From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E8A1D383C76; Mon, 20 Apr 2026 06:15:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776665713; cv=none; b=jK3S5kuV7rhcsbrSvLXZlaLQuTK2M0+xuQX64L6W2zSzm5HUlDaQBNcGwedwFY6iVIEnrE2vk6AsHhEKaayROC15IQjzVVkg3CD8FESc/j5h4uH2cl/h1F3RPE1UEh2GtwSEBXmHz60AneeWRS17okKejYFHljMxKTxaU/mZSpA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776665713; c=relaxed/simple; bh=i83T7lPEeSfxD2tPEEjjzZ7Urcsl8UtRe/aTW9tn7PY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a+/jG+Oayp5Ky8nOB9V66XrkHmaeH8vzZzHUXWHRI2ujuNKR5Q7SCN/mp7jN+ef1/YuB2czdBbBymt01SmHDdLCqCSY/HuMvf7rvkrf5hrkF33wjiAbHUoooUpubNEXUCYJvO61SRNgImz5rgwfJ+3STMi7jq2JjbEjy47/kOzs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NfedlZDD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NfedlZDD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B4E7C19425; Mon, 20 Apr 2026 06:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776665712; bh=i83T7lPEeSfxD2tPEEjjzZ7Urcsl8UtRe/aTW9tn7PY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NfedlZDDoGMnGL2pu1vTNzYznOu1i6+iFKp/bvNw1LENQH6QARDZRkE2M6ueF5P0m vlezf87FQCXbtPN/2QBxdWjcIJUjQA+Th5wJTEeGW2BfYzqmQE9QvTa+qj6s45j4Xo 0DbmjS04Rtyj0frEx7OiPiPiAMs8fIRuKIiet3j6Uy12y2AadHzL7rZ6H5Y6gGSFB8 YbYAYGQIMJajltlr/QzXiVVN9dCCmYIzJLwe3EOZAQEJ5AIW8H3cRFewO0JyAI8/7O 4HE355UTZKCQyZqax91Anu83oF5q2eEjlZp549Ew3x5bCAbc3bc/mNj8V3eOmr31XF ax915gp4m76Jg== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: robin.murphy@arm.com, m.szyprowski@samsung.com, will@kernel.org, maz@kernel.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, jiri@resnulli.us, jgg@ziepe.ca, aneesh.kumar@kernel.org, Mostafa Saleh Subject: [PATCH v2 8/8] dma-direct: select DMA address encoding from DMA_ATTR_CC_SHARED Date: Mon, 20 Apr 2026 11:44:15 +0530 Message-ID: <20260420061415.3650870-9-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260420061415.3650870-1-aneesh.kumar@kernel.org> References: <20260420061415.3650870-1-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_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() DMA_ATTR_CC_SHARED is actually set. Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/direct.c | 48 ++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 63a7b7bfff97..1239344f8585 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -24,11 +24,11 @@ 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, @@ -39,8 +39,9 @@ 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 - 1) << PAGE_SHIFT; - 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; } @@ -69,7 +70,8 @@ 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; @@ -79,17 +81,18 @@ 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"); @@ -177,7 +180,8 @@ static void *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_CC_SHARED)); return ret; } @@ -193,9 +197,11 @@ 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; } @@ -337,7 +343,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, goto out_encrypt_pages; } - *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_CC_SHARED)); return ret; out_encrypt_pages: @@ -447,11 +454,12 @@ 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_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_CC_SHARED)); return page; out_leak_pages: return NULL; @@ -461,8 +469,12 @@ void dma_direct_free_pages(struct device *dev, size_t size, struct page *page, dma_addr_t dma_addr, enum dma_data_direction dir) { + /* + * if the device had requested for an unencrypted buffer, + * convert it to encrypted on free + */ + bool mark_mem_encrypted = force_dma_unencrypted(dev); void *vaddr = page_address(page); - bool mark_mem_encrypted = true; /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && -- 2.43.0