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6152 use NULL dump segop as a shorthand for no-op
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--- old/usr/src/uts/sparc/v9/vm/seg_nf.c
+++ new/usr/src/uts/sparc/v9/vm/seg_nf.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
23 23 * Use is subject to license terms.
24 24 */
25 25
26 26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 27 /* All Rights Reserved */
28 28
29 29 /*
30 30 * Portions of this source code were derived from Berkeley 4.3 BSD
31 31 * under license from the Regents of the University of California.
32 32 */
33 33
34 34 /*
35 35 * VM - segment for non-faulting loads.
36 36 */
37 37
38 38 #include <sys/types.h>
39 39 #include <sys/t_lock.h>
40 40 #include <sys/param.h>
41 41 #include <sys/mman.h>
42 42 #include <sys/errno.h>
43 43 #include <sys/kmem.h>
44 44 #include <sys/cmn_err.h>
45 45 #include <sys/vnode.h>
46 46 #include <sys/proc.h>
47 47 #include <sys/conf.h>
48 48 #include <sys/debug.h>
49 49 #include <sys/archsystm.h>
50 50 #include <sys/lgrp.h>
51 51
52 52 #include <vm/page.h>
53 53 #include <vm/hat.h>
54 54 #include <vm/as.h>
55 55 #include <vm/seg.h>
56 56 #include <vm/vpage.h>
57 57
58 58 /*
59 59 * Private seg op routines.
60 60 */
61 61 static int segnf_dup(struct seg *seg, struct seg *newseg);
62 62 static int segnf_unmap(struct seg *seg, caddr_t addr, size_t len);
63 63 static void segnf_free(struct seg *seg);
64 64 static faultcode_t segnf_nomap(void);
65 65 static int segnf_setprot(struct seg *seg, caddr_t addr,
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66 66 size_t len, uint_t prot);
67 67 static int segnf_checkprot(struct seg *seg, caddr_t addr,
68 68 size_t len, uint_t prot);
69 69 static void segnf_badop(void);
70 70 static int segnf_nop(void);
71 71 static int segnf_getprot(struct seg *seg, caddr_t addr,
72 72 size_t len, uint_t *protv);
73 73 static u_offset_t segnf_getoffset(struct seg *seg, caddr_t addr);
74 74 static int segnf_gettype(struct seg *seg, caddr_t addr);
75 75 static int segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
76 -static void segnf_dump(struct seg *seg);
77 76 static int segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
78 77 struct page ***ppp, enum lock_type type, enum seg_rw rw);
79 78
80 79
81 80 struct seg_ops segnf_ops = {
82 81 .dup = segnf_dup,
83 82 .unmap = segnf_unmap,
84 83 .free = segnf_free,
85 84 .fault = (faultcode_t (*)(struct hat *, struct seg *, caddr_t,
86 85 size_t, enum fault_type, enum seg_rw))segnf_nomap,
87 86 .faulta = (faultcode_t (*)(struct seg *, caddr_t)) segnf_nomap,
88 87 .setprot = segnf_setprot,
89 88 .checkprot = segnf_checkprot,
90 89 .kluster = (int (*)())segnf_badop,
91 90 .sync = (int (*)(struct seg *, caddr_t, size_t, int, uint_t))
92 91 segnf_nop,
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93 92 .incore = (size_t (*)(struct seg *, caddr_t, size_t, char *))
94 93 segnf_nop,
95 94 .lockop = (int (*)(struct seg *, caddr_t, size_t, int, int,
96 95 ulong_t *, size_t))segnf_nop,
97 96 .getprot = segnf_getprot,
98 97 .getoffset = segnf_getoffset,
99 98 .gettype = segnf_gettype,
100 99 .getvp = segnf_getvp,
101 100 .advise = (int (*)(struct seg *, caddr_t, size_t, uint_t))
102 101 segnf_nop,
103 - .dump = segnf_dump,
104 102 .pagelock = segnf_pagelock,
105 103 };
106 104
107 105 /*
108 106 * vnode and page for the page of zeros we use for the nf mappings.
