dma_unmap_sg_attrs
dma_unmap_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
dma_unmap_sg_attrs(dev->dma_device, sg, nents, direction,
EXPORT_SYMBOL(dma_unmap_sg_attrs);