *seg, caddr_t addr, size_t len, char *vec)
7469 {
7470         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7471         struct vnode *vp, *avp;
7472         u_offset_t offset, aoffset;
7473         size_t p, ep;
7474         int ret;
7475         struct vpage *vpp;
7476         page_t *pp;
7477         uint_t start;
7478         struct anon_map *amp;           /* XXX - for locknest */
7479         struct anon *ap;
7480         uint_t attr;
7481         anon_sync_obj_t cookie;
7482 
7483         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7484 
7485         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7486         if (svd->amp == NULL && svd->vp == NULL) {
7487                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7488                 bzero(vec, btopr(len));
7489                 return (len);   /* no anonymous pages created yet */
7490         }
7491 
7492         p = seg_page(seg, addr);
7493         ep = seg_page(seg, addr + len);
7494         start = svd->vp ? SEG_PAGE_VNODEBACKED : 0;
7495 
7496         amp = svd->amp;
7497         for (; p < ep; p++, addr += PAGESIZE) {
7498                 vpp = (svd->vpage) ? &svd->vpage[p]: NULL;
7499                 ret = start;
7500                 ap = NULL;
7501                 avp = NULL;
7502                 /* Grab the vnode/offset for the anon slot */
7503                 if (amp != NULL) {
7504                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7505                         anon_array_enter(amp, svd->anon_index + p, &cookie);
7506                         ap = anon_get_ptr(amp->ahp, svd->anon_index + p);
7507                         if (ap != NULL) {
7508                                 swap_xlate(ap, &avp, &aoffset);
7509                         }
7510                         anon_array_exit(&cookie);
7511                         ANON_LOCK_EXIT(&amp->a_rwlock);
7512                 }
7513                 if ((avp != NULL) && page_exists(avp, aoffset)) {
7514                         /* A page exists for the anon slot */
7515                         ret |= SEG_PAGE_INCORE;
7516 
7517                         /*
7518                          * If page is mapped and writable
7519                          */
7520                         attr = (uint_t)0;
7521                         if ((hat_getattr(seg->s_as->a_hat, addr,
7522                             &attr) != -1) && (attr & PROT_WRITE)) {
7523                                 ret |= SEG_PAGE_ANON;
7524                         }
7525                         /*
7526                          * Don't get page_struct lock for lckcnt and cowcnt,
7527                          * since this is purely advisory.
7528                          */
7529                         if ((pp = page_lookup_nowait(avp, aoffset,
7530                             SE_SHARED)) != NULL) {
7531                                 if (pp->p_lckcnt)
7532                                         ret |= SEG_PAGE_SOFTLOCK;
7533                                 if (pp->p_cowcnt)
7534                                         ret |= SEG_PAGE_HASCOW;
7535                                 page_unlock(pp);
7536                         }
7537                 }
7538 
7539                 /* Gather vnode statistics */
7540                 vp = svd->vp;
7541                 offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7542 
7543                 if (vp != NULL) {
7544                         /*
7545                          * Try to obtain a "shared" lock on the page
7546                          * without blocking.  If this fails, determine
7547                          * if the page is in memory.
7548                          */
7549                         pp = page_lookup_nowait(vp, offset, SE_SHARED);
7550                         if ((pp == NULL) && (page_exists(vp, offset))) {
7551                                 /* Page is incore, and is named */
7552                                 ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7553                         }
7554                         /*
7555                          * Don't get page_struct lock for lckcnt and cowcnt,
7556                          * since this is purely advisory.
7557                          */
7558                         if (pp != NULL) {
7559                                 ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7560                                 if (pp->p_lckcnt)
7561                                         ret |= SEG_PAGE_SOFTLOCK;
7562                                 if (pp->p_cowcnt)
7563                                         ret |= SEG_PAGE_HASCOW;
7564                                 page_unlock(pp);
7565                         }
7566                 }
7567 
7568                 /* Gather virtual page information */
7569                 if (vpp) {
7570                         if (VPP_ISPPLOCK(vpp))
7571                                 ret |= SEG_PAGE_LOCKED;
7572                         vpp++;
7573                 }
7574 
7575                 *vec++ = (char)ret;
7576         }
7577         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7578         return (len);
7579 }
7580 
7581 /*
7582  * Statement for p_cowcnts/p_lckcnts.
7583  *
7584  * p_cowcnt is updated while mlock/munlocking MAP_PRIVATE and PROT_WRITE region
7585  * irrespective of the following factors or anything else:
7586  *
7587  *      (1) anon slots are populated or not
7588  *      (2) cow is broken or not
7589  *      (3) refcnt on ap is 1 or greater than 1
7590  *
7591  * If it's not MAP_PRIVATE and PROT_WRITE, p_lckcnt is updated during mlock
7592  * and munlock.
7593  *
7594  *
7595  * Handling p_cowcnts/p_lckcnts during copy-on-write fault:
7596  *
7597  *      if vpage has PROT_WRITE
7598  *              transfer cowcnt on the oldpage -> cowcnt on the newpage
7599  *      else
7600  *              transfer lckcnt on the oldpage -> lckcnt on the newpage
7601  *
7602  *      During copy-on-write, decrement p_cowcnt on the oldpage and increment
7603  *      p_cowcnt on the newpage *if* the corresponding vpage has PROT_WRITE.
7604  *
7605  *      We may also break COW if softlocking on read access in the physio case.
7606  *      In this case, vpage may not have PROT_WRITE. So, we need to decrement
7607  *      p_lckcnt on the oldpage and increment p_lckcnt on the newpage *if* the
7608  *      vpage doesn't have PROT_WRITE.
7609  *
7610  *
7611  * Handling p_cowcnts/p_lckcnts during mprotect on mlocked region:
7612  *
7613  *      If a MAP_PRIVATE region loses PROT_WRITE, we decrement p_cowcnt and
7614  *      increment p_lckcnt by calling page_subclaim() which takes care of
7615  *      availrmem accounting and p_lckcnt overflow.
7616  *
7617  *      If a MAP_PRIVATE region gains PROT_WRITE, we decrement p_lckcnt and
7618  *      increment p_cowcnt by calling page_addclaim() which takes care of
7619  *      availrmem availability and p_cowcnt overflow.
7620  */
7621 
7622 /*
7623  * Lock down (or unlock) pages mapped by this segment.
7624  *
7625  * XXX only creates PAGESIZE pages if anon slots are not initialized.
7626  * At fault time they will be relocated into larger pages.
7627  */
7628 static int
7629 segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
7630     int attr, int op, ulong_t *lockmap, size_t pos)
7631 {
7632         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7633         struct vpage *vpp;
7634         struct vpage *evp;
7635         page_t *pp;
7636         u_offset_t offset;
7637         u_offset_t off;
7638         int segtype;
7639         int pageprot;
7640         int claim;
7641         struct vnode *vp;
7642         ulong_t anon_index;
7643         struct anon_map *amp;
7644         struct anon *ap;
7645         struct vattr va;
7646         anon_sync_obj_t cookie;
7647         struct kshmid *sp = NULL;
7648         struct proc     *p = curproc;
7649         kproject_t      *proj = NULL;
7650         int chargeproc = 1;
7651         size_t locked_bytes = 0;
7652         size_t unlocked_bytes = 0;
7653         int err = 0;
7654 
7655         /*
7656          * Hold write lock on address space because may split or concatenate
7657          * segments
7658          */
7659         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7660 
7661         /*
7662          * If this is a shm, use shm's project and zone, else use
7663          * project and zone of calling process
7664          */
7665 
7666         /* Determine if this segment backs a sysV shm */
7667         if (svd->amp != NULL && svd->amp->a_sp != NULL) {
7668                 ASSERT(svd->type == MAP_SHARED);
7669                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
7670                 sp = svd->amp->a_sp;
7671                 proj = sp->shm_perm.ipc_proj;
7672                 chargeproc = 0;
7673         }
7674 
7675         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
7676         if (attr) {
7677                 pageprot = attr & ~(SHARED|PRIVATE);
7678                 segtype = attr & SHARED ? MAP_SHARED : MAP_PRIVATE;
7679 
7680                 /*
7681                  * We are done if the segment types don't match
7682                  * or if we have segment level protections and
7683                  * they don't match.
7684                  */
7685                 if (svd->type != segtype) {
7686                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7687                         return (0);
7688                 }
7689                 if (svd->pageprot == 0 && svd->prot != pageprot) {
7690                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7691                         return (0);
7692                 }
7693         }
7694 
7695         if (op == MC_LOCK) {
7696                 if (svd->tr_state == SEGVN_TR_INIT) {
7697                         svd->tr_state = SEGVN_TR_OFF;
7698                 } else if (svd->tr_state == SEGVN_TR_ON) {
7699                         ASSERT(svd->amp != NULL);
7700                         segvn_textunrepl(seg, 0);
7701                         ASSERT(svd->amp == NULL &&
7702                             svd->tr_state == SEGVN_TR_OFF);
7703                 }
7704         }
7705 
7706         /*
7707          * If we're locking, then we must create a vpage structure if
7708          * none exists.  If we're unlocking, then check to see if there
7709          * is a vpage --  if not, then we could not have locked anything.
7710          */
7711 
7712         if ((vpp = svd->vpage) == NULL) {
7713                 if (op == MC_LOCK) {
7714                         segvn_vpage(seg);
7715                         if (svd->vpage == NULL) {
7716                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7717                                 return (ENOMEM);
7718                         }
7719                 } else {
7720                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7721                         return (0);
7722                 }
7723         }
7724 
7725         /*
7726          * The anonymous data vector (i.e., previously
7727          * unreferenced mapping to swap space) can be allocated
7728          * by lazily testing for its existence.
7729          */
7730         if (op == MC_LOCK && svd->amp == NULL && svd->vp == NULL) {
7731                 ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
7732                 svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
7733                 svd->amp->a_szc = seg->s_szc;
7734         }
7735 
7736         if ((amp = svd->amp) != NULL) {
7737                 anon_index = svd->anon_index + seg_page(seg, addr);
7738         }
7739 
7740         offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7741         evp = &svd->vpage[seg_page(seg, addr + len)];
7742 
7743         if (sp != NULL)
7744                 mutex_enter(&sp->shm_mlock);
7745 
7746         /* determine number of unlocked bytes in range for lock operation */
7747         if (op == MC_LOCK) {
7748 
7749                 if (sp == NULL) {
7750                         for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7751                             vpp++) {
7752                                 if (!VPP_ISPPLOCK(vpp))
7753                                         unlocked_bytes += PAGESIZE;
7754                         }
7755                 } else {
7756                         ulong_t         i_idx, i_edx;
7757                         anon_sync_obj_t i_cookie;
7758                         struct anon     *i_ap;
7759                         struct vnode    *i_vp;
7760                         u_offset_t      i_off;
7761 
7762                         /* Only count sysV pages once for locked memory */
7763                         i_edx = svd->anon_index + seg_page(seg, addr + len);
7764                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7765                         for (i_idx = anon_index; i_idx < i_edx; i_idx++) {
7766                                 anon_array_enter(amp, i_idx, &i_cookie);
7767                                 i_ap = anon_get_ptr(amp->ahp, i_idx);
7768                                 if (i_ap == NULL) {
7769                                         unlocked_bytes += PAGESIZE;
7770                                         anon_array_exit(&i_cookie);
7771                                         continue;
7772                                 }
7773                                 swap_xlate(i_ap, &i_vp, &i_off);
7774                                 anon_array_exit(&i_cookie);
7775                                 pp = page_lookup(i_vp, i_off, SE_SHARED);
7776                                 if (pp == NULL) {
7777                                         unlocked_bytes += PAGESIZE;
7778                                         continue;
7779                                 } else if (pp->p_lckcnt == 0)
7780                                         unlocked_bytes += PAGESIZE;
7781                                 page_unlock(pp);
7782                         }
7783                         ANON_LOCK_EXIT(&amp->a_rwlock);
7784                 }
7785 
7786                 mutex_enter(&p->p_lock);
7787                 err = rctl_incr_locked_mem(p, proj, unlocked_bytes,
7788                     chargeproc);
7789                 mutex_exit(&p->p_lock);
7790 
7791                 if (err) {
7792                         if (sp != NULL)
7793                                 mutex_exit(&sp->shm_mlock);
7794                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7795                         return (err);
7796                 }
7797         }
7798         /*
7799          * Loop over all pages in the range.  Process if we're locking and
7800          * page has not already been locked in this mapping; or if we're
7801          * unlocking and the page has been locked.
7802          */
7803         for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7804             vpp++, pos++, addr += PAGESIZE, offset += PAGESIZE, anon_index++) {
7805                 if ((attr == 0 || VPP_PROT(vpp) == pageprot) &&
7806                     ((op == MC_LOCK && !VPP_ISPPLOCK(vpp)) ||
7807                     (op == MC_UNLOCK && VPP_ISPPLOCK(vpp)))) {
7808 
7809                         if (amp != NULL)
7810                                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7811                         /*
7812                          * If this isn't a MAP_NORESERVE segment and
7813                          * we're locking, allocate anon slots if they
7814                          * don't exist.  The page is brought in later on.
7815                          */
7816                         if (op == MC_LOCK && svd->vp == NULL &&
7817                             ((svd->flags & MAP_NORESERVE) == 0) &&
7818                             amp != NULL &&
7819                             ((ap = anon_get_ptr(amp->ahp, anon_index))
7820                             == NULL)) {
7821                                 anon_array_enter(amp, anon_index, &cookie);
7822 
7823                                 if ((ap = anon_get_ptr(amp->ahp,
7824                                     anon_index)) == NULL) {
7825                                         pp = anon_zero(seg, addr, &ap,
7826                                             svd->cred);
7827                                         if (pp == NULL) {
7828                                                 anon_array_exit(&cookie);
7829                                                 ANON_LOCK_EXIT(&amp->a_rwlock);
7830                                                 err = ENOMEM;
7831                                                 goto out;
7832                                         }
7833                                         ASSERT(anon_get_ptr(amp->ahp,
7834                                             anon_index) == NULL);
7835                                         (void) anon_set_ptr(amp->ahp,
7836                                             anon_index, ap, ANON_SLEEP);
7837                                         page_unlock(pp);
7838                                 }
7839                                 anon_array_exit(&cookie);
7840                         }
7841 
7842                         /*
7843                          * Get name for page, accounting for
7844                          * existence of private copy.
