From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes Date: Tue, 25 Jun 2013 13:34:14 +0100 Message-ID: <20130625123414.GG31838@mudshark.cambridge.arm.com> References: <1370889285-22799-4-git-send-email-will.deacon@arm.com> <20130625131215.d3cea2a5668a3d41dbbeb064@nvidia.com> <20130625113714.GF31838@mudshark.cambridge.arm.com> <20130625.145226.1632119404634300971.hdoyu@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20130625.145226.1632119404634300971.hdoyu-DDmLM1+adcrQT0dZR+AlfA@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: Hiroshi Doyu Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Tue, Jun 25, 2013 at 12:52:26PM +0100, Hiroshi Doyu wrote: > Will Deacon wrote @ Tue, 25 Jun 2013 13:37:14 +0200: > ... > > > Do we need similar changes for map_sg case as well? They still passes '0' as prot. > > > > Yes, we could use the same trick there (probably worth moving the logic into > > a helper function for translating dma_data_direction into IOMMU_* values). > > > > There are also iommu_map calls when allocating DMA buffers, but I think 0 is > > the right thing to pass there (i.e. no permission until pages have been > > explicitly mapped). Although, to be honest, I don't see why we need to map > > the buffer at all when we allocate it. > > Yes, I thought too. I have a patch for that as below. If you like, > I'll rebase and send for merge with the one which changes > dma-mapping.c. Yes, please send the series and I'll take a look. Marek's already picked up my original patch, so it's better if you can base against a stable branch from him. Will From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 25 Jun 2013 13:34:14 +0100 Subject: [PATCH 3/9] ARM: dma-mapping: convert DMA direction into IOMMU protection attributes In-Reply-To: <20130625.145226.1632119404634300971.hdoyu@nvidia.com> References: <1370889285-22799-4-git-send-email-will.deacon@arm.com> <20130625131215.d3cea2a5668a3d41dbbeb064@nvidia.com> <20130625113714.GF31838@mudshark.cambridge.arm.com> <20130625.145226.1632119404634300971.hdoyu@nvidia.com> Message-ID: <20130625123414.GG31838@mudshark.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 25, 2013 at 12:52:26PM +0100, Hiroshi Doyu wrote: > Will Deacon wrote @ Tue, 25 Jun 2013 13:37:14 +0200: > ... > > > Do we need similar changes for map_sg case as well? They still passes '0' as prot. > > > > Yes, we could use the same trick there (probably worth moving the logic into > > a helper function for translating dma_data_direction into IOMMU_* values). > > > > There are also iommu_map calls when allocating DMA buffers, but I think 0 is > > the right thing to pass there (i.e. no permission until pages have been > > explicitly mapped). Although, to be honest, I don't see why we need to map > > the buffer at all when we allocate it. > > Yes, I thought too. I have a patch for that as below. If you like, > I'll rebase and send for merge with the one which changes > dma-mapping.c. Yes, please send the series and I'll take a look. Marek's already picked up my original patch, so it's better if you can base against a stable branch from him. Will