IOMMU_BTOPR
mp->dmai_ndvmapages = IOMMU_BTOPR(offset + mp->dmai_object.dmao_size);
len = IOMMU_BTOPR(len + pg_off); /* # of pages */
npages = IOMMU_BTOPR(len + offset);
iommu_map_pages(iommu_p, mp, dvma_pg, IOMMU_BTOPR(win_size), pfn_index);
index = IOMMU_BTOPR(offset);
idx = IOMMU_BTOPR(offset);
npgs = IOMMU_BTOPR(length);