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 48 TAILQ_HEAD(pagerlst, vm_object); 49 struct vnode; 50 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, 53 struct ucred *); 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); 65 typedef void pgo_set_writeable_dirty_t(vm_object_t); 66 typedef bool pgo_mightbedirty_t(vm_object_t); 67 typedef void pgo_getvp_t(vm_object_t object, struct vnode **vpp, 68 bool *vp_heldp); 69 typedef void pgo_freespace_t(vm_object_t object, vm_pindex_t start, 70 vm_size_t size); 71 typedef void pgo_page_inserted_t(vm_object_t object, vm_page_t m); 72 typedef void pgo_page_removed_t(vm_object_t object, vm_page_t m); 73 typedef boolean_t pgo_can_alloc_page_t(vm_object_t object, vm_pindex_t pindex); 74 75 struct 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 97 extern const struct pagerops defaultpagerops; 98 extern const struct pagerops swappagerops; 99 extern const struct pagerops vnodepagerops; 100 extern const struct pagerops devicepagerops; 101 extern const struct pagerops physpagerops; 102 extern const struct pagerops sgpagerops; 103 extern const struct pagerops mgtdevicepagerops; 104 extern 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 128 129 extern const struct pagerops *pagertab[] __read_mostly; 130 extern 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) 137 138 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 139 vm_ooffset_t, struct ucred *); 140 void vm_pager_bufferinit(void); 141 void vm_pager_deallocate(vm_object_t); 142 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *); 143 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *, 144 pgo_getpages_iodone_t, void *); 145 void vm_pager_init(void); 146 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 147 148 static __inline void 149 vm_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 */ 167 static __inline boolean_t 168 vm_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 } 178 179 static __inline int 180 vm_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 */ 201 static __inline void 202 vm_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 } 210 211 static __inline void 212 vm_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 } 221 222 static __inline void 223 vm_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 } 232 233 static __inline void 234 vm_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 } 245 246 static __inline void 247 vm_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 } 256 257 static __inline void 258 vm_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 } 266 267 static __inline void 268 vm_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 } 276 277 static __inline bool 278 vm_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 } 285 286 int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type); 287 void vm_pager_free_dyn_type(objtype_t type); 288 289 struct 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 }; 299 300 vm_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); 303 vm_object_t cdev_pager_lookup(void *handle); 304 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 305 306 struct 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 }; 318 extern const struct phys_pager_ops default_phys_pg_ops; 319 vm_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_ */ 325