From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932938AbdEWJCC (ORCPT ); Tue, 23 May 2017 05:02:02 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:35314 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762469AbdEWJBg (ORCPT ); Tue, 23 May 2017 05:01:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 126CB6028D Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sricharan@codeaurora.org Subject: Re: [PATCH V11 08/11] drivers: acpi: Handle IOMMU lookup failure with deferred probing or error To: Lorenzo Pieralisi , Nate Watterson Cc: robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, tn@semihalf.com, hanjun.guo@linaro.org, okaya@codeaurora.org, robh+dt@kernel.org, frowand.list@gmail.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, linux-arch@vger.kernel.org, gregkh@linuxfoundation.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> From: Sricharan R Message-ID: Date: Tue, 23 May 2017 14:31:17 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <20170523085241.GA18204@red-moon> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Regards, Sricharan > Lorenzo > > -- >8 -- > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index c5fecf9..e326f2a 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -666,14 +666,6 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, > int ret = -ENODEV; > struct fwnode_handle *iort_fwnode; > > - /* > - * If we already translated the fwspec there > - * is nothing left to do, return the iommu_ops. > - */ > - ops = iort_fwspec_iommu_ops(dev->iommu_fwspec); > - if (ops) > - return ops; > - > if (node) { > iort_fwnode = iort_get_fwnode(node); > if (!iort_fwnode) > @@ -735,6 +727,14 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) > u32 streamid = 0; > int err; > > + /* > + * If we already translated the fwspec there > + * is nothing left to do, return the iommu_ops. > + */ > + ops = iort_fwspec_iommu_ops(dev->iommu_fwspec); > + if (ops) > + return ops; > + > if (dev_is_pci(dev)) { > struct pci_bus *bus = to_pci_dev(dev)->bus; > u32 rid; > > -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation