void intel_logical_ring_stop(struct intel_engine_cs *engine);
void intel_logical_ring_cleanup(struct intel_engine_cs *engine);
int intel_logical_rings_init(struct drm_device *dev);
-int intel_logical_ring_begin(struct drm_i915_gem_request *req, int num_dwords);
int logical_ring_flush_all_caches(struct drm_i915_gem_request *req);
/**