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 1.4 2004/05/13 17:40:19 dillon Exp $ 41 */ 42 43 /* 44 * Pager routine interface definition. 45 */ 46 47 #ifndef _VM_PAGER_ 48 #define _VM_PAGER_ 49 50 #include <sys/queue.h> 51 52 TAILQ_HEAD(pagerlst, vm_object); 53 54 struct buf; 55 56 struct pagerops { 57 void (*pgo_init) (void); /* Initialize pager. */ 58 vm_object_t (*pgo_alloc) (void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */ 59 void (*pgo_dealloc) (vm_object_t); /* Disassociate. */ 60 int (*pgo_getpages) (vm_object_t, vm_page_t *, int, int); /* Get (read) page. */ 61 void (*pgo_putpages) (vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */ 62 boolean_t (*pgo_haspage) (vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */ 63 void (*pgo_pageunswapped) (vm_page_t); 64 void (*pgo_strategy) (vm_object_t, struct buf *); 65 }; 66 67 /* 68 * get/put return values 69 * OK operation was successful 70 * BAD specified data was out of the accepted range 71 * FAIL specified data was in range, but doesn't exist 72 * PEND operations was initiated but not completed 73 * ERROR error while accessing data that is in range and exists 74 * AGAIN temporary resource shortage prevented operation from happening 75 */ 76 #define VM_PAGER_OK 0 77 #define VM_PAGER_BAD 1 78 #define VM_PAGER_FAIL 2 79 #define VM_PAGER_PEND 3 80 #define VM_PAGER_ERROR 4 81 #define VM_PAGER_AGAIN 5 82 83 #define VM_PAGER_PUT_SYNC 0x0001 84 #define VM_PAGER_PUT_INVAL 0x0002 85 #define VM_PAGER_IGNORE_CLEANCHK 0x0004 86 #define VM_PAGER_CLUSTER_OK 0x0008 87 88 #ifdef _KERNEL 89 90 #ifdef MALLOC_DECLARE 91 MALLOC_DECLARE(M_VMPGDATA); 92 #endif 93 94 extern vm_map_t pager_map; 95 extern int pager_map_size; 96 extern struct pagerops *pagertab[]; 97 98 vm_object_t vm_pager_allocate (objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); 99 void vm_pager_bufferinit (void); 100 void vm_pager_deallocate (vm_object_t); 101 static __inline int vm_pager_get_pages (vm_object_t, vm_page_t *, int, int); 102 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t, int *, int *); 103 void vm_pager_init (void); 104 vm_object_t vm_pager_object_lookup (struct pagerlst *, void *); 105 void vm_pager_sync (void); 106 void vm_pager_strategy (vm_object_t object, struct buf *bp); 107 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags); 108 void flushchainbuf(struct buf *nbp); 109 void waitchainbuf(struct buf *bp, int count, int done); 110 void autochaindone(struct buf *bp); 111 112 /* 113 * vm_page_get_pages: 114 * 115 * Retrieve pages from the VM system in order to map them into an object 116 * ( or into VM space somewhere ). If the pagein was successful, we 117 * must fully validate it. 118 */ 119 120 static __inline int 121 vm_pager_get_pages( 122 vm_object_t object, 123 vm_page_t *m, 124 int count, 125 int reqpage 126 ) { 127 int r; 128 129 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 130 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 131 vm_page_zero_invalid(m[reqpage], TRUE); 132 } 133 return(r); 134 } 135 136 static __inline void 137 vm_pager_put_pages( 138 vm_object_t object, 139 vm_page_t *m, 140 int count, 141 int flags, 142 int *rtvals 143 ) { 144 (*pagertab[object->type]->pgo_putpages) 145 (object, m, count, flags, rtvals); 146 } 147 148 /* 149 * vm_pager_haspage 150 * 151 * Check to see if an object's pager has the requested page. The 152 * object's pager will also set before and after to give the caller 153 * some idea of the number of pages before and after the requested 154 * page can be I/O'd efficiently. 155 * 156 * This routine does not have to be called at any particular spl. 157 */ 158 159 static __inline boolean_t 160 vm_pager_has_page( 161 vm_object_t object, 162 vm_pindex_t offset, 163 int *before, 164 int *after 165 ) { 166 return ((*pagertab[object->type]->pgo_haspage) (object, offset, before, after)); 167 } 168 169 /* 170 * vm_pager_page_unswapped 171 * 172 * called at splvm() to destroy swap associated with the page. 173 * 174 * This function may not block. 175 */ 176 177 static __inline void 178 vm_pager_page_unswapped(vm_page_t m) 179 { 180 if (pagertab[m->object->type]->pgo_pageunswapped) 181 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 182 } 183 184 #endif 185 186 #endif /* _VM_PAGER_ */ 187