2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990 University of Utah.
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
41 * Pager routine interface definition.
47 #include <sys/queue.h>
49 TAILQ_HEAD(pagerlst, vm_object);
51 typedef void pgo_init_t(void);
52 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
54 typedef void pgo_dealloc_t(vm_object_t);
55 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
56 typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
57 typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
58 pgo_getpages_iodone_t, void *);
59 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
60 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
61 typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t,
62 vm_pindex_t *, vm_pindex_t *);
63 typedef void pgo_pageunswapped_t(vm_page_t);
64 typedef void pgo_writecount_t(vm_object_t, vm_offset_t, vm_offset_t);
67 pgo_init_t *pgo_init; /* Initialize pager. */
68 pgo_alloc_t *pgo_alloc; /* Allocate pager. */
69 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
70 pgo_getpages_t *pgo_getpages; /* Get (read) page. */
71 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */
72 pgo_putpages_t *pgo_putpages; /* Put (write) page. */
73 pgo_haspage_t *pgo_haspage; /* Query page. */
74 pgo_populate_t *pgo_populate; /* Bulk spec pagein. */
75 pgo_pageunswapped_t *pgo_pageunswapped;
76 /* Operations for specialized writecount handling */
77 pgo_writecount_t *pgo_update_writecount;
78 pgo_writecount_t *pgo_release_writecount;
81 extern struct pagerops defaultpagerops;
82 extern struct pagerops swappagerops;
83 extern struct pagerops vnodepagerops;
84 extern struct pagerops devicepagerops;
85 extern struct pagerops physpagerops;
86 extern struct pagerops sgpagerops;
87 extern struct pagerops mgtdevicepagerops;
90 * get/put return values
91 * OK operation was successful
92 * BAD specified data was out of the accepted range
93 * FAIL specified data was in range, but doesn't exist
94 * PEND operations was initiated but not completed
95 * ERROR error while accessing data that is in range and exists
96 * AGAIN temporary resource shortage prevented operation from happening
99 #define VM_PAGER_BAD 1
100 #define VM_PAGER_FAIL 2
101 #define VM_PAGER_PEND 3
102 #define VM_PAGER_ERROR 4
103 #define VM_PAGER_AGAIN 5
105 #define VM_PAGER_PUT_SYNC 0x0001
106 #define VM_PAGER_PUT_INVAL 0x0002
107 #define VM_PAGER_PUT_NOREUSE 0x0004
108 #define VM_PAGER_CLUSTER_OK 0x0008
112 extern struct pagerops *pagertab[];
113 extern struct mtx_padalign pbuf_mtx;
115 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
116 vm_ooffset_t, struct ucred *);
117 void vm_pager_bufferinit(void);
118 void vm_pager_deallocate(vm_object_t);
119 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
120 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
121 pgo_getpages_iodone_t, void *);
122 void vm_pager_init(void);
123 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
133 VM_OBJECT_ASSERT_WLOCKED(object);
134 (*pagertab[object->type]->pgo_putpages)
135 (object, m, count, flags, rtvals);
141 * Check to see if an object's pager has the requested page. The
142 * object's pager will also set before and after to give the caller
143 * some idea of the number of pages before and after the requested
144 * page can be I/O'd efficiently.
146 * The object must be locked.
148 static __inline boolean_t
157 VM_OBJECT_ASSERT_LOCKED(object);
158 ret = (*pagertab[object->type]->pgo_haspage)
159 (object, offset, before, after);
164 vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
165 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
168 MPASS((object->flags & OBJ_POPULATE) != 0);
169 MPASS(pidx < object->size);
170 MPASS(blockcount_read(&object->paging_in_progress) > 0);
171 return ((*pagertab[object->type]->pgo_populate)(object, pidx,
172 fault_type, max_prot, first, last));
176 * vm_pager_page_unswapped
178 * Destroy swap associated with the page.
180 * XXX: A much better name would be "vm_pager_page_dirtied()"
181 * XXX: It is not obvious if this could be profitably used by any
182 * XXX: pagers besides the swap_pager or if it should even be a
183 * XXX: generic pager_op in the first place.
186 vm_pager_page_unswapped(vm_page_t m)
189 if (pagertab[m->object->type]->pgo_pageunswapped)
190 (*pagertab[m->object->type]->pgo_pageunswapped)(m);
194 vm_pager_update_writecount(vm_object_t object, vm_offset_t start,
198 if (pagertab[object->type]->pgo_update_writecount)
199 pagertab[object->type]->pgo_update_writecount(object, start,
204 vm_pager_release_writecount(vm_object_t object, vm_offset_t start,
208 if (pagertab[object->type]->pgo_release_writecount)
209 pagertab[object->type]->pgo_release_writecount(object, start,
213 struct cdev_pager_ops {
214 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
215 int prot, vm_page_t *mres);
216 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
217 int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
219 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
220 vm_ooffset_t foff, struct ucred *cred, u_short *color);
221 void (*cdev_pg_dtor)(void *handle);
224 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
225 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
226 vm_ooffset_t foff, struct ucred *cred);
227 vm_object_t cdev_pager_lookup(void *handle);
228 void cdev_pager_free_page(vm_object_t object, vm_page_t m);
230 struct phys_pager_ops {
231 int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count,
232 int *rbehind, int *rahead);
233 int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
234 int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
236 boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex,
237 int *before, int *after);
238 void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot,
239 vm_ooffset_t foff, struct ucred *cred);
240 void (*phys_pg_dtor)(vm_object_t vm_obj);
242 extern struct phys_pager_ops default_phys_pg_ops;
243 vm_object_t phys_pager_allocate(void *handle, struct phys_pager_ops *ops,
244 void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff,
248 #endif /* _VM_PAGER_ */