DMAR_FSTS_REG
dmar_read4(unit, DMAR_FSTS_REG),
dmar_write4(unit, DMAR_FSTS_REG, clear);
fsts = dmar_read4(unit, DMAR_FSTS_REG);
dmar_write4(unit, DMAR_FSTS_REG, DMAR_FSTS_PFO);
fsts = dmar_read4(unit, DMAR_FSTS_REG);
dmar_write4(unit, DMAR_FSTS_REG, fsts);