6.13-stable review patch. If anyone has any objections, please let me know.
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From: Suzuki K Poulose suzuki.poulose@arm.com
[ Upstream commit c380931712d16e23f6aa90703f438330139e9731 ]
phys_to_dma() sets the encryption bit on the translated DMA address. But dma_to_phys() clears the encryption bit after it has been translated back to the physical address, which could fail if the device uses DMA ranges.
AMD SME doesn't use the DMA ranges and thus this is harmless. But as we are about to add support for other architectures, let us fix this.
Reported-by: Aneesh Kumar K.V aneesh.kumar@kernel.org Link: https://lkml.kernel.org/r/yq5amsen9stc.fsf@kernel.org Cc: Will Deacon will@kernel.org Cc: Jean-Philippe Brucker jean-philippe@linaro.org Cc: Robin Murphy robin.murphy@arm.com Cc: Steven Price steven.price@arm.com Cc: Christoph Hellwig hch@lst.de Cc: Marek Szyprowski m.szyprowski@samsung.com Cc: Tom Lendacky thomas.lendacky@amd.com Reviewed-by: Robin Murphy robin.murphy@arm.com Acked-by: Tom Lendacky thomas.lendacky@amd.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Reviewed-by: Gavin Shan gshan@redhat.com Acked-by: Marek Szyprowski m.szyprowski@samsung.com Fixes: 42be24a4178f ("arm64: Enable memory encrypt for Realms") Acked-by: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20250227144150.1667735-2-suzuki.poulose@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/dma-direct.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index d7e30d4f7503a..d20ecc24cb0f5 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -101,12 +101,13 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) { phys_addr_t paddr;
+ dma_addr = __sme_clr(dma_addr); if (dev->dma_range_map) paddr = translate_dma_to_phys(dev, dma_addr); else paddr = dma_addr;
- return __sme_clr(paddr); + return paddr; } #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */