2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
38 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
39 * $FreeBSD: src/sys/vm/vm_pager.h,v 1.24.2.2 2002/12/31 09:34:51 dillon Exp $
40 * $DragonFly: src/sys/vm/vm_pager.h,v 1.9 2006/12/28 21:24:02 dillon Exp $
44 * Pager routine interface definition.
47 #ifndef _VM_VM_PAGER_H_
48 #define _VM_VM_PAGER_H_
51 #include <sys/queue.h>
53 #ifndef _VM_VM_PAGE_H_
54 #include <vm/vm_page.h>
56 #ifndef _VM_VM_OBJECT_H_
57 #include <vm/vm_object.h>
64 void (*pgo_init) (void); /* Initialize pager. */
65 vm_object_t (*pgo_alloc) (void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */
66 void (*pgo_dealloc) (vm_object_t); /* Disassociate. */
67 int (*pgo_getpage) (vm_object_t, vm_page_t *, int);
68 void (*pgo_putpages) (vm_object_t, vm_page_t *, int, int, int *);
69 boolean_t (*pgo_haspage) (vm_object_t, vm_pindex_t);
70 void (*pgo_pageunswapped) (vm_page_t);
71 void (*pgo_strategy) (vm_object_t, struct bio *);
75 * get/put return values
76 * OK operation was successful
77 * BAD specified data was out of the accepted range
78 * FAIL specified data was in range, but doesn't exist
79 * PEND operations was initiated but not completed
80 * ERROR error while accessing data that is in range and exists
81 * AGAIN temporary resource shortage prevented operation from happening
84 #define VM_PAGER_BAD 1
85 #define VM_PAGER_FAIL 2
86 #define VM_PAGER_PEND 3
87 #define VM_PAGER_ERROR 4
88 #define VM_PAGER_AGAIN 5
90 #define VM_PAGER_PUT_SYNC 0x0001
91 #define VM_PAGER_PUT_INVAL 0x0002
92 #define VM_PAGER_IGNORE_CLEANCHK 0x0004
93 #define VM_PAGER_CLUSTER_OK 0x0008
98 MALLOC_DECLARE(M_VMPGDATA);
103 extern struct vm_map pager_map;
104 extern int pager_map_size;
105 extern struct pagerops *pagertab[];
107 vm_object_t vm_pager_allocate (objtype_t, void *, off_t, vm_prot_t, off_t);
108 void vm_pager_bufferinit (void);
109 void vm_pager_deallocate (vm_object_t);
110 static __inline int vm_pager_get_page (vm_object_t, vm_page_t *, int);
111 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t);
112 void vm_pager_init (void);
113 void vm_pager_sync (void);
114 void vm_pager_strategy (vm_object_t object, struct bio *bio);
115 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags);
116 void flushchainbuf(struct buf *nbp);
117 void waitchainbuf(struct buf *bp, int count, int done);
118 void autochaindone(struct buf *bp);
123 * Retrieve the contents of the page from the object pager. Note that the
124 * object pager might replace the page.
126 * If the pagein was successful, we must fully validate it so it can be
131 vm_pager_get_page(vm_object_t object, vm_page_t *m, int seqaccess)
135 r = (*pagertab[object->type]->pgo_getpage)(object, m, seqaccess);
136 if (r == VM_PAGER_OK && (*m)->valid != VM_PAGE_BITS_ALL) {
137 vm_page_zero_invalid(*m, TRUE);
150 (*pagertab[object->type]->pgo_putpages)
151 (object, m, count, flags, rtvals);
157 * Check to see if an object's pager has the requested page. The
158 * object's pager will also set before and after to give the caller
159 * some idea of the number of pages before and after the requested
160 * page can be I/O'd efficiently.
162 * This routine does not have to be called at any particular spl.
165 static __inline boolean_t
166 vm_pager_has_page(vm_object_t object, vm_pindex_t offset)
168 return ((*pagertab[object->type]->pgo_haspage)(object, offset));
172 * vm_pager_page_unswapped
174 * called at splvm() to destroy swap associated with the page.
176 * This function may not block.
180 vm_pager_page_unswapped(vm_page_t m)
182 if (pagertab[m->object->type]->pgo_pageunswapped)
183 (*pagertab[m->object->type]->pgo_pageunswapped)(m);
188 #endif /* _VM_VM_PAGER_H_ */