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See http://www.infradead.org/rpr.html Cc: janghyuck.kim@samsung.com, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, hyesoo.yu@samsung.com, iommu@lists.linux-foundation.org, Cho KyongHo , robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Aug 18, 2020 at 11:07:57AM +0100, Will Deacon wrote: > > > so I'm not sure > > > that we should be complicating the implementation like this to try to > > > make it "fast". > > > > > I agree that this patch makes the implementation of dma API a bit more > > but I don't think this does not impact its complication seriously. > > It's death by a thousand cuts; this patch further fragments the architecture > backends and leads to arm64-specific behaviour which consequently won't get > well tested by anybody else. Now, it might be worth it, but there's not > enough information here to make that call. So it turns out I misread the series (*cough*, crazy long lines, *cough*), and it does not actually expose a new API as I thought, but it still makes a total mess of the internal interface. It turns out that on the for cpu side we already have arch_sync_dma_for_cpu_all, which should do all that is needed. We could do the equivalent for the to device side, but only IFF there really is a major benefit for something that actually is mainstream and matters. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu