vm_pager.h revision 58714
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: head/sys/vm/vm_pager.h 58708 2000-03-27 21:33:32Z dillon $ 40 */ 41 42/* 43 * Pager routine interface definition. 44 */ 45 46#ifndef _VM_PAGER_ 47#define _VM_PAGER_ 48 49#include <sys/queue.h> 50 51TAILQ_HEAD(pagerlst, vm_object); 52 53struct buf; 54 55struct pagerops { 56 void (*pgo_init) __P((void)); /* Initialize pager. */ 57 vm_object_t (*pgo_alloc) __P((void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t)); /* Allocate pager. */ 58 void (*pgo_dealloc) __P((vm_object_t)); /* Disassociate. */ 59 int (*pgo_getpages) __P((vm_object_t, vm_page_t *, int, int)); /* Get (read) page. */ 60 void (*pgo_putpages) __P((vm_object_t, vm_page_t *, int, int, int *)); /* Put (write) page. */ 61 boolean_t (*pgo_haspage) __P((vm_object_t, vm_pindex_t, int *, int *)); /* Does pager have page? */ 62 void (*pgo_pageunswapped) __P((vm_page_t)); 63 void (*pgo_strategy) __P((vm_object_t, struct buf *)); 64}; 65 66/* 67 * get/put return values 68 * OK operation was successful 69 * BAD specified data was out of the accepted range 70 * FAIL specified data was in range, but doesn't exist 71 * PEND operations was initiated but not completed 72 * ERROR error while accessing data that is in range and exists 73 * AGAIN temporary resource shortage prevented operation from happening 74 */ 75#define VM_PAGER_OK 0 76#define VM_PAGER_BAD 1 77#define VM_PAGER_FAIL 2 78#define VM_PAGER_PEND 3 79#define VM_PAGER_ERROR 4 80#define VM_PAGER_AGAIN 5 81 82#define VM_PAGER_PUT_SYNC 0x1 83#define VM_PAGER_PUT_INVAL 0x2 84 85#ifdef _KERNEL 86 87#ifdef MALLOC_DECLARE 88MALLOC_DECLARE(M_VMPGDATA); 89#endif 90 91extern vm_map_t pager_map; 92extern int pager_map_size; 93extern struct pagerops *pagertab[]; 94 95vm_object_t vm_pager_allocate __P((objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t)); 96void vm_pager_bufferinit __P((void)); 97void vm_pager_deallocate __P((vm_object_t)); 98static __inline int vm_pager_get_pages __P((vm_object_t, vm_page_t *, int, int)); 99static __inline boolean_t vm_pager_has_page __P((vm_object_t, vm_pindex_t, int *, int *)); 100void vm_pager_init __P((void)); 101vm_object_t vm_pager_object_lookup __P((struct pagerlst *, void *)); 102vm_offset_t vm_pager_map_pages __P((vm_page_t *, int, boolean_t)); 103vm_offset_t vm_pager_map_page __P((vm_page_t)); 104void vm_pager_sync __P((void)); 105void vm_pager_unmap_pages __P((vm_offset_t, int)); 106void vm_pager_unmap_page __P((vm_offset_t)); 107void vm_pager_strategy __P((vm_object_t object, struct buf *bp)); 108struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags); 109void flushchainbuf(struct buf *nbp); 110void waitchainbuf(struct buf *bp, int count, int done); 111void autochaindone(struct buf *bp); 112 113/* 114 * vm_page_get_pages: 115 * 116 * Retrieve pages from the VM system in order to map them into an object 117 * ( or into VM space somewhere ). If the pagein was successful, we 118 * must fully validate it. 119 */ 120 121static __inline int 122vm_pager_get_pages( 123 vm_object_t object, 124 vm_page_t *m, 125 int count, 126 int reqpage 127) { 128 int r; 129 130 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 131 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 132 vm_page_zero_invalid(m[reqpage], TRUE); 133 } 134 return(r); 135} 136 137static __inline void 138vm_pager_put_pages( 139 vm_object_t object, 140 vm_page_t *m, 141 int count, 142 int flags, 143 int *rtvals 144) { 145 (*pagertab[object->type]->pgo_putpages) 146 (object, m, count, flags, rtvals); 147} 148 149/* 150 * vm_pager_haspage 151 * 152 * Check to see if an object's pager has the requested page. The 153 * object's pager will also set before and after to give the caller 154 * some idea of the number of pages before and after the requested 155 * page can be I/O'd efficiently. 156 * 157 * This routine does not have to be called at any particular spl. 158 */ 159 160static __inline boolean_t 161vm_pager_has_page( 162 vm_object_t object, 163 vm_pindex_t offset, 164 int *before, 165 int *after 166) { 167 return ((*pagertab[object->type]->pgo_haspage) (object, offset, before, after)); 168} 169 170/* 171 * vm_pager_page_unswapped 172 * 173 * called at splvm() to destroy swap associated with the page. 174 * 175 * This function may not block. 176 */ 177 178static __inline void 179vm_pager_page_unswapped(vm_page_t m) 180{ 181 if (pagertab[m->object->type]->pgo_pageunswapped) 182 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 183} 184 185#endif 186 187#endif /* _VM_PAGER_ */ 188