1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_AGP_H
3#define _ASM_X86_AGP_H
4
5#include <asm/pgtable.h>
6#include <asm/cacheflush.h>
7
8/*
9 * Functions to keep the agpgart mappings coherent with the MMU. The
10 * GART gives the CPU a physical alias of pages in memory. The alias
11 * region is mapped uncacheable. Make sure there are no conflicting
12 * mappings with different cachability attributes for the same
13 * page. This avoids data corruption on some CPUs.
14 */
15
16#define map_page_into_agp(page) set_pages_uc(page, 1)
17#define unmap_page_from_agp(page) set_pages_wb(page, 1)
18
19/*
20 * Could use CLFLUSH here if the cpu supports it. But then it would
21 * need to be called for each cacheline of the whole page so it may
22 * not be worth it. Would need a page for it.
23 */
24#define flush_agp_cache() wbinvd()
25
26/* GATT allocation. Returns/accepts GATT kernel virtual address. */
27#define alloc_gatt_pages(order) \
28 ((char *)__get_free_pages(GFP_KERNEL, (order)))
29#define free_gatt_pages(table, order) \
30 free_pages((unsigned long)(table), (order))
31
32#endif /* _ASM_X86_AGP_H */
33