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/11.0/sys/vm/vm_pager.h 292373 2015-12-16 21:30:45Z glebius $
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 typedef void pgo_init_t(void);
50 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
51 struct ucred *);
52 typedef void pgo_dealloc_t(vm_object_t);
53 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
54 typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
55 typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
56 pgo_getpages_iodone_t, void *);
57 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
58 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
59 typedef void pgo_pageunswapped_t(vm_page_t);
60
61 struct pagerops {
62 pgo_init_t *pgo_init; /* Initialize pager. */
63 pgo_alloc_t *pgo_alloc; /* Allocate pager. */
64 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
65 pgo_getpages_t *pgo_getpages; /* Get (read) page. */
66 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */
67 pgo_putpages_t *pgo_putpages; /* Put (write) page. */
68 pgo_haspage_t *pgo_haspage; /* Query page. */
69 pgo_pageunswapped_t *pgo_pageunswapped;
70 };
71
72 extern struct pagerops defaultpagerops;
73 extern struct pagerops swappagerops;
74 extern struct pagerops vnodepagerops;
75 extern struct pagerops devicepagerops;
76 extern struct pagerops physpagerops;
77 extern struct pagerops sgpagerops;
78 extern struct pagerops mgtdevicepagerops;
79
80 /*
81 * get/put return values
82 * OK operation was successful
83 * BAD specified data was out of the accepted range
84 * FAIL specified data was in range, but doesn't exist
85 * PEND operations was initiated but not completed
86 * ERROR error while accessing data that is in range and exists
87 * AGAIN temporary resource shortage prevented operation from happening
88 */
89 #define VM_PAGER_OK 0
90 #define VM_PAGER_BAD 1
91 #define VM_PAGER_FAIL 2
92 #define VM_PAGER_PEND 3
93 #define VM_PAGER_ERROR 4
94 #define VM_PAGER_AGAIN 5
95
96 #define VM_PAGER_PUT_SYNC 0x0001
97 #define VM_PAGER_PUT_INVAL 0x0002
98 #define VM_PAGER_CLUSTER_OK 0x0008
99
100 #ifdef _KERNEL
101
102 extern struct pagerops *pagertab[];
103 extern struct mtx_padalign pbuf_mtx;
104
105 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
106 vm_ooffset_t, struct ucred *);
107 void vm_pager_bufferinit(void);
108 void vm_pager_deallocate(vm_object_t);
109 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
110 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
111 pgo_getpages_iodone_t, void *);
112 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
113 void vm_pager_init(void);
114 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
115
116 static __inline void
117 vm_pager_put_pages(
118 vm_object_t object,
119 vm_page_t *m,
120 int count,
121 int flags,
122 int *rtvals
123 ) {
124
125 VM_OBJECT_ASSERT_WLOCKED(object);
126 (*pagertab[object->type]->pgo_putpages)
127 (object, m, count, flags, rtvals);
128 }
129
130 /*
131 * vm_pager_haspage
132 *
133 * Check to see if an object's pager has the requested page. The
134 * object's pager will also set before and after to give the caller
135 * some idea of the number of pages before and after the requested
136 * page can be I/O'd efficiently.
137 *
138 * The object must be locked.
139 */
140 static __inline boolean_t
141 vm_pager_has_page(
142 vm_object_t object,
143 vm_pindex_t offset,
144 int *before,
145 int *after
146 ) {
147 boolean_t ret;
148
149 VM_OBJECT_ASSERT_WLOCKED(object);
150 ret = (*pagertab[object->type]->pgo_haspage)
151 (object, offset, before, after);
152 return (ret);
153 }
154
155 /*
156 * vm_pager_page_unswapped
157 *
158 * Destroy swap associated with the page.
159 *
160 * The object containing the page must be locked.
161 * This function may not block.
162 *
163 * XXX: A much better name would be "vm_pager_page_dirtied()"
164 * XXX: It is not obvious if this could be profitably used by any
165 * XXX: pagers besides the swap_pager or if it should even be a
166 * XXX: generic pager_op in the first place.
167 */
168 static __inline void
169 vm_pager_page_unswapped(vm_page_t m)
170 {
171
172 VM_OBJECT_ASSERT_LOCKED(m->object);
173 if (pagertab[m->object->type]->pgo_pageunswapped)
174 (*pagertab[m->object->type]->pgo_pageunswapped)(m);
175 }
176
177 struct cdev_pager_ops {
178 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
179 int prot, vm_page_t *mres);
180 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
181 vm_ooffset_t foff, struct ucred *cred, u_short *color);
182 void (*cdev_pg_dtor)(void *handle);
183 };
184
185 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
186 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
187 vm_ooffset_t foff, struct ucred *cred);
188 vm_object_t cdev_pager_lookup(void *handle);
189 void cdev_pager_free_page(vm_object_t object, vm_page_t m);
190
191 #endif /* _KERNEL */
192 #endif /* _VM_PAGER_ */
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