iommu/dma: skip swiotlb bounce for DMA_ATTR_MMIO in iommu_dma_map_phys

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MMIO resources mapped via dma_map_resource() carry DMA_ATTR_MMIO. These
never need swiotlb bounce buffering, but the current code enters the
swiotlb path when the physical address is not page-aligned, then rejects
the mapping because MMIO cannot be bounced.

Move the DMA_ATTR_MMIO check before the swiotlb block so the entire bounce
path is skipped for MMIO, falling through directly to __iommu_dma_map()
which creates the IOVA mapping.

Fixes: f9374de14c ("iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()")
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Robin Murphy <robin.murphy@arm.comn>
Link: https://lore.kernel.org/r/20260916-iommu-dma-fix-v1-1-a59a0c45ec5b@nxp.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

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Peng Fan 2026-09-16 23:23:33 +08:00 • committed by Marek Szyprowski

parent 55a8e14518

commit 057e5e0742

1 changed files with 2 additions and 2 deletions

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drivers/iommu/dma-iommu.c

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