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 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 }; 91 92 extern const struct pagerops defaultpagerops; 93 extern const struct pagerops swappagerops; 94 extern const struct pagerops vnodepagerops; 95 extern const struct pagerops devicepagerops; 96 extern const struct pagerops physpagerops; 97 extern const struct pagerops sgpagerops; 98 extern const struct pagerops mgtdevicepagerops; 99 extern const struct pagerops swaptmpfspagerops; 100 101 /* 102 * get/put return values 103 * OK operation was successful 104 * BAD specified data was out of the accepted range 105 * FAIL specified data was in range, but doesn't exist 106 * PEND operations was initiated but not completed 107 * ERROR error while accessing data that is in range and exists 108 * AGAIN temporary resource shortage prevented operation from happening 109 */ 110 #define VM_PAGER_OK 0 111 #define VM_PAGER_BAD 1 112 #define VM_PAGER_FAIL 2 113 #define VM_PAGER_PEND 3 114 #define VM_PAGER_ERROR 4 115 #define VM_PAGER_AGAIN 5 116 117 #define VM_PAGER_PUT_SYNC 0x0001 118 #define VM_PAGER_PUT_INVAL 0x0002 119 #define VM_PAGER_PUT_NOREUSE 0x0004 120 #define VM_PAGER_CLUSTER_OK 0x0008 121 122 #ifdef _KERNEL 123 124 extern const struct pagerops *pagertab[] __read_mostly; 125 extern struct mtx_padalign pbuf_mtx; 126 127 /* 128 * Number of pages that pbuf buffer can store in b_pages. 129 * It is +1 to allow for unaligned data buffer of maxphys size. 130 */ 131 #define PBUF_PAGES (atop(maxphys) + 1) 132 133 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 134 vm_ooffset_t, struct ucred *); 135 void vm_pager_bufferinit(void); 136 void vm_pager_deallocate(vm_object_t); 137 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *); 138 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *, 139 pgo_getpages_iodone_t, void *); 140 void vm_pager_init(void); 141 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 142 143 static __inline void 144 vm_pager_put_pages(vm_object_t object, vm_page_t *m, int count, int flags, 145 int *rtvals) 146 { 147 VM_OBJECT_ASSERT_WLOCKED(object); 148 (*pagertab[object->type]->pgo_putpages) 149 (object, m, count, flags, rtvals); 150 } 151 152 /* 153 * vm_pager_haspage 154 * 155 * Check to see if an object's pager has the requested page. The 156 * object's pager will also set before and after to give the caller 157 * some idea of the number of pages before and after the requested 158 * page can be I/O'd efficiently. 159 * 160 * The object must be locked. 161 */ 162 static __inline boolean_t 163 vm_pager_has_page(vm_object_t object, vm_pindex_t offset, int *before, 164 int *after) 165 { 166 boolean_t ret; 167 168 VM_OBJECT_ASSERT_LOCKED(object); 169 ret = (*pagertab[object->type]->pgo_haspage) 170 (object, offset, before, after); 171 return (ret); 172 } 173 174 static __inline int 175 vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 176 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 177 { 178 179 MPASS((object->flags & OBJ_POPULATE) != 0); 180 MPASS(pidx < object->size); 181 MPASS(blockcount_read(&object->paging_in_progress) > 0); 182 return ((*pagertab[object->type]->pgo_populate)(object, pidx, 183 fault_type, max_prot, first, last)); 184 } 185 186 /* 187 * vm_pager_page_unswapped 188 * 189 * Destroy swap associated with the page. 190 * 191 * XXX: A much better name would be "vm_pager_page_dirtied()" 192 * XXX: It is not obvious if this could be profitably used by any 193 * XXX: pagers besides the swap_pager or if it should even be a 194 * XXX: generic pager_op in the first place. 195 */ 196 static __inline void 197 vm_pager_page_unswapped(vm_page_t m) 198 { 199 pgo_pageunswapped_t *method; 200 201 method = pagertab[m->object->type]->pgo_pageunswapped; 202 if (method != NULL) 203 method(m); 204 } 205 206 static __inline void 207 vm_pager_update_writecount(vm_object_t object, vm_offset_t start, 208 vm_offset_t end) 209 { 210 pgo_writecount_t *method; 211 212 method = pagertab[object->type]->pgo_update_writecount; 213 if (method != NULL) 214 method(object, start, end); 215 } 216 217 static __inline void 218 vm_pager_release_writecount(vm_object_t object, vm_offset_t start, 219 vm_offset_t end) 220 { 221 pgo_writecount_t *method; 222 223 method = pagertab[object->type]->pgo_release_writecount; 224 if (method != NULL) 225 method(object, start, end); 226 } 227 228 static __inline void 229 vm_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 230 { 231 pgo_getvp_t *method; 232 233 *vpp = NULL; 234 if (vp_heldp != NULL) 235 *vp_heldp = false; 236 method = pagertab[object->type]->pgo_getvp; 237 if (method != NULL) 238 method(object, vpp, vp_heldp); 239 } 240 241 static __inline void 242 vm_pager_freespace(vm_object_t object, vm_pindex_t start, 243 vm_size_t size) 244 { 245 pgo_freespace_t *method; 246 247 method = pagertab[object->type]->pgo_freespace; 248 if (method != NULL) 249 method(object, start, size); 250 } 251 252 int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type); 253 void vm_pager_free_dyn_type(objtype_t type); 254 255 struct cdev_pager_ops { 256 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 257 int prot, vm_page_t *mres); 258 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 259 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 260 vm_pindex_t *last); 261 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 262 vm_ooffset_t foff, struct ucred *cred, u_short *color); 263 void (*cdev_pg_dtor)(void *handle); 264 }; 265 266 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 267 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 268 vm_ooffset_t foff, struct ucred *cred); 269 vm_object_t cdev_pager_lookup(void *handle); 270 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 271 272 struct phys_pager_ops { 273 int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count, 274 int *rbehind, int *rahead); 275 int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 276 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 277 vm_pindex_t *last); 278 boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex, 279 int *before, int *after); 280 void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot, 281 vm_ooffset_t foff, struct ucred *cred); 282 void (*phys_pg_dtor)(vm_object_t vm_obj); 283 }; 284 extern const struct phys_pager_ops default_phys_pg_ops; 285 vm_object_t phys_pager_allocate(void *handle, const struct phys_pager_ops *ops, 286 void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, 287 struct ucred *cred); 288 289 #endif /* _KERNEL */ 290 #endif /* _VM_PAGER_ */ 291