FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_pager.h
1 /*
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
35 * $FreeBSD: releng/5.3/sys/vm/vm_pager.h 128038 2004-04-08 19:08:49Z alc $
36 */
37
38 /*
39 * Pager routine interface definition.
40 */
41
42 #ifndef _VM_PAGER_
43 #define _VM_PAGER_
44
45 #include <sys/queue.h>
46
47 TAILQ_HEAD(pagerlst, vm_object);
48
49 struct bio;
50
51 struct pagerops {
52 void (*pgo_init)(void); /* Initialize pager. */
53 vm_object_t (*pgo_alloc)(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */
54 void (*pgo_dealloc)(vm_object_t); /* Disassociate. */
55 int (*pgo_getpages)(vm_object_t, vm_page_t *, int, int); /* Get (read) page. */
56 void (*pgo_putpages)(vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */
57 boolean_t (*pgo_haspage)(vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */
58 void (*pgo_pageunswapped)(vm_page_t);
59 };
60
61 extern struct pagerops defaultpagerops;
62 extern struct pagerops swappagerops;
63 extern struct pagerops vnodepagerops;
64 extern struct pagerops devicepagerops;
65 extern struct pagerops physpagerops;
66
67 /*
68 * get/put return values
69 * OK operation was successful
70 * BAD specified data was out of the accepted range
71 * FAIL specified data was in range, but doesn't exist
72 * PEND operations was initiated but not completed
73 * ERROR error while accessing data that is in range and exists
74 * AGAIN temporary resource shortage prevented operation from happening
75 */
76 #define VM_PAGER_OK 0
77 #define VM_PAGER_BAD 1
78 #define VM_PAGER_FAIL 2
79 #define VM_PAGER_PEND 3
80 #define VM_PAGER_ERROR 4
81 #define VM_PAGER_AGAIN 5
82
83 #define VM_PAGER_PUT_SYNC 0x0001
84 #define VM_PAGER_PUT_INVAL 0x0002
85 #define VM_PAGER_IGNORE_CLEANCHK 0x0004
86 #define VM_PAGER_CLUSTER_OK 0x0008
87
88 #ifdef _KERNEL
89 #ifdef MALLOC_DECLARE
90 MALLOC_DECLARE(M_VMPGDATA);
91 #endif
92
93 extern vm_map_t pager_map;
94 extern struct pagerops *pagertab[];
95 extern struct mtx pbuf_mtx;
96
97 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t);
98 void vm_pager_bufferinit(void);
99 void vm_pager_deallocate(vm_object_t);
100 static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
101 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
102 void vm_pager_init(void);
103 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
104
105 /*
106 * vm_page_get_pages:
107 *
108 * Retrieve pages from the VM system in order to map them into an object
109 * ( or into VM space somewhere ). If the pagein was successful, we
110 * must fully validate it.
111 */
112 static __inline int
113 vm_pager_get_pages(
114 vm_object_t object,
115 vm_page_t *m,
116 int count,
117 int reqpage
118 ) {
119 int r;
120
121 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
122 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
123 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
124 vm_page_zero_invalid(m[reqpage], TRUE);
125 }
126 return (r);
127 }
128
129 static __inline void
130 vm_pager_put_pages(
131 vm_object_t object,
132 vm_page_t *m,
133 int count,
134 int flags,
135 int *rtvals
136 ) {
137
138 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
139 (*pagertab[object->type]->pgo_putpages)
140 (object, m, count, flags, rtvals);
141 }
142
143 /*
144 * vm_pager_haspage
145 *
146 * Check to see if an object's pager has the requested page. The
147 * object's pager will also set before and after to give the caller
148 * some idea of the number of pages before and after the requested
149 * page can be I/O'd efficiently.
150 *
151 * This routine does not have to be called at any particular spl.
152 */
153 static __inline boolean_t
154 vm_pager_has_page(
155 vm_object_t object,
156 vm_pindex_t offset,
157 int *before,
158 int *after
159 ) {
160 boolean_t ret;
161
162 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
163 ret = (*pagertab[object->type]->pgo_haspage)
164 (object, offset, before, after);
165 return (ret);
166 }
167
168 /*
169 * vm_pager_page_unswapped
170 *
171 * called at splvm() to destroy swap associated with the page.
172 *
173 * This function may not block.
174 *
175 * XXX: A much better name would be "vm_pager_page_dirtied()"
176 * XXX: It is not obvious if this could be profitably used by any
177 * XXX: pagers besides the swap_pager or if it should even be a
178 * XXX: generic pager_op in the first place.
179 */
180 static __inline void
181 vm_pager_page_unswapped(vm_page_t m)
182 {
183
184 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
185 if (pagertab[m->object->type]->pgo_pageunswapped)
186 (*pagertab[m->object->type]->pgo_pageunswapped)(m);
187 }
188
189 #endif /* _KERNEL */
190 #endif /* _VM_PAGER_ */
Cache object: a37e2419407d1ed74fbd4d8ad8579410
|