7845                          */
7846                         ap = NULL;
7847                         if (amp != NULL) {
7848                                 anon_array_enter(amp, anon_index, &cookie);
7849                                 ap = anon_get_ptr(amp->ahp, anon_index);
7850                                 if (ap != NULL) {
7851                                         swap_xlate(ap, &vp, &off);
7852                                 } else {
7853                                         if (svd->vp == NULL &&
7854                                             (svd->flags & MAP_NORESERVE)) {
7855                                                 anon_array_exit(&cookie);
7856                                                 ANON_LOCK_EXIT(&amp->a_rwlock);
7857                                                 continue;
7858                                         }
7859                                         vp = svd->vp;
7860                                         off = offset;
7861                                 }
7862                                 if (op != MC_LOCK || ap == NULL) {
7863                                         anon_array_exit(&cookie);
7864                                         ANON_LOCK_EXIT(&amp->a_rwlock);
7865                                 }
7866                         } else {
7867                                 vp = svd->vp;
7868                                 off = offset;
7869                         }
7870 
7871                         /*
7872                          * Get page frame.  It's ok if the page is
7873                          * not available when we're unlocking, as this
7874                          * may simply mean that a page we locked got
7875                          * truncated out of existence after we locked it.
7876                          *
7877                          * Invoke VOP_GETPAGE() to obtain the page struct
7878                          * since we may need to read it from disk if its
7879                          * been paged out.
7880                          */
7881                         if (op != MC_LOCK)
7882                                 pp = page_lookup(vp, off, SE_SHARED);
7883                         else {
7884                                 page_t *pl[1 + 1];
7885                                 int error;
7886 
7887                                 ASSERT(vp != NULL);
7888 
7889                                 error = VOP_GETPAGE(vp, (offset_t)off, PAGESIZE,
7890                                     (uint_t *)NULL, pl, PAGESIZE, seg, addr,
7891                                     S_OTHER, svd->cred, NULL);
7892 
7893                                 if (error && ap != NULL) {
7894                                         anon_array_exit(&cookie);
7895                                         ANON_LOCK_EXIT(&amp->a_rwlock);
7896                                 }
7897 
7898                                 /*
7899                                  * If the error is EDEADLK then we must bounce
7900                                  * up and drop all vm subsystem locks and then
7901                                  * retry the operation later
7902                                  * This behavior is a temporary measure because
7903                                  * ufs/sds logging is badly designed and will
7904                                  * deadlock if we don't allow this bounce to
7905                                  * happen.  The real solution is to re-design
7906                                  * the logging code to work properly.  See bug
7907                                  * 4125102 for details of the problem.
7908                                  */
7909                                 if (error == EDEADLK) {
7910                                         err = error;
7911                                         goto out;
7912                                 }
7913                                 /*
7914                                  * Quit if we fail to fault in the page.  Treat
7915                                  * the failure as an error, unless the addr
7916                                  * is mapped beyond the end of a file.
7917                                  */
7918                                 if (error && svd->vp) {
7919                                         va.va_mask = AT_SIZE;
7920                                         if (VOP_GETATTR(svd->vp, &va, 0,
7921                                             svd->cred, NULL) != 0) {
7922                                                 err = EIO;
7923                                                 goto out;
7924                                         }
7925                                         if (btopr(va.va_size) >=
7926                                             btopr(off + 1)) {
7927                                                 err = EIO;
7928                                                 goto out;
7929                                         }
7930                                         goto out;
7931 
7932                                 } else if (error) {
7933                                         err = EIO;
7934                                         goto out;
7935                                 }
7936                                 pp = pl[0];
7937                                 ASSERT(pp != NULL);
7938                         }
7939 
7940                         /*
7941                          * See Statement at the beginning of this routine.
7942                          *
7943                          * claim is always set if MAP_PRIVATE and PROT_WRITE
7944                          * irrespective of following factors:
7945                          *
7946                          * (1) anon slots are populated or not
7947                          * (2) cow is broken or not
7948                          * (3) refcnt on ap is 1 or greater than 1
7949                          *
7950                          * See 4140683 for details
7951                          */
7952                         claim = ((VPP_PROT(vpp) & PROT_WRITE) &&
7953                             (svd->type == MAP_PRIVATE));
7954 
7955                         /*
7956                          * Perform page-level operation appropriate to
7957                          * operation.  If locking, undo the SOFTLOCK
7958                          * performed to bring the page into memory
7959                          * after setting the lock.  If unlocking,
7960                          * and no page was found, account for the claim
7961                          * separately.
7962                          */
7963                         if (op == MC_LOCK) {
7964                                 int ret = 1;    /* Assume success */
7965 
7966                                 ASSERT(!VPP_ISPPLOCK(vpp));
7967 
7968                                 ret = page_pp_lock(pp, claim, 0);
7969                                 if (ap != NULL) {
7970                                         if (ap->an_pvp != NULL) {
7971                                                 anon_swap_free(ap, pp);
7972                                         }
7973                                         anon_array_exit(&cookie);
7974                                         ANON_LOCK_EXIT(&amp->a_rwlock);
7975                                 }
7976                                 if (ret == 0) {
7977                                         /* locking page failed */
7978                                         page_unlock(pp);
7979                                         err = EAGAIN;
7980                                         goto out;
7981                                 }
7982                                 VPP_SETPPLOCK(vpp);
7983                                 if (sp != NULL) {
7984                                         if (pp->p_lckcnt == 1)
7985                                                 locked_bytes += PAGESIZE;
7986                                 } else
7987                                         locked_bytes += PAGESIZE;
7988 
7989                                 if (lockmap != (ulong_t *)NULL)
7990                                         BT_SET(lockmap, pos);
7991 
7992                                 page_unlock(pp);
7993                         } else {
7994                                 ASSERT(VPP_ISPPLOCK(vpp));
7995                                 if (pp != NULL) {
7996                                         /* sysV pages should be locked */
7997                                         ASSERT(sp == NULL || pp->p_lckcnt > 0);
7998                                         page_pp_unlock(pp, claim, 0);
7999                                         if (sp != NULL) {
8000                                                 if (pp->p_lckcnt == 0)
8001                                                         unlocked_bytes
8002                                                             += PAGESIZE;
8003                                         } else
8004                                                 unlocked_bytes += PAGESIZE;
8005                                         page_unlock(pp);
8006                                 } else {
8007                                         ASSERT(sp == NULL);
8008                                         unlocked_bytes += PAGESIZE;
8009                                 }
8010                                 VPP_CLRPPLOCK(vpp);
8011                         }
8012                 }
8013         }
8014 out:
8015         if (op == MC_LOCK) {
8016                 /* Credit back bytes that did not get locked */
8017                 if ((unlocked_bytes - locked_bytes) > 0) {
8018                         if (proj == NULL)
8019                                 mutex_enter(&p->p_lock);
8020                         rctl_decr_locked_mem(p, proj,
8021                             (unlocked_bytes - locked_bytes), chargeproc);
8022                         if (proj == NULL)
8023                                 mutex_exit(&p->p_lock);
8024                 }
8025 
8026         } else {
8027                 /* Account bytes that were unlocked */
8028                 if (unlocked_bytes > 0) {
8029                         if (proj == NULL)
8030                                 mutex_enter(&p->p_lock);
8031                         rctl_decr_locked_mem(p, proj, unlocked_bytes,
8032                             chargeproc);
8033                         if (proj == NULL)
8034                                 mutex_exit(&p->p_lock);
8035                 }
8036         }
8037         if (sp != NULL)
8038                 mutex_exit(&sp->shm_mlock);
8039         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8040 
8041         return (err);
8042 }
8043 
8044 /*
8045  * Set advice from user for specified pages
8046  * There are 9 types of advice:
8047  *      MADV_NORMAL     - Normal (default) behavior (whatever that is)
8048  *      MADV_RANDOM     - Random page references
8049  *                              do not allow readahead or 'klustering'
8050  *      MADV_SEQUENTIAL - Sequential page references
8051  *                              Pages previous to the one currently being
8052  *                              accessed (determined by fault) are 'not needed'
8053  *                              and are freed immediately
8054  *      MADV_WILLNEED   - Pages are likely to be used (fault ahead in mctl)
8055  *      MADV_DONTNEED   - Pages are not needed (synced out in mctl)
8056  *      MADV_FREE       - Contents can be discarded
8057  *      MADV_ACCESS_DEFAULT- Default access
8058  *      MADV_ACCESS_LWP - Next LWP will access heavily
8059  *      MADV_ACCESS_MANY- Many LWPs or processes will access heavily
8060  */
8061 static int
8062 segvn_advise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
8063 {
8064         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8065         size_t page;
8066         int err = 0;
8067         int already_set;
8068         struct anon_map *amp;
8069         ulong_t anon_index;
8070         struct seg *next;
8071         lgrp_mem_policy_t policy;
8072         struct seg *prev;
8073         struct vnode *vp;
8074 
8075         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8076 
8077         /*
8078          * In case of MADV_FREE, we won't be modifying any segment private
8079          * data structures; so, we only need to grab READER's lock
8080          */
8081         if (behav != MADV_FREE) {
8082                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
8083                 if (svd->tr_state != SEGVN_TR_OFF) {
8084                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8085                         return (0);
8086                 }
8087         } else {
8088                 SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8089         }
8090 
8091         /*
8092          * Large pages are assumed to be only turned on when accesses to the
8093          * segment's address range have spatial and temporal locality. That
8094          * justifies ignoring MADV_SEQUENTIAL for large page segments.
8095          * Also, ignore advice affecting lgroup memory allocation
8096          * if don't need to do lgroup optimizations on this system
8097          */
8098 
8099         if ((behav == MADV_SEQUENTIAL &&
8100             (seg->s_szc != 0 || HAT_IS_REGION_COOKIE_VALID(svd->rcookie))) ||
8101             (!lgrp_optimizations() && (behav == MADV_ACCESS_DEFAULT ||
8102             behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY))) {
8103                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8104                 return (0);
8105         }
8106 
8107         if (behav == MADV_SEQUENTIAL || behav == MADV_ACCESS_DEFAULT ||
8108             behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY) {
8109                 /*
8110                  * Since we are going to unload hat mappings
8111                  * we first have to flush the cache. Otherwise
8112                  * this might lead to system panic if another
8113                  * thread is doing physio on the range whose
8114                  * mappings are unloaded by madvise(3C).
8115                  */
8116                 if (svd->softlockcnt > 0) {
8117                         /*
8118                          * If this is shared segment non 0 softlockcnt
8119                          * means locked pages are still in use.
8120                          */
8121                         if (svd->type == MAP_SHARED) {
8122                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8123                                 return (EAGAIN);
8124                         }
8125                         /*
8126                          * Since we do have the segvn writers lock
8127                          * nobody can fill the cache with entries
8128                          * belonging to this seg during the purge.
8129                          * The flush either succeeds or we still
8130                          * have pending I/Os. In the later case,
8131                          * madvise(3C) fails.
8132                          */
8133                         segvn_purge(seg);
8134                         if (svd->softlockcnt > 0) {
8135                                 /*
8136                                  * Since madvise(3C) is advisory and
8137                                  * it's not part of UNIX98, madvise(3C)
8138                                  * failure here doesn't cause any hardship.
8139                                  * Note that we don't block in "as" layer.
8140                                  */
8141                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8142                                 return (EAGAIN);
8143                         }
8144                 } else if (svd->type == MAP_SHARED && svd->amp != NULL &&
8145                     svd->amp->a_softlockcnt > 0) {
8146                         /*
8147                          * Try to purge this amp's entries from pcache. It
8148                          * will succeed only if other segments that share the
8149                          * amp have no outstanding softlock's.
8150                          */
8151                         segvn_purge(seg);
8152                 }
8153         }
8154 
8155         amp = svd->amp;
8156         vp = svd->vp;
8157         if (behav == MADV_FREE) {
8158                 /*
8159                  * MADV_FREE is not supported for segments with
8160                  * underlying object; if anonmap is NULL, anon slots
8161                  * are not yet populated and there is nothing for
8162                  * us to do. As MADV_FREE is advisory, we don't
8163                  * return error in either case.
8164                  */
8165                 if (vp != NULL || amp == NULL) {
8166                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8167                         return (0);
8168                 }
8169 
8170                 segvn_purge(seg);
8171 
8172                 page = seg_page(seg, addr);
8173                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8174                 anon_disclaim(amp, svd->anon_index + page, len);
8175                 ANON_LOCK_EXIT(&amp->a_rwlock);
8176                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8177                 return (0);
8178         }
8179 
8180         /*
8181          * If advice is to be applied to entire segment,
8182          * use advice field in seg_data structure
8183          * otherwise use appropriate vpage entry.
8184          */
8185         if ((addr == seg->s_base) && (len == seg->s_size)) {
8186                 switch (behav) {
8187                 case MADV_ACCESS_LWP:
8188                 case MADV_ACCESS_MANY:
8189                 case MADV_ACCESS_DEFAULT:
8190                         /*
8191                          * Set memory allocation policy for this segment
8192                          */
8193                         policy = lgrp_madv_to_policy(behav, len, svd->type);
8194                         if (svd->type == MAP_SHARED)
8195                                 already_set = lgrp_shm_policy_set(policy, amp,
8196                                     svd->anon_index, vp, svd->offset, len);
8197                         else {
8198                                 /*
8199                                  * For private memory, need writers lock on
8200                                  * address space because the segment may be
8201                                  * split or concatenated when changing policy
8202                                  */
8203                                 if (AS_READ_HELD(seg->s_as,
8204                                     &seg->s_as->a_lock)) {
8205                                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8206                                         return (IE_RETRY);
8207                                 }
8208 
8209                                 already_set = lgrp_privm_policy_set(policy,
8210                                     &svd->policy_info, len);
8211                         }
8212 
8213                         /*
8214                          * If policy set already and it shouldn't be reapplied,
8215                          * don't do anything.
