minix/servers/vm/pb.c
Ben Gras 16c3870b2e VM: abstract datastructures a bit
. a little less duplication in region.c
2012-09-18 13:17:51 +02:00

120 lines
2.5 KiB
C

#define _SYSTEM 1
#include <minix/com.h>
#include <minix/callnr.h>
#include <minix/type.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/debug.h>
#include <minix/bitmap.h>
#include <minix/hash.h>
#include <sys/mman.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <stdint.h>
#include <memory.h>
#include <sys/param.h>
#include "vm.h"
#include "proto.h"
#include "util.h"
#include "glo.h"
#include "region.h"
#include "sanitycheck.h"
#include "physravl.h"
#include "memlist.h"
struct phys_block *pb_new(phys_bytes phys)
{
struct phys_block *newpb;
if(!SLABALLOC(newpb)) {
printf("vm: pb_new: couldn't allocate phys block\n");
return NULL;
}
assert(!(phys % VM_PAGE_SIZE));
assert(phys != MAP_NONE);
USE(newpb,
newpb->phys = phys;
newpb->refcount = 0;
newpb->firstregion = NULL;
);
return newpb;
}
struct phys_region *pb_reference(struct phys_block *newpb, vir_bytes offset, struct vir_region *region)
{
struct phys_region *newphysr;
if(!SLABALLOC(newphysr)) {
printf("vm: pb_reference: couldn't allocate phys region\n");
return NULL;
}
/* New physical region. */
USE(newphysr,
newphysr->offset = offset;
newphysr->ph = newpb;
newphysr->parent = region;
newphysr->next_ph_list = newpb->firstregion;
newpb->firstregion = newphysr;);
newpb->refcount++;
physr_insert(region->phys, newphysr);
return newphysr;
}
/*===========================================================================*
* pb_unreferenced *
*===========================================================================*/
void pb_unreferenced(struct vir_region *region, struct phys_region *pr)
{
struct phys_block *pb;
pb = pr->ph;
assert(pb->refcount > 0);
USE(pb, pb->refcount--;);
assert(pb->refcount >= 0);
if(pb->firstregion == pr) {
USE(pb, pb->firstregion = pr->next_ph_list;);
} else {
struct phys_region *others;
for(others = pb->firstregion; others;
others = others->next_ph_list) {
assert(others->ph == pb);
if(others->next_ph_list == pr) {
USE(others, others->next_ph_list = pr->next_ph_list;);
break;
}
}
assert(others); /* Otherwise, wasn't on the list. */
}
if(pb->refcount == 0) {
assert(!pb->firstregion);
if(region->flags & VR_ANON) {
free_mem(ABS2CLICK(pb->phys), 1);
} else if(region->flags & VR_DIRECT) {
; /* No action required. */
} else {
panic("strange phys flags");
}
SLABFREE(pb);
}
physr_remove(region->phys, pr->offset);
}