Re: [PATCH v5 3/7] iommu: Allow the dma-iommu api to use bounce buffers

[Christoph Hellwig]

> +	/*
> +	 * If both the physical buffer start address and size are
> +	 * page aligned, we don't need to use a bounce page.
> +	 */
> +	if (IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev) &&
> +	    iova_offset(iovad, phys | org_size)) {
> +		aligned_size = iova_align(iovad, org_size);
> +		phys = swiotlb_tbl_map_single(dev,
> +				phys_to_dma(dev, io_tlb_start),
> +				phys, org_size, aligned_size, dir, attrs);

swiotlb_tbl_map_single takes one less argument in 5.10-rc now.