The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/vm/phys_pager.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2000 Peter Wemm
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  *
   13  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
   14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
   17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   23  * SUCH DAMAGE.
   24  */
   25 
   26 #include <sys/cdefs.h>
   27 __FBSDID("$FreeBSD$");
   28 
   29 #include <sys/param.h>
   30 #include <sys/systm.h>
   31 #include <sys/conf.h>
   32 #include <sys/kernel.h>
   33 #include <sys/lock.h>
   34 #include <sys/proc.h>
   35 #include <sys/mutex.h>
   36 #include <sys/mman.h>
   37 #include <sys/rwlock.h>
   38 #include <sys/sysctl.h>
   39 
   40 #include <vm/vm.h>
   41 #include <vm/vm_param.h>
   42 #include <vm/vm_object.h>
   43 #include <vm/vm_page.h>
   44 #include <vm/vm_pager.h>
   45 
   46 /* list of phys pager objects */
   47 static struct pagerlst phys_pager_object_list;
   48 /* protect access to phys_pager_object_list */
   49 static struct mtx phys_pager_mtx;
   50 
   51 static void
   52 phys_pager_init(void)
   53 {
   54 
   55         TAILQ_INIT(&phys_pager_object_list);
   56         mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF);
   57 }
   58 
   59 static vm_object_t
   60 phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
   61     vm_ooffset_t foff, struct ucred *cred)
   62 {
   63         vm_object_t object, object1;
   64         vm_pindex_t pindex;
   65 
   66         /*
   67          * Offset should be page aligned.
   68          */
   69         if (foff & PAGE_MASK)
   70                 return (NULL);
   71 
   72         pindex = OFF_TO_IDX(foff + PAGE_MASK + size);
   73 
   74         if (handle != NULL) {
   75                 mtx_lock(&phys_pager_mtx);
   76                 /*
   77                  * Look up pager, creating as necessary.
   78                  */
   79                 object1 = NULL;
   80                 object = vm_pager_object_lookup(&phys_pager_object_list, handle);
   81                 if (object == NULL) {
   82                         /*
   83                          * Allocate object and associate it with the pager.
   84                          */
   85                         mtx_unlock(&phys_pager_mtx);
   86                         object1 = vm_object_allocate(OBJT_PHYS, pindex);
   87                         mtx_lock(&phys_pager_mtx);
   88                         object = vm_pager_object_lookup(&phys_pager_object_list,
   89                             handle);
   90                         if (object != NULL) {
   91                                 /*
   92                                  * We raced with other thread while
   93                                  * allocating object.
   94                                  */
   95                                 if (pindex > object->size)
   96                                         object->size = pindex;
   97                         } else {
   98                                 object = object1;
   99                                 object1 = NULL;
  100                                 object->handle = handle;
  101                                 TAILQ_INSERT_TAIL(&phys_pager_object_list,
  102                                     object, pager_object_list);
  103                         }
  104                 } else {
  105                         if (pindex > object->size)
  106                                 object->size = pindex;
  107                 }
  108                 mtx_unlock(&phys_pager_mtx);
  109                 vm_object_deallocate(object1);
  110         } else {
  111                 object = vm_object_allocate(OBJT_PHYS, pindex);
  112         }
  113 
  114         return (object);
  115 }
  116 
  117 static void
  118 phys_pager_dealloc(vm_object_t object)
  119 {
  120 
  121         if (object->handle != NULL) {
  122                 VM_OBJECT_WUNLOCK(object);
  123                 mtx_lock(&phys_pager_mtx);
  124                 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
  125                 mtx_unlock(&phys_pager_mtx);
  126                 VM_OBJECT_WLOCK(object);
  127         }
  128         object->handle = NULL;
  129         object->type = OBJT_DEAD;
  130 }
  131 
  132 /*
  133  * Fill as many pages as vm_fault has allocated for us.
  134  */
  135 static int
  136 phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
  137 {
  138         int i;
  139 
  140         VM_OBJECT_ASSERT_WLOCKED(object);
  141         for (i = 0; i < count; i++) {
  142                 if (m[i]->valid == 0) {
  143                         if ((m[i]->flags & PG_ZERO) == 0)
  144                                 pmap_zero_page(m[i]);
  145                         m[i]->valid = VM_PAGE_BITS_ALL;
  146                 }
  147                 KASSERT(m[i]->valid == VM_PAGE_BITS_ALL,
  148                     ("phys_pager_getpages: partially valid page %p", m[i]));
  149                 KASSERT(m[i]->dirty == 0,
  150                     ("phys_pager_getpages: dirty page %p", m[i]));
  151                 /* The requested page must remain busy, the others not. */
  152                 if (i == reqpage) {
  153                         vm_page_lock(m[i]);
  154                         vm_page_flash(m[i]);
  155                         vm_page_unlock(m[i]);
  156                 } else
  157                         vm_page_xunbusy(m[i]);
  158         }
  159         return (VM_PAGER_OK);
  160 }
  161 
  162 static void
  163 phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
  164     int *rtvals)
  165 {
  166 
  167         panic("phys_pager_putpage called");
  168 }
  169 
  170 /*
  171  * Implement a pretty aggressive clustered getpages strategy.  Hint that
  172  * everything in an entire 4MB window should be prefaulted at once.
  173  *
  174  * XXX 4MB (1024 slots per page table page) is convenient for x86,
  175  * but may not be for other arches.
  176  */
  177 #ifndef PHYSCLUSTER
  178 #define PHYSCLUSTER 1024
  179 #endif
  180 static boolean_t
  181 phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
  182     int *after)
  183 {
  184         vm_pindex_t base, end;
  185 
  186         base = pindex & (~(PHYSCLUSTER - 1));
  187         end = base + (PHYSCLUSTER - 1);
  188         if (before != NULL)
  189                 *before = pindex - base;
  190         if (after != NULL)
  191                 *after = end - pindex;
  192         return (TRUE);
  193 }
  194 
  195 struct pagerops physpagerops = {
  196         .pgo_init =     phys_pager_init,
  197         .pgo_alloc =    phys_pager_alloc,
  198         .pgo_dealloc =  phys_pager_dealloc,
  199         .pgo_getpages = phys_pager_getpages,
  200         .pgo_putpages = phys_pager_putpages,
  201         .pgo_haspage =  phys_pager_haspage,
  202 };

Cache object: 59a56dcd130200d2acb8df1d2811d244


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.