void init_swap(){
swap_blk = block_get_role(BLOCK_SWAP);
ASSERT(swap_blk!=NULL);
uint32_t sectors_num = block_size (swap_blk);
// each sector is 512K, one page has 8 sectors
uint32_t slots_num = sectors_num/8;
size_t bm_pages = DIV_ROUND_UP (bitmap_buf_size (slots_num), PGSIZE);
uint8_t* base = palloc_get_multiple (PAL_ZERO|PAL_ASSERT, bm_pages);
swap_table = bitmap_create_in_buf (slots_num, base, bm_pages * PGSIZE);
lock_init(&swap_lock);
}
void buffer_cache_init (void) {
buffer_vaddr = palloc_get_multiple(PAL_ZERO | PAL_USER, 8);
if(buffer_vaddr == NULL)
PANIC("BUFFER PALLOC FAILED!");
int i;
for (i=0; i<BUFFER_SIZE; i++){
buffer_info_array[i].sector_num = -2;
buffer_info_array[i].dirty = false;
buffer_info_array[i].recentlyUsed = false;
}
}
/*! Initializes the swap allocator. */
void swalloc_init(void)
{
uint32_t i;
swap_disk = block_get_role(BLOCK_SWAP);
swap_slots = block_size(swap_disk) / PAGE_SECTORS;
/* Initialize swap table */
uint32_t num_pages_used = sizeof(struct swap) * swap_slots;
num_pages_used = (uint32_t) pg_round_up((void *) num_pages_used) / PGSIZE;
/* Get pages for swap table */
swap_list = palloc_get_multiple(PAL_ASSERT | PAL_PAGING | PAL_ZERO, num_pages_used);
/* Initialize list */
list_init(open_swap_list);
/* Initialize swap entries */
for (i = 0; i < swap_slots; ++i)
{
swap_list[i].start_sector = i * PAGE_SECTORS;
swap_list[i].in_use = false;
list_push_back(open_swap_list, &(swap_list[i].open_elem));
}
}
bool
allocator_init (struct allocator *a,
bool userspace,
size_t members,
size_t item_size)
{
ASSERT (a != NULL);
ASSERT (members > 0);
ASSERT (item_size > 0);
memset (a, 0, sizeof (*a));
a->item_size = item_size;
a->used_map = bitmap_create (members);
if (a->used_map == NULL)
return false;
size_t pages = (members*item_size + PGSIZE-1) / PGSIZE;
a->items = palloc_get_multiple (userspace ? PAL_USER : 0, pages);
if (!a->items)
{
bitmap_destroy (a->used_map);
return false;
}
return true;
}
/* Obtains a single free page and returns its kernel virtual
address.
If PAL_USER is set, the page is obtained from the user pool,
otherwise from the kernel pool. If PAL_ZERO is set in FLAGS,
then the page is filled with zeros. If no pages are
available, returns a null pointer, unless PAL_ASSERT is set in
FLAGS, in which case the kernel panics. */
void *
palloc_get_page (enum palloc_flags flags)
{
return palloc_get_multiple (flags, 1);
}