109 107 */
110 108 static kmutex_t segnf_lock;
111 109 static struct vnode nfvp;
112 110 static struct page **nfpp;
113 111
114 112 #define addr_to_vcolor(addr) \
115 113 (shm_alignment) ? \
116 114 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0
117 115
118 116 /*
119 117 * We try to limit the number of Non-fault segments created.
120 118 * Non fault segments are created to optimize sparc V9 code which uses
121 119 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT).
122 120 *
123 121 * There are several reasons why creating too many non-fault segments
124 122 * could cause problems.
125 123 *
126 124 * First, excessive allocation of kernel resources for the seg
127 125 * structures and the HAT data to map the zero pages.
128 126 *
129 127 * Secondly, creating nofault segments actually uses up user virtual
130 128 * address space. This makes it unavailable for subsequent mmap(0, ...)
131 129 * calls which use as_gap() to find empty va regions. Creation of too
132 130 * many nofault segments could thus interfere with the ability of the
133 131 * runtime linker to load a shared object.
134 132 */
135 133 #define MAXSEGFORNF (10000)
136 134 #define MAXNFSEARCH (5)
137 135
138 136
139 137 /*
140 138 * Must be called from startup()
141 139 */
142 140 void
143 141 segnf_init()
144 142 {
145 143 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL);
146 144 }
147 145
148 146
149 147 /*
150 148 * Create a no-fault segment.
151 149 *
152 150 * The no-fault segment is not technically necessary, as the code in
153 151 * nfload() in trap.c will emulate the SPARC instruction and load
154 152 * a value of zero in the destination register.
155 153 *
156 154 * However, this code tries to put a page of zero's at the nofault address
157 155 * so that subsequent non-faulting loads to the same page will not
158 156 * trap with a tlb miss.
159 157 *
160 158 * In order to help limit the number of segments we merge adjacent nofault
161 159 * segments into a single segment. If we get a large number of segments
162 160 * we'll also try to delete a random other nf segment.
163 161 */
164 162 /* ARGSUSED */
165 163 int
166 164 segnf_create(struct seg *seg, void *argsp)
167 165 {
168 166 uint_t prot;
169 167 pgcnt_t vacpgs;
170 168 u_offset_t off = 0;
171 169 caddr_t vaddr = NULL;
172 170 int i, color;
173 171 struct seg *s1;
174 172 struct seg *s2;
175 173 size_t size;
176 174 struct as *as = seg->s_as;
177 175
178 176 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock));
179 177
180 178 /*
181 179 * Need a page per virtual color or just 1 if no vac.
182 180 */
183 181 mutex_enter(&segnf_lock);
184 182 if (nfpp == NULL) {
185 183 struct seg kseg;
186 184
187 185 vacpgs = 1;
188 186 if (shm_alignment > PAGESIZE) {
189 187 vacpgs = shm_alignment >> PAGESHIFT;
190 188 }
191 189
192 190 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP);
193 191
194 192 kseg.s_as = &kas;
195 193 for (i = 0; i < vacpgs; i++, off += PAGESIZE,
196 194 vaddr += PAGESIZE) {
197 195 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE,
198 196 PG_WAIT | PG_NORELOC, &kseg, vaddr);
199 197 page_io_unlock(nfpp[i]);
200 198 page_downgrade(nfpp[i]);
201 199 pagezero(nfpp[i], 0, PAGESIZE);
202 200 }
203 201 }
204 202 mutex_exit(&segnf_lock);
205 203
206 204 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
207 205
208 206 /*
209 207 * s_data can't be NULL because of ASSERTS in the common vm code.
