From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nate Watterson Subject: Re: [PATCH V11 08/11] drivers: acpi: Handle IOMMU lookup failure with deferred probing or error Date: Tue, 23 May 2017 07:27:38 -0400 Message-ID: <647cbf74-d171-365c-7ef5-9f1e5986716c@codeaurora.org> References: <1491823266-1209-1-git-send-email-sricharan@codeaurora.org> <1491823266-1209-9-git-send-email-sricharan@codeaurora.org> <41668eff-271c-1c4c-7665-3bf0faa74669@codeaurora.org> <20170523085241.GA18204@red-moon> <20170523092659.GA19999@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170523092659.GA19999@red-moon> Content-Language: en-US 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: Lorenzo Pieralisi , Sricharan R Cc: catalin.marinas-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tn-nYOzD4b6Jr9Wk0Htik3J/w@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, sudeep.holla-5wv7dgnIgG8@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Lorenzo, On 5/23/2017 5:26 AM, Lorenzo Pieralisi wrote: > On Tue, May 23, 2017 at 02:31:17PM +0530, Sricharan R wrote: >> Hi Lorenzo, >> >> On 5/23/2017 2:22 PM, Lorenzo Pieralisi wrote: >>> On Tue, May 23, 2017 at 02:26:10AM -0400, Nate Watterson wrote: >>>> Hi Sricharan, >>>> >>>> On 4/10/2017 7:21 AM, Sricharan R wrote: >>>>> This is an equivalent to the DT's handling of the iommu master's probe >>>>> with deferred probing when the corrsponding iommu is not probed yet. >>>>> The lack of a registered IOMMU can be caused by the lack of a driver for >>>>> the IOMMU, the IOMMU device probe not having been performed yet, having >>>>> been deferred, or having failed. >>>>> >>>>> The first case occurs when the firmware describes the bus master and >>>>> IOMMU topology correctly but no device driver exists for the IOMMU yet >>>>> or the device driver has not been compiled in. Return NULL, the caller >>>>> will configure the device without an IOMMU. >>>>> >>>>> The second and third cases are handled by deferring the probe of the bus >>>>> master device which will eventually get reprobed after the IOMMU. >>>>> >>>>> The last case is currently handled by deferring the probe of the bus >>>>> master device as well. A mechanism to either configure the bus master >>>>> device without an IOMMU or to fail the bus master device probe depending >>>>> on whether the IOMMU is optional or mandatory would be a good >>>>> enhancement. >>>>> >>>>> Tested-by: Hanjun Guo >>>>> Reviewed-by: Robin Murphy >>>>> [Lorenzo: Added fixes for dma_coherent_mask overflow, acpi_dma_configure >>>>> called multiple times for same device] >>>>> Signed-off-by: Lorenzo Pieralisi >>>>> Signed-off-by: Sricharan R >>>>> --- >>>>> drivers/acpi/arm64/iort.c | 33 ++++++++++++++++++++++++++++++++- >>>>> drivers/acpi/scan.c | 11 ++++++++--- >>>>> drivers/base/dma-mapping.c | 2 +- >>>>> include/acpi/acpi_bus.h | 2 +- >>>>> include/linux/acpi.h | 7 +++++-- >>>>> 5 files changed, 47 insertions(+), 8 deletions(-) >>>>> >>>>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c >>>>> index 3dd9ec3..e323ece 100644 >>>>> --- a/drivers/acpi/arm64/iort.c >>>>> +++ b/drivers/acpi/arm64/iort.c >>>>> @@ -543,6 +543,14 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, >>>>> const struct iommu_ops *ops = NULL; >>>>> int ret = -ENODEV; >>>>> struct fwnode_handle *iort_fwnode; >>>>> + struct iommu_fwspec *fwspec = dev->iommu_fwspec; >>>>> + >>>>> + /* >>>>> + * If we already translated the fwspec there >>>>> + * is nothing left to do, return the iommu_ops. >>>>> + */ >>>>> + if (fwspec && fwspec->ops) >>>>> + return fwspec->ops; >>>> >>>> Is this logic strictly required? It breaks masters with multiple SIDs >>>> as only the first SID is actually added to the master's fwspec. >>> >>> My bad, that's indeed a silly bug I introduced. Please let me know if the >>> patch below fixes it, we will send it upstream shortly. >>> >> >> oops, i think emails crossed. Please let me know if you are ok to add >> this to the other fixes. > > No worries, yes I am ok thanks but please give Nate some time to report > back to make sure the diff I sent actually fixes the problem. The patch you sent fixes the problem. Thanks for the quick turnaround. > > Apologies for the breakage. > > Lorenzo > >> >> Regards, >> Sricharan >> -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.