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 /* 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