agp.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _ASM_X86_AGP_H
 3#define _ASM_X86_AGP_H
 4
 5#include <linux/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 cacheability 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#endif /* _ASM_X86_AGP_H */