I915_GEM_GPU_DOMAINS
if ((write_domain | read_domains) & I915_GEM_GPU_DOMAINS)
& ~I915_GEM_GPU_DOMAINS)) {
GEM_BUG_ON(obj->read_domains & I915_GEM_GPU_DOMAINS);
GEM_BUG_ON(obj->write_domain & I915_GEM_GPU_DOMAINS);
obj->read_domains |= I915_GEM_GPU_DOMAINS;