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 "physravl.h"
  31 #include "memlist.h"
  32
  33 struct  phys_block *pb_new(phys_bytes phys)
  34 {
  35         struct phys_block *newpb;
  36
  37         if(!SLABALLOC(newpb)) {
  38                 printf("vm: pb_new: couldn't allocate phys block\n");
  39                 return NULL;
  40         }
  41
  42         if(phys != MAP_NONE)
  43                 assert(!(phys % VM_PAGE_SIZE));
  44
  45 USE(newpb,
  46         newpb->phys = phys;
  47         newpb->refcount = 0;
  48         newpb->firstregion = NULL;
  49         );
  50
  51         return newpb;
  52 }
  53
  54 void pb_free(struct phys_block *pb)
  55 {
  56         if(pb->phys != MAP_NONE)
  57                 free_mem(ABS2CLICK(pb->phys), 1);
  58         SLABFREE(pb);
  59 }
  60
  61 void pb_link(struct phys_region *newphysr, struct phys_block *newpb,
  62         vir_bytes offset, struct vir_region *parent)
  63 {
  64 USE(newphysr,
  65         newphysr->offset = offset;
  66         newphysr->ph = newpb;
  67         newphysr->parent = parent;
  68         newphysr->next_ph_list = newpb->firstregion;
  69         newphysr->memtype = parent->memtype;
  70         newpb->firstregion = newphysr;);
  71         newpb->refcount++;
  72 }
  73
  74 struct  phys_region *pb_reference(struct phys_block *newpb,
  75         vir_bytes offset, struct vir_region *region)
  76 {
  77         struct phys_region *newphysr;
  78
  79         if(!SLABALLOC(newphysr)) {
  80         printf("vm: pb_reference: couldn't allocate phys region\n");
  81         return NULL;
  82         }
  83
  84         /* New physical region. */
  85         pb_link(newphysr, newpb, offset, region);
  86
  87         physr_insert(region->phys, newphysr);
  88
  89         return newphysr;
  90 }
  91
  92 /*===========================================================================*
  93  *                              pb_unreferenced                              *
  94  *===========================================================================*/
  95 void pb_unreferenced(struct vir_region *region, struct phys_region *pr, int rm)
  96 {
  97         struct phys_block *pb;
  98
  99         pb = pr->ph;
 100         assert(pb->refcount > 0);
 101         USE(pb, pb->refcount--;);
 102         assert(pb->refcount >= 0);
 103
 104         if(pb->firstregion == pr) {
 105                 USE(pb, pb->firstregion = pr->next_ph_list;);
 106         } else {
 107                 struct phys_region *others;
 108
 109                 for(others = pb->firstregion; others;
 110                         others = others->next_ph_list) {
 111                         assert(others->ph == pb);
 112                         if(others->next_ph_list == pr) {
 113                                 USE(others, others->next_ph_list = pr->next_ph_list;);
 114                                 break;
 115                         }
 116                 }
 117
 118                 assert(others); /* Otherwise, wasn't on the list. */
 119         }
 120
 121         if(pb->refcount == 0) {
 122                 assert(!pb->firstregion);
 123                 int r;
 124                 if((r = region->memtype->ev_unreference(pr)) != OK)
 125                         panic("unref failed, %d", r);
 126
 127                 SLABFREE(pb);
 128         }
 129
 130         pr->ph = NULL;
 131
 132         if(rm) physr_remove(region->phys, pr->offset);
 133 }