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authorLeon Romanovsky <leonro@nvidia.com>2026-03-16 21:06:49 +0200
committerMarek Szyprowski <m.szyprowski@samsung.com>2026-03-20 12:05:56 +0100
commit2536617f20ddc7c2f4cef59b549aa45d166b03b1 (patch)
tree3c27457b0690ee70a18362799c69f6dfc860bc2a /kernel
parente6a58fa2556203a7f6731b4071705dc81cca5ca5 (diff)
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: 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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma/direct.h7
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index e89f175e9c2d..6184ff303f08 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -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;