8216                          */
8217                         if (already_set &&
8218                             !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8219                                 break;
8220 
8221                         /*
8222                          * Mark any existing pages in given range for
8223                          * migration
8224                          */
8225                         page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8226                             vp, svd->offset, 1);
8227 
8228                         /*
8229                          * If same policy set already or this is a shared
8230                          * memory segment, don't need to try to concatenate
8231                          * segment with adjacent ones.
8232                          */
8233                         if (already_set || svd->type == MAP_SHARED)
8234                                 break;
8235 
8236                         /*
8237                          * Try to concatenate this segment with previous
8238                          * one and next one, since we changed policy for
8239                          * this one and it may be compatible with adjacent
8240                          * ones now.
8241                          */
8242                         prev = AS_SEGPREV(seg->s_as, seg);
8243                         next = AS_SEGNEXT(seg->s_as, seg);
8244 
8245                         if (next && next->s_ops == &segvn_ops &&
8246                             addr + len == next->s_base)
8247                                 (void) segvn_concat(seg, next, 1);
8248 
8249                         if (prev && prev->s_ops == &segvn_ops &&
8250                             addr == prev->s_base + prev->s_size) {
8251                                 /*
8252                                  * Drop lock for private data of current
8253                                  * segment before concatenating (deleting) it
8254                                  * and return IE_REATTACH to tell as_ctl() that
8255                                  * current segment has changed
8256                                  */
8257                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8258                                 if (!segvn_concat(prev, seg, 1))
8259                                         err = IE_REATTACH;
8260 
8261                                 return (err);
8262                         }
8263                         break;
8264 
8265                 case MADV_SEQUENTIAL:
8266                         /*
8267                          * unloading mapping guarantees
8268                          * detection in segvn_fault
8269                          */
8270                         ASSERT(seg->s_szc == 0);
8271                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8272                         hat_unload(seg->s_as->a_hat, addr, len,
8273                             HAT_UNLOAD);
8274                         /* FALLTHROUGH */
8275                 case MADV_NORMAL:
8276                 case MADV_RANDOM:
8277                         svd->advice = (uchar_t)behav;
8278                         svd->pageadvice = 0;
8279                         break;
8280                 case MADV_WILLNEED:     /* handled in memcntl */
8281                 case MADV_DONTNEED:     /* handled in memcntl */
8282                 case MADV_FREE:         /* handled above */
8283                         break;
8284                 default:
8285                         err = EINVAL;
8286                 }
8287         } else {
8288                 caddr_t                 eaddr;
8289                 struct seg              *new_seg;
8290                 struct segvn_data       *new_svd;
8291                 u_offset_t              off;
8292                 caddr_t                 oldeaddr;
8293 
8294                 page = seg_page(seg, addr);
8295 
8296                 segvn_vpage(seg);
8297                 if (svd->vpage == NULL) {
8298                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8299                         return (ENOMEM);
8300                 }
8301 
8302                 switch (behav) {
8303                         struct vpage *bvpp, *evpp;
8304 
8305                 case MADV_ACCESS_LWP:
8306                 case MADV_ACCESS_MANY:
8307                 case MADV_ACCESS_DEFAULT:
8308                         /*
8309                          * Set memory allocation policy for portion of this
8310                          * segment
8311                          */
8312 
8313                         /*
8314                          * Align address and length of advice to page
8315                          * boundaries for large pages
8316                          */
8317                         if (seg->s_szc != 0) {
8318                                 size_t  pgsz;
8319 
8320                                 pgsz = page_get_pagesize(seg->s_szc);
8321                                 addr = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
8322                                 len = P2ROUNDUP(len, pgsz);
8323                         }
8324 
8325                         /*
8326                          * Check to see whether policy is set already
8327                          */
8328                         policy = lgrp_madv_to_policy(behav, len, svd->type);
8329 
8330                         anon_index = svd->anon_index + page;
8331                         off = svd->offset + (uintptr_t)(addr - seg->s_base);
8332 
8333                         if (svd->type == MAP_SHARED)
8334                                 already_set = lgrp_shm_policy_set(policy, amp,
8335                                     anon_index, vp, off, len);
8336                         else
8337                                 already_set =
8338                                     (policy == svd->policy_info.mem_policy);
8339 
8340                         /*
8341                          * If policy set already and it shouldn't be reapplied,
8342                          * don't do anything.
8343                          */
8344                         if (already_set &&
8345                             !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8346                                 break;
8347 
8348                         /*
8349                          * For private memory, need writers lock on
8350                          * address space because the segment may be
8351                          * split or concatenated when changing policy
8352                          */
8353                         if (svd->type == MAP_PRIVATE &&
8354                             AS_READ_HELD(seg->s_as, &seg->s_as->a_lock)) {
8355                                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8356                                 return (IE_RETRY);
8357                         }
8358 
8359                         /*
8360                          * Mark any existing pages in given range for
8361                          * migration
8362                          */
8363                         page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8364                             vp, svd->offset, 1);
8365 
8366                         /*
8367                          * Don't need to try to split or concatenate
8368                          * segments, since policy is same or this is a shared
8369                          * memory segment
8370                          */
8371                         if (already_set || svd->type == MAP_SHARED)
8372                                 break;
8373 
8374                         if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
8375                                 ASSERT(svd->amp == NULL);
8376                                 ASSERT(svd->tr_state == SEGVN_TR_OFF);
8377                                 ASSERT(svd->softlockcnt == 0);
8378                                 hat_leave_region(seg->s_as->a_hat, svd->rcookie,
8379                                     HAT_REGION_TEXT);
8380                                 svd->rcookie = HAT_INVALID_REGION_COOKIE;
8381                         }
8382 
8383                         /*
8384                          * Split off new segment if advice only applies to a
8385                          * portion of existing segment starting in middle
8386                          */
8387                         new_seg = NULL;
8388                         eaddr = addr + len;
8389                         oldeaddr = seg->s_base + seg->s_size;
8390                         if (addr > seg->s_base) {
8391                                 /*
8392                                  * Must flush I/O page cache
8393                                  * before splitting segment
8394                                  */
8395                                 if (svd->softlockcnt > 0)
8396                                         segvn_purge(seg);
8397 
8398                                 /*
8399                                  * Split segment and return IE_REATTACH to tell
8400                                  * as_ctl() that current segment changed
8401                                  */
8402                                 new_seg = segvn_split_seg(seg, addr);
8403                                 new_svd = (struct segvn_data *)new_seg->s_data;
8404                                 err = IE_REATTACH;
8405 
8406                                 /*
8407                                  * If new segment ends where old one
8408                                  * did, try to concatenate the new
8409                                  * segment with next one.
8410                                  */
8411                                 if (eaddr == oldeaddr) {
8412                                         /*
8413                                          * Set policy for new segment
8414                                          */
8415                                         (void) lgrp_privm_policy_set(policy,
8416                                             &new_svd->policy_info,
8417                                             new_seg->s_size);
8418 
8419                                         next = AS_SEGNEXT(new_seg->s_as,
8420                                             new_seg);
8421 
8422                                         if (next &&
8423                                             next->s_ops == &segvn_ops &&
8424                                             eaddr == next->s_base)
8425                                                 (void) segvn_concat(new_seg,
8426                                                     next, 1);
8427                                 }
8428                         }
8429 
8430                         /*
8431                          * Split off end of existing segment if advice only
8432                          * applies to a portion of segment ending before
8433                          * end of the existing segment
8434                          */
8435                         if (eaddr < oldeaddr) {
8436                                 /*
8437                                  * Must flush I/O page cache
8438                                  * before splitting segment
8439                                  */
8440                                 if (svd->softlockcnt > 0)
8441                                         segvn_purge(seg);
8442 
8443                                 /*
8444                                  * If beginning of old segment was already
8445                                  * split off, use new segment to split end off
8446                                  * from.
8447                                  */
8448                                 if (new_seg != NULL && new_seg != seg) {
8449                                         /*
8450                                          * Split segment
8451                                          */
8452                                         (void) segvn_split_seg(new_seg, eaddr);
8453 
8454                                         /*
8455                                          * Set policy for new segment
8456                                          */
8457                                         (void) lgrp_privm_policy_set(policy,
8458                                             &new_svd->policy_info,
8459                                             new_seg->s_size);
8460                                 } else {
8461                                         /*
8462                                          * Split segment and return IE_REATTACH
8463                                          * to tell as_ctl() that current
8464                                          * segment changed
8465                                          */
8466                                         (void) segvn_split_seg(seg, eaddr);
8467                                         err = IE_REATTACH;
8468 
8469                                         (void) lgrp_privm_policy_set(policy,
8470                                             &svd->policy_info, seg->s_size);
8471 
8472                                         /*
8473                                          * If new segment starts where old one
8474                                          * did, try to concatenate it with
8475                                          * previous segment.
8476                                          */
8477                                         if (addr == seg->s_base) {
8478                                                 prev = AS_SEGPREV(seg->s_as,
8479                                                     seg);
8480 
8481                                                 /*
8482                                                  * Drop lock for private data
8483                                                  * of current segment before
8484                                                  * concatenating (deleting) it
8485                                                  */
8486                                                 if (prev &&
8487                                                     prev->s_ops ==
8488                                                     &segvn_ops &&
8489                                                     addr == prev->s_base +
8490                                                     prev->s_size) {
8491                                                         SEGVN_LOCK_EXIT(
8492                                                             seg->s_as,
8493                                                             &svd->lock);
8494                                                         (void) segvn_concat(
8495                                                             prev, seg, 1);
8496                                                         return (err);
8497                                                 }
8498                                         }
8499                                 }
8500                         }
8501                         break;
8502                 case MADV_SEQUENTIAL:
8503                         ASSERT(seg->s_szc == 0);
8504                         ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8505                         hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
8506                         /* FALLTHROUGH */
8507                 case MADV_NORMAL:
8508                 case MADV_RANDOM:
8509                         bvpp = &svd->vpage[page];
8510                         evpp = &svd->vpage[page + (len >> PAGESHIFT)];
8511                         for (; bvpp < evpp; bvpp++)
8512                                 VPP_SETADVICE(bvpp, behav);
8513                         svd->advice = MADV_NORMAL;
8514                         break;
8515                 case MADV_WILLNEED:     /* handled in memcntl */
8516                 case MADV_DONTNEED:     /* handled in memcntl */
8517                 case MADV_FREE:         /* handled above */
8518                         break;
8519                 default:
8520                         err = EINVAL;
8521                 }
8522         }
8523         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8524         return (err);
8525 }
8526 
8527 /*
8528  * There is one kind of inheritance that can be specified for pages:
8529  *
8530  *     SEGP_INH_ZERO - Pages should be zeroed in the child
8531  */
8532 static int
8533 segvn_inherit(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
8534 {
8535         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8536         struct vpage *bvpp, *evpp;
8537         size_t page;
8538         int ret = 0;
8539 
8540         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8541 
8542         /* Can't support something we don't know about */
8543         if (behav != SEGP_INH_ZERO)
8544                 return (ENOTSUP);
8545 
8546         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
8547 
8548         /*
8549          * This must be a straightforward anonymous segment that is mapped
8550          * privately and is not backed by a vnode.
8551          */
8552         if (svd->tr_state != SEGVN_TR_OFF ||
8553             svd->type != MAP_PRIVATE ||
8554             svd->vp != NULL) {
8555                 ret = EINVAL;
8556                 goto out;
8557         }
8558 
8559         /*
8560          * If the entire segment has been marked as inherit zero, then no reason
8561          * to do anything else.
8562          */
8563         if (svd->svn_inz == SEGVN_INZ_ALL) {
8564                 ret = 0;
8565                 goto out;
8566         }
8567 
8568         /*
8569          * If this applies to the entire segment, simply mark it and we're done.
8570          */
8571         if ((addr == seg->s_base) && (len == seg->s_size)) {
8572                 svd->svn_inz = SEGVN_INZ_ALL;
8573                 ret = 0;
8574                 goto out;
8575         }
8576 
8577         /*
8578          * We've been asked to mark a subset of this segment as inherit zero,
8579          * therefore we need to mainpulate its vpages.
8580          */
8581         if (svd->vpage == NULL) {
8582                 segvn_vpage(seg);
8583                 if (svd->vpage == NULL) {
8584                         ret = ENOMEM;
8585                         goto out;
8586                 }
8587         }
8588 
8589         svd->svn_inz = SEGVN_INZ_VPP;
8590         page = seg_page(seg, addr);
8591         bvpp = &svd->vpage[page];
8592         evpp = &svd->vpage[page + (len >> PAGESHIFT)];
8593         for (; bvpp < evpp; bvpp++)
8594                 VPP_SETINHZERO(bvpp);
8595         ret = 0;
8596 
8597 out:
8598         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8599         return (ret);
8600 }
8601 
8602 /*
8603  * Create a vpage structure for this seg.
8604  */
8605 static void
8606 segvn_vpage(struct seg *seg)
8607 {
8608         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8609         struct vpage *vp, *evp;
8610         static pgcnt_t page_limit = 0;
8611 
8612         ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
8613 
8614         /*
8615          * If no vpage structure exists, allocate one.  Copy the protections
8616          * and the advice from the segment itself to the individual pages.
8617          */
8618         if (svd->vpage == NULL) {
8619                 /*
8620                  * Start by calculating the number of pages we must allocate to
8621                  * track the per-page vpage structs needs for this entire
8622                  * segment. If we know now that it will require more than our
8623                  * heuristic for the maximum amount of kmem we can consume then
8624                  * fail. We do this here, instead of trying to detect this deep
8625                  * in page_resv and propagating the error up, since the entire
8626                  * memory allocation stack is not amenable to passing this
8627                  * back. Instead, it wants to keep trying.
8628                  *
8629                  * As a heuristic we set a page limit of 5/8s of total_pages
8630                  * for this allocation. We use shifts so that no floating
8631                  * point conversion takes place and only need to do the
8632                  * calculation once.
