vm_pager.h revision 118528
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 118528 2003-08-06 10:51:40Z phk $ 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}; 64 65extern struct pagerops defaultpagerops; 66extern struct pagerops swappagerops; 67extern struct pagerops vnodepagerops; 68extern struct pagerops devicepagerops; 69extern struct pagerops physpagerops; 70 71/* 72 * get/put return values 73 * OK operation was successful 74 * BAD specified data was out of the accepted range 75 * FAIL specified data was in range, but doesn't exist 76 * PEND operations was initiated but not completed 77 * ERROR error while accessing data that is in range and exists 78 * AGAIN temporary resource shortage prevented operation from happening 79 */ 80#define VM_PAGER_OK 0 81#define VM_PAGER_BAD 1 82#define VM_PAGER_FAIL 2 83#define VM_PAGER_PEND 3 84#define VM_PAGER_ERROR 4 85#define VM_PAGER_AGAIN 5 86 87#define VM_PAGER_PUT_SYNC 0x0001 88#define VM_PAGER_PUT_INVAL 0x0002 89#define VM_PAGER_IGNORE_CLEANCHK 0x0004 90#define VM_PAGER_CLUSTER_OK 0x0008 91 92#ifdef _KERNEL 93#ifdef MALLOC_DECLARE 94MALLOC_DECLARE(M_VMPGDATA); 95#endif 96 97extern vm_map_t pager_map; 98extern int pager_map_size; 99extern struct pagerops *pagertab[]; 100extern struct mtx pbuf_mtx; 101 102vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); 103void vm_pager_bufferinit(void); 104void vm_pager_deallocate(vm_object_t); 105static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 106static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 107void vm_pager_init(void); 108vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 109vm_offset_t vm_pager_map_page(vm_page_t); 110void vm_pager_unmap_page(vm_offset_t); 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 */ 119static __inline int 120vm_pager_get_pages( 121 vm_object_t object, 122 vm_page_t *m, 123 int count, 124 int reqpage 125) { 126 int r; 127 128 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 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 136static __inline void 137vm_pager_put_pages( 138 vm_object_t object, 139 vm_page_t *m, 140 int count, 141 int flags, 142 int *rtvals 143) { 144 GIANT_REQUIRED; 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 */ 159static __inline boolean_t 160vm_pager_has_page( 161 vm_object_t object, 162 vm_pindex_t offset, 163 int *before, 164 int *after 165) { 166 boolean_t ret; 167 168 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 169 ret = (*pagertab[object->type]->pgo_haspage) 170 (object, offset, before, after); 171 return (ret); 172} 173 174/* 175 * vm_pager_page_unswapped 176 * 177 * called at splvm() to destroy swap associated with the page. 178 * 179 * This function may not block. 180 * 181 * XXX: A much better name would be "vm_pager_page_dirtied()" 182 * XXX: It is not obvious if this could be profitably used by any 183 * XXX: pagers besides the swap_pager or if it should even be a 184 * XXX: generic pager_op in the first place. 185 */ 186static __inline void 187vm_pager_page_unswapped(vm_page_t m) 188{ 189 GIANT_REQUIRED; 190 if (pagertab[m->object->type]->pgo_pageunswapped) 191 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 192} 193 194#endif /* _KERNEL */ 195#endif /* _VM_PAGER_ */ 196