PCICTL_PCIINTST
bus_space_write_4(iot, ioh, PCICTL_PCIINTST, 0xffffffff);
interrupts = bus_space_read_4(iot, ioh, PCICTL_PCIINTST);
bus_space_write_4(iot, ioh, PCICTL_PCIINTST, PCIINT_INA);
bus_space_write_4(iot, ioh, PCICTL_PCIINTST, interrupts);