I915_READ_HEAD
ee->head = I915_READ_HEAD(engine);
if ((I915_READ_HEAD(engine) & HEAD_ADDR) !=
head = I915_READ_HEAD(engine) & HEAD_ADDR;
if (I915_READ_HEAD(engine) != I915_READ_TAIL(engine))
return (I915_READ_HEAD(engine) & HEAD_ADDR) == 0;
I915_READ_HEAD(engine),
I915_READ_HEAD(engine),
I915_READ_HEAD(engine);
if (I915_READ_HEAD(engine))
engine->name, I915_READ_HEAD(engine));
I915_READ_HEAD(engine), ring->head,