servers/vm/pb.c

   1
   2 #define _SYSTEM 1
   3
   4 #include <minix/com.h>
   5 #include <minix/callnr.h>
   6 #include <minix/type.h>
   7 #include <minix/config.h>
   8 #include <minix/const.h>
   9 #include <minix/sysutil.h>
  10 #include <minix/syslib.h>
  11 #include <minix/debug.h>
  12 #include <minix/bitmap.h>
  13 #include <minix/hash.h>
  14
  15 #include <sys/mman.h>
  16
  17 #include <limits.h>
  18 #include <string.h>
  19 #include <errno.h>
  20 #include <assert.h>
  21 #include <stdint.h>
  22 #include <sys/param.h>
  23
  24 #include "vm.h"
  25 #include "proto.h"
  26 #include "util.h"
  27 #include "glo.h"
  28 #include "region.h"
  29 #include "sanitycheck.h"
  30 #include "memlist.h"
  31
  32 struct  phys_block *pb_new(phys_bytes phys)
  33 {
  34         struct phys_block *newpb;
  35
  36         if(!SLABALLOC(newpb)) {
  37                 printf("vm: pb_new: couldn't allocate phys block\n");
  38                 return NULL;
  39         }
  40
  41         if(phys != MAP_NONE)
  42                 assert(!(phys % VM_PAGE_SIZE));
  43
  44 USE(newpb,
  45         newpb->phys = phys;
  46         newpb->refcount = 0;
  47         newpb->firstregion = NULL;
  48         );
  49
  50         return newpb;
  51 }
  52
  53 void pb_free(struct phys_block *pb)
  54 {
  55         if(pb->phys != MAP_NONE)
  56                 free_mem(ABS2CLICK(pb->phys), 1);
  57         SLABFREE(pb);
  58 }
  59
  60 void pb_link(struct phys_region *newphysr, struct phys_block *newpb,
  61         vir_bytes offset, struct vir_region *parent)
  62 {
  63 USE(newphysr,
  64         newphysr->offset = offset;
  65         newphysr->ph = newpb;
  66         newphysr->parent = parent;
  67         newphysr->next_ph_list = newpb->firstregion;
  68         newphysr->memtype = parent->memtype;
  69         newpb->firstregion = newphysr;);
  70         newpb->refcount++;
  71 }
  72
  73 struct  phys_region *pb_reference(struct phys_block *newpb,
  74         vir_bytes offset, struct vir_region *region)
  75 {
  76         struct phys_region *newphysr;
  77
  78         if(!SLABALLOC(newphysr)) {
  79         printf("vm: pb_reference: couldn't allocate phys region\n");
  80         return NULL;
  81         }
  82
  83         /* New physical region. */
  84         pb_link(newphysr, newpb, offset, region);
  85
  86         physblock_set(region, offset, newphysr);
  87
  88         return newphysr;
  89 }
  90
  91 /*===========================================================================*
  92  *                              pb_unreferenced                              *
  93  *===========================================================================*/
  94 void pb_unreferenced(struct vir_region *region, struct phys_region *pr, int rm)
  95 {
  96         struct phys_block *pb;
  97
  98         pb = pr->ph;
  99         assert(pb->refcount > 0);
 100         USE(pb, pb->refcount--;);
 101         assert(pb->refcount >= 0);
 102
 103         if(pb->firstregion == pr) {
 104                 USE(pb, pb->firstregion = pr->next_ph_list;);
 105         } else {
 106                 struct phys_region *others;
 107
 108                 for(others = pb->firstregion; others;
 109                         others = others->next_ph_list) {
 110                         assert(others->ph == pb);
 111                         if(others->next_ph_list == pr) {
 112                                 USE(others, others->next_ph_list = pr->next_ph_list;);
 113                                 break;
 114                         }
 115                 }
 116
 117                 assert(others); /* Otherwise, wasn't on the list. */
 118         }
 119
 120         if(pb->refcount == 0) {
 121                 assert(!pb->firstregion);
 122                 int r;
 123                 if((r = region->memtype->ev_unreference(pr)) != OK)
 124                         panic("unref failed, %d", r);
 125
 126                 SLABFREE(pb);
 127         }
 128
 129         pr->ph = NULL;
 130
 131         if(rm) physblock_set(region, pr->offset, NULL);
 132 }