From mboxrd@z Thu Jan 1 00:00:00 1970 From: Murali Karicheri Subject: Re: [PATCH v3 0/4] PCI: get DMA configuration from parent device Date: Wed, 7 Jan 2015 18:04:41 -0500 Message-ID: <54ADBB89.8070503@ti.com> References: <1420656594-8908-1-git-send-email-m-karicheri2@ti.com> <4057859.4ynbgz66iN@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4057859.4ynbgz66iN@wuerfel> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnd Bergmann , bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org List-Id: devicetree@vger.kernel.org On 01/07/2015 04:18 PM, Arnd Bergmann wrote: > On Wednesday 07 January 2015 13:49:50 Murali Karicheri wrote: >> PCI devices on Keystone doesn't have correct dma_pfn_offset set. This patch >> add capability to set the dma configuration such as dma-mask, dma_pfn_offset, >> and dma ops etc using the information from DT. The prior RFCs and discussions >> are available at [1] and [2] below. >> >> [2] : https://www.mail-archive.com/linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org/msg790244.html >> [1] : http://www.gossamer-threads.com/lists/linux/kernel/2024591 > > Looks all good to me in this version, I'm just unsure about one thing: > >> - Limit the of_iommu_configure to non pci devices > > My last recommendation was to pass the b/d/f number into > of_pci_dma_configure to handle this correctly. What was your > reason for not doing it in the end? Arnd, I had responded to this already on the list and reproduced below your remark and my response below from that thread. ---------------cut------------------------------------------------------- > Actually regarding the bit I wrote above, it might be helpful to pass > the PCI_DEVID() into both of_iommu_configure and of_dma_configure. > > While this may or may not be sufficient, I think there is no question > about it being needed for the ARM SMMU with PCI, so we may as well add > it at the point when you touch the same lines already. In the platform > bus case, just pass zero here. Arnd, PCI_DEVID() is defined as #define PCI_DEVID(bus, devfn) ((((u16)(bus)) << 8) | (devfn)) So PCI_DEVID of 0 is a valid PCI DEVID. How about checking if the device is PCI in of_iommu_configure() using dev_is_pci(dev) macro and return immediately for PCI? Need to include pci.h in this file though. Some of the iommu drivers already include this. a0868495@ares-ubuntu:~/projects/linux-keystone$ grep -r pci.h drivers/iommu/ drivers/iommu/amd_iommu_v2.c:#include drivers/iommu/dmar.c:#include drivers/iommu/amd_iommu_types.h:#include drivers/iommu/amd_iommu.c:#include drivers/iommu/fsl_pamu_domain.c:#include drivers/iommu/iommu.c:#include drivers/iommu/intel-iommu.c:#include drivers/iommu/intel_irq_remapping.c:#include drivers/iommu/arm-smmu.c:#include drivers/iommu/amd_iommu_init.c:#include drivers/iommu/irq_remapping.c:#include This will allow us to re-visit this later for IOMMU support for PCI without polluting the API. -----------------------cut-end--------------------------------------- I assumed you want to use value of zero for b/d/f to indicate it is for platform. Also use the non zero value to skip the DT attribute parsing for IOMMU DT attribute in of_iommu_configure() for PCI. I did dev_is_pci() for skipping the processing for PCI. I thought it is better to add the b/d/f argument later when this is re-visited later. BTW, I still haven't received any comment from Bjorn w.r.t PCI part. BJorn, could you review and comment on 3/4 and 4/4? Regards, Murali > > We will likely have to change this again if we take your current version, > but that can be a follow-up patch. I believe AMD requires it to use > PCI on their their Seattle platform. > > Arnd > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Murali Karicheri Linux Kernel, Texas Instruments -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html