8633                  */
8634                 ulong_t mem_needed = seg_pages(seg) * sizeof (struct vpage);
8635                 pgcnt_t npages = mem_needed >> PAGESHIFT;
8636 
8637                 if (page_limit == 0)
8638                         page_limit = (total_pages >> 1) + (total_pages >> 3);
8639 
8640                 if (npages > page_limit)
8641                         return;
8642 
8643                 svd->pageadvice = 1;
8644                 svd->vpage = kmem_zalloc(mem_needed, KM_SLEEP);
8645                 evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
8646                 for (vp = svd->vpage; vp < evp; vp++) {
8647                         VPP_SETPROT(vp, svd->prot);
8648                         VPP_SETADVICE(vp, svd->advice);
8649                 }
8650         }
8651 }
8652 
8653 /*
8654  * Dump the pages belonging to this segvn segment.
8655  */
8656 static void
8657 segvn_dump(struct seg *seg)
8658 {
8659         struct segvn_data *svd;
8660         page_t *pp;
8661         struct anon_map *amp;
8662         ulong_t anon_index;
8663         struct vnode *vp;
8664         u_offset_t off, offset;
8665         pfn_t pfn;
8666         pgcnt_t page, npages;
8667         caddr_t addr;
8668 
8669         npages = seg_pages(seg);
8670         svd = (struct segvn_data *)seg->s_data;
8671         vp = svd->vp;
8672         off = offset = svd->offset;
8673         addr = seg->s_base;
8674 
8675         if ((amp = svd->amp) != NULL) {
8676                 anon_index = svd->anon_index;
8677                 ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8678         }
8679 
8680         for (page = 0; page < npages; page++, offset += PAGESIZE) {
8681                 struct anon *ap;
8682                 int we_own_it = 0;
8683 
8684                 if (amp && (ap = anon_get_ptr(svd->amp->ahp, anon_index++))) {
8685                         swap_xlate_nopanic(ap, &vp, &off);
8686                 } else {
8687                         vp = svd->vp;
8688                         off = offset;
8689                 }
8690 
8691                 /*
8692                  * If pp == NULL, the page either does not exist
8693                  * or is exclusively locked.  So determine if it
8694                  * exists before searching for it.
8695                  */
8696 
8697                 if ((pp = page_lookup_nowait(vp, off, SE_SHARED)))
8698                         we_own_it = 1;
8699                 else
8700                         pp = page_exists(vp, off);
8701 
8702                 if (pp) {
8703                         pfn = page_pptonum(pp);
8704                         dump_addpage(seg->s_as, addr, pfn);
8705                         if (we_own_it)
8706                                 page_unlock(pp);
8707                 }
8708                 addr += PAGESIZE;
8709                 dump_timeleft = dump_timeout;
8710         }
8711 
8712         if (amp != NULL)
8713                 ANON_LOCK_EXIT(&amp->a_rwlock);
8714 }
8715 
8716 #ifdef DEBUG
8717 static uint32_t segvn_pglock_mtbf = 0;
8718 #endif
8719 
8720 #define PCACHE_SHWLIST          ((page_t *)-2)
8721 #define NOPCACHE_SHWLIST        ((page_t *)-1)
8722 
8723 /*
8724  * Lock/Unlock anon pages over a given range. Return shadow list. This routine
8725  * uses global segment pcache to cache shadow lists (i.e. pp arrays) of pages
8726  * to avoid the overhead of per page locking, unlocking for subsequent IOs to
8727  * the same parts of the segment. Currently shadow list creation is only
8728  * supported for pure anon segments. MAP_PRIVATE segment pcache entries are
8729  * tagged with segment pointer, starting virtual address and length. This
8730  * approach for MAP_SHARED segments may add many pcache entries for the same
8731  * set of pages and lead to long hash chains that decrease pcache lookup
8732  * performance. To avoid this issue for shared segments shared anon map and
8733  * starting anon index are used for pcache entry tagging. This allows all
8734  * segments to share pcache entries for the same anon range and reduces pcache
8735  * chain's length as well as memory overhead from duplicate shadow lists and
8736  * pcache entries.
8737  *
8738  * softlockcnt field in segvn_data structure counts the number of F_SOFTLOCK'd
8739  * pages via segvn_fault() and pagelock'd pages via this routine. But pagelock
8740  * part of softlockcnt accounting is done differently for private and shared
8741  * segments. In private segment case softlock is only incremented when a new
8742  * shadow list is created but not when an existing one is found via
8743  * seg_plookup(). pcache entries have reference count incremented/decremented
8744  * by each seg_plookup()/seg_pinactive() operation. Only entries that have 0
8745  * reference count can be purged (and purging is needed before segment can be
8746  * freed). When a private segment pcache entry is purged segvn_reclaim() will
8747  * decrement softlockcnt. Since in private segment case each of its pcache
8748  * entries only belongs to this segment we can expect that when
8749  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8750  * segment purge will succeed and softlockcnt will drop to 0. In shared
8751  * segment case reference count in pcache entry counts active locks from many
8752  * different segments so we can't expect segment purging to succeed even when
8753  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8754  * segment. To be able to determine when there're no pending pagelocks in
8755  * shared segment case we don't rely on purging to make softlockcnt drop to 0
8756  * but instead softlockcnt is incremented and decremented for every
8757  * segvn_pagelock(L_PAGELOCK/L_PAGEUNLOCK) call regardless if a new shadow
8758  * list was created or an existing one was found. When softlockcnt drops to 0
8759  * this segment no longer has any claims for pcached shadow lists and the
8760  * segment can be freed even if there're still active pcache entries
8761  * shared by this segment anon map. Shared segment pcache entries belong to
8762  * anon map and are typically removed when anon map is freed after all
8763  * processes destroy the segments that use this anon map.
8764  */
8765 static int
8766 segvn_pagelock(struct seg *seg, caddr_t addr, size_t len, struct page ***ppp,
8767     enum lock_type type, enum seg_rw rw)
8768 {
8769         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8770         size_t np;
8771         pgcnt_t adjustpages;
8772         pgcnt_t npages;
8773         ulong_t anon_index;
8774         uint_t protchk = (rw == S_READ) ? PROT_READ : PROT_WRITE;
8775         uint_t error;
8776         struct anon_map *amp;
8777         pgcnt_t anpgcnt;
8778         struct page **pplist, **pl, *pp;
8779         caddr_t a;
8780         size_t page;
8781         caddr_t lpgaddr, lpgeaddr;
8782         anon_sync_obj_t cookie;
8783         int anlock;
8784         struct anon_map *pamp;
8785         caddr_t paddr;
8786         seg_preclaim_cbfunc_t preclaim_callback;
8787         size_t pgsz;
8788         int use_pcache;
8789         size_t wlen;
8790         uint_t pflags = 0;
8791         int sftlck_sbase = 0;
8792         int sftlck_send = 0;
8793 
8794 #ifdef DEBUG
8795         if (type == L_PAGELOCK && segvn_pglock_mtbf) {
8796                 hrtime_t ts = gethrtime();
8797                 if ((ts % segvn_pglock_mtbf) == 0) {
8798                         return (ENOTSUP);
8799                 }
8800                 if ((ts % segvn_pglock_mtbf) == 1) {
8801                         return (EFAULT);
8802                 }
8803         }
8804 #endif
8805 
8806         TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_START,
8807             "segvn_pagelock: start seg %p addr %p", seg, addr);
8808 
8809         ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8810         ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
8811 
8812         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8813 
8814         /*
8815          * for now we only support pagelock to anon memory. We would have to
8816          * check protections for vnode objects and call into the vnode driver.
8817          * That's too much for a fast path. Let the fault entry point handle
8818          * it.
8819          */
8820         if (svd->vp != NULL) {
8821                 if (type == L_PAGELOCK) {
8822                         error = ENOTSUP;
8823                         goto out;
8824                 }
8825                 panic("segvn_pagelock(L_PAGEUNLOCK): vp != NULL");
8826         }
8827         if ((amp = svd->amp) == NULL) {
8828                 if (type == L_PAGELOCK) {
8829                         error = EFAULT;
8830                         goto out;
8831                 }
8832                 panic("segvn_pagelock(L_PAGEUNLOCK): amp == NULL");
8833         }
8834         if (rw != S_READ && rw != S_WRITE) {
8835                 if (type == L_PAGELOCK) {
8836                         error = ENOTSUP;
8837                         goto out;
8838                 }
8839                 panic("segvn_pagelock(L_PAGEUNLOCK): bad rw");
8840         }
8841 
8842         if (seg->s_szc != 0) {
8843                 /*
8844                  * We are adjusting the pagelock region to the large page size
8845                  * boundary because the unlocked part of a large page cannot
8846                  * be freed anyway unless all constituent pages of a large
8847                  * page are locked. Bigger regions reduce pcache chain length
8848                  * and improve lookup performance. The tradeoff is that the
8849                  * very first segvn_pagelock() call for a given page is more
8850                  * expensive if only 1 page_t is needed for IO. This is only
8851                  * an issue if pcache entry doesn't get reused by several
8852                  * subsequent calls. We optimize here for the case when pcache
8853                  * is heavily used by repeated IOs to the same address range.
8854                  *
8855                  * Note segment's page size cannot change while we are holding
8856                  * as lock.  And then it cannot change while softlockcnt is
8857                  * not 0. This will allow us to correctly recalculate large
8858                  * page size region for the matching pageunlock/reclaim call
8859                  * since as_pageunlock() caller must always match
8860                  * as_pagelock() call's addr and len.
8861                  *
8862                  * For pageunlock *ppp points to the pointer of page_t that
8863                  * corresponds to the real unadjusted start address. Similar
8864                  * for pagelock *ppp must point to the pointer of page_t that
8865                  * corresponds to the real unadjusted start address.
8866                  */
8867                 pgsz = page_get_pagesize(seg->s_szc);
8868                 CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
8869                 adjustpages = btop((uintptr_t)(addr - lpgaddr));
8870         } else if (len < segvn_pglock_comb_thrshld) {
8871                 lpgaddr = addr;
8872                 lpgeaddr = addr + len;
8873                 adjustpages = 0;
8874                 pgsz = PAGESIZE;
8875         } else {
8876                 /*
8877                  * Align the address range of large enough requests to allow
8878                  * combining of different shadow lists into 1 to reduce memory
8879                  * overhead from potentially overlapping large shadow lists
8880                  * (worst case is we have a 1MB IO into buffers with start
8881                  * addresses separated by 4K).  Alignment is only possible if
8882                  * padded chunks have sufficient access permissions. Note
8883                  * permissions won't change between L_PAGELOCK and
8884                  * L_PAGEUNLOCK calls since non 0 softlockcnt will force
8885                  * segvn_setprot() to wait until softlockcnt drops to 0. This
8886                  * allows us to determine in L_PAGEUNLOCK the same range we
8887                  * computed in L_PAGELOCK.
8888                  *
8889                  * If alignment is limited by segment ends set
8890                  * sftlck_sbase/sftlck_send flags. In L_PAGELOCK case when
8891                  * these flags are set bump softlockcnt_sbase/softlockcnt_send
8892                  * per segment counters. In L_PAGEUNLOCK case decrease
8893                  * softlockcnt_sbase/softlockcnt_send counters if
8894                  * sftlck_sbase/sftlck_send flags are set.  When
8895                  * softlockcnt_sbase/softlockcnt_send are non 0
8896                  * segvn_concat()/segvn_extend_prev()/segvn_extend_next()
8897                  * won't merge the segments. This restriction combined with
8898                  * restriction on segment unmapping and splitting for segments
8899                  * that have non 0 softlockcnt allows L_PAGEUNLOCK to
8900                  * correctly determine the same range that was previously
8901                  * locked by matching L_PAGELOCK.
8902                  */
8903                 pflags = SEGP_PSHIFT | (segvn_pglock_comb_bshift << 16);
8904                 pgsz = PAGESIZE;
8905                 if (svd->type == MAP_PRIVATE) {
8906                         lpgaddr = (caddr_t)P2ALIGN((uintptr_t)addr,
8907                             segvn_pglock_comb_balign);
8908                         if (lpgaddr < seg->s_base) {
8909                                 lpgaddr = seg->s_base;
8910                                 sftlck_sbase = 1;
8911                         }
8912                 } else {
8913                         ulong_t aix = svd->anon_index + seg_page(seg, addr);
8914                         ulong_t aaix = P2ALIGN(aix, segvn_pglock_comb_palign);
8915                         if (aaix < svd->anon_index) {
8916                                 lpgaddr = seg->s_base;
8917                                 sftlck_sbase = 1;
8918                         } else {
8919                                 lpgaddr = addr - ptob(aix - aaix);
8920                                 ASSERT(lpgaddr >= seg->s_base);
8921                         }
8922                 }
8923                 if (svd->pageprot && lpgaddr != addr) {
8924                         struct vpage *vp = &svd->vpage[seg_page(seg, lpgaddr)];
8925                         struct vpage *evp = &svd->vpage[seg_page(seg, addr)];
8926                         while (vp < evp) {
8927                                 if ((VPP_PROT(vp) & protchk) == 0) {
8928                                         break;
8929                                 }
8930                                 vp++;
8931                         }
8932                         if (vp < evp) {
8933                                 lpgaddr = addr;
8934                                 pflags = 0;
8935                         }
8936                 }
8937                 lpgeaddr = addr + len;
8938                 if (pflags) {
8939                         if (svd->type == MAP_PRIVATE) {
8940                                 lpgeaddr = (caddr_t)P2ROUNDUP(
8941                                     (uintptr_t)lpgeaddr,
8942                                     segvn_pglock_comb_balign);
8943                         } else {
8944                                 ulong_t aix = svd->anon_index +
8945                                     seg_page(seg, lpgeaddr);
8946                                 ulong_t aaix = P2ROUNDUP(aix,
8947                                     segvn_pglock_comb_palign);
8948                                 if (aaix < aix) {
8949                                         lpgeaddr = 0;
8950                                 } else {
8951                                         lpgeaddr += ptob(aaix - aix);
8952                                 }
8953                         }
8954                         if (lpgeaddr == 0 ||
8955                             lpgeaddr > seg->s_base + seg->s_size) {
8956                                 lpgeaddr = seg->s_base + seg->s_size;
8957                                 sftlck_send = 1;
8958                         }
8959                 }
8960                 if (svd->pageprot && lpgeaddr != addr + len) {
8961                         struct vpage *vp;
8962                         struct vpage *evp;
8963 
8964                         vp = &svd->vpage[seg_page(seg, addr + len)];
8965                         evp = &svd->vpage[seg_page(seg, lpgeaddr)];
8966 
8967                         while (vp < evp) {
8968                                 if ((VPP_PROT(vp) & protchk) == 0) {
8969                                         break;
8970                                 }
8971                                 vp++;
8972                         }
8973                         if (vp < evp) {
8974                                 lpgeaddr = addr + len;
8975                         }
8976                 }
8977                 adjustpages = btop((uintptr_t)(addr - lpgaddr));
8978         }
8979 
8980         /*
8981          * For MAP_SHARED segments we create pcache entries tagged by amp and
8982          * anon index so that we can share pcache entries with other segments
8983          * that map this amp.  For private segments pcache entries are tagged
8984          * with segment and virtual address.
