linux-2.6.33/agp_allocate_memory() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-2.6.33/agp_allocate_memory() へ行く。
  • 1 (2013-09-05 (木) 02:44:49)

参照元†

説明†

• パス: linux-2.6.33/char/agp/generic.c

• FIXME: これは何？
  • 説明

引数†

• struct agp_bridge_data *bridge
  • linux-2.6.33/agp_bridge_data
• size_t page_count
• u32 type

返り値†

• agp_memory *
  • linux-2.6.33/agp_memory

参考†

実装†

/**
 *	agp_allocate_memory  -  allocate a group of pages of a certain type.
 *
 *	@page_count:	size_t argument of the number of pages
 *	@type:	u32 argument of the type of memory to be allocated.
 *
 *	Every agp bridge device will allow you to allocate AGP_NORMAL_MEMORY which
 *	maps to physical ram.  Any other type is device dependent.
 *
 *	It returns NULL whenever memory is unavailable.
 */
struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge,
					size_t page_count, u32 type)
{
	int scratch_pages;
	struct agp_memory *new;
	size_t i;

	if (!bridge)
		return NULL;

	if ((atomic_read(&bridge->current_memory_agp) + page_count) > bridge->max_memory_agp)
		return NULL;

• • linux-2.6.33/atomic_read()

	if (type >= AGP_USER_TYPES) {
		new = agp_generic_alloc_user(page_count, type);
		if (new)
			new->bridge = bridge;
		return new;
	}

• • linux-2.6.33/AGP_USER_TYPES

• linux-2.6.33/agp_generic_alloc_user()

	if (type != 0) {
		new = bridge->driver->alloc_by_type(page_count, type);
		if (new)
			new->bridge = bridge;
		return new;
	}

• bridge->driver は 型のメンバ
  • [[linux-2.6.33/]]

	scratch_pages = (page_count + ENTRIES_PER_PAGE - 1) / ENTRIES_PER_PAGE;

	new = agp_create_memory(scratch_pages);

	if (new == NULL)
		return NULL;

• • linux-2.6.33/ENTRIES_PER_PAGE

• linux-2.6.33/agp_create_memory()

	if (bridge->driver->agp_alloc_pages) {
		if (bridge->driver->agp_alloc_pages(bridge, new, page_count)) {
			agp_free_memory(new);
			return NULL;
		}
		new->bridge = bridge;
		return new;
	}

• • linux-2.6.33/agp_free_memory()

	for (i = 0; i < page_count; i++) {
		struct page *page = bridge->driver->agp_alloc_page(bridge);

		if (page == NULL) {
			agp_free_memory(new);
			return NULL;
		}
		new->pages[i] = page;
		new->page_count++;
	}
	new->bridge = bridge;

	return new;
}
EXPORT_SYMBOL(agp_allocate_memory);

• モジュールのライセンスに関係なくシンボルを公開する。
  • linux-2.6.33/EXPORT_SYMBOL()

コメント†