iommu_dvma_alloc
int iommu_dvma_alloc(struct iommu_softc *, bus_dmamap_t, vaddr_t,
if ((error = iommu_dvma_alloc(sc, map, va, buflen, flags,
if ((error = iommu_dvma_alloc(sc, map, segs[0]._ds_va, size,