8985          */
8986         if (svd->type == MAP_SHARED) {
8987                 pamp = amp;
8988                 paddr = (caddr_t)((lpgaddr - seg->s_base) +
8989                     ptob(svd->anon_index));
8990                 preclaim_callback = shamp_reclaim;
8991         } else {
8992                 pamp = NULL;
8993                 paddr = lpgaddr;
8994                 preclaim_callback = segvn_reclaim;
8995         }
8996 
8997         if (type == L_PAGEUNLOCK) {
8998                 VM_STAT_ADD(segvnvmstats.pagelock[0]);
8999 
9000                 /*
9001                  * update hat ref bits for /proc. We need to make sure
9002                  * that threads tracing the ref and mod bits of the
9003                  * address space get the right data.
9004                  * Note: page ref and mod bits are updated at reclaim time
9005                  */
9006                 if (seg->s_as->a_vbits) {
9007                         for (a = addr; a < addr + len; a += PAGESIZE) {
9008                                 if (rw == S_WRITE) {
9009                                         hat_setstat(seg->s_as, a,
9010                                             PAGESIZE, P_REF | P_MOD);
9011                                 } else {
9012                                         hat_setstat(seg->s_as, a,
9013                                             PAGESIZE, P_REF);
9014                                 }
9015                         }
9016                 }
9017 
9018                 /*
9019                  * Check the shadow list entry after the last page used in
9020                  * this IO request. If it's NOPCACHE_SHWLIST the shadow list
9021                  * was not inserted into pcache and is not large page
9022                  * adjusted.  In this case call reclaim callback directly and
9023                  * don't adjust the shadow list start and size for large
9024                  * pages.
9025                  */
9026                 npages = btop(len);
9027                 if ((*ppp)[npages] == NOPCACHE_SHWLIST) {
9028                         void *ptag;
9029                         if (pamp != NULL) {
9030                                 ASSERT(svd->type == MAP_SHARED);
9031                                 ptag = (void *)pamp;
9032                                 paddr = (caddr_t)((addr - seg->s_base) +
9033                                     ptob(svd->anon_index));
9034                         } else {
9035                                 ptag = (void *)seg;
9036                                 paddr = addr;
9037                         }
9038                         (*preclaim_callback)(ptag, paddr, len, *ppp, rw, 0);
9039                 } else {
9040                         ASSERT((*ppp)[npages] == PCACHE_SHWLIST ||
9041                             IS_SWAPFSVP((*ppp)[npages]->p_vnode));
9042                         len = lpgeaddr - lpgaddr;
9043                         npages = btop(len);
9044                         seg_pinactive(seg, pamp, paddr, len,
9045                             *ppp - adjustpages, rw, pflags, preclaim_callback);
9046                 }
9047 
9048                 if (pamp != NULL) {
9049                         ASSERT(svd->type == MAP_SHARED);
9050                         ASSERT(svd->softlockcnt >= npages);
9051                         atomic_add_long((ulong_t *)&svd->softlockcnt, -npages);
9052                 }
9053 
9054                 if (sftlck_sbase) {
9055                         ASSERT(svd->softlockcnt_sbase > 0);
9056                         atomic_dec_ulong((ulong_t *)&svd->softlockcnt_sbase);
9057                 }
9058                 if (sftlck_send) {
9059                         ASSERT(svd->softlockcnt_send > 0);
9060                         atomic_dec_ulong((ulong_t *)&svd->softlockcnt_send);
9061                 }
9062 
9063                 /*
9064                  * If someone is blocked while unmapping, we purge
9065                  * segment page cache and thus reclaim pplist synchronously
9066                  * without waiting for seg_pasync_thread. This speeds up
9067                  * unmapping in cases where munmap(2) is called, while
9068                  * raw async i/o is still in progress or where a thread
9069                  * exits on data fault in a multithreaded application.
9070                  */
9071                 if (AS_ISUNMAPWAIT(seg->s_as)) {
9072                         if (svd->softlockcnt == 0) {
9073                                 mutex_enter(&seg->s_as->a_contents);
9074                                 if (AS_ISUNMAPWAIT(seg->s_as)) {
9075                                         AS_CLRUNMAPWAIT(seg->s_as);
9076                                         cv_broadcast(&seg->s_as->a_cv);
9077                                 }
9078                                 mutex_exit(&seg->s_as->a_contents);
9079                         } else if (pamp == NULL) {
9080                                 /*
9081                                  * softlockcnt is not 0 and this is a
9082                                  * MAP_PRIVATE segment. Try to purge its
9083                                  * pcache entries to reduce softlockcnt.
9084                                  * If it drops to 0 segvn_reclaim()
9085                                  * will wake up a thread waiting on
9086                                  * unmapwait flag.
9087                                  *
9088                                  * We don't purge MAP_SHARED segments with non
9089                                  * 0 softlockcnt since IO is still in progress
9090                                  * for such segments.
9091                                  */
9092                                 ASSERT(svd->type == MAP_PRIVATE);
9093                                 segvn_purge(seg);
9094                         }
9095                 }
9096                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9097                 TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_UNLOCK_END,
9098                     "segvn_pagelock: unlock seg %p addr %p", seg, addr);
9099                 return (0);
9100         }
9101 
9102         /* The L_PAGELOCK case ... */
9103 
9104         VM_STAT_ADD(segvnvmstats.pagelock[1]);
9105 
9106         /*
9107          * For MAP_SHARED segments we have to check protections before
9108          * seg_plookup() since pcache entries may be shared by many segments
9109          * with potentially different page protections.
9110          */
9111         if (pamp != NULL) {
9112                 ASSERT(svd->type == MAP_SHARED);
9113                 if (svd->pageprot == 0) {
9114                         if ((svd->prot & protchk) == 0) {
9115                                 error = EACCES;
9116                                 goto out;
9117                         }
9118                 } else {
9119                         /*
9120                          * check page protections
9121                          */
9122                         caddr_t ea;
9123 
9124                         if (seg->s_szc) {
9125                                 a = lpgaddr;
9126                                 ea = lpgeaddr;
9127                         } else {
9128                                 a = addr;
9129                                 ea = addr + len;
9130                         }
9131                         for (; a < ea; a += pgsz) {
9132                                 struct vpage *vp;
9133 
9134                                 ASSERT(seg->s_szc == 0 ||
9135                                     sameprot(seg, a, pgsz));
9136                                 vp = &svd->vpage[seg_page(seg, a)];
9137                                 if ((VPP_PROT(vp) & protchk) == 0) {
9138                                         error = EACCES;
9139                                         goto out;
9140                                 }
9141                         }
9142                 }
9143         }
9144 
9145         /*
9146          * try to find pages in segment page cache
9147          */
9148         pplist = seg_plookup(seg, pamp, paddr, lpgeaddr - lpgaddr, rw, pflags);
9149         if (pplist != NULL) {
9150                 if (pamp != NULL) {
9151                         npages = btop((uintptr_t)(lpgeaddr - lpgaddr));
9152                         ASSERT(svd->type == MAP_SHARED);
9153                         atomic_add_long((ulong_t *)&svd->softlockcnt,
9154                             npages);
9155                 }
9156                 if (sftlck_sbase) {
9157                         atomic_inc_ulong((ulong_t *)&svd->softlockcnt_sbase);
9158                 }
9159                 if (sftlck_send) {
9160                         atomic_inc_ulong((ulong_t *)&svd->softlockcnt_send);
9161                 }
9162                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9163                 *ppp = pplist + adjustpages;
9164                 TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_HIT_END,
9165                     "segvn_pagelock: cache hit seg %p addr %p", seg, addr);
9166                 return (0);
9167         }
9168 
9169         /*
9170          * For MAP_SHARED segments we already verified above that segment
9171          * protections allow this pagelock operation.
9172          */
9173         if (pamp == NULL) {
9174                 ASSERT(svd->type == MAP_PRIVATE);
9175                 if (svd->pageprot == 0) {
9176                         if ((svd->prot & protchk) == 0) {
9177                                 error = EACCES;
9178                                 goto out;
9179                         }
9180                         if (svd->prot & PROT_WRITE) {
9181                                 wlen = lpgeaddr - lpgaddr;
9182                         } else {
9183                                 wlen = 0;
9184                                 ASSERT(rw == S_READ);
9185                         }
9186                 } else {
9187                         int wcont = 1;
9188                         /*
9189                          * check page protections
9190                          */
9191                         for (a = lpgaddr, wlen = 0; a < lpgeaddr; a += pgsz) {
9192                                 struct vpage *vp;
9193 
9194                                 ASSERT(seg->s_szc == 0 ||
9195                                     sameprot(seg, a, pgsz));
9196                                 vp = &svd->vpage[seg_page(seg, a)];
9197                                 if ((VPP_PROT(vp) & protchk) == 0) {
9198                                         error = EACCES;
9199                                         goto out;
9200                                 }
9201                                 if (wcont && (VPP_PROT(vp) & PROT_WRITE)) {
9202                                         wlen += pgsz;
9203                                 } else {
9204                                         wcont = 0;
9205                                         ASSERT(rw == S_READ);
9206                                 }
9207                         }
9208                 }
9209                 ASSERT(rw == S_READ || wlen == lpgeaddr - lpgaddr);
9210                 ASSERT(rw == S_WRITE || wlen <= lpgeaddr - lpgaddr);
9211         }
9212 
9213         /*
9214          * Only build large page adjusted shadow list if we expect to insert
9215          * it into pcache. For large enough pages it's a big overhead to
9216          * create a shadow list of the entire large page. But this overhead
9217          * should be amortized over repeated pcache hits on subsequent reuse
9218          * of this shadow list (IO into any range within this shadow list will
9219          * find it in pcache since we large page align the request for pcache
9220          * lookups). pcache performance is improved with bigger shadow lists
9221          * as it reduces the time to pcache the entire big segment and reduces
9222          * pcache chain length.
9223          */
9224         if (seg_pinsert_check(seg, pamp, paddr,
9225             lpgeaddr - lpgaddr, pflags) == SEGP_SUCCESS) {
9226                 addr = lpgaddr;
9227                 len = lpgeaddr - lpgaddr;
9228                 use_pcache = 1;
9229         } else {
9230                 use_pcache = 0;
9231                 /*
9232                  * Since this entry will not be inserted into the pcache, we
9233                  * will not do any adjustments to the starting address or
9234                  * size of the memory to be locked.
9235                  */
9236                 adjustpages = 0;
9237         }
9238         npages = btop(len);
9239 
9240         pplist = kmem_alloc(sizeof (page_t *) * (npages + 1), KM_SLEEP);
9241         pl = pplist;
9242         *ppp = pplist + adjustpages;
9243         /*
9244          * If use_pcache is 0 this shadow list is not large page adjusted.
9245          * Record this info in the last entry of shadow array so that
9246          * L_PAGEUNLOCK can determine if it should large page adjust the
9247          * address range to find the real range that was locked.
9248          */
9249         pl[npages] = use_pcache ? PCACHE_SHWLIST : NOPCACHE_SHWLIST;
9250 
9251         page = seg_page(seg, addr);
9252         anon_index = svd->anon_index + page;
9253 
9254         anlock = 0;
9255         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9256         ASSERT(amp->a_szc >= seg->s_szc);
9257         anpgcnt = page_get_pagecnt(amp->a_szc);
9258         for (a = addr; a < addr + len; a += PAGESIZE, anon_index++) {
9259                 struct anon *ap;
9260                 struct vnode *vp;
9261                 u_offset_t off;
9262 
9263                 /*
9264                  * Lock and unlock anon array only once per large page.
9265                  * anon_array_enter() locks the root anon slot according to
9266                  * a_szc which can't change while anon map is locked.  We lock
9267                  * anon the first time through this loop and each time we
9268                  * reach anon index that corresponds to a root of a large
9269                  * page.
9270                  */
9271                 if (a == addr || P2PHASE(anon_index, anpgcnt) == 0) {
9272                         ASSERT(anlock == 0);
9273                         anon_array_enter(amp, anon_index, &cookie);
9274                         anlock = 1;
9275                 }
9276                 ap = anon_get_ptr(amp->ahp, anon_index);
9277 
9278                 /*
9279                  * We must never use seg_pcache for COW pages
9280                  * because we might end up with original page still
9281                  * lying in seg_pcache even after private page is
9282                  * created. This leads to data corruption as
9283                  * aio_write refers to the page still in cache
9284                  * while all other accesses refer to the private
9285                  * page.
