DAXDEV_ALIVE
return test_bit(DAXDEV_ALIVE, &dax_dev->flags);
clear_bit(DAXDEV_ALIVE, &dax_dev->flags);
set_bit(DAXDEV_ALIVE, &dax_dev->flags);
WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags),
set_bit(DAXDEV_ALIVE, &dax_dev->flags);
if (!test_bit(DAXDEV_ALIVE, &dax_dev->flags))