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 <memory.h>
  23 #include <sys/param.h>
  24
  25 #include "vm.h"
  26 #include "proto.h"
  27 #include "util.h"
  28 #include "glo.h"
  29 #include "region.h"
  30 #include "sanitycheck.h"
  31 #include "physravl.h"
  32 #include "memlist.h"
  33
  34 struct  phys_block *pb_new(phys_bytes phys)
  35 {
  36         struct phys_block *newpb;
  37
  38         if(!SLABALLOC(newpb)) {
  39                 printf("vm: pb_new: couldn't allocate phys block\n");
  40                 return NULL;
  41         }
  42
  43         assert(!(phys % VM_PAGE_SIZE));
  44         assert(phys != MAP_NONE);
  45
  46 USE(newpb,
  47         newpb->phys = phys;
  48         newpb->refcount = 0;
  49         newpb->firstregion = NULL;
  50         );
  51
  52         return newpb;
  53 }
  54
  55 struct  phys_region *pb_reference(struct phys_block *newpb, vir_bytes offset, struct vir_region *region)
  56 {
  57         struct phys_region *newphysr;
  58
  59         if(!SLABALLOC(newphysr)) {
  60         printf("vm: pb_reference: couldn't allocate phys region\n");
  61         return NULL;
  62         }
  63
  64         /* New physical region. */
  65 USE(newphysr,
  66         newphysr->offset = offset;
  67         newphysr->ph = newpb;
  68         newphysr->parent = region;
  69         newphysr->next_ph_list = newpb->firstregion;
  70         newpb->firstregion = newphysr;);
  71
  72         newpb->refcount++;
  73         physr_insert(region->phys, newphysr);
  74
  75         return newphysr;
  76 }
  77
  78 /*===========================================================================*
  79  *                              pb_unreferenced                              *
  80  *===========================================================================*/
  81 void pb_unreferenced(struct vir_region *region, struct phys_region *pr, int rm)
  82 {
  83         struct phys_block *pb;
  84
  85         pb = pr->ph;
  86         assert(pb->refcount > 0);
  87         USE(pb, pb->refcount--;);
  88         assert(pb->refcount >= 0);
  89
  90         if(pb->firstregion == pr) {
  91                 USE(pb, pb->firstregion = pr->next_ph_list;);
  92         } else {
  93                 struct phys_region *others;
  94
  95                 for(others = pb->firstregion; others;
  96                         others = others->next_ph_list) {
  97                         assert(others->ph == pb);
  98                         if(others->next_ph_list == pr) {
  99                                 USE(others, others->next_ph_list = pr->next_ph_list;);
 100                                 break;
 101                         }
 102                 }
 103
 104                 assert(others); /* Otherwise, wasn't on the list. */
 105         }
 106
 107         if(pb->refcount == 0) {
 108                 assert(!pb->firstregion);
 109                 if(region->flags & VR_ANON) {
 110                         free_mem(ABS2CLICK(pb->phys), 1);
 111                 } else if(region->flags & VR_DIRECT) {
 112                         ; /* No action required. */
 113                 } else {
 114                         panic("strange phys flags");
 115                 }
 116                 SLABFREE(pb);
 117         }
 118
 119         if(rm) physr_remove(region->phys, pr->offset);
 120 }