9286                  */
9287                 if (ap == NULL || ap->an_refcnt != 1) {
9288                         struct vpage *vpage;
9289 
9290                         if (seg->s_szc) {
9291                                 error = EFAULT;
9292                                 break;
9293                         }
9294                         if (svd->vpage != NULL) {
9295                                 vpage = &svd->vpage[seg_page(seg, a)];
9296                         } else {
9297                                 vpage = NULL;
9298                         }
9299                         ASSERT(anlock);
9300                         anon_array_exit(&cookie);
9301                         anlock = 0;
9302                         pp = NULL;
9303                         error = segvn_faultpage(seg->s_as->a_hat, seg, a, 0,
9304                             vpage, &pp, 0, F_INVAL, rw, 1);
9305                         if (error) {
9306                                 error = fc_decode(error);
9307                                 break;
9308                         }
9309                         anon_array_enter(amp, anon_index, &cookie);
9310                         anlock = 1;
9311                         ap = anon_get_ptr(amp->ahp, anon_index);
9312                         if (ap == NULL || ap->an_refcnt != 1) {
9313                                 error = EFAULT;
9314                                 break;
9315                         }
9316                 }
9317                 swap_xlate(ap, &vp, &off);
9318                 pp = page_lookup_nowait(vp, off, SE_SHARED);
9319                 if (pp == NULL) {
9320                         error = EFAULT;
9321                         break;
9322                 }
9323                 if (ap->an_pvp != NULL) {
9324                         anon_swap_free(ap, pp);
9325                 }
9326                 /*
9327                  * Unlock anon if this is the last slot in a large page.
9328                  */
9329                 if (P2PHASE(anon_index, anpgcnt) == anpgcnt - 1) {
9330                         ASSERT(anlock);
9331                         anon_array_exit(&cookie);
9332                         anlock = 0;
9333                 }
9334                 *pplist++ = pp;
9335         }
9336         if (anlock) {           /* Ensure the lock is dropped */
9337                 anon_array_exit(&cookie);
9338         }
9339         ANON_LOCK_EXIT(&amp->a_rwlock);
9340 
9341         if (a >= addr + len) {
9342                 atomic_add_long((ulong_t *)&svd->softlockcnt, npages);
9343                 if (pamp != NULL) {
9344                         ASSERT(svd->type == MAP_SHARED);
9345                         atomic_add_long((ulong_t *)&pamp->a_softlockcnt,
9346                             npages);
9347                         wlen = len;
9348                 }
9349                 if (sftlck_sbase) {
9350                         atomic_inc_ulong((ulong_t *)&svd->softlockcnt_sbase);
9351                 }
9352                 if (sftlck_send) {
9353                         atomic_inc_ulong((ulong_t *)&svd->softlockcnt_send);
9354                 }
9355                 if (use_pcache) {
9356                         (void) seg_pinsert(seg, pamp, paddr, len, wlen, pl,
9357                             rw, pflags, preclaim_callback);
9358                 }
9359                 SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9360                 TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_FILL_END,
9361                     "segvn_pagelock: cache fill seg %p addr %p", seg, addr);
9362                 return (0);
9363         }
9364 
9365         pplist = pl;
9366         np = ((uintptr_t)(a - addr)) >> PAGESHIFT;
9367         while (np > (uint_t)0) {
9368                 ASSERT(PAGE_LOCKED(*pplist));
9369                 page_unlock(*pplist);
9370                 np--;
9371                 pplist++;
9372         }
9373         kmem_free(pl, sizeof (page_t *) * (npages + 1));
9374 out:
9375         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9376         *ppp = NULL;
9377         TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_MISS_END,
9378             "segvn_pagelock: cache miss seg %p addr %p", seg, addr);
9379         return (error);
9380 }
9381 
9382 /*
9383  * purge any cached pages in the I/O page cache
9384  */
9385 static void
9386 segvn_purge(struct seg *seg)
9387 {
9388         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9389 
9390         /*
9391          * pcache is only used by pure anon segments.
9392          */
9393         if (svd->amp == NULL || svd->vp != NULL) {
9394                 return;
9395         }
9396 
9397         /*
9398          * For MAP_SHARED segments non 0 segment's softlockcnt means
9399          * active IO is still in progress via this segment. So we only
9400          * purge MAP_SHARED segments when their softlockcnt is 0.
9401          */
9402         if (svd->type == MAP_PRIVATE) {
9403                 if (svd->softlockcnt) {
9404                         seg_ppurge(seg, NULL, 0);
9405                 }
9406         } else if (svd->softlockcnt == 0 && svd->amp->a_softlockcnt != 0) {
9407                 seg_ppurge(seg, svd->amp, 0);
9408         }
9409 }
9410 
9411 /*
9412  * If async argument is not 0 we are called from pcache async thread and don't
9413  * hold AS lock.
9414  */
9415 
9416 /*ARGSUSED*/
9417 static int
9418 segvn_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9419         enum seg_rw rw, int async)
9420 {
9421         struct seg *seg = (struct seg *)ptag;
9422         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9423         pgcnt_t np, npages;
9424         struct page **pl;
9425 
9426         npages = np = btop(len);
9427         ASSERT(npages);
9428 
9429         ASSERT(svd->vp == NULL && svd->amp != NULL);
9430         ASSERT(svd->softlockcnt >= npages);
9431         ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9432 
9433         pl = pplist;
9434 
9435         ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9436         ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9437 
9438         while (np > (uint_t)0) {
9439                 if (rw == S_WRITE) {
9440                         hat_setrefmod(*pplist);
9441                 } else {
9442                         hat_setref(*pplist);
9443                 }
9444                 page_unlock(*pplist);
9445                 np--;
9446                 pplist++;
9447         }
9448 
9449         kmem_free(pl, sizeof (page_t *) * (npages + 1));
9450 
9451         /*
9452          * If we are pcache async thread we don't hold AS lock. This means if
9453          * softlockcnt drops to 0 after the decrement below address space may
9454          * get freed. We can't allow it since after softlock derement to 0 we
9455          * still need to access as structure for possible wakeup of unmap
9456          * waiters. To prevent the disappearance of as we take this segment
9457          * segfree_syncmtx. segvn_free() also takes this mutex as a barrier to
9458          * make sure this routine completes before segment is freed.
9459          *
9460          * The second complication we have to deal with in async case is a
9461          * possibility of missed wake up of unmap wait thread. When we don't
9462          * hold as lock here we may take a_contents lock before unmap wait
9463          * thread that was first to see softlockcnt was still not 0. As a
9464          * result we'll fail to wake up an unmap wait thread. To avoid this
9465          * race we set nounmapwait flag in as structure if we drop softlockcnt
9466          * to 0 when we were called by pcache async thread.  unmapwait thread
9467          * will not block if this flag is set.
9468          */
9469         if (async) {
9470                 mutex_enter(&svd->segfree_syncmtx);
9471         }
9472 
9473         if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -npages)) {
9474                 if (async || AS_ISUNMAPWAIT(seg->s_as)) {
9475                         mutex_enter(&seg->s_as->a_contents);
9476                         if (async) {
9477                                 AS_SETNOUNMAPWAIT(seg->s_as);
9478                         }
9479                         if (AS_ISUNMAPWAIT(seg->s_as)) {
9480                                 AS_CLRUNMAPWAIT(seg->s_as);
9481                                 cv_broadcast(&seg->s_as->a_cv);
9482                         }
9483                         mutex_exit(&seg->s_as->a_contents);
9484                 }
9485         }
9486 
9487         if (async) {
9488                 mutex_exit(&svd->segfree_syncmtx);
9489         }
9490         return (0);
9491 }
9492 
9493 /*ARGSUSED*/
9494 static int
9495 shamp_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9496         enum seg_rw rw, int async)
9497 {
9498         amp_t *amp = (amp_t *)ptag;
9499         pgcnt_t np, npages;
9500         struct page **pl;
9501 
9502         npages = np = btop(len);
9503         ASSERT(npages);
9504         ASSERT(amp->a_softlockcnt >= npages);
9505 
9506         pl = pplist;
9507 
9508         ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9509         ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9510 
9511         while (np > (uint_t)0) {
9512                 if (rw == S_WRITE) {
9513                         hat_setrefmod(*pplist);
9514                 } else {
9515                         hat_setref(*pplist);
9516                 }
9517                 page_unlock(*pplist);
9518                 np--;
9519                 pplist++;
9520         }
9521 
9522         kmem_free(pl, sizeof (page_t *) * (npages + 1));
9523 
9524         /*
9525          * If somebody sleeps in anonmap_purge() wake them up if a_softlockcnt
9526          * drops to 0. anon map can't be freed until a_softlockcnt drops to 0
9527          * and anonmap_purge() acquires a_purgemtx.
9528          */
9529         mutex_enter(&amp->a_purgemtx);
9530         if (!atomic_add_long_nv((ulong_t *)&amp->a_softlockcnt, -npages) &&
9531             amp->a_purgewait) {
9532                 amp->a_purgewait = 0;
9533                 cv_broadcast(&amp->a_purgecv);
9534         }
9535         mutex_exit(&amp->a_purgemtx);
9536         return (0);
9537 }
9538 
9539 /*
9540  * get a memory ID for an addr in a given segment
9541  *
9542  * XXX only creates PAGESIZE pages if anon slots are not initialized.
9543  * At fault time they will be relocated into larger pages.
9544  */
9545 static int
9546 segvn_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
9547 {
9548         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9549         struct anon     *ap = NULL;
9550         ulong_t         anon_index;
9551         struct anon_map *amp;
9552         anon_sync_obj_t cookie;
9553 
9554         if (svd->type == MAP_PRIVATE) {
9555                 memidp->val[0] = (uintptr_t)seg->s_as;
9556                 memidp->val[1] = (uintptr_t)addr;
9557                 return (0);
9558         }
9559 
9560         if (svd->type == MAP_SHARED) {
9561                 if (svd->vp) {
9562                         memidp->val[0] = (uintptr_t)svd->vp;
9563                         memidp->val[1] = (u_longlong_t)svd->offset +
9564                             (uintptr_t)(addr - seg->s_base);
9565                         return (0);
9566                 } else {
9567 
9568                         SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
9569                         if ((amp = svd->amp) != NULL) {
9570                                 anon_index = svd->anon_index +
9571                                     seg_page(seg, addr);
9572                         }
9573                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9574 
9575                         ASSERT(amp != NULL);
9576 
9577                         ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9578                         anon_array_enter(amp, anon_index, &cookie);
9579                         ap = anon_get_ptr(amp->ahp, anon_index);
9580                         if (ap == NULL) {
9581                                 page_t          *pp;
9582 
9583                                 pp = anon_zero(seg, addr, &ap, svd->cred);
9584                                 if (pp == NULL) {
9585                                         anon_array_exit(&cookie);
9586                                         ANON_LOCK_EXIT(&amp->a_rwlock);
9587                                         return (ENOMEM);
9588                                 }
9589                                 ASSERT(anon_get_ptr(amp->ahp, anon_index)
9590                                     == NULL);
9591                                 (void) anon_set_ptr(amp->ahp, anon_index,
9592                                     ap, ANON_SLEEP);
9593                                 page_unlock(pp);
9594                         }
9595 
9596                         anon_array_exit(&cookie);
9597                         ANON_LOCK_EXIT(&amp->a_rwlock);
9598 
9599                         memidp->val[0] = (uintptr_t)ap;
9600                         memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
9601                         return (0);
9602                 }
9603         }
9604         return (EINVAL);
9605 }
9606 
9607 static int
9608 sameprot(struct seg *seg, caddr_t a, size_t len)
9609 {
9610         struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9611         struct vpage *vpage;
9612         spgcnt_t pages = btop(len);
9613         uint_t prot;
9614 
9615         if (svd->pageprot == 0)
9616                 return (1);
9617 
9618         ASSERT(svd->vpage != NULL);
9619 
9620         vpage = &svd->vpage[seg_page(seg, a)];
9621         prot = VPP_PROT(vpage);
9622         vpage++;
9623         pages--;
9624         while (pages-- > 0) {
9625                 if (prot != VPP_PROT(vpage))
9626                         return (0);
9627                 vpage++;
9628         }
9629         return (1);
9630 }
9631 
9632 /*
9633  * Get memory allocation policy info for specified address in given segment
9634  */
9635 static lgrp_mem_policy_info_t *
9636 segvn_getpolicy(struct seg *seg, caddr_t addr)
9637 {
9638         struct anon_map         *amp;
9639         ulong_t                 anon_index;
9640         lgrp_mem_policy_info_t  *policy_info;
9641         struct segvn_data       *svn_data;
9642         u_offset_t              vn_off;
9643         vnode_t                 *vp;
9644 
9645         ASSERT(seg != NULL);
9646 
9647         svn_data = (struct segvn_data *)seg->s_data;
9648         if (svn_data == NULL)
9649                 return (NULL);
9650 
9651         /*
9652          * Get policy info for private or shared memory
9653          */
9654         if (svn_data->type != MAP_SHARED) {
9655                 if (svn_data->tr_state != SEGVN_TR_ON) {
9656                         policy_info = &svn_data->policy_info;
9657                 } else {
9658                         policy_info = &svn_data->tr_policy_info;
9659                         ASSERT(policy_info->mem_policy ==
9660                             LGRP_MEM_POLICY_NEXT_SEG);
9661                 }
9662         } else {
9663                 amp = svn_data->amp;
9664                 anon_index = svn_data->anon_index + seg_page(seg, addr);
9665                 vp = svn_data->vp;
9666                 vn_off = svn_data->offset + (uintptr_t)(addr - seg->s_base);
9667                 policy_info = lgrp_shm_policy_get(amp, anon_index, vp, vn_off);
9668         }
9669 
9670         return (policy_info);
9671 }
9672 
9673 /*ARGSUSED*/
9674 static int
9675 segvn_capable(struct seg *seg, segcapability_t capability)
9676 {
9677         return (0);
9678 }
9679 
9680 /*
9681  * Bind text vnode segment to an amp. If we bind successfully mappings will be
9682  * established to per vnode mapping per lgroup amp pages instead of to vnode
9683  * pages. There's one amp per vnode text mapping per lgroup. Many processes
9684  * may share the same text replication amp. If a suitable amp doesn't already
9685  * exist in svntr hash table create a new one.  We may fail to bind to amp if
9686  * segment is not eligible for text replication.  Code below first checks for
9687  * these conditions. If binding is successful segment tr_state is set to on
9688  * and svd->amp points to the amp to use. Otherwise tr_state is set to off and
9689  * svd->amp remains as NULL.
