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 * $FreeBSD$ 38 */ 39 40 /* 41 * Pager routine interface definition. 42 */ 43 44 #ifndef _VM_PAGER_ 45 #define _VM_PAGER_ 46 47 #include <sys/systm.h> 48 49 TAILQ_HEAD(pagerlst, vm_object); 50 struct vnode; 51 52 typedef void pgo_init_t(void); 53 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, 54 struct ucred *); 55 typedef void pgo_dealloc_t(vm_object_t); 56 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *); 57 typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int); 58 typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *, 59 pgo_getpages_iodone_t, void *); 60 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 61 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 62 typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t, 63 vm_pindex_t *, vm_pindex_t *); 64 typedef void pgo_pageunswapped_t(vm_page_t); 65 typedef void pgo_writecount_t(vm_object_t, vm_offset_t, vm_offset_t); 66 typedef void pgo_set_writeable_dirty_t(vm_object_t); 67 typedef bool pgo_mightbedirty_t(vm_object_t); 68 typedef void pgo_getvp_t(vm_object_t object, struct vnode **vpp, 69 bool *vp_heldp); 70 typedef void pgo_freespace_t(vm_object_t object, vm_pindex_t start, 71 vm_size_t size); 72 typedef void pgo_page_inserted_t(vm_object_t object, vm_page_t m); 73 typedef void pgo_page_removed_t(vm_object_t object, vm_page_t m); 74 typedef boolean_t pgo_can_alloc_page_t(vm_object_t object, vm_pindex_t pindex); 75 76 struct pagerops { 77 int pgo_kvme_type; 78 pgo_init_t *pgo_init; /* Initialize pager. */ 79 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 80 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 81 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 82 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */ 83 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 84 pgo_haspage_t *pgo_haspage; /* Query page. */ 85 pgo_populate_t *pgo_populate; /* Bulk spec pagein. */ 86 pgo_pageunswapped_t *pgo_pageunswapped; 87 pgo_writecount_t *pgo_update_writecount; 88 pgo_writecount_t *pgo_release_writecount; 89 pgo_set_writeable_dirty_t *pgo_set_writeable_dirty; 90 pgo_mightbedirty_t *pgo_mightbedirty; 91 pgo_getvp_t *pgo_getvp; 92 pgo_freespace_t *pgo_freespace; 93 pgo_page_inserted_t *pgo_page_inserted; 94 pgo_page_removed_t *pgo_page_removed; 95 pgo_can_alloc_page_t *pgo_can_alloc_page; 96 }; 97 98 extern const struct pagerops defaultpagerops; 99 extern const struct pagerops swappagerops; 100 extern const struct pagerops vnodepagerops; 101 extern const struct pagerops devicepagerops; 102 extern const struct pagerops physpagerops; 103 extern const struct pagerops sgpagerops; 104 extern const struct pagerops mgtdevicepagerops; 105 extern const struct pagerops swaptmpfspagerops; 106 107 /* 108 * get/put return values 109 * OK operation was successful 110 * BAD specified data was out of the accepted range 111 * FAIL specified data was in range, but doesn't exist 112 * PEND operations was initiated but not completed 113 * ERROR error while accessing data that is in range and exists 114 * AGAIN temporary resource shortage prevented operation from happening 115 */ 116 #define VM_PAGER_OK 0 117 #define VM_PAGER_BAD 1 118 #define VM_PAGER_FAIL 2 119 #define VM_PAGER_PEND 3 120 #define VM_PAGER_ERROR 4 121 #define VM_PAGER_AGAIN 5 122 123 #define VM_PAGER_PUT_SYNC 0x0001 124 #define VM_PAGER_PUT_INVAL 0x0002 125 #define VM_PAGER_PUT_NOREUSE 0x0004 126 #define VM_PAGER_CLUSTER_OK 0x0008 127 128 #ifdef _KERNEL 129 130 extern const struct pagerops *pagertab[] __read_mostly; 131 extern struct mtx_padalign pbuf_mtx; 132 133 /* 134 * Number of pages that pbuf buffer can store in b_pages. 135 * It is +1 to allow for unaligned data buffer of maxphys size. 136 */ 137 #define PBUF_PAGES (atop(maxphys) + 1) 138 139 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 140 vm_ooffset_t, struct ucred *); 141 void vm_pager_bufferinit(void); 142 void vm_pager_deallocate(vm_object_t); 143 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *); 144 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *, 145 pgo_getpages_iodone_t, void *); 146 void vm_pager_init(void); 147 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 148 149 static __inline void 150 vm_pager_put_pages(vm_object_t object, vm_page_t *m, int count, int flags, 151 int *rtvals) 152 { 153 VM_OBJECT_ASSERT_WLOCKED(object); 154 (*pagertab[object->type]->pgo_putpages) 155 (object, m, count, flags, rtvals); 156 } 157 158 /* 159 * vm_pager_haspage 160 * 161 * Check to see if an object's pager has the requested page. The 162 * object's pager will also set before and after to give the caller 163 * some idea of the number of pages before and after the requested 164 * page can be I/O'd efficiently. 165 * 166 * The object must be locked. 