From c380931712d16e23f6aa90703f438330139e9731 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Thu, 27 Feb 2025 14:41:48 +0000 Subject: [PATCH] dma: Fix encryption bit clearing for dma_to_phys 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 Link: https://lkml.kernel.org/r/yq5amsen9stc.fsf@kernel.org Cc: Will Deacon Cc: Jean-Philippe Brucker Cc: Robin Murphy Cc: Steven Price Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Tom Lendacky Reviewed-by: Robin Murphy Acked-by: Tom Lendacky Signed-off-by: Suzuki K Poulose Reviewed-by: Gavin Shan Acked-by: Marek Szyprowski Fixes: 42be24a4178f ("arm64: Enable memory encrypt for Realms") Acked-by: Will Deacon Link: https://lore.kernel.org/r/20250227144150.1667735-2-suzuki.poulose@arm.com Signed-off-by: Catalin Marinas --- 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 */