bd_md_add_seg
error = bd_md_add_seg(md, BUSDMA_MD_VIRT, ioc.u.md.virt_addr, len);
error = bd_md_add_seg(md, BUSDMA_MD_PHYS, ioc.u.md.phys_addr, len);
error = bd_md_add_seg(md, BUSDMA_MD_BUS, ioc.u.md.bus_addr, len);
error = bd_md_add_seg(md, BUSDMA_MD_PHYS, ioc.u.md.phys_addr,
error = bd_md_add_seg(md, BUSDMA_MD_BUS, ioc.u.md.bus_addr,
error = bd_md_add_seg(md, BUSDMA_MD_VIRT, addr, tag->u.tag.maxsz);