From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: DMA mapping API(IOMMU) for ARM64? Date: Tue, 18 Jun 2013 12:32:44 +0200 Message-ID: <5159282.rrJMaZuYMv@wuerfel> References: <20130618.053955.305832937374936961.hdoyu@nvidia.com> <20130618101914.GB3539@mudshark.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130618101914.GB3539-MRww78TxoiP5vMa5CHWGZ34zcgK1vI+I0E9HWUfgJXw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Catalin Marinas , Will Deacon , "linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" List-Id: iommu@lists.linux-foundation.org On Tuesday 18 June 2013 11:19:14 Will Deacon wrote: > > I've spoken briefly with Catalin about this and it seems like there might be > *some* scope for sharing common dma-mapping code between architectures. > There doesn't really need to be any architecture-specific details in > allocating iova space and the interface to the iommu drivers is > well-defined. The arch-specific stuff is bogged down in the non-coherent > buffer management, but that doesn't necessarily equate to lots of code. > > So, the best bet would be to figure out how to split up what we have under > arch/arm/ so that it can be re-used by arm64 and potentially other > architectures (powerpc has some simple stuff for coherent mappings and some > less-simple stuff for non-coherent buffers). I'm sure that other architectures are interested in sharing the code. Best move it into the global mm/ directory, at least the version for coherent mappings. Arnd