vm_pager.h revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990 University of Utah. 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94 37 * $FreeBSD: stable/11/sys/vm/vm_pager.h 330897 2018-03-14 03:19:51Z eadler $ 38 */ 39 40/* 41 * Pager routine interface definition. 42 */ 43 44#ifndef _VM_PAGER_ 45#define _VM_PAGER_ 46 47#include <sys/queue.h> 48 49TAILQ_HEAD(pagerlst, vm_object); 50 51typedef void pgo_init_t(void); 52typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, 53 struct ucred *); 54typedef void pgo_dealloc_t(vm_object_t); 55typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *); 56typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int); 57typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *, 58 pgo_getpages_iodone_t, void *); 59typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 60typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 61typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t, 62 vm_pindex_t *, vm_pindex_t *); 63typedef void pgo_pageunswapped_t(vm_page_t); 64 65struct pagerops { 66 pgo_init_t *pgo_init; /* Initialize pager. */ 67 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 68 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 69 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 70 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */ 71 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 72 pgo_haspage_t *pgo_haspage; /* Query page. */ 73 pgo_populate_t *pgo_populate; /* Bulk spec pagein. */ 74 pgo_pageunswapped_t *pgo_pageunswapped; 75}; 76 77extern struct pagerops defaultpagerops; 78extern struct pagerops swappagerops; 79extern struct pagerops vnodepagerops; 80extern struct pagerops devicepagerops; 81extern struct pagerops physpagerops; 82extern struct pagerops sgpagerops; 83extern struct pagerops mgtdevicepagerops; 84 85/* 86 * get/put return values 87 * OK operation was successful 88 * BAD specified data was out of the accepted range 89 * FAIL specified data was in range, but doesn't exist 90 * PEND operations was initiated but not completed 91 * ERROR error while accessing data that is in range and exists 92 * AGAIN temporary resource shortage prevented operation from happening 93 */ 94#define VM_PAGER_OK 0 95#define VM_PAGER_BAD 1 96#define VM_PAGER_FAIL 2 97#define VM_PAGER_PEND 3 98#define VM_PAGER_ERROR 4 99#define VM_PAGER_AGAIN 5 100 101#define VM_PAGER_PUT_SYNC 0x0001 102#define VM_PAGER_PUT_INVAL 0x0002 103#define VM_PAGER_PUT_NOREUSE 0x0004 104#define VM_PAGER_CLUSTER_OK 0x0008 105 106#ifdef _KERNEL 107 108extern struct pagerops *pagertab[]; 109extern struct mtx_padalign pbuf_mtx; 110 111vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 112 vm_ooffset_t, struct ucred *); 113void vm_pager_bufferinit(void); 114void vm_pager_deallocate(vm_object_t); 115int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *); 116int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *, 117 pgo_getpages_iodone_t, void *); 118void vm_pager_init(void); 119vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 120 121static __inline void 122vm_pager_put_pages( 123 vm_object_t object, 124 vm_page_t *m, 125 int count, 126 int flags, 127 int *rtvals 128) { 129 130 VM_OBJECT_ASSERT_WLOCKED(object); 131 (*pagertab[object->type]->pgo_putpages) 132 (object, m, count, flags, rtvals); 133} 134 135/* 136 * vm_pager_haspage 137 * 138 * Check to see if an object's pager has the requested page. The 139 * object's pager will also set before and after to give the caller 140 * some idea of the number of pages before and after the requested 141 * page can be I/O'd efficiently. 142 * 143 * The object must be locked. 144 */ 145static __inline boolean_t 146vm_pager_has_page( 147 vm_object_t object, 148 vm_pindex_t offset, 149 int *before, 150 int *after 151) { 152 boolean_t ret; 153 154 VM_OBJECT_ASSERT_WLOCKED(object); 155 ret = (*pagertab[object->type]->pgo_haspage) 156 (object, offset, before, after); 157 return (ret); 158} 159 160static __inline int 161vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 162 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 163{ 164 165 MPASS((object->flags & OBJ_POPULATE) != 0); 166 MPASS(pidx < object->size); 167 MPASS(object->paging_in_progress > 0); 168 return ((*pagertab[object->type]->pgo_populate)(object, pidx, 169 fault_type, max_prot, first, last)); 170} 171 172 173/* 174 * vm_pager_page_unswapped 175 * 176 * Destroy swap associated with the page. 177 * 178 * The object containing the page must be locked. 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{ 189 190 VM_OBJECT_ASSERT_LOCKED(m->object); 191 if (pagertab[m->object->type]->pgo_pageunswapped) 192 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 193} 194 195struct cdev_pager_ops { 196 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 197 int prot, vm_page_t *mres); 198 int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx, 199 int fault_type, vm_prot_t max_prot, vm_pindex_t *first, 200 vm_pindex_t *last); 201 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 202 vm_ooffset_t foff, struct ucred *cred, u_short *color); 203 void (*cdev_pg_dtor)(void *handle); 204}; 205 206vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 207 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 208 vm_ooffset_t foff, struct ucred *cred); 209vm_object_t cdev_pager_lookup(void *handle); 210void cdev_pager_free_page(vm_object_t object, vm_page_t m); 211 212#endif /* _KERNEL */ 213#endif /* _VM_PAGER_ */ 214