RING_BBADDR_UDW
bbaddr = ENGINE_READ64(engine, RING_BBADDR, RING_BBADDR_UDW);
{ RING_BBADDR_UDW(0), 0, 0, "RING_BBADDR_UP32" }, \
ee->bbaddr |= (u64)ENGINE_READ(engine, RING_BBADDR_UDW) << 32;
MMIO_RING_D(RING_BBADDR_UDW);