210 208 */
211 209 seg->s_ops = &segnf_ops;
212 210 seg->s_data = seg;
213 211 seg->s_flags |= S_PURGE;
214 212
215 213 mutex_enter(&as->a_contents);
216 214 as->a_flags |= AS_NEEDSPURGE;
217 215 mutex_exit(&as->a_contents);
218 216
219 217 prot = PROT_READ;
220 218 color = addr_to_vcolor(seg->s_base);
221 219 if (as != &kas)
222 220 prot |= PROT_USER;
223 221 hat_memload(as->a_hat, seg->s_base, nfpp[color],
224 222 prot | HAT_NOFAULT, HAT_LOAD);
225 223
226 224 /*
227 225 * At this point see if we can concatenate a segment to
228 226 * a non-fault segment immediately before and/or after it.
229 227 */
230 228 if ((s1 = AS_SEGPREV(as, seg)) != NULL &&
231 229 s1->s_ops == &segnf_ops &&
232 230 s1->s_base + s1->s_size == seg->s_base) {
233 231 size = s1->s_size;
234 232 seg_free(s1);
235 233 seg->s_base -= size;
236 234 seg->s_size += size;
237 235 }
238 236
239 237 if ((s2 = AS_SEGNEXT(as, seg)) != NULL &&
240 238 s2->s_ops == &segnf_ops &&
241 239 seg->s_base + seg->s_size == s2->s_base) {
242 240 size = s2->s_size;
243 241 seg_free(s2);
244 242 seg->s_size += size;
245 243 }
246 244
247 245 /*
248 246 * if we already have a lot of segments, try to delete some other
249 247 * nofault segment to reduce the probability of uncontrolled segment
250 248 * creation.
251 249 *
252 250 * the code looks around quickly (no more than MAXNFSEARCH segments
253 251 * each way) for another NF segment and then deletes it.
254 252 */
255 253 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) {
256 254 size = 0;
257 255 s2 = NULL;
258 256 s1 = AS_SEGPREV(as, seg);
259 257 while (size++ < MAXNFSEARCH && s1 != NULL) {
260 258 if (s1->s_ops == &segnf_ops)
261 259 s2 = s1;
262 260 s1 = AS_SEGPREV(s1->s_as, seg);
263 261 }
264 262 if (s2 == NULL) {
265 263 s1 = AS_SEGNEXT(as, seg);
266 264 while (size-- > 0 && s1 != NULL) {
267 265 if (s1->s_ops == &segnf_ops)
268 266 s2 = s1;
269 267 s1 = AS_SEGNEXT(as, seg);
270 268 }
271 269 }
272 270 if (s2 != NULL)
273 271 seg_unmap(s2);
274 272 }
275 273
276 274 return (0);
277 275 }
278 276
279 277 /*
280 278 * Never really need "No fault" segments, so they aren't dup'd.
281 279 */
282 280 /* ARGSUSED */
283 281 static int
284 282 segnf_dup(struct seg *seg, struct seg *newseg)
285 283 {
286 284 panic("segnf_dup");
287 285 return (0);
288 286 }
289 287
290 288 /*
291 289 * Split a segment at addr for length len.
292 290 */
293 291 static int
294 292 segnf_unmap(struct seg *seg, caddr_t addr, size_t len)
295 293 {
296 294 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
297 295
298 296 /*
299 297 * Check for bad sizes.
300 298 */
301 299 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
302 300 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
303 301 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size");
304 302 }
305 303
306 304 /*
307 305 * Unload any hardware translations in the range to be taken out.
308 306 */
309 307 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP);
310 308
311 309 if (addr == seg->s_base && len == seg->s_size) {
312 310 /*
313 311 * Freeing entire segment.
314 312 */
315 313 seg_free(seg);
316 314 } else if (addr == seg->s_base) {
317 315 /*
318 316 * Freeing the beginning of the segment.
319 317 */
320 318 seg->s_base += len;
321 319 seg->s_size -= len;
322 320 } else if (addr + len == seg->s_base + seg->s_size) {
323 321 /*
324 322 * Freeing the end of the segment.
