svm_range_dma_unmap_dev
svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
svm_range_dma_unmap_dev(dev, dma_addr, 0, prange->npages);
void svm_range_dma_unmap_dev(struct device *dev, dma_addr_t *dma_addr,