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 A877B1B6CE9; Fri, 22 May 2026 04:30:54 +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=1779424255; cv=none; b=NgGl/LFPPDIsEncR5J3D2rc1bsKj1g8H9tT50J6phxNL+QcDQZbKXAynt3YorkOriVo4/KmoBqg9TqJemWHnGnKngekJObzxEWG9qQzMSYSwH0ap5pDy/86rfgvao4LZQULWM7x1K2m+kNfVRNvmcr4Uw7XEFBUP+VUXRHQhU/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779424255; c=relaxed/simple; bh=/8UQbJFSflm14frKSxWfIhVf5QX1/sjbU1+q7i87uEw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DU0SOwaR0Zt7Ic6PYgJr0Uh34hd95FzbohhXeK6iYgsiiY144GEDVQG/OL69IxDbozDWk8v3drN1pSjrY1rYW1BowMOCZ+1Yz29UcUSnwNFb3BV9+qUqpJlioa4EHWwkatpdp5EIio2ToiIYLZOuEFFj9k3nQiBC9iFNsiczeuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nVVwpu4U; 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="nVVwpu4U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C36641F000E9; Fri, 22 May 2026 04:30:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779424254; bh=mVHtjAJQlp0gV8B0Nq6WpIH3y5hTEG8y8BlmpuaiuX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nVVwpu4U5NOqV4Ms01DgRonDxuS/cyHuEXXmiRp6ZPvczMe2Aq0PjseIgGYy1H7wl 6L6+eVeJOapMW4Ziz4RAKAPRXmc/ojvzypwHGhNXvOrZHoW//v+/uFdLphsT2FJ5ng c5nthmnYe0A68XIxH0E0z7Olac5Ld+nZHzihjKafuw0kvVBBlhgjDqyuyaBanC9WAl Me8X84fE1ushAOr06vo2BX2sEK5sO2EjJjOnlktKupeSgOYK8LUKwWvklf2fslffbt iWYSJ/68iPU83wUmNs+VE/eD0ImMJUiwAkKfY3FpXv6zLIfDPNRbi4NIgVEUe2BUpt iL4niyYWhRLVw== 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, Jiri Pirko Subject: [PATCH v5 12/20] dma-direct: select DMA address encoding from DMA_ATTR_CC_SHARED Date: Fri, 22 May 2026 09:58:07 +0530 Message-ID: <20260522042815.370873-13-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260522042815.370873-1-aneesh.kumar@kernel.org> References: <20260522042815.370873-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev 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() when DMA_ATTR_CC_SHARED is actually set. Tested-by: Jiri Pirko Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/direct.c | 42 +++++++++++++++++++++++++----------------- 1 file changed, 25 insertions(+), 17 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index d7eee77f95af..6f3aff8448a0 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"); @@ -169,7 +172,8 @@ 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; } @@ -185,9 +189,11 @@ 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; } @@ -332,7 +338,8 @@ 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_CC_SHARED)); return ret; @@ -455,11 +462,12 @@ 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; -- 2.43.0