struct page *alloc_pages(struct buddy *pool, unsigned int order)
{
struct buddy_freelist *freelist = &pool->free[order];
struct list *head, *curr;
struct page *page;
unsigned int i;
for (i = order; i < BUDDY_MAX_ORDER; i++, freelist++) {
head = &freelist->list;
curr = head->next;
if (curr != head) {
page = get_container_of(curr, struct page, link);
list_del(curr);
BITMAP_TOGGLE(freelist->bitmap,
PAGE_INDEX(page->addr), i);
/* if allocating from higher order, split in half to add
* one of them to current order. */
while (i > order) {
freelist--;
i--;
list_add(&page->link, &freelist->list);
BITMAP_TOGGLE(freelist->bitmap,
PAGE_INDEX(page->addr), i);
page += 1 << i;
}
pool->nr_free -= 1 << order;
SET_PAGE_ORDER(page, order);
SET_PAGE_FLAG(page, PAGE_BUDDY);
return page;
}
}
void free_pages(struct buddy *pool, struct page *page)
{
struct page *buddy;
struct buddy_freelist *freelist;
unsigned int order, index;
order = GET_PAGE_ORDER(page);
freelist = &pool->free[order];
index = PAGE_INDEX(page->addr);
pool->nr_free += 1U << order;
while (order < BUDDY_MAX_ORDER) {
BITMAP_TOGGLE(freelist->bitmap, index, order);
/* If it was 0 before toggling, it means both of buddies
* were allocated. So nothing can be merged to upper order
* as one of them is still allocated. Otherwise, both of
* them are free now. Therefore merge it to upper order. */
if (BITMAP_MASK(freelist->bitmap, index, order))
break;
/* find buddy and detach it from current order to merge */
buddy = &mem_map[index ^ (1U << order)];
list_del(&buddy->link);
/* grab the first address of merging buddies */
index &= ~(1U << order);
order++;
freelist++;
}
list_add(&mem_map[index].link, &freelist->list);
RESET_PAGE_FLAG(page, PAGE_BUDDY);
}
/* Write data to specified page
*/
RV NandDevice04::WritePage(BLOCK_ID blockID,
PAGE_ID pageID,
const BYTE * buffer,
int offset,
int size)
{
ASSERT(eraseCounter);
ASSERT(blockID >= 0 && blockID < info.blockCount);
ASSERT(pageID >= 0 && pageID < info.pageCountPerBlock);
if (eraseCounter[blockID] >= info.eraseLimitation) {
return RV_ERROR_FLASH_BLOCK_BROKEN;
}
// write process
vfImage.seekg(blockID * blockSize + pageID * info.pageSize, ios::beg);
vfImage.write((const char *)buffer, info.pageSize);
vfImage.flush();
writeCounter[PAGE_INDEX(blockID, pageID)] ++;
writeLatencyTotal += info.programTime;
return RV_OK;
}