325 323 */
326 324 seg->s_size -= len;
327 325 } else {
328 326 /*
329 327 * The section to go is in the middle of the segment, so we
330 328 * have to cut it into two segments. We shrink the existing
331 329 * "seg" at the low end, and create "nseg" for the high end.
332 330 */
333 331 caddr_t nbase = addr + len;
334 332 size_t nsize = (seg->s_base + seg->s_size) - nbase;
335 333 struct seg *nseg;
336 334
337 335 /*
338 336 * Trim down "seg" before trying to stick "nseg" into the as.
339 337 */
340 338 seg->s_size = addr - seg->s_base;
341 339 nseg = seg_alloc(seg->s_as, nbase, nsize);
342 340 if (nseg == NULL)
343 341 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed");
344 342
345 343 /*
346 344 * s_data can't be NULL because of ASSERTs in common VM code.
347 345 */
348 346 nseg->s_ops = seg->s_ops;
349 347 nseg->s_data = nseg;
350 348 nseg->s_flags |= S_PURGE;
351 349 mutex_enter(&seg->s_as->a_contents);
352 350 seg->s_as->a_flags |= AS_NEEDSPURGE;
353 351 mutex_exit(&seg->s_as->a_contents);
354 352 }
355 353
356 354 return (0);
357 355 }
358 356
359 357 /*
360 358 * Free a segment.
361 359 */
362 360 static void
363 361 segnf_free(struct seg *seg)
364 362 {
365 363 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
366 364 }
367 365
368 366 /*
369 367 * No faults allowed on segnf.
370 368 */
371 369 static faultcode_t
372 370 segnf_nomap(void)
373 371 {
374 372 return (FC_NOMAP);
375 373 }
376 374
377 375 /* ARGSUSED */
378 376 static int
379 377 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
380 378 {
381 379 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
382 380 return (EACCES);
383 381 }
384 382
385 383 /* ARGSUSED */
386 384 static int
387 385 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
388 386 {
389 387 uint_t sprot;
390 388 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
391 389
392 390 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER;
393 391 return ((prot & sprot) == prot ? 0 : EACCES);
394 392 }
395 393
396 394 static void
397 395 segnf_badop(void)
398 396 {
399 397 panic("segnf_badop");
400 398 /*NOTREACHED*/
401 399 }
402 400
403 401 static int
404 402 segnf_nop(void)
405 403 {
406 404 return (0);
407 405 }
408 406
409 407 static int
410 408 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
411 409 {
412 410 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
413 411 size_t p;
414 412 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
415 413
416 414 for (p = 0; p < pgno; ++p)
417 415 protv[p] = PROT_READ;
418 416 return (0);
419 417 }
420 418
421 419 /* ARGSUSED */
422 420 static u_offset_t
423 421 segnf_getoffset(struct seg *seg, caddr_t addr)
424 422 {
425 423 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
426 424
427 425 return ((u_offset_t)0);
428 426 }
429 427
430 428 /* ARGSUSED */
431 429 static int
432 430 segnf_gettype(struct seg *seg, caddr_t addr)
433 431 {
434 432 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
435 433
436 434 return (MAP_SHARED);
437 435 }
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438 436
439 437 /* ARGSUSED */
440 438 static int
441 439 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
442 440 {
443 441 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
444 442
445 443 *vpp = &nfvp;
446 444 return (0);
447 445 }
448 -
449 -/*
450 - * segnf pages are not dumped, so we just return
451 - */
452 -/* ARGSUSED */
453 -static void
454 -segnf_dump(struct seg *seg)
455 -{}
456 446
457 447 /*ARGSUSED*/
458 448 static int
459 449 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len,
460 450 struct page ***ppp, enum lock_type type, enum seg_rw rw)
461 451 {
462 452 return (ENOTSUP);
463 453 }
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