master
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990 University of Utah.
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
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.
23 *
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
34 * SUCH DAMAGE.
35 *
36 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
37 */
38
39/*
40 * Pager routine interface definition.
41 */
42
43#ifndef _VM_PAGER_
44#define _VM_PAGER_
45
46#include <sys/systm.h>
47
48TAILQ_HEAD(pagerlst, vm_object);
49struct vnode;
50
51typedef void pgo_init_t(void);
52typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
53 struct ucred *);
54typedef void pgo_dealloc_t(vm_object_t);
55typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
56typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
57typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
58 pgo_getpages_iodone_t, void *);
59typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
60typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
61typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t,
62 vm_pindex_t *, vm_pindex_t *);
63typedef void pgo_pageunswapped_t(vm_page_t);
64typedef void pgo_writecount_t(vm_object_t, vm_offset_t, vm_offset_t);
65typedef void pgo_set_writeable_dirty_t(vm_object_t);
66typedef bool pgo_mightbedirty_t(vm_object_t);
67typedef void pgo_getvp_t(vm_object_t object, struct vnode **vpp,
68 bool *vp_heldp);
69typedef void pgo_freespace_t(vm_object_t object, vm_pindex_t start,
70 vm_size_t size);
71typedef void pgo_page_inserted_t(vm_object_t object, vm_page_t m);
72typedef void pgo_page_removed_t(vm_object_t object, vm_page_t m);
73typedef boolean_t pgo_can_alloc_page_t(vm_object_t object, vm_pindex_t pindex);
74
75struct pagerops {
76 int pgo_kvme_type;
77 pgo_init_t *pgo_init; /* Initialize pager. */
78 pgo_alloc_t *pgo_alloc; /* Allocate pager. */
79 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
80 pgo_getpages_t *pgo_getpages; /* Get (read) page. */
81 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */
82 pgo_putpages_t *pgo_putpages; /* Put (write) page. */
83 pgo_haspage_t *pgo_haspage; /* Query page. */
84 pgo_populate_t *pgo_populate; /* Bulk spec pagein. */
85 pgo_pageunswapped_t *pgo_pageunswapped;
86 pgo_writecount_t *pgo_update_writecount;
87 pgo_writecount_t *pgo_release_writecount;
88 pgo_set_writeable_dirty_t *pgo_set_writeable_dirty;
89 pgo_mightbedirty_t *pgo_mightbedirty;
90 pgo_getvp_t *pgo_getvp;
91 pgo_freespace_t *pgo_freespace;
92 pgo_page_inserted_t *pgo_page_inserted;
93 pgo_page_removed_t *pgo_page_removed;
94 pgo_can_alloc_page_t *pgo_can_alloc_page;
95};
96
97extern const struct pagerops defaultpagerops;
98extern const struct pagerops swappagerops;
99extern const struct pagerops vnodepagerops;
100extern const struct pagerops devicepagerops;
101extern const struct pagerops physpagerops;
102extern const struct pagerops sgpagerops;
103extern const struct pagerops mgtdevicepagerops;
104extern const struct pagerops swaptmpfspagerops;
105
106/*
107 * get/put return values
108 * OK operation was successful
109 * BAD specified data was out of the accepted range
110 * FAIL specified data was in range, but doesn't exist
111 * PEND operations was initiated but not completed
112 * ERROR error while accessing data that is in range and exists
113 * AGAIN temporary resource shortage prevented operation from happening
114 */
115#define VM_PAGER_OK 0
116#define VM_PAGER_BAD 1
117#define VM_PAGER_FAIL 2
118#define VM_PAGER_PEND 3
119#define VM_PAGER_ERROR 4
120#define VM_PAGER_AGAIN 5
121
122#define VM_PAGER_PUT_SYNC 0x0001
123#define VM_PAGER_PUT_INVAL 0x0002
124#define VM_PAGER_PUT_NOREUSE 0x0004
125#define VM_PAGER_CLUSTER_OK 0x0008
126
127#ifdef _KERNEL
128
129extern const struct pagerops *pagertab[] __read_mostly;
130extern struct mtx_padalign pbuf_mtx;
131
132/*
133 * Number of pages that pbuf buffer can store in b_pages.
134 * It is +1 to allow for unaligned data buffer of maxphys size.
135 */
136#define PBUF_PAGES (atop(maxphys) + 1)
137
138vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
139 vm_ooffset_t, struct ucred *);
140void vm_pager_bufferinit(void);
141void vm_pager_deallocate(vm_object_t);
142int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
143int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
144 pgo_getpages_iodone_t, void *);
145void vm_pager_init(void);
146vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
147
148static __inline void
149vm_pager_put_pages(vm_object_t object, vm_page_t *m, int count, int flags,
150 int *rtvals)
151{
152 VM_OBJECT_ASSERT_WLOCKED(object);
153 (*pagertab[object->type]->pgo_putpages)
154 (object, m, count, flags, rtvals);
155}
156
157/*
158 * vm_pager_haspage
159 *
160 * Check to see if an object's pager has the requested page. The
161 * object's pager will also set before and after to give the caller
162 * some idea of the number of pages before and after the requested
163 * page can be I/O'd efficiently.
