UBA_CANTWAIT
if ((error = uballoc(uh, &ui, UBA_CANTWAIT))) {
if (ubmemalloc(sc->sc_uh, &sc->sc_ui, UBA_CANTWAIT))
int waitok = (flags & UBA_CANTWAIT) == 0;
int waitok = (flags & UBA_CANTWAIT ? BUS_DMA_NOWAIT : BUS_DMA_WAITOK);
if ((error = ubmemalloc(sc->sc_uh, &sc->sc_ui, UBA_CANTWAIT)))