OS_BUS_BARRIER_REG
OS_BUS_BARRIER_REG(ah, reg, OS_BUS_BARRIER_WRITE);
OS_BUS_BARRIER_REG(ah, reg, OS_BUS_BARRIER_READ);
OS_BUS_BARRIER_REG(ah, reg, OS_BUS_BARRIER_WRITE);
OS_BUS_BARRIER_REG(ah, reg, OS_BUS_BARRIER_READ);