167 */ 168 static __inline boolean_t 169 vm_pager_has_page(vm_object_t object, vm_pindex_t offset, int *before, 170 int *after) 171 { 172 boolean_t ret; 173 174 VM_OBJECT_ASSERT_LOCKED(object); 175 ret = (*pagertab[object->type]->pgo_haspage) 176 (object, offset, before, after); 177 return (ret); 178 } 179 180 static __inline int 181 vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 182 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 183 { 184 185 MPASS((object->flags & OBJ_POPULATE) != 0); 186 MPASS(pidx < object->size); 187 MPASS(blockcount_read(&object->paging_in_progress) > 0); 188 return ((*pagertab[object->type]->pgo_populate)(object, pidx, 189 fault_type, max_prot, first, last)); 190 } 191 192 /* 193 * vm_pager_page_unswapped 194 * 195 * Destroy swap associated with the page. 196 * 197 * XXX: A much better name would be "vm_pager_page_dirtied()" 198 * XXX: It is not obvious if this could be profitably used by any 199 * XXX: pagers besides the swap_pager or if it should even be a 200 * XXX: generic pager_op in the first place. 201 */ 202 static __inline void 203 vm_pager_page_unswapped(vm_page_t m) 204 { 205 pgo_pageunswapped_t *method; 206 207 method = pagertab[m->object->type]->pgo_pageunswapped; 208 if (method != NULL) 209 method(m); 210 } 211 212 static __inline void 213 vm_pager_update_writecount(vm_object_t object, vm_offset_t start, 214 vm_offset_t end) 215 { 216 pgo_writecount_t *method; 217 218 method = pagertab[object->type]->pgo_update_writecount; 219 if (method != NULL) 220 method(object, start, end); 221 } 222 223 static __inline void 224 vm_pager_release_writecount(vm_object_t object, vm_offset_t start, 225 vm_offset_t end) 226 { 227 pgo_writecount_t *method; 228 229 method = pagertab[object->type]->pgo_release_writecount; 230 if (method != NULL) 231 method(object, start, end); 232 } 233 234 static __inline void 235 vm_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 236 { 237 pgo_getvp_t *method; 238 239 *vpp = NULL; 240 if (vp_heldp != NULL) 241 *vp_heldp = false; 242 method = pagertab[object->type]->pgo_getvp; 243 if (method != NULL) 244 method(object, vpp, vp_heldp); 245 } 246 247 static __inline void 248 vm_pager_freespace(vm_object_t object, vm_pindex_t start, 249 vm_size_t size) 250 { 251 pgo_freespace_t *method; 252 253 method = pagertab[object->type]->pgo_freespace; 254 if (method != NULL) 255 method(object, start, size); 256 } 257 258 static __inline void 259 vm_pager_page_inserted(vm_object_t object, vm_page_t m) 260 { 261 pgo_page_inserted_t *method; 262 263 method = pagertab[object->type]->pgo_page_inserted; 264 if (method != NULL) 265 method(object, m); 266 } 267 268 static __inline void 269 vm_pager_page_removed(vm_object_t object, vm_page_t m) 270 { 271 pgo_page_removed_t *method; 272 273 method = pagertab[object->type]->pgo_page_removed; 274 if (method != NULL) 275 method(object, m); 276 } 277 278 static __inline bool 279 vm_pager_can_alloc_page(vm_object_t object, vm_pindex_t pindex) 280 { 281 pgo_can_alloc_page_t *method; 282 283 method = pagertab[object->type]->pgo_can_alloc_page; 284 return (method != NULL ? method(object, pindex) : true); 285 } 286 287 int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type); 288 void vm_pager_free_dyn_type(objtype_t type); 289 290 struct cdev_pager_ops { 291 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 292 int prot, vm_page_t *mres); 293 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 294 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 295 vm_pindex_t *last); 296 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 297 vm_ooffset_t foff, struct ucred *cred, u_short *color); 298 void (*cdev_pg_dtor)(void *handle); 299 }; 300 301 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 302 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 303 vm_ooffset_t foff, struct ucred *cred); 304 vm_object_t cdev_pager_lookup(void *handle); 305 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 306 307 struct phys_pager_ops { 308 int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count, 309 int *rbehind, int *rahead); 310 int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 311 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 312 vm_pindex_t *last); 313 boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex, 314 int *before, int *after); 315 void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot, 316 vm_ooffset_t foff, struct ucred *cred); 317 void (*phys_pg_dtor)(vm_object_t vm_obj); 318 }; 319 extern const struct phys_pager_ops default_phys_pg_ops; 320 vm_object_t phys_pager_allocate(void *handle, const struct phys_pager_ops *ops, 321 void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, 322 struct ucred *cred); 323 324 #endif /* _KERNEL */ 325 #endif /* _VM_PAGER_ */ 326