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 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 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 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 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 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 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 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 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 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 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 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