_bus_load_buffer
error = _bus_load_buffer(dmat, buf, buflen, flags,
error = _bus_load_buffer(dmat, map->bounce_buffer, buflen, flags,
error = _bus_load_buffer(dmat, m->m_data, m->m_len,
error = _bus_load_buffer(dmat, map->bounce_buffer, mb->m_pkthdr.len, flags,