9690  */
9691 static void
9692 segvn_textrepl(struct seg *seg)
9693 {
9694         struct segvn_data       *svd = (struct segvn_data *)seg->s_data;
9695         vnode_t                 *vp = svd->vp;
9696         u_offset_t              off = svd->offset;
9697         size_t                  size = seg->s_size;
9698         u_offset_t              eoff = off + size;
9699         uint_t                  szc = seg->s_szc;
9700         ulong_t                 hash = SVNTR_HASH_FUNC(vp);
9701         svntr_t                 *svntrp;
9702         struct vattr            va;
9703         proc_t                  *p = seg->s_as->a_proc;
9704         lgrp_id_t               lgrp_id;
9705         lgrp_id_t               olid;
9706         int                     first;
9707         struct anon_map         *amp;
9708 
9709         ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9710         ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9711         ASSERT(p != NULL);
9712         ASSERT(svd->tr_state == SEGVN_TR_INIT);
9713         ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9714         ASSERT(svd->flags & MAP_TEXT);
9715         ASSERT(svd->type == MAP_PRIVATE);
9716         ASSERT(vp != NULL && svd->amp == NULL);
9717         ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
9718         ASSERT(!(svd->flags & MAP_NORESERVE) && svd->swresv == 0);
9719         ASSERT(seg->s_as != &kas);
9720         ASSERT(off < eoff);
9721         ASSERT(svntr_hashtab != NULL);
9722 
9723         /*
9724          * If numa optimizations are no longer desired bail out.
9725          */
9726         if (!lgrp_optimizations()) {
9727                 svd->tr_state = SEGVN_TR_OFF;
9728                 return;
9729         }
9730 
9731         /*
9732          * Avoid creating anon maps with size bigger than the file size.
9733          * If VOP_GETATTR() call fails bail out.
9734          */
9735         va.va_mask = AT_SIZE | AT_MTIME | AT_CTIME;
9736         if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL) != 0) {
9737                 svd->tr_state = SEGVN_TR_OFF;
9738                 SEGVN_TR_ADDSTAT(gaerr);
9739                 return;
9740         }
9741         if (btopr(va.va_size) < btopr(eoff)) {
9742                 svd->tr_state = SEGVN_TR_OFF;
9743                 SEGVN_TR_ADDSTAT(overmap);
9744                 return;
9745         }
9746 
9747         /*
9748          * VVMEXEC may not be set yet if exec() prefaults text segment. Set
9749          * this flag now before vn_is_mapped(V_WRITE) so that MAP_SHARED
9750          * mapping that checks if trcache for this vnode needs to be
9751          * invalidated can't miss us.
9752          */
9753         if (!(vp->v_flag & VVMEXEC)) {
9754                 mutex_enter(&vp->v_lock);
9755                 vp->v_flag |= VVMEXEC;
9756                 mutex_exit(&vp->v_lock);
9757         }
9758         mutex_enter(&svntr_hashtab[hash].tr_lock);
9759         /*
9760          * Bail out if potentially MAP_SHARED writable mappings exist to this
9761          * vnode.  We don't want to use old file contents from existing
9762          * replicas if this mapping was established after the original file
9763          * was changed.
9764          */
9765         if (vn_is_mapped(vp, V_WRITE)) {
9766                 mutex_exit(&svntr_hashtab[hash].tr_lock);
9767                 svd->tr_state = SEGVN_TR_OFF;
9768                 SEGVN_TR_ADDSTAT(wrcnt);
9769                 return;
9770         }
9771         svntrp = svntr_hashtab[hash].tr_head;
9772         for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9773                 ASSERT(svntrp->tr_refcnt != 0);
9774                 if (svntrp->tr_vp != vp) {
9775                         continue;
9776                 }
9777 
9778                 /*
9779                  * Bail out if the file or its attributes were changed after
9780                  * this replication entry was created since we need to use the
9781                  * latest file contents. Note that mtime test alone is not
9782                  * sufficient because a user can explicitly change mtime via
9783                  * utimes(2) interfaces back to the old value after modifiying
9784                  * the file contents. To detect this case we also have to test
9785                  * ctime which among other things records the time of the last
9786                  * mtime change by utimes(2). ctime is not changed when the file
9787                  * is only read or executed so we expect that typically existing
9788                  * replication amp's can be used most of the time.
9789                  */
9790                 if (!svntrp->tr_valid ||
9791                     svntrp->tr_mtime.tv_sec != va.va_mtime.tv_sec ||
9792                     svntrp->tr_mtime.tv_nsec != va.va_mtime.tv_nsec ||
9793                     svntrp->tr_ctime.tv_sec != va.va_ctime.tv_sec ||
9794                     svntrp->tr_ctime.tv_nsec != va.va_ctime.tv_nsec) {
9795                         mutex_exit(&svntr_hashtab[hash].tr_lock);
9796                         svd->tr_state = SEGVN_TR_OFF;
9797                         SEGVN_TR_ADDSTAT(stale);
9798                         return;
9799                 }
9800                 /*
9801                  * if off, eoff and szc match current segment we found the
9802                  * existing entry we can use.
9803                  */
9804                 if (svntrp->tr_off == off && svntrp->tr_eoff == eoff &&
9805                     svntrp->tr_szc == szc) {
9806                         break;
9807                 }
9808                 /*
9809                  * Don't create different but overlapping in file offsets
9810                  * entries to avoid replication of the same file pages more
9811                  * than once per lgroup.
9812                  */
9813                 if ((off >= svntrp->tr_off && off < svntrp->tr_eoff) ||
9814                     (eoff > svntrp->tr_off && eoff <= svntrp->tr_eoff)) {
9815                         mutex_exit(&svntr_hashtab[hash].tr_lock);
9816                         svd->tr_state = SEGVN_TR_OFF;
9817                         SEGVN_TR_ADDSTAT(overlap);
9818                         return;
9819                 }
9820         }
9821         /*
9822          * If we didn't find existing entry create a new one.
9823          */
9824         if (svntrp == NULL) {
9825                 svntrp = kmem_cache_alloc(svntr_cache, KM_NOSLEEP);
9826                 if (svntrp == NULL) {
9827                         mutex_exit(&svntr_hashtab[hash].tr_lock);
9828                         svd->tr_state = SEGVN_TR_OFF;
9829                         SEGVN_TR_ADDSTAT(nokmem);
9830                         return;
9831                 }
9832 #ifdef DEBUG
9833                 {
9834                         lgrp_id_t i;
9835                         for (i = 0; i < NLGRPS_MAX; i++) {
9836                                 ASSERT(svntrp->tr_amp[i] == NULL);
9837                         }
9838                 }
9839 #endif /* DEBUG */
9840                 svntrp->tr_vp = vp;
9841                 svntrp->tr_off = off;
9842                 svntrp->tr_eoff = eoff;
9843                 svntrp->tr_szc = szc;
9844                 svntrp->tr_valid = 1;
9845                 svntrp->tr_mtime = va.va_mtime;
9846                 svntrp->tr_ctime = va.va_ctime;
9847                 svntrp->tr_refcnt = 0;
9848                 svntrp->tr_next = svntr_hashtab[hash].tr_head;
9849                 svntr_hashtab[hash].tr_head = svntrp;
9850         }
9851         first = 1;
9852 again:
9853         /*
9854          * We want to pick a replica with pages on main thread's (t_tid = 1,
9855          * aka T1) lgrp. Currently text replication is only optimized for
9856          * workloads that either have all threads of a process on the same
9857          * lgrp or execute their large text primarily on main thread.
9858          */
9859         lgrp_id = p->p_t1_lgrpid;
9860         if (lgrp_id == LGRP_NONE) {
9861                 /*
9862                  * In case exec() prefaults text on non main thread use
9863                  * current thread lgrpid.  It will become main thread anyway
9864                  * soon.
9865                  */
9866                 lgrp_id = lgrp_home_id(curthread);
9867         }
9868         /*
9869          * Set p_tr_lgrpid to lgrpid if it hasn't been set yet.  Otherwise
9870          * just set it to NLGRPS_MAX if it's different from current process T1
9871          * home lgrp.  p_tr_lgrpid is used to detect if process uses text
9872          * replication and T1 new home is different from lgrp used for text
9873          * replication. When this happens asyncronous segvn thread rechecks if
9874          * segments should change lgrps used for text replication.  If we fail
9875          * to set p_tr_lgrpid with atomic_cas_32 then set it to NLGRPS_MAX
9876          * without cas if it's not already NLGRPS_MAX and not equal lgrp_id
9877          * we want to use.  We don't need to use cas in this case because
9878          * another thread that races in between our non atomic check and set
9879          * may only change p_tr_lgrpid to NLGRPS_MAX at this point.
9880          */
9881         ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9882         olid = p->p_tr_lgrpid;
9883         if (lgrp_id != olid && olid != NLGRPS_MAX) {
9884                 lgrp_id_t nlid = (olid == LGRP_NONE) ? lgrp_id : NLGRPS_MAX;
9885                 if (atomic_cas_32((uint32_t *)&p->p_tr_lgrpid, olid, nlid) !=
9886                     olid) {
9887                         olid = p->p_tr_lgrpid;
9888                         ASSERT(olid != LGRP_NONE);
9889                         if (olid != lgrp_id && olid != NLGRPS_MAX) {
9890                                 p->p_tr_lgrpid = NLGRPS_MAX;
9891                         }
9892                 }
9893                 ASSERT(p->p_tr_lgrpid != LGRP_NONE);
9894                 membar_producer();
9895                 /*
9896                  * lgrp_move_thread() won't schedule async recheck after
9897                  * p->p_t1_lgrpid update unless p->p_tr_lgrpid is not
9898                  * LGRP_NONE. Recheck p_t1_lgrpid once now that p->p_tr_lgrpid
9899                  * is not LGRP_NONE.
9900                  */
9901                 if (first && p->p_t1_lgrpid != LGRP_NONE &&
9902                     p->p_t1_lgrpid != lgrp_id) {
9903                         first = 0;
9904                         goto again;
9905                 }
9906         }
9907         /*
9908          * If no amp was created yet for lgrp_id create a new one as long as
9909          * we have enough memory to afford it.
9910          */
9911         if ((amp = svntrp->tr_amp[lgrp_id]) == NULL) {
9912                 size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
9913                 if (trmem > segvn_textrepl_max_bytes) {
9914                         SEGVN_TR_ADDSTAT(normem);
9915                         goto fail;
9916                 }
9917                 if (anon_try_resv_zone(size, NULL) == 0) {
9918                         SEGVN_TR_ADDSTAT(noanon);
9919                         goto fail;
9920                 }
9921                 amp = anonmap_alloc(size, size, ANON_NOSLEEP);
9922                 if (amp == NULL) {
9923                         anon_unresv_zone(size, NULL);
9924                         SEGVN_TR_ADDSTAT(nokmem);
9925                         goto fail;
9926                 }
9927                 ASSERT(amp->refcnt == 1);
9928                 amp->a_szc = szc;
9929                 svntrp->tr_amp[lgrp_id] = amp;
9930                 SEGVN_TR_ADDSTAT(newamp);
9931         }
9932         svntrp->tr_refcnt++;
9933         ASSERT(svd->svn_trnext == NULL);
9934         ASSERT(svd->svn_trprev == NULL);
9935         svd->svn_trnext = svntrp->tr_svnhead;
9936         svd->svn_trprev = NULL;
9937         if (svntrp->tr_svnhead != NULL) {
9938                 svntrp->tr_svnhead->svn_trprev = svd;
9939         }
9940         svntrp->tr_svnhead = svd;
9941         ASSERT(amp->a_szc == szc && amp->size == size && amp->swresv == size);
9942         ASSERT(amp->refcnt >= 1);
9943         svd->amp = amp;
9944         svd->anon_index = 0;
9945         svd->tr_policy_info.mem_policy = LGRP_MEM_POLICY_NEXT_SEG;
9946         svd->tr_policy_info.mem_lgrpid = lgrp_id;
9947         svd->tr_state = SEGVN_TR_ON;
9948         mutex_exit(&svntr_hashtab[hash].tr_lock);
9949         SEGVN_TR_ADDSTAT(repl);
9950         return;
9951 fail:
9952         ASSERT(segvn_textrepl_bytes >= size);
9953         atomic_add_long(&segvn_textrepl_bytes, -size);
9954         ASSERT(svntrp != NULL);
9955         ASSERT(svntrp->tr_amp[lgrp_id] == NULL);
9956         if (svntrp->tr_refcnt == 0) {
9957                 ASSERT(svntrp == svntr_hashtab[hash].tr_head);
9958                 svntr_hashtab[hash].tr_head = svntrp->tr_next;
9959                 mutex_exit(&svntr_hashtab[hash].tr_lock);
9960                 kmem_cache_free(svntr_cache, svntrp);
9961         } else {
9962                 mutex_exit(&svntr_hashtab[hash].tr_lock);
9963         }
9964         svd->tr_state = SEGVN_TR_OFF;
9965 }
9966 
9967 /*
9968  * Convert seg back to regular vnode mapping seg by unbinding it from its text
9969  * replication amp.  This routine is most typically called when segment is
9970  * unmapped but can also be called when segment no longer qualifies for text
9971  * replication (e.g. due to protection changes). If unload_unmap is set use
9972  * HAT_UNLOAD_UNMAP flag in hat_unload_callback().  If we are the last user of
9973  * svntr free all its anon maps and remove it from the hash table.
