Commit 2536617f authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Marek Szyprowski
Browse files

dma-direct: prevent SWIOTLB path when DMA_ATTR_REQUIRE_COHERENT is set 



DMA_ATTR_REQUIRE_COHERENT indicates that SWIOTLB must not be used.
Ensure the SWIOTLB path is declined whenever the DMA direct path is
selected.

Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260316-dma-debug-overlap-v3-5-1dde90a7f08b@nvidia.com
parent e6a58fa2

kernel/dma/direct.h

+4 −3
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev, 
	dma_addr_t dma_addr;



	if (is_swiotlb_force_bounce(dev)) {

		if (attrs & DMA_ATTR_MMIO)

		if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))

			return DMA_MAPPING_ERROR;



		return swiotlb_map(dev, phys, size, dir, attrs);
@@ -98,7 +98,8 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev, 
		dma_addr = phys_to_dma(dev, phys);

		if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||

		    dma_kmalloc_needs_bounce(dev, size, dir)) {

			if (is_swiotlb_active(dev))

			if (is_swiotlb_active(dev) &&

			    !(attrs & DMA_ATTR_REQUIRE_COHERENT))

				return swiotlb_map(dev, phys, size, dir, attrs);



			goto err_overflow;
@@ -123,7 +124,7 @@ static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr, 
{

	phys_addr_t phys;



	if (attrs & DMA_ATTR_MMIO)

	if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))

		/* nothing to do: uncached and no swiotlb */

		return;