sys/vm/vm_pager.h

   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. 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: src/sys/vm/vm_pager.h,v 1.24.2.2 2002/12/31 09:34:51 dillon Exp $
  36  */
  37
  38 /*
  39  * Pager routine interface definition.
  40  */
  41
  42 #ifndef _VM_VM_PAGER_H_
  43 #define _VM_VM_PAGER_H_
  44
  45 #ifndef _SYS_QUEUE_H_
  46 #include <sys/queue.h>
  47 #endif
  48 #ifndef _VM_VM_PAGE_H_
  49 #include <vm/vm_page.h>
  50 #endif
  51 #ifndef _VM_VM_OBJECT_H_
  52 #include <vm/vm_object.h>
  53 #endif
  54
  55 TAILQ_HEAD(pagerlst, vm_object);
  56
  57 struct buf;
  58 struct bio;
  59
  60 struct pagerops {
  61         void (*pgo_dealloc) (vm_object_t);
  62         int (*pgo_getpage) (vm_object_t, vm_page_t *, int);
  63         void (*pgo_putpages) (vm_object_t, vm_page_t *, int, int, int *);
  64         boolean_t (*pgo_haspage) (vm_object_t, vm_pindex_t);
  65 };
  66
  67 /*
  68  * get/put return values
  69  * OK    operation was successful
  70  * BAD   specified data was out of the accepted range
  71  * FAIL  specified data was in range, but doesn't exist
  72  * PEND  operations was initiated but not completed
  73  * ERROR error while accessing data that is in range and exists
  74  * AGAIN temporary resource shortage prevented operation from happening
  75  */
  76 #define VM_PAGER_OK     0
  77 #define VM_PAGER_BAD    1
  78 #define VM_PAGER_FAIL   2
  79 #define VM_PAGER_PEND   3
  80 #define VM_PAGER_ERROR  4
  81 #define VM_PAGER_AGAIN  5
  82
  83 #define VM_PAGER_PUT_SYNC               0x0001
  84 #define VM_PAGER_PUT_INVAL              0x0002
  85 #define VM_PAGER_IGNORE_CLEANCHK        0x0004
  86 #define VM_PAGER_CLUSTER_OK             0x0008
  87 #define VM_PAGER_TRY_TO_CACHE           0x0010
  88 #define VM_PAGER_ALLOW_ACTIVE           0x0020
  89
  90 #ifdef _KERNEL
  91
  92 struct vnode;
  93
  94 extern struct vm_map pager_map;
  95 extern int pager_map_size;
  96 extern struct pagerops *pagertab[];
  97
  98 vm_object_t default_pager_alloc(void *, off_t, vm_prot_t, off_t);
  99 vm_object_t dev_pager_alloc(void *, off_t, vm_prot_t, off_t);
 100 vm_object_t phys_pager_alloc(void *, off_t, vm_prot_t, off_t);
 101 vm_object_t swap_pager_alloc(void *, off_t, vm_prot_t, off_t);
 102 vm_object_t vnode_pager_alloc (void *, off_t, vm_prot_t, off_t, int, int);
 103 vm_object_t vnode_pager_reference (struct vnode *);
 104
 105 void vm_pager_deallocate (vm_object_t);
 106 static __inline int vm_pager_get_page (vm_object_t, vm_page_t *, int);
 107 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t);
 108 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
 109 void vm_pager_sync (void);
 110 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags);
 111 void flushchainbuf(struct buf *nbp);
 112 void waitchainbuf(struct buf *bp, int count, int done);
 113 void autochaindone(struct buf *bp);
 114 void swap_pager_strategy(vm_object_t object, struct bio *bio);
 115 void swap_pager_unswapped (vm_page_t m);
 116
 117 /*
 118  * vm_page_get_pages:
 119  *
 120  * Retrieve the contents of the page from the object pager.  Note that the
 121  * object pager might replace the page.
 122  *
 123  * If the pagein was successful, we must fully validate it so it can be
 124  * memory mapped.
 125  */
 126
 127 static __inline int
 128 vm_pager_get_page(vm_object_t object, vm_page_t *m, int seqaccess)
 129 {
 130         int r;
 131
 132         r = (*pagertab[object->type]->pgo_getpage)(object, m, seqaccess);
 133         if (r == VM_PAGER_OK && (*m)->valid != VM_PAGE_BITS_ALL) {
 134                 vm_page_zero_invalid(*m, TRUE);
 135         }
 136         return(r);
 137 }
 138
 139 static __inline void
 140 vm_pager_put_pages(
 141         vm_object_t object,
 142         vm_page_t *m,
 143         int count,
 144         int flags,
 145         int *rtvals
 146 ) {
 147         (*pagertab[object->type]->pgo_putpages)
 148             (object, m, count, flags, rtvals);
 149 }
 150
 151 /*
 152  *      vm_pager_haspage
 153  *
 154  *      Check to see if an object's pager has the requested page.  The
 155  *      object's pager will also set before and after to give the caller
 156  *      some idea of the number of pages before and after the requested
 157  *      page can be I/O'd efficiently.
 158  *
 159  *      This routine does not have to be called at any particular spl.
 160  */
 161
 162 static __inline boolean_t
 163 vm_pager_has_page(vm_object_t object, vm_pindex_t offset)
 164 {
 165         return ((*pagertab[object->type]->pgo_haspage)(object, offset));
 166 }
 167
 168 struct cdev_pager_ops {
 169         int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
 170             int prot, vm_page_t *mres);
 171         int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
 172             vm_ooffset_t foff, struct ucred *cred, u_short *color);
 173         void (*cdev_pg_dtor)(void *handle);
 174 };
 175
 176 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
 177     struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
 178     vm_ooffset_t foff, struct ucred *cred);
 179 vm_object_t cdev_pager_lookup(void *handle);
 180 void cdev_pager_free_page(vm_object_t object, vm_page_t m);
 181
 182 #endif
 183
 184 #endif                          /* _VM_VM_PAGER_H_ */