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