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See http://www.infradead.org/rpr.html X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jun 26, 2019 at 10:12:45PM +0530, Pankaj Suryawanshi wrote: > [CC: linux kernel and Vlastimil Babka] The right list is the list for the DMA mapping subsystem, which is iommu@lists.linux-foundation.org. I've also added that. > > I am writing driver in which I used DMA_ATTR_NO_KERNEL_MAPPING attribute > > for cma allocation using dma_alloc_attr(), as per kernel docs > > https://www.kernel.org/doc/Documentation/DMA-attributes.txt buffers > > allocated with this attribute can be only passed to user space by calling > > dma_mmap_attrs(). > > > > how can I mapped in kernel space (after dma_alloc_attr with > > DMA_ATTR_NO_KERNEL_MAPPING ) ? You can't. And that is the whole point of that API.