On Mon, Jul 20, 2020 at 09:43:00AM -0700, Ashok Raj wrote:
> PASID and PRI capabilities are only enumerated in PF devices. VF devices
> do not enumerate these capabilites. IOMMU drivers also need to enumerate
> them before enabling features in the IOMMU. Extending the same support as
> PASID feature discovery (pci_pasid_features) for PRI.
>
> Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Hi Ashok,
When you update this for the 0-day implicit declaration thing, can you
update the subject to say what the patch *does*, as opposed to what it
is solving? Also, no need for a period at the end.
Does this fix a regression? Is it associated with a commit that we
could add as a "Fixes:" tag so we know how far back to try to apply
to stable kernels?
> To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> To: Joerg Roedel <joro@xxxxxxxxxx>
> To: Lu Baolu <baolu.lu@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
> Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> ---
> drivers/iommu/intel/iommu.c | 2 +-
> drivers/pci/ats.c | 14 ++++++++++++++
> include/linux/pci-ats.h | 1 +
> 3 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index d759e7234e98..276452f5e6a7 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -2560,7 +2560,7 @@ 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..ffb4de8c5a77 100644
> --- a/drivers/pci/ats.c
> +++ b/drivers/pci/ats.c
> @@ -461,6 +461,20 @@ int pci_pasid_features(struct pci_dev *pdev)
> }
> EXPORT_SYMBOL_GPL(pci_pasid_features);
>
> +/**
> + * pci_pri_supported - Check if PRI is supported.
> + * @pdev: PCI device structure
> + *
> + * Returns false when no PRI capability is present.
> + * Returns true if PRI feature is supported and enabled
> + */
> +bool pci_pri_supported(struct pci_dev *pdev)
> +{
> + /* VFs share the PF PRI configuration */
> + return !!(pci_physfn(pdev)->pri_cap);
> +}
> +EXPORT_SYMBOL_GPL(pci_pri_supported);
> +
> #define PASID_NUMBER_SHIFT 8
> #define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT)
> /**
> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
> index f75c307f346d..073d57292445 100644
> --- a/include/linux/pci-ats.h
> +++ b/include/linux/pci-ats.h
> @@ -28,6 +28,7 @@ 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);
> #endif /* CONFIG_PCI_PRI */
>
> #ifdef CONFIG_PCI_PASID
> --
> 2.7.4
>
