vr_dmamem
int vr_dmamem_alloc(struct vr_softc *, struct vr_dmamem *,
void vr_dmamem_free(struct vr_softc *, struct vr_dmamem *);
vr_dmamem_alloc(struct vr_softc *sc, struct vr_dmamem *vrm,
vr_dmamem_free(struct vr_softc *sc, struct vr_dmamem *vrm)
struct vr_dmamem sc_listmap; /* descriptor list map */
struct vr_dmamem sc_zeromap; /* zero pad map */