1 /* 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94 39 * $FreeBSD: src/sys/vm/vm_pager.h,v 1.24.2.2 2002/12/31 09:34:51 dillon Exp $ 40 * $DragonFly: src/sys/vm/vm_pager.h,v 1.9 2006/12/28 21:24:02 dillon Exp $ 41 */ 42 43 /* 44 * Pager routine interface definition. 45 */ 46 47 #ifndef _VM_VM_PAGER_H_ 48 #define _VM_VM_PAGER_H_ 49 50 #ifndef _SYS_QUEUE_H_ 51 #include <sys/queue.h> 52 #endif 53 #ifndef _VM_VM_PAGE_H_ 54 #include <vm/vm_page.h> 55 #endif 56 #ifndef _VM_VM_OBJECT_H_ 57 #include <vm/vm_object.h> 58 #endif 59 60 TAILQ_HEAD(pagerlst, vm_object); 61 62 struct buf; 63 struct bio; 64 65 struct pagerops { 66 void (*pgo_init) (void); /* Initialize pager. */ 67 vm_object_t (*pgo_alloc) (void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */ 68 void (*pgo_dealloc) (vm_object_t); /* Disassociate. */ 69 int (*pgo_getpages) (vm_object_t, vm_page_t *, int, int); /* Get (read) page. */ 70 void (*pgo_putpages) (vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */ 71 boolean_t (*pgo_haspage) (vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */ 72 void (*pgo_pageunswapped) (vm_page_t); 73 void (*pgo_strategy) (vm_object_t, struct bio *); 74 }; 75 76 /* 77 * get/put return values 78 * OK operation was successful 79 * BAD specified data was out of the accepted range 80 * FAIL specified data was in range, but doesn't exist 81 * PEND operations was initiated but not completed 82 * ERROR error while accessing data that is in range and exists 83 * AGAIN temporary resource shortage prevented operation from happening 84 */ 85 #define VM_PAGER_OK 0 86 #define VM_PAGER_BAD 1 87 #define VM_PAGER_FAIL 2 88 #define VM_PAGER_PEND 3 89 #define VM_PAGER_ERROR 4 90 #define VM_PAGER_AGAIN 5 91 92 #define VM_PAGER_PUT_SYNC 0x0001 93 #define VM_PAGER_PUT_INVAL 0x0002 94 #define VM_PAGER_IGNORE_CLEANCHK 0x0004 95 #define VM_PAGER_CLUSTER_OK 0x0008 96 97 #ifdef _KERNEL 98 99 #ifdef MALLOC_DECLARE 100 MALLOC_DECLARE(M_VMPGDATA); 101 #endif 102 103 struct vnode; 104 105 extern struct vm_map pager_map; 106 extern int pager_map_size; 107 extern struct pagerops *pagertab[]; 108 109 vm_object_t vm_pager_allocate (objtype_t, void *, off_t, vm_prot_t, off_t); 110 void vm_pager_bufferinit (void); 111 void vm_pager_deallocate (vm_object_t); 112 static __inline int vm_pager_get_pages (vm_object_t, vm_page_t *, int, int); 113 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t, int *, int *); 114 void vm_pager_init (void); 115 vm_object_t vm_pager_object_lookup (struct pagerlst *, void *); 116 void vm_pager_sync (void); 117 void vm_pager_strategy (vm_object_t object, struct bio *bio); 118 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags); 119 void flushchainbuf(struct buf *nbp); 120 void waitchainbuf(struct buf *bp, int count, int done); 121 void autochaindone(struct buf *bp); 122 123 /* 124 * vm_page_get_pages: 125 * 126 * Retrieve pages from the VM system in order to map them into an object 127 * ( or into VM space somewhere ). If the pagein was successful, we 128 * must fully validate it. 129 */ 130 131 static __inline int 132 vm_pager_get_pages( 133 vm_object_t object, 134 vm_page_t *m, 135 int count, 136 int reqpage 137 ) { 138 int r; 139 140 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 141 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 142 vm_page_zero_invalid(m[reqpage], TRUE); 143 } 144 return(r); 145 } 146 147 static __inline void 148 vm_pager_put_pages( 149 vm_object_t object, 150 vm_page_t *m, 151 int count, 152 int flags, 153 int *rtvals 154 ) { 155 (*pagertab[object->type]->pgo_putpages) 156 (object, m, count, flags, rtvals); 157 } 158 159 /* 160 * vm_pager_haspage 161 * 162 * Check to see if an object's pager has the requested page. The 163 * object's pager will also set before and after to give the caller 164 * some idea of the number of pages before and after the requested 165 * page can be I/O'd efficiently. 166 * 167 * This routine does not have to be called at any particular spl. 168 */ 169 170 static __inline boolean_t 171 vm_pager_has_page( 172 vm_object_t object, 173 vm_pindex_t offset, 174 int *before, 175 int *after 176 ) { 177 return ((*pagertab[object->type]->pgo_haspage) (object, offset, before, after)); 178 } 179 180 /* 181 * vm_pager_page_unswapped 182 * 183 * called at splvm() to destroy swap associated with the page. 184 * 185 * This function may not block. 186 */ 187 188 static __inline void 189 vm_pager_page_unswapped(vm_page_t m) 190 { 191 if (pagertab[m->object->type]->pgo_pageunswapped) 192 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 193 } 194 195 #endif 196 197 #endif /* _VM_VM_PAGER_H_ */ 198