xref: /openbmc/linux/arch/x86/include/asm/agp.h (revision 7dd65feb)
1 #ifndef _ASM_X86_AGP_H
2 #define _ASM_X86_AGP_H
3 
4 #include <asm/pgtable.h>
5 #include <asm/cacheflush.h>
6 
7 /*
8  * Functions to keep the agpgart mappings coherent with the MMU. The
9  * GART gives the CPU a physical alias of pages in memory. The alias
10  * region is mapped uncacheable. Make sure there are no conflicting
11  * mappings with different cachability attributes for the same
12  * page. This avoids data corruption on some CPUs.
13  */
14 
15 #define map_page_into_agp(page) set_pages_uc(page, 1)
16 #define unmap_page_from_agp(page) set_pages_wb(page, 1)
17 
18 /*
19  * Could use CLFLUSH here if the cpu supports it. But then it would
20  * need to be called for each cacheline of the whole page so it may
21  * not be worth it. Would need a page for it.
22  */
23 #define flush_agp_cache() wbinvd()
24 
25 /* GATT allocation. Returns/accepts GATT kernel virtual address. */
26 #define alloc_gatt_pages(order)		\
27 	((char *)__get_free_pages(GFP_KERNEL, (order)))
28 #define free_gatt_pages(table, order)	\
29 	free_pages((unsigned long)(table), (order))
30 
31 #endif /* _ASM_X86_AGP_H */
32