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 #ifdef _KERNEL
  56 TAILQ_HEAD(pagerlst, vm_object);
  57
  58 struct buf;
  59 struct bio;
  60
  61 typedef void pgo_dealloc_t(vm_object_t);
  62 typedef int pgo_getpage_t(vm_object_t, vm_pindex_t, vm_page_t *, int);
  63 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
  64 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t);
  65
  66 struct pagerops {
  67         pgo_dealloc_t   *pgo_dealloc;
  68         pgo_getpage_t   *pgo_getpage;
  69         pgo_putpages_t  *pgo_putpages;
  70         pgo_haspage_t   *pgo_haspage;
  71 };
  72 #endif  /* _KERNEL */
  73
  74 /*
  75  * get/put return values
  76  * OK    operation was successful
  77  * BAD   specified data was out of the accepted range
  78  * FAIL  specified data was in range, but doesn't exist
  79  * PEND  operations was initiated but not completed
  80  * ERROR error while accessing data that is in range and exists
  81  * AGAIN temporary resource shortage prevented operation from happening
  82  */
  83 #define VM_PAGER_OK     0
  84 #define VM_PAGER_BAD    1
  85 #define VM_PAGER_FAIL   2
  86 #define VM_PAGER_PEND   3
  87 #define VM_PAGER_ERROR  4
  88 #define VM_PAGER_AGAIN  5
  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_pindex_t,
 107                         vm_page_t *, int);
 108 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t);
 109 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
 110 void vm_pager_sync (void);
 111 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags);
 112 void flushchainbuf(struct buf *nbp);
 113 void waitchainbuf(struct buf *bp, int count, int done);
 114 void autochaindone(struct buf *bp);
 115 void swap_pager_strategy(vm_object_t object, struct bio *bio);
 116 void swap_pager_unswapped (vm_page_t m);
 117
 118 /*
 119  * vm_page_get_pages:
 120  *
 121  * Retrieve the contents of the page from the object pager.  Note that the
 122  * object pager might replace the page.
 123  *
 124  * If the pagein was successful, we must fully validate it so it can be
 125  * memory mapped.
 126  */
 127
 128 static __inline int
 129 vm_pager_get_page(vm_object_t object, vm_pindex_t pindex,
 130                   vm_page_t *m, int seqaccess)
 131 {
 132         int r;
 133
 134         r = (*pagertab[object->type]->pgo_getpage)(object, pindex,
 135                                                    m, seqaccess);
 136         if (r == VM_PAGER_OK && (*m)->valid != VM_PAGE_BITS_ALL) {
 137                 vm_page_zero_invalid(*m, TRUE);
 138         }
 139         return(r);
 140 }
 141
 142 static __inline void
 143 vm_pager_put_pages(
 144         vm_object_t object,
 145         vm_page_t *m,
 146         int count,
 147         int flags,
 148         int *rtvals
 149 ) {
 150         (*pagertab[object->type]->pgo_putpages)
 151             (object, m, count, flags, rtvals);
 152 }
 153
 154 /*
 155  *      vm_pager_haspage
 156  *
 157  *      Check to see if an object's pager has the requested page.  The
 158  *      object's pager will also set before and after to give the caller
 159  *      some idea of the number of pages before and after the requested
 160  *      page can be I/O'd efficiently.
 161  *
 162  *      This routine does not have to be called at any particular spl.
 163  */
 164
 165 static __inline boolean_t
 166 vm_pager_has_page(vm_object_t object, vm_pindex_t offset)
 167 {
 168         return ((*pagertab[object->type]->pgo_haspage)(object, offset));
 169 }
 170
 171 struct cdev_pager_ops {
 172         int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
 173             int prot, vm_page_t *mres);
 174         int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
 175             vm_ooffset_t foff, struct ucred *cred, u_short *color);
 176         void (*cdev_pg_dtor)(void *handle);
 177 };
 178
 179 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
 180     struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
 181     vm_ooffset_t foff, struct ucred *cred);
 182 vm_object_t cdev_pager_lookup(void *handle);
 183 void cdev_pager_free_page(vm_object_t object, vm_page_t m);
 184
 185 #endif  /* _KERNEL */
 186
 187 #endif  /* _VM_VM_PAGER_H_ */