BRIDGE_LOCK_OBJ
bif->bif_linkstate_hook, BRIDGE_LOCK_OBJ(sc));
bif->bif_ifdetach_hook, BRIDGE_LOCK_OBJ(sc));
#define BRIDGE_LOCK(_sc) mutex_enter(BRIDGE_LOCK_OBJ(_sc))
#define BRIDGE_UNLOCK(_sc) mutex_exit(BRIDGE_LOCK_OBJ(_sc))
#define BRIDGE_LOCKED(_sc) mutex_owned(BRIDGE_LOCK_OBJ(_sc))