From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Philippe Brucker Subject: Re: [PATCH 27/37] iommu/arm-smmu-v3: Register fault workqueue Date: Wed, 14 Mar 2018 13:08:25 +0000 Message-ID: <78551b46-2a54-76cf-da61-72aeae4b0002@arm.com> References: <20180212183352.22730-1-jean-philippe.brucker@arm.com> <20180212183352.22730-28-jean-philippe.brucker@arm.com> <20180308184454.00000b4e@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180308184454.00000b4e-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> 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: Jonathan Cameron Cc: Mark Rutland , "ilias.apalodimas-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "xuzaibo-hv44wF8Li93QT0dZR+AlfA@public.gmane.org" , Will Deacon , "okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org" , "ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "bharatku-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org" , "linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Catalin Marinas , "rfranz-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org" , "lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "devicetree-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" , "dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org" , rjw@rjwyso List-Id: linux-acpi@vger.kernel.org On 08/03/18 17:44, Jonathan Cameron wrote: >> @@ -3168,6 +3260,13 @@ static int arm_smmu_device_probe(struct platform_device *pdev) >> if (ret) >> return ret; >> >> + if (smmu->features & (ARM_SMMU_FEAT_STALLS | ARM_SMMU_FEAT_PRI)) { >> + smmu->faultq_nb.notifier_call = arm_smmu_flush_queues; >> + ret = iommu_fault_queue_register(&smmu->faultq_nb); > Here you register only if this smmu supports stalls or pri which is fine, but > see the unregister path. > >> + if (ret) >> + return ret; >> + } >> + >> /* And we're up. Go go go! */ >> ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, >> "smmu3.%pa", &ioaddr); >> @@ -3210,6 +3309,8 @@ static int arm_smmu_device_remove(struct platform_device *pdev) >> { >> struct arm_smmu_device *smmu = platform_get_drvdata(pdev); >> >> + iommu_fault_queue_unregister(&smmu->faultq_nb); > > Here you unregister from the fault queue unconditionally. That is mostly > safe but it seems to decrement and potentially destroy the work queue that > is in use by another smmu instance that does support page faulting. Ah yes, we'll need to check this Thanks, Jean From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Re: [PATCH 27/37] iommu/arm-smmu-v3: Register fault workqueue To: Jonathan Cameron References: <20180212183352.22730-1-jean-philippe.brucker@arm.com> <20180212183352.22730-28-jean-philippe.brucker@arm.com> <20180308184454.00000b4e@huawei.com> From: Jean-Philippe Brucker Message-ID: <78551b46-2a54-76cf-da61-72aeae4b0002@arm.com> Date: Wed, 14 Mar 2018 13:08:25 +0000 MIME-Version: 1.0 In-Reply-To: <20180308184454.00000b4e@huawei.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "xieyisheng1@huawei.com" , "ilias.apalodimas@linaro.org" , "kvm@vger.kernel.org" , "linux-pci@vger.kernel.org" , "xuzaibo@huawei.com" , Will Deacon , "okaya@codeaurora.org" , "yi.l.liu@intel.com" , Lorenzo Pieralisi , "ashok.raj@intel.com" , "tn@semihalf.com" , "joro@8bytes.org" , "robdclark@gmail.com" , "bharatku@xilinx.com" , "linux-acpi@vger.kernel.org" , Catalin Marinas , "rfranz@cavium.com" , "lenb@kernel.org" , "devicetree@vger.kernel.org" , "jacob.jun.pan@linux.intel.com" , "alex.williamson@redhat.com" , "robh+dt@kernel.org" , "thunder.leizhen@huawei.com" , "bhelgaas@google.com" , "linux-arm-kernel@lists.infradead.org" , "shunyong.yang@hxt-semitech.com" , "dwmw2@infradead.org" , "liubo95@huawei.com" , "rjw@rjwysocki.net" , "jcrouse@codeaurora.org" , "iommu@lists.linux-foundation.org" , "hanjun.guo@linaro.org" , Sudeep Holla , Robin Murphy , "christian.koenig@amd.com" , "nwatters@codeaurora.org" Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: On 08/03/18 17:44, Jonathan Cameron wrote: >> @@ -3168,6 +3260,13 @@ static int arm_smmu_device_probe(struct platform_device *pdev) >> if (ret) >> return ret; >> >> + if (smmu->features & (ARM_SMMU_FEAT_STALLS | ARM_SMMU_FEAT_PRI)) { >> + smmu->faultq_nb.notifier_call = arm_smmu_flush_queues; >> + ret = iommu_fault_queue_register(&smmu->faultq_nb); > Here you register only if this smmu supports stalls or pri which is fine, but > see the unregister path. > >> + if (ret) >> + return ret; >> + } >> + >> /* And we're up. Go go go! */ >> ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, >> "smmu3.%pa", &ioaddr); >> @@ -3210,6 +3309,8 @@ static int arm_smmu_device_remove(struct platform_device *pdev) >> { >> struct arm_smmu_device *smmu = platform_get_drvdata(pdev); >> >> + iommu_fault_queue_unregister(&smmu->faultq_nb); > > Here you unregister from the fault queue unconditionally. That is mostly > safe but it seems to decrement and potentially destroy the work queue that > is in use by another smmu instance that does support page faulting. Ah yes, we'll need to check this Thanks, Jean _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: jean-philippe.brucker@arm.com (Jean-Philippe Brucker) Date: Wed, 14 Mar 2018 13:08:25 +0000 Subject: [PATCH 27/37] iommu/arm-smmu-v3: Register fault workqueue In-Reply-To: <20180308184454.00000b4e@huawei.com> References: <20180212183352.22730-1-jean-philippe.brucker@arm.com> <20180212183352.22730-28-jean-philippe.brucker@arm.com> <20180308184454.00000b4e@huawei.com> Message-ID: <78551b46-2a54-76cf-da61-72aeae4b0002@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/03/18 17:44, Jonathan Cameron wrote: >> @@ -3168,6 +3260,13 @@ static int arm_smmu_device_probe(struct platform_device *pdev) >> if (ret) >> return ret; >> >> + if (smmu->features & (ARM_SMMU_FEAT_STALLS | ARM_SMMU_FEAT_PRI)) { >> + smmu->faultq_nb.notifier_call = arm_smmu_flush_queues; >> + ret = iommu_fault_queue_register(&smmu->faultq_nb); > Here you register only if this smmu supports stalls or pri which is fine, but > see the unregister path. > >> + if (ret) >> + return ret; >> + } >> + >> /* And we're up. Go go go! */ >> ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, >> "smmu3.%pa", &ioaddr); >> @@ -3210,6 +3309,8 @@ static int arm_smmu_device_remove(struct platform_device *pdev) >> { >> struct arm_smmu_device *smmu = platform_get_drvdata(pdev); >> >> + iommu_fault_queue_unregister(&smmu->faultq_nb); > > Here you unregister from the fault queue unconditionally. That is mostly > safe but it seems to decrement and potentially destroy the work queue that > is in use by another smmu instance that does support page faulting. Ah yes, we'll need to check this Thanks, Jean