RING_BBADDR_UDW
ee->bbaddr |= (u64) I915_READ(RING_BBADDR_UDW(engine->mmio_base)) << 32;
RING_BBADDR_UDW(engine->mmio_base));
CTX_REG(regs, CTX_BB_HEAD_U, RING_BBADDR_UDW(base), 0);