The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3f9a7a13fe4cb6e119e4e4745fbf975d30bfac9b Mon Sep 17 00:00:00 2001
From: Ashok Raj ashok.raj@intel.com Date: Thu, 23 Jul 2020 15:37:29 -0700 Subject: [PATCH] PCI/ATS: Add pci_pri_supported() to check device or associated PF
For SR-IOV, the PF PRI is shared between the PF and any associated VFs, and the PRI Capability is allowed for PFs but not for VFs. Searching for the PRI Capability on a VF always fails, even if its associated PF supports PRI.
Add pci_pri_supported() to check whether device or its associated PF supports PRI.
[bhelgaas: commit log, avoid "!!"] Fixes: b16d0cb9e2fc ("iommu/vt-d: Always enable PASID/PRI PCI capabilities before ATS") Link: https://lore.kernel.org/r/1595543849-19692-1-git-send-email-ashok.raj@intel.... Signed-off-by: Ashok Raj ashok.raj@intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Acked-by: Joerg Roedel jroedel@suse.de Cc: stable@vger.kernel.org # v4.4+
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 9129663a7406..5552e7d5d2b1 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2554,7 +2554,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, }
if (info->ats_supported && ecap_prs(iommu->ecap) && - pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI)) + pci_pri_supported(pdev)) info->pri_supported = 1; } } diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index b761c1f72f67..647e097530a8 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -325,6 +325,21 @@ int pci_prg_resp_pasid_required(struct pci_dev *pdev)
return pdev->pasid_required; } + +/** + * pci_pri_supported - Check if PRI is supported. + * @pdev: PCI device structure + * + * Returns true if PRI capability is present, false otherwise. + */ +bool pci_pri_supported(struct pci_dev *pdev) +{ + /* VFs share the PF PRI */ + if (pci_physfn(pdev)->pri_cap) + return true; + return false; +} +EXPORT_SYMBOL_GPL(pci_pri_supported); #endif /* CONFIG_PCI_PRI */
#ifdef CONFIG_PCI_PASID diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h index f75c307f346d..df54cd5b15db 100644 --- a/include/linux/pci-ats.h +++ b/include/linux/pci-ats.h @@ -28,6 +28,10 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs); void pci_disable_pri(struct pci_dev *pdev); int pci_reset_pri(struct pci_dev *pdev); int pci_prg_resp_pasid_required(struct pci_dev *pdev); +bool pci_pri_supported(struct pci_dev *pdev); +#else +static inline bool pci_pri_supported(struct pci_dev *pdev) +{ return false; } #endif /* CONFIG_PCI_PRI */
#ifdef CONFIG_PCI_PASID