MUTEX_DRIVER
mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_SOFTNET);
mutex_init(&unit->hci_devlock, MUTEX_DRIVER, hci_if->ipl);
mutex_init(&nfsd_lock, MUTEX_DRIVER, IPL_SOFTNET);
mutex_init(&slp->ns_lock, MUTEX_DRIVER, IPL_SOFTNET);
mutex_init(&slp->ns_alock, MUTEX_DRIVER, IPL_SOFTNET);
mutex_init(&ctx.nwc_lock, MUTEX_DRIVER, IPL_VM);
mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE);
mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM);