void
vm_tlbshootdown(const struct tlbshootdown *ts)
{
vm_tlbflush(ts->target);
V(ts->sem);
}
int
as_copy(struct addrspace *old, struct addrspace **ret)
{
struct addrspace *newas;
int i,j, errno, retval, offset, region_len;
struct region *old_region, *new_region;
void *buffer;
struct pt_entry *old_entry, *new_entry;
newas = as_create();
if (newas==NULL) {
return ENOMEM;
}
buffer = kmalloc(PAGE_SIZE);
newas->heap_start = old->heap_start;
newas->heap_end = old->heap_end;
// Copy regions
region_len = array_num(old->as_regions);
for (i = 0; i < region_len; i++) {
old_region = array_get(old->as_regions, i);
new_region = kmalloc(sizeof(struct region));
if (old_region == NULL || new_region == NULL) {
goto err0;
}
new_region->base = old_region->base;
new_region->size = old_region->size;
new_region->permission = old_region->permission;
errno = array_add(newas->as_regions, new_region, NULL);
if (errno) {
goto err0;
}
}
// Copy page table
for (i = 0; i < PT_LEVEL_SIZE; i++){
if (old->pagetable[i] != NULL){
newas->pagetable[i] = kmalloc(PT_LEVEL_SIZE * sizeof(struct pt_entry));
memset(newas->pagetable[i], 0, PT_LEVEL_SIZE * sizeof(struct pt_entry));
// For each page table entry
// Lock the entire L2 pagetable
lock_acquire(old->pt_locks[i]);
for (j = 0; j < PT_LEVEL_SIZE; j++){
// We're about to copy this page. Make sure it can't be written to
vm_tlbflush((i << 22) & (j << 12));
old_entry = &old->pagetable[i][j];
new_entry = &newas->pagetable[i][j];
// For every valid pagetable entry...
if (old_entry->allocated){
offset = bs_alloc_index();
if (old_entry->in_memory){
// Write it to disk if it's in memory
retval = bs_write_page((void *) PADDR_TO_KVADDR(old_entry->p_addr), offset);
KASSERT(retval == 0);
} else {
// Or copy it to the new disk spot if not
retval = bs_read_page(buffer, old_entry->store_index);
KASSERT(retval == 0);
retval = bs_write_page(buffer, offset);
KASSERT(retval == 0);
}
// Update entry
// TODO: this will be caught by coremap
new_entry->p_addr = 0;
new_entry->store_index = offset;
new_entry->in_memory = false;
new_entry->allocated = true;
}
}
lock_release(old->pt_locks[i]);
}
}
kfree(buffer);
*ret = newas;
return 0;
err0:
for (i=0; i < (int)region_len; i++){
new_region = (struct region *)array_get(newas->as_regions,i);
if (new_region != NULL)
kfree(new_region);
}
return ENOMEM;
}
