drm/i915: Do not clflush snooped objects

Rely on the GPU snooping into the CPU cache for appropriately bound
objects on MI_FLUSH. Or perhaps one day we will have a cache-coherent
CPU/GPU package...

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Keith Packard <keithp@keithp.com>
This commit is contained in:
Chris Wilson 2011-03-29 16:59:52 -07:00 committed by Keith Packard
parent 93dfb40cd8
commit 9c23f7fc4c

View file

@ -2878,6 +2878,17 @@ i915_gem_clflush_object(struct drm_i915_gem_object *obj)
if (obj->pages == NULL)
return;
/* If the GPU is snooping the contents of the CPU cache,
* we do not need to manually clear the CPU cache lines. However,
* the caches are only snooped when the render cache is
* flushed/invalidated. As we always have to emit invalidations
* and flushes when moving into and out of the RENDER domain, correct
* snooping behaviour occurs naturally as the result of our domain
* tracking.
*/
if (obj->cache_level != I915_CACHE_NONE)
return;
trace_i915_gem_object_clflush(obj);
drm_clflush_pages(obj->pages, obj->base.size / PAGE_SIZE);