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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94 35 * $FreeBSD$ 36 */ 37 38 /* 39 * Pager routine interface definition. 40 */ 41 42 #ifndef _VM_PAGER_ 43 #define _VM_PAGER_ 44 45 #include <sys/queue.h> 46 47 TAILQ_HEAD(pagerlst, vm_object); 48 49 typedef void pgo_init_t(void); 50 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, 51 struct ucred *); 52 typedef void pgo_dealloc_t(vm_object_t); 53 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int); 54 typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int); 55 typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int, 56 pgo_getpages_iodone_t, void *); 57 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 58 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 59 typedef void pgo_pageunswapped_t(vm_page_t); 60 61 struct pagerops { 62 pgo_init_t *pgo_init; /* Initialize pager. */ 63 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 64 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 65 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 66 pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */ 67 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 68 pgo_haspage_t *pgo_haspage; /* Query page. */ 69 pgo_pageunswapped_t *pgo_pageunswapped; 70 }; 71 72 extern struct pagerops defaultpagerops; 73 extern struct pagerops swappagerops; 74 extern struct pagerops vnodepagerops; 75 extern struct pagerops devicepagerops; 76 extern struct pagerops physpagerops; 77 extern struct pagerops sgpagerops; 78 extern struct pagerops mgtdevicepagerops; 79 80 /* 81 * get/put return values 82 * OK operation was successful 83 * BAD specified data was out of the accepted range 84 * FAIL specified data was in range, but doesn't exist 85 * PEND operations was initiated but not completed 86 * ERROR error while accessing data that is in range and exists 87 * AGAIN temporary resource shortage prevented operation from happening 88 */ 89 #define VM_PAGER_OK 0 90 #define VM_PAGER_BAD 1 91 #define VM_PAGER_FAIL 2 92 #define VM_PAGER_PEND 3 93 #define VM_PAGER_ERROR 4 94 #define VM_PAGER_AGAIN 5 95 96 #define VM_PAGER_PUT_SYNC 0x0001 97 #define VM_PAGER_PUT_INVAL 0x0002 98 #define VM_PAGER_CLUSTER_OK 0x0008 99 100 #ifdef _KERNEL 101 102 extern struct pagerops *pagertab[]; 103 extern struct mtx_padalign pbuf_mtx; 104 105 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 106 vm_ooffset_t, struct ucred *); 107 void vm_pager_bufferinit(void); 108 void vm_pager_deallocate(vm_object_t); 109 static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 110 static inline int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, 111 int, pgo_getpages_iodone_t, void *); 112 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 113 void vm_pager_init(void); 114 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 115 void vm_pager_free_nonreq(vm_object_t object, vm_page_t ma[], int reqpage, 116 int npages); 117 118 /* 119 * vm_page_get_pages: 120 * 121 * Retrieve pages from the VM system in order to map them into an object 122 * ( or into VM space somewhere ). If the pagein was successful, we 123 * must fully validate it. 124 */ 125 static __inline int 126 vm_pager_get_pages( 127 vm_object_t object, 128 vm_page_t *m, 129 int count, 130 int reqpage 131 ) { 132 int r; 133 134 VM_OBJECT_ASSERT_WLOCKED(object); 135 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 136 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 137 vm_page_zero_invalid(m[reqpage], TRUE); 138 } 139 return (r); 140 } 141 142 static inline int 143 vm_pager_get_pages_async(vm_object_t object, vm_page_t *m, int count, 144 int reqpage, pgo_getpages_iodone_t iodone, void *arg) 145 { 146 147 VM_OBJECT_ASSERT_WLOCKED(object); 148 return ((*pagertab[object->type]->pgo_getpages_async)(object, m, 149 count, reqpage, iodone, arg)); 150 } 151 152 static __inline void 153 vm_pager_put_pages( 154 vm_object_t object, 155 vm_page_t *m, 156 int count, 157 int flags, 158 int *rtvals 159 ) { 160 161 VM_OBJECT_ASSERT_WLOCKED(object); 162 (*pagertab[object->type]->pgo_putpages) 163 (object, m, count, flags, rtvals); 164 } 165 166 /* 167 * vm_pager_haspage 168 * 169 * Check to see if an object's pager has the requested page. The 170 * object's pager will also set before and after to give the caller 171 * some idea of the number of pages before and after the requested 172 * page can be I/O'd efficiently. 173 * 174 * The object must be locked. 175 */ 176 static __inline boolean_t 177 vm_pager_has_page( 178 vm_object_t object, 179 vm_pindex_t offset, 180 int *before, 181 int *after 182 ) { 183 boolean_t ret; 184 185 VM_OBJECT_ASSERT_WLOCKED(object); 186 ret = (*pagertab[object->type]->pgo_haspage) 187 (object, offset, before, after); 188 return (ret); 189 } 190 191 /* 192 * vm_pager_page_unswapped 193 * 194 * Destroy swap associated with the page. 195 * 196 * The object containing the page must be locked. 197 * This function may not block. 198 * 199 * XXX: A much better name would be "vm_pager_page_dirtied()" 200 * XXX: It is not obvious if this could be profitably used by any 201 * XXX: pagers besides the swap_pager or if it should even be a 202 * XXX: generic pager_op in the first place. 203 */ 204 static __inline void 205 vm_pager_page_unswapped(vm_page_t m) 206 { 207 208 VM_OBJECT_ASSERT_LOCKED(m->object); 209 if (pagertab[m->object->type]->pgo_pageunswapped) 210 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 211 } 212 213 struct cdev_pager_ops { 214 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 215 int prot, vm_page_t *mres); 216 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 217 vm_ooffset_t foff, struct ucred *cred, u_short *color); 218 void (*cdev_pg_dtor)(void *handle); 219 }; 220 221 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 222 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 223 vm_ooffset_t foff, struct ucred *cred); 224 vm_object_t cdev_pager_lookup(void *handle); 225 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 226 227 #endif /* _KERNEL */ 228 #endif /* _VM_PAGER_ */ 229