vm_pager.h revision 99196
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 99196 2002-07-01 02:38:05Z alc $ 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 bio; 54 55struct pagerops { 56 void (*pgo_init)(void); /* Initialize pager. */ 57 vm_object_t (*pgo_alloc)(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */ 58 void (*pgo_dealloc)(vm_object_t); /* Disassociate. */ 59 int (*pgo_getpages)(vm_object_t, vm_page_t *, int, int); /* Get (read) page. */ 60 void (*pgo_putpages)(vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */ 61 boolean_t (*pgo_haspage)(vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */ 62 void (*pgo_pageunswapped)(vm_page_t); 63 void (*pgo_strategy)(vm_object_t, struct bio *); 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#ifdef MALLOC_DECLARE 87MALLOC_DECLARE(M_VMPGDATA); 88#endif 89 90extern vm_map_t pager_map; 91extern int pager_map_size; 92extern struct pagerops *pagertab[]; 93extern struct mtx pbuf_mtx; 94 95vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); 96void vm_pager_bufferinit(void); 97void vm_pager_deallocate(vm_object_t); 98static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 99static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 100void vm_pager_init(void); 101vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 102vm_offset_t vm_pager_map_page(vm_page_t); 103void vm_pager_unmap_page(vm_offset_t); 104void vm_pager_strategy(vm_object_t object, struct bio *bp); 105 106/* 107 * vm_page_get_pages: 108 * 109 * Retrieve pages from the VM system in order to map them into an object 110 * ( or into VM space somewhere ). If the pagein was successful, we 111 * must fully validate it. 112 */ 113static __inline int 114vm_pager_get_pages( 115 vm_object_t object, 116 vm_page_t *m, 117 int count, 118 int reqpage 119) { 120 int r; 121 122 GIANT_REQUIRED; 123 124 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 125 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 126 vm_page_zero_invalid(m[reqpage], TRUE); 127 } 128 return (r); 129} 130 131static __inline void 132vm_pager_put_pages( 133 vm_object_t object, 134 vm_page_t *m, 135 int count, 136 int flags, 137 int *rtvals 138) { 139 GIANT_REQUIRED; 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 * This routine does not have to be called at any particular spl. 153 */ 154static __inline boolean_t 155vm_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 GIANT_REQUIRED; 164 ret = (*pagertab[object->type]->pgo_haspage) 165 (object, offset, before, after); 166 return (ret); 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 */ 176static __inline void 177vm_pager_page_unswapped(vm_page_t m) 178{ 179 GIANT_REQUIRED; 180 if (pagertab[m->object->type]->pgo_pageunswapped) 181 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 182} 183 184#endif /* _KERNEL */ 185#endif /* _VM_PAGER_ */ 186