drm/i915: swizzling support for snb/ivb
We have to do this manually. Somebody had a Great Idea.
I've measured speed-ups just a few percent above the noise level
(below 5% for the best case), but no slowdows. Chris Wilson measured
quite a bit more (10-20% above the usual snb variance) on a more
recent and better tuned version of sna, but also recorded a few
slow-downs on benchmarks know for uglier amounts of snb-induced
variance.
v2: Incorporate Ben Widawsky's preliminary review comments and
elaborate a bit about the performance impact in the changelog.
v3: Add a comment as to why we don't need to check the 3rd memory
channel.
v4: Fixup whitespace.
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 865de80..0845419 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1187,7 +1187,8 @@
uint32_t read_domains,
uint32_t write_domain);
int __must_check i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj);
-int __must_check i915_gem_init_ringbuffer(struct drm_device *dev);
+int __must_check i915_gem_init_hw(struct drm_device *dev);
+void i915_gem_init_swizzling(struct drm_device *dev);
void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
void i915_gem_do_init(struct drm_device *dev,
unsigned long start,