From 07eee78ea8ba2d0b7b20551c35a3e7dd158d50bb Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Wed, 30 Mar 2005 13:17:04 -0800 Subject: [PATCH] AGP fix for Xen VMM When Linux is running on the Xen virtual machine monitor, physical addresses are virtualised and cannot be directly referenced by the AGP GART. This patch fixes the GART driver for Xen by adding a layer of abstraction between physical addresses and 'GART addresses'. Architecture-specific functions are also defined for allocating and freeing the GATT. Xen requires this to ensure that table really is contiguous from the point of view of the GART. These extra interface functions are defined as 'no-ops' for all existing architectures that use the GART driver. Signed-off-by: Keir Fraser Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/asm-x86_64/agp.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/asm-x86_64') diff --git a/include/asm-x86_64/agp.h b/include/asm-x86_64/agp.h index 0bb9019d58a..06c52ee9c06 100644 --- a/include/asm-x86_64/agp.h +++ b/include/asm-x86_64/agp.h @@ -19,4 +19,14 @@ int unmap_page_from_agp(struct page *page); worth it. Would need a page for it. */ #define flush_agp_cache() asm volatile("wbinvd":::"memory") +/* Convert a physical address to an address suitable for the GART. */ +#define phys_to_gart(x) (x) +#define gart_to_phys(x) (x) + +/* GATT allocation. Returns/accepts GATT kernel virtual address. */ +#define alloc_gatt_pages(order) \ + ((char *)__get_free_pages(GFP_KERNEL, (order))) +#define free_gatt_pages(table, order) \ + free_pages((unsigned long)(table), (order)) + #endif -- cgit v1.2.3-70-g09d2