// print buddy system status
//void dump_print(struct mem_zone * zone);
//void dump_print_dot(struct mem_zone * zone);
//---###---
public static void buddy_system_init(mem_zone *zone,
page *start_page,
uint start_addr,
uint page_num)
{
uint i;
page * page = null;
free_area *area = null;
// init memory zone
zone->page_num = page_num;
zone->page_size = BUDDY_PAGE_SIZE;
zone->first_page = start_page;
zone->start_addr = start_addr;
zone->end_addr = start_addr + (page_num * BUDDY_PAGE_SIZE);
// TODO: init zone->lock
// init each area
for (i = 0; i < BUDDY_MAX_ORDER; i++)
{
area = zone->free_area + i;
INIT_LIST_HEAD(&area->free_list);
area->nr_free = 0;
}
memset((byte *)start_page, 0, page_num * (uint)sizeof(page));
// init and free each page
for (i = 0; i < page_num; i++)
{
page = zone->first_page + i;
INIT_LIST_HEAD(&page->lru);
// TODO: init page->lock
buddy_free_pages(zone, page);
}
}
static page *expand(zone *zone, page *page, int low, int high, free_area *area)
{
uint size = (uint)1 << (byte)high;
while (high > low)
{
area--;
high--;
size >>= 1;
//BUG_ON(bad_range(zone, &page[size]));
list_add(&page[size].Lru, &area->Free_list);
area->Nr_free++;
set_page_order(&page[size], high);
}
return(page);
}
/// <summary>
/// Split the combined page to get the page of the desired size
/// </summary>
static void expand(mem_zone *zone, page *page,
byte low_order, byte high_order,
free_area *area)
{
uint size = (1U << high_order);
while (high_order > low_order)
{
area--;
high_order--;
size >>= 1;
list_add(&page[size].lru, &area->free_list);
area->nr_free++;
// set page order
set_page_order_buddy(&page[size], high_order);
}
}
static page *__alloc_page(byte order,
mem_zone *zone)
{
page * page = null;
free_area *area = null;
byte current_order = 0;
for (current_order = order;
current_order < BUDDY_MAX_ORDER; current_order++)
{
area = zone->free_area + current_order;
if (list_empty(&area->free_list))
{
continue;
}
// remove closest size page
//page = list_entry(area->free_list.next, struct page, lru);
page = (page *)&((page *)area->free_list.next)->lru;
list_del(&page->lru);
rmv_page_order_buddy(page);
area->nr_free--;
// expand to lower order
expand(zone, page, order, current_order, area);
// compound page
if (order > 0)
{
prepare_compound_pages(page, order);
}
else // single page
{
page->order = 0;
}
return(page);
}
return(null);
}