From: Lu Baolu Date: Thu, 13 Apr 2023 04:06:34 +0000 (+0800) Subject: iommu/vt-d: Remove unnecessary checks in iopf disabling path X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7b8aa998d627afeef576ab61bf8e286f56439bb2;p=linux.git iommu/vt-d: Remove unnecessary checks in iopf disabling path iommu_unregister_device_fault_handler() and iopf_queue_remove_device() are called after device has stopped issuing new page falut requests and all outstanding page requests have been drained. They should never fail. Trigger a warning if it happens unfortunately. Reviewed-by: Kevin Tian Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20230324120234.313643-7-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index cd3a3c4b5e648..c771233d6f2ae 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4707,7 +4707,6 @@ static int intel_iommu_disable_iopf(struct device *dev) { struct device_domain_info *info = dev_iommu_priv_get(dev); struct intel_iommu *iommu = info->iommu; - int ret; if (!info->pri_enabled) return -EINVAL; @@ -4723,15 +4722,15 @@ static int intel_iommu_disable_iopf(struct device *dev) pci_disable_pri(to_pci_dev(dev)); info->pri_enabled = 0; - ret = iommu_unregister_device_fault_handler(dev); - if (ret) - return ret; - - ret = iopf_queue_remove_device(iommu->iopf_queue, dev); - if (ret) - iommu_register_device_fault_handler(dev, iommu_queue_iopf, dev); + /* + * With PRI disabled and outstanding PRQs drained, unregistering + * fault handler and removing device from iopf queue should never + * fail. + */ + WARN_ON(iommu_unregister_device_fault_handler(dev)); + WARN_ON(iopf_queue_remove_device(iommu->iopf_queue, dev)); - return ret; + return 0; } static int