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/queue.h> 48 49 TAILQ_HEAD(pagerlst, vm_object); 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 66 struct pagerops { 67 pgo_init_t *pgo_init; /* Initialize pager. */ 68 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 69 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 70 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 71 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */ 72 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 73 pgo_haspage_t *pgo_haspage; /* Query page. */ 74 pgo_populate_t *pgo_populate; /* Bulk spec pagein. */ 75 pgo_pageunswapped_t *pgo_pageunswapped; 76 /* Operations for specialized writecount handling */ 77 pgo_writecount_t *pgo_update_writecount; 78 pgo_writecount_t *pgo_release_writecount; 79 }; 80 81 extern struct pagerops defaultpagerops; 82 extern struct pagerops swappagerops; 83 extern struct pagerops vnodepagerops; 84 extern struct pagerops devicepagerops; 85 extern struct pagerops physpagerops; 86 extern struct pagerops sgpagerops; 87 extern struct pagerops mgtdevicepagerops; 88 89 /* 90 * get/put return values 91 * OK operation was successful 92 * BAD specified data was out of the accepted range 93 * FAIL specified data was in range, but doesn't exist 94 * PEND operations was initiated but not completed 95 * ERROR error while accessing data that is in range and exists 96 * AGAIN temporary resource shortage prevented operation from happening 97 */ 98 #define VM_PAGER_OK 0 99 #define VM_PAGER_BAD 1 100 #define VM_PAGER_FAIL 2 101 #define VM_PAGER_PEND 3 102 #define VM_PAGER_ERROR 4 103 #define VM_PAGER_AGAIN 5 104 105 #define VM_PAGER_PUT_SYNC 0x0001 106 #define VM_PAGER_PUT_INVAL 0x0002 107 #define VM_PAGER_PUT_NOREUSE 0x0004 108 #define VM_PAGER_CLUSTER_OK 0x0008 109 110 #ifdef _KERNEL 111 112 extern struct pagerops *pagertab[]; 113 extern struct mtx_padalign pbuf_mtx; 114 115 /* 116 * Number of pages that pbuf buffer can store in b_pages. 117 * It is +1 to allow for unaligned data buffer of maxphys size. 118 */ 119 #define PBUF_PAGES (atop(maxphys) + 1) 120 121 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 122 vm_ooffset_t, struct ucred *); 123 void vm_pager_bufferinit(void); 124 void vm_pager_deallocate(vm_object_t); 125 int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *); 126 int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *, 127 pgo_getpages_iodone_t, void *); 128 void vm_pager_init(void); 129 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 130 131 static __inline void 132 vm_pager_put_pages( 133 vm_object_t object, 134 vm_page_t *m, 135 int count, 136 int flags, 137 int *rtvals 138 ) { 139 VM_OBJECT_ASSERT_WLOCKED(object); 140 (*pagertab[object->type]->pgo_putpages) 141 (object, m, count, flags, rtvals); 142 } 143 144 /* 145 * vm_pager_haspage 146 * 147 * Check to see if an object's pager has the requested page. The 148 * object's pager will also set before and after to give the caller 149 * some idea of the number of pages before and after the requested 150 * page can be I/O'd efficiently. 151 * 152 * The object must be locked. 153 */ 154 static __inline boolean_t 155 vm_pager_has_page( 156 vm_object_t object, 157 vm_pindex_t offset, 158 int *before, 159 int *after 160 ) { 161 boolean_t ret; 162 163 VM_OBJECT_ASSERT_LOCKED(object); 164 ret = (*pagertab[object->type]->pgo_haspage) 165 (object, offset, before, after); 166 return (ret); 167 } 168 169 static __inline int 170 vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 171 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 172 { 173 174 MPASS((object->flags & OBJ_POPULATE) != 0); 175 MPASS(pidx < object->size); 176 MPASS(blockcount_read(&object->paging_in_progress) > 0); 177 return ((*pagertab[object->type]->pgo_populate)(object, pidx, 178 fault_type, max_prot, first, last)); 179 } 180 181 /* 182 * vm_pager_page_unswapped 183 * 184 * Destroy swap associated with the page. 185 * 186 * XXX: A much better name would be "vm_pager_page_dirtied()" 187 * XXX: It is not obvious if this could be profitably used by any 188 * XXX: pagers besides the swap_pager or if it should even be a 189 * XXX: generic pager_op in the first place. 190 */ 191 static __inline void 192 vm_pager_page_unswapped(vm_page_t m) 193 { 194 195 if (pagertab[m->object->type]->pgo_pageunswapped) 196 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 197 } 198 199 static __inline void 200 vm_pager_update_writecount(vm_object_t object, vm_offset_t start, 201 vm_offset_t end) 202 { 203 204 if (pagertab[object->type]->pgo_update_writecount) 205 pagertab[object->type]->pgo_update_writecount(object, start, 206 end); 207 } 208 209 static __inline void 210 vm_pager_release_writecount(vm_object_t object, vm_offset_t start, 211 vm_offset_t end) 212 { 213 214 if (pagertab[object->type]->pgo_release_writecount) 215 pagertab[object->type]->pgo_release_writecount(object, start, 216 end); 217 } 218 219 struct cdev_pager_ops { 220 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 221 int prot, vm_page_t *mres); 222 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 223 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 224 vm_pindex_t *last); 225 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 226 vm_ooffset_t foff, struct ucred *cred, u_short *color); 227 void (*cdev_pg_dtor)(void *handle); 228 }; 229 230 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 231 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 232 vm_ooffset_t foff, struct ucred *cred); 233 vm_object_t cdev_pager_lookup(void *handle); 234 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 235 236 struct phys_pager_ops { 237 int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count, 238 int *rbehind, int *rahead); 239 int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 240 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 241 vm_pindex_t *last); 242 boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex, 243 int *before, int *after); 244 void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot, 245 vm_ooffset_t foff, struct ucred *cred); 246 void (*phys_pg_dtor)(vm_object_t vm_obj); 247 }; 248 extern struct phys_pager_ops default_phys_pg_ops; 249 vm_object_t phys_pager_allocate(void *handle, struct phys_pager_ops *ops, 250 void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, 251 struct ucred *cred); 252 253 #endif /* _KERNEL */ 254 #endif /* _VM_PAGER_ */ 255