Commit a5fb217f authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: reflow dma_supported 



dma_supported has become too much spaghetti for my taste.  Reflow it to
remove the duplicate use_dma_iommu condition and make the main path more
obvious.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarLeon Romanovsky <leon@kernel.org>
parent f45cfab2

kernel/dma/mapping.c

+14 −11
Original line number Diff line number Diff line
@@ -841,22 +841,25 @@ static int dma_supported(struct device *dev, u64 mask) 
{

	const struct dma_map_ops *ops = get_dma_ops(dev);



	if (WARN_ON(ops && use_dma_iommu(dev)))

	if (use_dma_iommu(dev)) {

		if (WARN_ON(ops))

			return false;



	if (use_dma_iommu(dev))

		return true;

	}



	/*

	 * ->dma_supported sets the bypass flag, so we must always call

	 * into the method here unless the device is truly direct mapped.

	 * ->dma_supported sets and clears the bypass flag, so ignore it here

	 * and always call into the method if there is one.

	 */

	if (!ops)

		return dma_direct_supported(dev, mask);

	if (ops) {

		if (!ops->dma_supported)

		return 1;

			return true;

		return ops->dma_supported(dev, mask);

	}



	return dma_direct_supported(dev, mask);

}



bool dma_pci_p2pdma_supported(struct device *dev)

{

	const struct dma_map_ops *ops = get_dma_ops(dev);