From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93142376A10; Fri, 17 Jul 2026 18:08:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784311724; cv=none; b=Y/VyTe3lkJgSNzeNr9GhvrzESvlbdt0LXz9dTHfddUAeg725plH6chA/sgR0mitjkm11h6jcYTubPgW3OGHrj5fEgYNhAWv/50eJ0CbH0cCVPx7EvYAB7G0rJFC9OtgysV7wNiMLyfOOuElMZqKf86vv8EocO17Y6HMtSdS12HY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784311724; c=relaxed/simple; bh=IWt4DT8zbxEVNr7Hsx2WH1ZhX/xIxKzGuVhjRtq3j+8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TYttpz5q4EPZ8t2q8SN3Y4pF+7zeolDrquS2902IXRUi5TdWIyFdVlgreZu6ALdRevfuqS+s1wvh6B3ChBIH5jad22dFWY9vyxlfRB+l1chm/enMMJyyf4nc4NKDQileFSdls6ciX5meaNhQ7CV5R4TrE/1lnyX22fLqRBENgNw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=m8fJtpWw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="m8fJtpWw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DC221F00A3A; Fri, 17 Jul 2026 18:08:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784311723; bh=5bS+J6Rwxh/WXwnquOaDBNcfrARTnQLlbkZ3NkMBgPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=m8fJtpWwBWHB9Ahirb07ZBZx03wpyr0HvEFiaOWqchFPaIHlOfOF8nIxp255RlCqc SA5lvDtSPSORHGBbXXe4ESMuP1HJ9TN2IktHo7lqFU4dEvpGz6SdLKKWBU3Jqy3dX8 dgDnw9Z4VAp5LeDo7M07SWRQ0ucTOCo4445a2InOiCz+dHLvzFSjW+KIWHYr6MTTid HCl/6afcZD5n5aVyJfVbbvZmRaMv9fI/ZA6mzhnlGUuldBmAZMvl8HImPa6Kb2BaTj aXPintlcklxZ6GlqObb+V/NV2vZBAQxpaENAkHBkzy/kvt74XPCY9FobR3QT/5MGXi u4DoaX4q93Pqg== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev Cc: "Aneesh Kumar K.V (Arm)" , Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org, Jason Gunthorpe , Jiri Pirko , Michael Kelley Subject: [PATCH v8 19/23] dma-direct: select DMA address encoding from __DMA_ATTR_ALLOC_CC_SHARED Date: Fri, 17 Jul 2026 23:34:37 +0530 Message-ID: <20260717180442.110954-20-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260717180442.110954-1-aneesh.kumar@kernel.org> References: <20260717180442.110954-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Make the dma-direct helpers derive the DMA address encoding from __DMA_ATTR_ALLOC_CC_SHARED instead of implicitly relying on force_dma_unencrypted() inside phys_to_dma_direct() Pass an explicit unencrypted/decrypted state into phys_to_dma_direct(), make the alloc paths return DMA addresses that match the requested buffer encryption state. Also only call dma_set_decrypted() when __DMA_ATTR_ALLOC_CC_SHARED is actually set. Reviewed-by: Jason Gunthorpe Tested-by: Jiri Pirko Tested-by: Michael Kelley Tested-by: Mostafa Saleh Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/direct.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f7f064323bd9..eb0ce0787885 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -26,11 +26,11 @@ u64 zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); static inline dma_addr_t phys_to_dma_direct(struct device *dev, - phys_addr_t phys) + phys_addr_t phys, bool unencrypted) { - if (force_dma_unencrypted(dev)) + if (unencrypted) return phys_to_dma_unencrypted(dev, phys); - return phys_to_dma(dev, phys); + return phys_to_dma_encrypted(dev, phys); } static inline struct page *dma_direct_to_page(struct device *dev, @@ -41,8 +41,9 @@ static inline struct page *dma_direct_to_page(struct device *dev, u64 dma_direct_get_required_mask(struct device *dev) { + bool require_decrypted = force_dma_unencrypted(dev); phys_addr_t phys = ((phys_addr_t)max_pfn << PAGE_SHIFT) - 1; - u64 max_dma = phys_to_dma_direct(dev, phys); + u64 max_dma = phys_to_dma_direct(dev, phys, require_decrypted); return (1ULL << (fls64(max_dma) - 1)) * 2 - 1; } @@ -71,7 +72,8 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit) bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) { - dma_addr_t dma_addr = phys_to_dma_direct(dev, phys); + bool require_decrypted = force_dma_unencrypted(dev); + dma_addr_t dma_addr = phys_to_dma_direct(dev, phys, require_decrypted); if (dma_addr == DMA_MAPPING_ERROR) return false; @@ -81,17 +83,18 @@ bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) static int dma_set_decrypted(struct device *dev, void *vaddr, size_t size) { - if (!force_dma_unencrypted(dev)) - return 0; - return set_memory_decrypted((unsigned long)vaddr, PFN_UP(size)); + int ret; + + ret = set_memory_decrypted((unsigned long)vaddr, PFN_UP(size)); + if (ret) + pr_warn_ratelimited("leaking DMA memory that can't be decrypted\n"); + return ret; } static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size) { int ret; - if (!force_dma_unencrypted(dev)) - return 0; ret = set_memory_encrypted((unsigned long)vaddr, PFN_UP(size)); if (ret) pr_warn_ratelimited("leaking DMA memory that can't be re-encrypted\n"); @@ -171,7 +174,8 @@ static struct page *dma_direct_alloc_from_pool(struct device *dev, size_t size, dma_coherent_ok); if (!page) return NULL; - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); + *dma_handle = phys_to_dma_direct(dev, page_to_phys(page), + attrs & __DMA_ATTR_ALLOC_CC_SHARED); return page; } @@ -187,9 +191,11 @@ static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size, /* remove any dirty cache lines on the kernel alias */ if (!PageHighMem(page)) arch_dma_prep_coherent(page, size); - - /* return the page pointer as the opaque cookie */ - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); + /* + * return the page pointer as the opaque cookie. + * Never used for unencrypted allocation + */ + *dma_handle = phys_to_dma_encrypted(dev, page_to_phys(page)); return page; } @@ -329,7 +335,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, ret = uncached_cpu_addr; } - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); + *dma_handle = phys_to_dma_direct(dev, page_to_phys(page), + attrs & __DMA_ATTR_ALLOC_CC_SHARED); return ret; @@ -450,11 +457,13 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, return NULL; ret = page_address(page); - if (dma_set_decrypted(dev, ret, size)) + if ((attrs & __DMA_ATTR_ALLOC_CC_SHARED) && + dma_set_decrypted(dev, ret, size)) goto out_leak_pages; setup_page: memset(ret, 0, size); - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); + *dma_handle = phys_to_dma_direct(dev, page_to_phys(page), + attrs & __DMA_ATTR_ALLOC_CC_SHARED); return page; out_leak_pages: return NULL; -- 2.43.0