9974  */
9975 static void
9976 segvn_textunrepl(struct seg *seg, int unload_unmap)
9977 {
9978         struct segvn_data       *svd = (struct segvn_data *)seg->s_data;
9979         vnode_t                 *vp = svd->vp;
9980         u_offset_t              off = svd->offset;
9981         size_t                  size = seg->s_size;
9982         u_offset_t              eoff = off + size;
9983         uint_t                  szc = seg->s_szc;
9984         ulong_t                 hash = SVNTR_HASH_FUNC(vp);
9985         svntr_t                 *svntrp;
9986         svntr_t                 **prv_svntrp;
9987         lgrp_id_t               lgrp_id = svd->tr_policy_info.mem_lgrpid;
9988         lgrp_id_t               i;
9989 
9990         ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9991         ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
9992             SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9993         ASSERT(svd->tr_state == SEGVN_TR_ON);
9994         ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9995         ASSERT(svd->amp != NULL);
9996         ASSERT(svd->amp->refcnt >= 1);
9997         ASSERT(svd->anon_index == 0);
9998         ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9999         ASSERT(svntr_hashtab != NULL);
10000 
10001         mutex_enter(&svntr_hashtab[hash].tr_lock);
10002         prv_svntrp = &svntr_hashtab[hash].tr_head;
10003         for (; (svntrp = *prv_svntrp) != NULL; prv_svntrp = &svntrp->tr_next) {
10004                 ASSERT(svntrp->tr_refcnt != 0);
10005                 if (svntrp->tr_vp == vp && svntrp->tr_off == off &&
10006                     svntrp->tr_eoff == eoff && svntrp->tr_szc == szc) {
10007                         break;
10008                 }
10009         }
10010         if (svntrp == NULL) {
10011                 panic("segvn_textunrepl: svntr record not found");
10012         }
10013         if (svntrp->tr_amp[lgrp_id] != svd->amp) {
10014                 panic("segvn_textunrepl: amp mismatch");
10015         }
10016         svd->tr_state = SEGVN_TR_OFF;
10017         svd->amp = NULL;
10018         if (svd->svn_trprev == NULL) {
10019                 ASSERT(svntrp->tr_svnhead == svd);
10020                 svntrp->tr_svnhead = svd->svn_trnext;
10021                 if (svntrp->tr_svnhead != NULL) {
10022                         svntrp->tr_svnhead->svn_trprev = NULL;
10023                 }
10024                 svd->svn_trnext = NULL;
10025         } else {
10026                 svd->svn_trprev->svn_trnext = svd->svn_trnext;
10027                 if (svd->svn_trnext != NULL) {
10028                         svd->svn_trnext->svn_trprev = svd->svn_trprev;
10029                         svd->svn_trnext = NULL;
10030                 }
10031                 svd->svn_trprev = NULL;
10032         }
10033         if (--svntrp->tr_refcnt) {
10034                 mutex_exit(&svntr_hashtab[hash].tr_lock);
10035                 goto done;
10036         }
10037         *prv_svntrp = svntrp->tr_next;
10038         mutex_exit(&svntr_hashtab[hash].tr_lock);
10039         for (i = 0; i < NLGRPS_MAX; i++) {
10040                 struct anon_map *amp = svntrp->tr_amp[i];
10041                 if (amp == NULL) {
10042                         continue;
10043                 }
10044                 ASSERT(amp->refcnt == 1);
10045                 ASSERT(amp->swresv == size);
10046                 ASSERT(amp->size == size);
10047                 ASSERT(amp->a_szc == szc);
10048                 if (amp->a_szc != 0) {
10049                         anon_free_pages(amp->ahp, 0, size, szc);
10050                 } else {
10051                         anon_free(amp->ahp, 0, size);
10052                 }
10053                 svntrp->tr_amp[i] = NULL;
10054                 ASSERT(segvn_textrepl_bytes >= size);
10055                 atomic_add_long(&segvn_textrepl_bytes, -size);
10056                 anon_unresv_zone(amp->swresv, NULL);
10057                 amp->refcnt = 0;
10058                 anonmap_free(amp);
10059         }
10060         kmem_cache_free(svntr_cache, svntrp);
10061 done:
10062         hat_unload_callback(seg->s_as->a_hat, seg->s_base, size,
10063             unload_unmap ? HAT_UNLOAD_UNMAP : 0, NULL);
10064 }
10065 
10066 /*
10067  * This is called when a MAP_SHARED writable mapping is created to a vnode
10068  * that is currently used for execution (VVMEXEC flag is set). In this case we
10069  * need to prevent further use of existing replicas.
10070  */
10071 static void
10072 segvn_inval_trcache(vnode_t *vp)
10073 {
10074         ulong_t                 hash = SVNTR_HASH_FUNC(vp);
10075         svntr_t                 *svntrp;
10076 
10077         ASSERT(vp->v_flag & VVMEXEC);
10078 
10079         if (svntr_hashtab == NULL) {
10080                 return;
10081         }
10082 
10083         mutex_enter(&svntr_hashtab[hash].tr_lock);
10084         svntrp = svntr_hashtab[hash].tr_head;
10085         for (; svntrp != NULL; svntrp = svntrp->tr_next) {
10086                 ASSERT(svntrp->tr_refcnt != 0);
10087                 if (svntrp->tr_vp == vp && svntrp->tr_valid) {
10088                         svntrp->tr_valid = 0;
10089                 }
10090         }
10091         mutex_exit(&svntr_hashtab[hash].tr_lock);
10092 }
10093 
10094 static void
10095 segvn_trasync_thread(void)
10096 {
10097         callb_cpr_t cpr_info;
10098         kmutex_t cpr_lock;      /* just for CPR stuff */
10099 
10100         mutex_init(&cpr_lock, NULL, MUTEX_DEFAULT, NULL);
10101 
10102         CALLB_CPR_INIT(&cpr_info, &cpr_lock,
10103             callb_generic_cpr, "segvn_async");
10104 
10105         if (segvn_update_textrepl_interval == 0) {
10106                 segvn_update_textrepl_interval = segvn_update_tr_time * hz;
10107         } else {
10108                 segvn_update_textrepl_interval *= hz;
10109         }
10110         (void) timeout(segvn_trupdate_wakeup, NULL,
10111             segvn_update_textrepl_interval);
10112 
10113         for (;;) {
10114                 mutex_enter(&cpr_lock);
10115                 CALLB_CPR_SAFE_BEGIN(&cpr_info);
10116                 mutex_exit(&cpr_lock);
10117                 sema_p(&segvn_trasync_sem);
10118                 mutex_enter(&cpr_lock);
10119                 CALLB_CPR_SAFE_END(&cpr_info, &cpr_lock);
10120                 mutex_exit(&cpr_lock);
10121                 segvn_trupdate();
10122         }
10123 }
10124 
10125 static uint64_t segvn_lgrp_trthr_migrs_snpsht = 0;
10126 
10127 static void
10128 segvn_trupdate_wakeup(void *dummy)
10129 {
10130         uint64_t cur_lgrp_trthr_migrs = lgrp_get_trthr_migrations();
10131 
10132         if (cur_lgrp_trthr_migrs != segvn_lgrp_trthr_migrs_snpsht) {
10133                 segvn_lgrp_trthr_migrs_snpsht = cur_lgrp_trthr_migrs;
10134                 sema_v(&segvn_trasync_sem);
10135         }
10136 
10137         if (!segvn_disable_textrepl_update &&
10138             segvn_update_textrepl_interval != 0) {
10139                 (void) timeout(segvn_trupdate_wakeup, dummy,
10140                     segvn_update_textrepl_interval);
10141         }
10142 }
10143 
10144 static void
10145 segvn_trupdate(void)
10146 {
10147         ulong_t         hash;
10148         svntr_t         *svntrp;
10149         segvn_data_t    *svd;
10150 
10151         ASSERT(svntr_hashtab != NULL);
10152 
10153         for (hash = 0; hash < svntr_hashtab_sz; hash++) {
10154                 mutex_enter(&svntr_hashtab[hash].tr_lock);
10155                 svntrp = svntr_hashtab[hash].tr_head;
10156                 for (; svntrp != NULL; svntrp = svntrp->tr_next) {
10157                         ASSERT(svntrp->tr_refcnt != 0);
10158                         svd = svntrp->tr_svnhead;
10159                         for (; svd != NULL; svd = svd->svn_trnext) {
10160                                 segvn_trupdate_seg(svd->seg, svd, svntrp,
10161                                     hash);
10162                         }
10163                 }
10164                 mutex_exit(&svntr_hashtab[hash].tr_lock);
10165         }
10166 }
10167 
10168 static void
10169 segvn_trupdate_seg(struct seg *seg,
10170         segvn_data_t *svd,
10171         svntr_t *svntrp,
10172         ulong_t hash)
10173 {
10174         proc_t                  *p;
10175         lgrp_id_t               lgrp_id;
10176         struct as               *as;
10177         size_t                  size;
10178         struct anon_map         *amp;
10179 
10180         ASSERT(svd->vp != NULL);
10181         ASSERT(svd->vp == svntrp->tr_vp);
10182         ASSERT(svd->offset == svntrp->tr_off);
10183         ASSERT(svd->offset + seg->s_size == svntrp->tr_eoff);
10184         ASSERT(seg != NULL);
10185         ASSERT(svd->seg == seg);
10186         ASSERT(seg->s_data == (void *)svd);
10187         ASSERT(seg->s_szc == svntrp->tr_szc);
10188         ASSERT(svd->tr_state == SEGVN_TR_ON);
10189         ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
10190         ASSERT(svd->amp != NULL);
10191         ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10192         ASSERT(svd->tr_policy_info.mem_lgrpid != LGRP_NONE);
10193         ASSERT(svd->tr_policy_info.mem_lgrpid < NLGRPS_MAX);
10194         ASSERT(svntrp->tr_amp[svd->tr_policy_info.mem_lgrpid] == svd->amp);
10195         ASSERT(svntrp->tr_refcnt != 0);
10196         ASSERT(mutex_owned(&svntr_hashtab[hash].tr_lock));
10197 
10198         as = seg->s_as;
10199         ASSERT(as != NULL && as != &kas);
10200         p = as->a_proc;
10201         ASSERT(p != NULL);
10202         ASSERT(p->p_tr_lgrpid != LGRP_NONE);
10203         lgrp_id = p->p_t1_lgrpid;
10204         if (lgrp_id == LGRP_NONE) {
10205                 return;
10206         }
10207         ASSERT(lgrp_id < NLGRPS_MAX);
10208         if (svd->tr_policy_info.mem_lgrpid == lgrp_id) {
10209                 return;
10210         }
10211 
10212         /*
10213          * Use tryenter locking since we are locking as/seg and svntr hash
10214          * lock in reverse from syncrounous thread order.
10215          */
10216         if (!AS_LOCK_TRYENTER(as, &as->a_lock, RW_READER)) {
10217                 SEGVN_TR_ADDSTAT(nolock);
10218                 if (segvn_lgrp_trthr_migrs_snpsht) {
10219                         segvn_lgrp_trthr_migrs_snpsht = 0;
10220                 }
10221                 return;
10222         }
10223         if (!SEGVN_LOCK_TRYENTER(seg->s_as, &svd->lock, RW_WRITER)) {
10224                 AS_LOCK_EXIT(as, &as->a_lock);
10225                 SEGVN_TR_ADDSTAT(nolock);
10226                 if (segvn_lgrp_trthr_migrs_snpsht) {
10227                         segvn_lgrp_trthr_migrs_snpsht = 0;
10228                 }
10229                 return;
10230         }
10231         size = seg->s_size;
10232         if (svntrp->tr_amp[lgrp_id] == NULL) {
10233                 size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
10234                 if (trmem > segvn_textrepl_max_bytes) {
10235                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10236                         AS_LOCK_EXIT(as, &as->a_lock);
10237                         atomic_add_long(&segvn_textrepl_bytes, -size);
10238                         SEGVN_TR_ADDSTAT(normem);
10239                         return;
10240                 }
10241                 if (anon_try_resv_zone(size, NULL) == 0) {
10242                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10243                         AS_LOCK_EXIT(as, &as->a_lock);
10244                         atomic_add_long(&segvn_textrepl_bytes, -size);
10245                         SEGVN_TR_ADDSTAT(noanon);
10246                         return;
10247                 }
10248                 amp = anonmap_alloc(size, size, KM_NOSLEEP);
10249                 if (amp == NULL) {
10250                         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10251                         AS_LOCK_EXIT(as, &as->a_lock);
10252                         atomic_add_long(&segvn_textrepl_bytes, -size);
10253                         anon_unresv_zone(size, NULL);
10254                         SEGVN_TR_ADDSTAT(nokmem);
10255                         return;
10256                 }
10257                 ASSERT(amp->refcnt == 1);
10258                 amp->a_szc = seg->s_szc;
10259                 svntrp->tr_amp[lgrp_id] = amp;
10260         }
10261         /*
10262          * We don't need to drop the bucket lock but here we give other
10263          * threads a chance.  svntr and svd can't be unlinked as long as
10264          * segment lock is held as a writer and AS held as well.  After we
10265          * retake bucket lock we'll continue from where we left. We'll be able
10266          * to reach the end of either list since new entries are always added
10267          * to the beginning of the lists.
10268          */
10269         mutex_exit(&svntr_hashtab[hash].tr_lock);
10270         hat_unload_callback(as->a_hat, seg->s_base, size, 0, NULL);
10271         mutex_enter(&svntr_hashtab[hash].tr_lock);
10272 
10273         ASSERT(svd->tr_state == SEGVN_TR_ON);
10274         ASSERT(svd->amp != NULL);
10275         ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10276         ASSERT(svd->tr_policy_info.mem_lgrpid != lgrp_id);
10277         ASSERT(svd->amp != svntrp->tr_amp[lgrp_id]);
10278 
10279         svd->tr_policy_info.mem_lgrpid = lgrp_id;
10280         svd->amp = svntrp->tr_amp[lgrp_id];
10281         p->p_tr_lgrpid = NLGRPS_MAX;
10282         SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10283         AS_LOCK_EXIT(as, &as->a_lock);
10284 
10285         ASSERT(svntrp->tr_refcnt != 0);
10286         ASSERT(svd->vp == svntrp->tr_vp);
10287         ASSERT(svd->tr_policy_info.mem_lgrpid == lgrp_id);
10288         ASSERT(svd->amp != NULL && svd->amp == svntrp->tr_amp[lgrp_id]);
10289         ASSERT(svd->seg == seg);
10290         ASSERT(svd->tr_state == SEGVN_TR_ON);
10291 
10292         SEGVN_TR_ADDSTAT(asyncrepl);
10293 }