minix/servers/vm/pb.c
Ben Gras d343041caa VM: make mapping types explicit
Introduce explicit abstractions for different mapping types,
handling the instantiation, forking, pagefaults and freeing of
anonymous memory, direct physical mappings, shared memory and
physically contiguous anonymous memory as separate types, making
region.c more generic.

Also some other genericification like merging the 3 munmap cases
into one.

COW and SMAP safemap code is still implicit in region.c.
2012-10-12 14:52:01 +02:00

134 lines
2.7 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;
}
if(phys != MAP_NONE)
assert(!(phys % VM_PAGE_SIZE));
USE(newpb,
newpb->phys = phys;
newpb->refcount = 0;
newpb->firstregion = NULL;
);
return newpb;
}
void pb_free(struct phys_block *pb)
{
if(pb->phys != MAP_NONE)
free_mem(ABS2CLICK(pb->phys), 1);
SLABFREE(pb);
}
void pb_link(struct phys_region *newphysr, struct phys_block *newpb,
vir_bytes offset, struct vir_region *parent)
{
USE(newphysr,
newphysr->offset = offset;
newphysr->ph = newpb;
newphysr->parent = parent;
newphysr->next_ph_list = newpb->firstregion;
newphysr->memtype = parent->memtype;
newpb->firstregion = newphysr;);
newpb->refcount++;
}
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. */
pb_link(newphysr, newpb, offset, region);
physr_insert(region->phys, newphysr);
return newphysr;
}
/*===========================================================================*
* pb_unreferenced *
*===========================================================================*/
void pb_unreferenced(struct vir_region *region, struct phys_region *pr, int rm)
{
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);
int r;
if((r = region->memtype->ev_unreference(pr)) != OK)
panic("unref failed, %d", r);
SLABFREE(pb);
}
pr->ph = NULL;
if(rm) physr_remove(region->phys, pr->offset);
}