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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #ifndef _VM_SEG_KP_H
28 #define _VM_SEG_KP_H
29
30 /*
31 * segkp (as in kernel pageable) is a segment driver that supports allocation
32 * of page-aligned variable size of vm resources.
33 *
34 * Each vm resource represents a page-aligned range of virtual addresses.
35 * The caller may specify whether the resource should include a redzone,
36 * be locked down, or be zero initialized.
37 */
38
39 #include <vm/seg.h>
40 #include <sys/vmem.h>
41
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45
46 #ifdef _KERNEL
47
48 /*
49 * Private information per overall segkp segment (as opposed
50 * to per resource within segment). There are as many anon slots
51 * allocated as there there are pages in the segment.
52 */
53 struct segkp_segdata {
54 struct anon_hdr *kpsd_anon; /* anon structs */
55 vmem_t *kpsd_arena; /* virtual memory descriptor */
56 struct segkp_data **kpsd_hash; /* Hash table for lookups */
57 };
58
59 #define SEGKP_VMEM(seg) (((struct segkp_segdata *)(seg)->s_data)->kpsd_arena)
60
61 /*
62 * A hash table is used to aid in the lookup of a kpd's based on vaddr.
63 * Since the heaviest use of segkp occurs from segkp_*get and segkp_*release,
64 * the hashing is based on the vaddr used by these routines.
65 */
66 #define SEGKP_HASHSZ 256 /* power of two */
67 #define SEGKP_HASHMASK (SEGKP_HASHSZ - 1)
68 #define SEGKP_HASH(vaddr) \
69 ((int)(((uintptr_t)vaddr >> PAGESHIFT) & SEGKP_HASHMASK))
70
71 struct segkp_data {
72 kmutex_t kp_lock; /* per resource lock */
73 caddr_t kp_base; /* starting addr of chunk */
74 size_t kp_len; /* # of bytes */
75 uint_t kp_flags; /* state info */
76 int kp_cookie; /* index into cache array */
77 ulong_t kp_anon_idx; /* index into main anon array */
78 /* in segkp_segdata */
79 struct anon_hdr *kp_anon; /* anon structs */
80 struct segkp_data *kp_next; /* ptr to next in hash chain */
81 };
82
83 /*
84 * Flag bits
85 *
86 */
87 #define KPD_ZERO 0x01 /* initialize resource with 0 */
88 #define KPD_LOCKED 0x02 /* resources locked */
89 #define KPD_NO_ANON 0x04 /* no swap resources required */
90 #define KPD_HASREDZONE 0x08 /* include a redzone */
91 #define KPD_NOWAIT 0x10 /* do not wait for res. if unavail. */
92 #define KPD_WRITEDIRTY 0x20 /* dirty pages should be flushed */
93 #define KPD_HASAMP 0x40 /* anon_hdr managed by caller */
94
95 /*
96 * A cache of segkp elements may be created via segkp_cache_init().
97 * The elements on the freelist all have the same len and flags value.
98 * The cookie passed to the client is an index into the freelist array.
99 */
100 struct segkp_cache {
101 int kpf_max; /* max # of elements allowed */
102 int kpf_count; /* current no. of elments */
103 int kpf_inuse; /* list inuse */
104 uint_t kpf_flags; /* seg_kp flag value */
105 size_t kpf_len; /* len of resource */
106 struct seg *kpf_seg; /* segment */
107 struct segkp_data *kpf_list; /* list of kpd's */
108 };
109 #define SEGKP_MAX_CACHE 4 /* Number of caches maintained */
110
111 /*
112 * Define redzone, and stack_to_memory macros.
113 * The redzone is PAGESIZE bytes.
114 */
115 #ifdef STACK_GROWTH_DOWN
116 #define KPD_REDZONE(kpd) (0)
117 #define stom(v, flags) (((flags) & KPD_HASREDZONE) ? (v) + PAGESIZE : (v))
118
119 #else /* STACK_GROWTH_DOWN */
120
121 #define KPD_REDZONE(kpd) (btop(kpd->kp_len) - 1)
122 #define stom(v) (v)
123 #endif /* STACK_GROWTH_DOWN */
124
125 #define SEGKP_MAPLEN(len, flags) \
126 (((flags) & KPD_HASREDZONE) ? (len) - PAGESIZE : (len))
127
128 extern struct seg *segkp;
129 /* If segkp becomes more than one seg this test will need changing. */
130 #define SEG_IS_SEGKP(SEG) ((SEG) == segkp)
131
132 /*
133 * Public routine declarations not part of the segment ops vector go here.
134 */
135 int segkp_create(struct seg *seg);
136 caddr_t segkp_get(struct seg *seg, size_t len, uint_t flags);
137 void segkp_release(struct seg *seg, caddr_t vaddr);
138 void * segkp_cache_init(struct seg *seg, int maxsize, size_t len,
139 uint_t flags);
140 void segkp_cache_free();
141 caddr_t segkp_cache_get(void *cookie);
142 int segkp_map_red(void);
143 void segkp_unmap_red(void);
144
145 /* Special currently only used by schedctl. */
146 struct anon_map; /* Make the compiler happy about the next line. */
147 caddr_t segkp_get_withanonmap(struct seg *, size_t, uint_t, struct anon_map *);
148
149 /*
150 * We allow explicit calls to segkp_fault, even though it's part
151 * of the segkp ops vector.
152 */
153 faultcode_t segkp_fault(struct hat *hat, struct seg *seg, caddr_t addr,
154 size_t len, enum fault_type type, enum seg_rw rw);
155
156 #endif /* _KERNEL */
157
158 #ifdef __cplusplus
159 }
160 #endif
161
162 #endif /* _VM_SEG_KP_H */