CMD_Q_HEAD_LO_BASE
headlo = ccp_read_queue_4(sc, q, CMD_Q_HEAD_LO_BASE);
ccp_write_queue_4(sc, queue, CMD_Q_HEAD_LO_BASE,
ccp_write_queue_4(sc, q, CMD_Q_HEAD_LO_BASE,
headlo = ccp_read_queue_4(sc, q, CMD_Q_HEAD_LO_BASE);