drm/radeon: Use direct mapping for fast fb access on RS690

This patch allows the CPU to map the stolen vram segment
directly rather than going through the PCI BAR.  This
significantly improves performance for certain workloads with
a properly patched ddx.

Use radeon.fastfb=1 to enable it (disabled by default).
Currently only supported on RS690, but support for RS780/880
and newer APUs may be added eventually.

Signed-off-by: Samuel Li <samuel.li@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Samuel Li
2013-04-08 17:25:47 -04:00
committed by Alex Deucher
parent 7c1c7c18fc
commit a0a53aa8c7
7 changed files with 43 additions and 2 deletions

View File

@@ -321,8 +321,10 @@ void radeon_bo_force_delete(struct radeon_device *rdev)
int radeon_bo_init(struct radeon_device *rdev)
{
/* Add an MTRR for the VRAM */
rdev->mc.vram_mtrr = mtrr_add(rdev->mc.aper_base, rdev->mc.aper_size,
if (!rdev->fastfb_working) {
rdev->mc.vram_mtrr = mtrr_add(rdev->mc.aper_base, rdev->mc.aper_size,
MTRR_TYPE_WRCOMB, 1);
}
DRM_INFO("Detected VRAM RAM=%lluM, BAR=%lluM\n",
rdev->mc.mc_vram_size >> 20,
(unsigned long long)rdev->mc.aper_size >> 20);