i915: use io-mapping interfaces instead of a variety of mapping kludges
Impact: optimize/clean-up the IO mapping implementation of the i915 DRM driver
Switch the i915 device aperture mapping to the io-mapping interface, taking
advantage of the cleaner API to extend it across all of the mapping uses,
including both pwrite and relocation updates.
This dramatically improves performance on 64-bit kernels which were using
the same slow path as 32-bit non-HIGHMEM kernels prior to this patch.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f20ffe1..126b2f1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -31,6 +31,7 @@
#define _I915_DRV_H_
#include "i915_reg.h"
+#include <linux/io-mapping.h>
/* General customization:
*/
@@ -246,6 +247,8 @@
struct {
struct drm_mm gtt_space;
+ struct io_mapping *gtt_mapping;
+
/**
* List of objects currently involved in rendering from the
* ringbuffer.