ringbuf->tail &= ringbuf->size - 1;
}
int __intel_ring_space(int head, int tail, int size);
+void intel_ring_update_space(struct intel_ringbuffer *ringbuf);
int intel_ring_space(struct intel_ringbuffer *ringbuf);
bool intel_ring_stopped(struct intel_engine_cs *ring);
void __intel_ring_advance(struct intel_engine_cs *ring);