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dma-direct: prevent SWIOTLB path when DMA_ATTR_REQUIRE_COHERENT is set

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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: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260316-dma-debug-overlap-v3-5-1dde90a7f08b@nvidia.com
This commit is contained in:
Leon Romanovsky
2026-03-16 21:06:49 +02:00
committed by Marek Szyprowski
parent e6a58fa255
commit 2536617f20
1 changed files with 4 additions and 3 deletions
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7
kernel/dma/direct.h
View File

@@ -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;