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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
39 * $FreeBSD: releng/5.2/sys/vm/vm_pager.h 121455 2003-10-24 06:43:04Z alc $
40 */
41
42 /*
43 * Pager routine interface definition.
44 */
45
46 #ifndef _VM_PAGER_
47 #define _VM_PAGER_
48
49 #include <sys/queue.h>
50
51 TAILQ_HEAD(pagerlst, vm_object);
52
53 struct bio;
54
55 struct pagerops {
56 void (*pgo_init)(void); /* Initialize pager. */
57 vm_object_t (*pgo_alloc)(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */
58 void (*pgo_dealloc)(vm_object_t); /* Disassociate. */
59 int (*pgo_getpages)(vm_object_t, vm_page_t *, int, int); /* Get (read) page. */
60 void (*pgo_putpages)(vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */
61 boolean_t (*pgo_haspage)(vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */
62 void (*pgo_pageunswapped)(vm_page_t);
63 };
64
65 extern struct pagerops defaultpagerops;
66 extern struct pagerops swappagerops;
67 extern struct pagerops vnodepagerops;
68 extern struct pagerops devicepagerops;
69 extern struct pagerops physpagerops;
70
71 /*
72 * get/put return values
73 * OK operation was successful
74 * BAD specified data was out of the accepted range
75 * FAIL specified data was in range, but doesn't exist
76 * PEND operations was initiated but not completed
77 * ERROR error while accessing data that is in range and exists
78 * AGAIN temporary resource shortage prevented operation from happening
79 */
80 #define VM_PAGER_OK 0
81 #define VM_PAGER_BAD 1
82 #define VM_PAGER_FAIL 2
83 #define VM_PAGER_PEND 3
84 #define VM_PAGER_ERROR 4
85 #define VM_PAGER_AGAIN 5
86
87 #define VM_PAGER_PUT_SYNC 0x0001
88 #define VM_PAGER_PUT_INVAL 0x0002
89 #define VM_PAGER_IGNORE_CLEANCHK 0x0004
90 #define VM_PAGER_CLUSTER_OK 0x0008
91
92 #ifdef _KERNEL
93 #ifdef MALLOC_DECLARE
94 MALLOC_DECLARE(M_VMPGDATA);
95 #endif
96
97 extern vm_map_t pager_map;
98 extern int pager_map_size;
99 extern struct pagerops *pagertab[];
100 extern struct mtx pbuf_mtx;
101
102 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t);
103 void vm_pager_bufferinit(void);
104 void vm_pager_deallocate(vm_object_t);
105 static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
106 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
107 void vm_pager_init(void);
108 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
109 vm_offset_t vm_pager_map_page(vm_page_t);
110 void vm_pager_unmap_page(vm_offset_t);
111
112 /*
113 * vm_page_get_pages:
114 *
115 * Retrieve pages from the VM system in order to map them into an object
116 * ( or into VM space somewhere ). If the pagein was successful, we
117 * must fully validate it.
118 */
119 static __inline int
120 vm_pager_get_pages(
121 vm_object_t object,
122 vm_page_t *m,
123 int count,
124 int reqpage
125 ) {
126 int r;
127
128 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
129 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
130 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
131 vm_page_zero_invalid(m[reqpage], TRUE);
132 }
133 return (r);
134 }
135
136 static __inline void
137 vm_pager_put_pages(
138 vm_object_t object,
139 vm_page_t *m,
140 int count,
141 int flags,
142 int *rtvals
143 ) {
144
145 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
146 (*pagertab[object->type]->pgo_putpages)
147 (object, m, count, flags, rtvals);
148 }
149
150 /*
151 * vm_pager_haspage
152 *
153 * Check to see if an object's pager has the requested page. The
154 * object's pager will also set before and after to give the caller
155 * some idea of the number of pages before and after the requested
156 * page can be I/O'd efficiently.
157 *
158 * This routine does not have to be called at any particular spl.
159 */
160 static __inline boolean_t
161 vm_pager_has_page(
162 vm_object_t object,
163 vm_pindex_t offset,
164 int *before,
165 int *after
166 ) {
167 boolean_t ret;
168
169 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
170 ret = (*pagertab[object->type]->pgo_haspage)
171 (object, offset, before, after);
172 return (ret);
173 }
174
175 /*
176 * vm_pager_page_unswapped
177 *
178 * called at splvm() to destroy swap associated with the page.
179 *
180 * This function may not block.
181 *
182 * XXX: A much better name would be "vm_pager_page_dirtied()"
183 * XXX: It is not obvious if this could be profitably used by any
184 * XXX: pagers besides the swap_pager or if it should even be a
185 * XXX: generic pager_op in the first place.
186 */
187 static __inline void
188 vm_pager_page_unswapped(vm_page_t m)
189 {
190
191 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
192 if (pagertab[m->object->type]->pgo_pageunswapped)
193 (*pagertab[m->object->type]->pgo_pageunswapped)(m);
194 }
195
196 #endif /* _KERNEL */
197 #endif /* _VM_PAGER_ */
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