engine_confdev
conf_dev = engine_confdev(engine);
conf_dev = engine_confdev(engine);
conf_dev = engine_confdev(engine);
rc = device_add(engine_confdev(engine));
put_device(engine_confdev(engine));
device_unregister(engine_confdev(engine));
device_unregister(engine_confdev(idxd->engines[i]));
device_unregister(engine_confdev(engine));