Ensure that we flush any cache dirt out to main memory before the user changes the cache-level as they may elect to bypass the cache (even after declaring their access cache-coherent) via use of unprivileged MOCS.
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/gem/i915_gem_domain.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c index 2e3ce2a69653..5d41e769a428 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -277,6 +277,11 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
list_for_each_entry(vma, &obj->vma.list, obj_link) vma->node.color = cache_level; + + /* Flush any previous cache dirt in case of cache bypass */ + if (obj->cache_dirty & ~obj->cache_coherent) + i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC); + i915_gem_object_set_cache_coherency(obj, cache_level); obj->cache_dirty = true; /* Always invalidate stale cachelines */