Commit 3f9a7a13 authored by Ashok Raj's avatar Ashok Raj Committed by Bjorn Helgaas
Browse files

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: b16d0cb9 ("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.com


Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Acked-by: default avatarJoerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org	# v4.4+
parent 1c026a18

drivers/iommu/intel/iommu.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

		}

	}

drivers/pci/ats.c

+15 −0
Original line number Diff line number Diff line
@@ -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

include/linux/pci-ats.h

+4 −0
Original line number Diff line number Diff line
@@ -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

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