From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH v4 1/6] of: iommu: add ptr to OF node arg to of_iommu_configure() Date: Wed, 28 Jan 2015 11:33:00 +0000 Message-ID: <20150128113300.GF1569@arm.com> References: <1422052359-12384-1-git-send-email-m-karicheri2@ti.com> <1422052359-12384-2-git-send-email-m-karicheri2@ti.com> <4711364.TTK5TCBdiy@avalon> <54C68C1D.5030605@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <54C68C1D.5030605-l0cyMroinI0@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: Murali Karicheri Cc: "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Russell King , Arnd Bergmann , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Rob Herring , Laurent Pinchart , Bjorn Helgaas , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org On Mon, Jan 26, 2015 at 06:49:01PM +0000, Murali Karicheri wrote: > On 01/25/2015 08:32 AM, Laurent Pinchart wrote: > > Hi Murali, > > > > Thank you for the patch. > > > > On Friday 23 January 2015 17:32:34 Murali Karicheri wrote: > >> Function of_iommu_configure() is called from of_dma_configure() to > >> setup iommu ops using DT property. This API is currently used for > >> platform devices for which DMA configuration (including iommu ops) > >> may come from device's parent. To extend this functionality for PCI > >> devices, this API need to take a parent node ptr as an argument > >> instead of assuming device's parent. This is needed since for PCI, the > >> dma configuration may be defined in the DT node of the root bus bridge's > >> parent device. Currently only dma-range is used for PCI and iommu is not > >> supported. So return error if the device is PCI. > >> > >> Cc: Joerg Roedel > >> Cc: Grant Likely > >> Cc: Rob Herring > >> Cc: Bjorn Helgaas > >> Cc: Will Deacon > >> Cc: Russell King > >> Cc: Arnd Bergmann > >> Cc: Suravee Suthikulpanit > >> > >> Signed-off-by: Murali Karicheri > >> --- > >> drivers/iommu/of_iommu.c | 10 ++++++++-- > >> drivers/of/platform.c | 2 +- > >> include/linux/of_iommu.h | 6 ++++-- > >> 3 files changed, 13 insertions(+), 5 deletions(-) > >> > >> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > >> index af1dc6a..439235b 100644 > >> --- a/drivers/iommu/of_iommu.c > >> +++ b/drivers/iommu/of_iommu.c > >> @@ -133,19 +133,25 @@ struct iommu_ops *of_iommu_get_ops(struct device_node > >> *np) return ops; > >> } > >> > >> -struct iommu_ops *of_iommu_configure(struct device *dev) > >> +struct iommu_ops *of_iommu_configure(struct device *dev, > >> + struct device_node *iommu_np) > >> { > >> struct of_phandle_args iommu_spec; > >> struct device_node *np; > >> struct iommu_ops *ops = NULL; > >> int idx = 0; > >> > >> + if (dev_is_pci(dev)) { > >> + dev_err(dev, "iommu is currently not supported for PCI\n"); > >> + return NULL; > >> + } > >> + > >> /* > >> * We don't currently walk up the tree looking for a parent IOMMU. > >> * See the `Notes:' section of > >> * Documentation/devicetree/bindings/iommu/iommu.txt > >> */ > > Wouldn't it be better to fix this rather than passing the device node pointer > > to the function ? The solution would be more generic. > Laurent, > > Will Deacon (Copied here) is working on this as we alteady discussed in > this thread. So it will be > addressed by him in another series. Well, "working on this" equates to "has it somewhere near the bottom of a very long list" :) Will