164 *
165 * The object must be locked.
166 */
167static __inline boolean_t
168vm_pager_has_page(vm_object_t object, vm_pindex_t offset, int *before,
169 int *after)
170{
171 boolean_t ret;
172
173 VM_OBJECT_ASSERT_LOCKED(object);
174 ret = (*pagertab[object->type]->pgo_haspage)
175 (object, offset, before, after);
176 return (ret);
177}
178
179static __inline int
180vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
181 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
182{
183
184 MPASS((object->flags & OBJ_POPULATE) != 0);
185 MPASS(pidx < object->size);
186 MPASS(blockcount_read(&object->paging_in_progress) > 0);
187 return ((*pagertab[object->type]->pgo_populate)(object, pidx,
188 fault_type, max_prot, first, last));
189}
190
191/*
192 * vm_pager_page_unswapped
193 *
194 * Destroy swap associated with the page.
195 *
196 * XXX: A much better name would be "vm_pager_page_dirtied()"
197 * XXX: It is not obvious if this could be profitably used by any
198 * XXX: pagers besides the swap_pager or if it should even be a
199 * XXX: generic pager_op in the first place.
200 */
201static __inline void
202vm_pager_page_unswapped(vm_page_t m)
203{
204 pgo_pageunswapped_t *method;
205
206 method = pagertab[m->object->type]->pgo_pageunswapped;
207 if (method != NULL)
208 method(m);
209}
210
211static __inline void
212vm_pager_update_writecount(vm_object_t object, vm_offset_t start,
213 vm_offset_t end)
214{
215 pgo_writecount_t *method;
216
217 method = pagertab[object->type]->pgo_update_writecount;
218 if (method != NULL)
219 method(object, start, end);
220}
221
222static __inline void
223vm_pager_release_writecount(vm_object_t object, vm_offset_t start,
224 vm_offset_t end)
225{
226 pgo_writecount_t *method;
227
228 method = pagertab[object->type]->pgo_release_writecount;
229 if (method != NULL)
230 method(object, start, end);
231}
232
233static __inline void
234vm_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
235{
236 pgo_getvp_t *method;
237
238 *vpp = NULL;
239 if (vp_heldp != NULL)
240 *vp_heldp = false;
241 method = pagertab[object->type]->pgo_getvp;
242 if (method != NULL)
243 method(object, vpp, vp_heldp);
244}
245
246static __inline void
247vm_pager_freespace(vm_object_t object, vm_pindex_t start,
248 vm_size_t size)
249{
250 pgo_freespace_t *method;
251
252 method = pagertab[object->type]->pgo_freespace;
253 if (method != NULL)
254 method(object, start, size);
255}
256
257static __inline void
258vm_pager_page_inserted(vm_object_t object, vm_page_t m)
259{
260 pgo_page_inserted_t *method;
261
262 method = pagertab[object->type]->pgo_page_inserted;
263 if (method != NULL)
264 method(object, m);
265}
266
267static __inline void
268vm_pager_page_removed(vm_object_t object, vm_page_t m)
269{
270 pgo_page_removed_t *method;
271
272 method = pagertab[object->type]->pgo_page_removed;
273 if (method != NULL)
274 method(object, m);
275}
276
277static __inline bool
278vm_pager_can_alloc_page(vm_object_t object, vm_pindex_t pindex)
279{
280 pgo_can_alloc_page_t *method;
281
282 method = pagertab[object->type]->pgo_can_alloc_page;
283 return (method != NULL ? method(object, pindex) : true);
284}
285
286int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type);
287void vm_pager_free_dyn_type(objtype_t type);
288
289struct cdev_pager_ops {
290 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
291 int prot, vm_page_t *mres);
292 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
293 int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
294 vm_pindex_t *last);
295 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
296 vm_ooffset_t foff, struct ucred *cred, u_short *color);
297 void (*cdev_pg_dtor)(void *handle);
298};
299
300vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
301 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
302 vm_ooffset_t foff, struct ucred *cred);
303vm_object_t cdev_pager_lookup(void *handle);
304void cdev_pager_free_page(vm_object_t object, vm_page_t m);
305
306struct phys_pager_ops {
307 int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count,
308 int *rbehind, int *rahead);
309 int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
310 int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
311 vm_pindex_t *last);
312 boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex,
313 int *before, int *after);
314 void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot,
315 vm_ooffset_t foff, struct ucred *cred);
316 void (*phys_pg_dtor)(vm_object_t vm_obj);
317};
318extern const struct phys_pager_ops default_phys_pg_ops;
319vm_object_t phys_pager_allocate(void *handle, const struct phys_pager_ops *ops,
320 void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff,
321 struct ucred *cred);
322
323#endif /* _KERNEL */
324#endif /* _VM_PAGER_ */