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#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 <sys/param.h>
#include "vm.h"
#include "proto.h"
#include "util.h"
#include "glo.h"
#include "region.h"
#include "sanitycheck.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;
newpb->flags = 0;
);
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;
newpb->firstregion = newphysr;);
newpb->refcount++;
}
struct phys_region *pb_reference(struct phys_block *newpb,
vir_bytes offset, struct vir_region *region, mem_type_t *memtype)
{
struct phys_region *newphysr;
if(!SLABALLOC(newphysr)) {
printf("vm: pb_reference: couldn't allocate phys region\n");
return NULL;
}
newphysr->memtype = memtype;
/* New physical region. */
pb_link(newphysr, newpb, offset, region);
physblock_set(region, offset, 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); */ /* always true */
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 = pr->memtype->ev_unreference(pr)) != OK)
panic("unref failed, %d", r);
SLABFREE(pb);
}
pr->ph = NULL;
if(rm) physblock_set(region, pr->offset, NULL);
}
int mem_cow(struct vir_region *region,
struct phys_region *ph, phys_bytes new_page_cl, phys_bytes new_page)
{
struct phys_block *pb;
if(new_page == MAP_NONE) {
u32_t allocflags;
allocflags = vrallocflags(region->flags);
if((new_page_cl = alloc_mem(1, allocflags)) == NO_MEM)
return ENOMEM;
new_page = CLICK2ABS(new_page_cl);
}
assert(ph->ph->phys != MAP_NONE);
if(sys_abscopy(ph->ph->phys, new_page, VM_PAGE_SIZE) != OK) {
panic("VM: abscopy failed\n");
return EFAULT;
}
if(!(pb = pb_new(new_page))) {
free_mem(new_page_cl, 1);
return ENOMEM;
}
pb_unreferenced(region, ph, 0);
pb_link(ph, pb, ph->offset, region);
ph->memtype = &mem_type_anon;
return OK;
}
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