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[80.230.31.118]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4324eaa64cesm99604028f8f.35.2026.01.05.00.23.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jan 2026 00:23:09 -0800 (PST) Date: Mon, 5 Jan 2026 03:23:05 -0500 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Cong Wang , Jonathan Corbet , Olivia Mackall , Herbert Xu , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Eugenio =?utf-8?B?UMOpcmV6?= , "James E.J. Bottomley" , "Martin K. Petersen" , Gerd Hoffmann , Xuan Zhuo , Marek Szyprowski , Robin Murphy , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Petr Tesarik , Leon Romanovsky , Jason Gunthorpe , Bartosz Golaszewski , linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, virtualization@lists.linux.dev, linux-scsi@vger.kernel.org, iommu@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2 04/15] docs: dma-api: document DMA_ATTR_CPU_CACHE_CLEAN Message-ID: <0720b4be31c1b7a38edca67fd0c97983d2a56936.1767601130.git.mst@redhat.com> References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Document DMA_ATTR_CPU_CACHE_CLEAN as implemented in the previous patch. Signed-off-by: Michael S. Tsirkin --- Documentation/core-api/dma-attributes.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 0bdc2be65e57..1d7bfad73b1c 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -148,3 +148,12 @@ DMA_ATTR_MMIO is appropriate. For architectures that require cache flushing for DMA coherence DMA_ATTR_MMIO will not perform any cache flushing. The address provided must never be mapped cacheable into the CPU. + +DMA_ATTR_CPU_CACHE_CLEAN +------------------------ + +This attribute indicates the CPU will not dirty any cacheline overlapping this +DMA_FROM_DEVICE/DMA_BIDIRECTIONAL buffer while it is mapped. This allows +multiple small buffers to safely share a cacheline without risk of data +corruption, suppressing DMA debug warnings about overlapping mappings. +All mappings sharing a cacheline should have this attribute. -- MST