SWSM_SMBI
if ((swsm & SWSM_SMBI) == 0)
swsm &= ~(SWSM_SMBI | SWSM_SWESMBI);
if ((reg & SWSM_SMBI) != 0)
CSR_WRITE(sc, WMREG_SWSM, reg & ~SWSM_SMBI);