diff options
Diffstat (limited to 'drivers/pci/ats.c')
| -rw-r--r-- | drivers/pci/ats.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index c6b266c772c8..ec6c8dbdc5e9 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -538,4 +538,37 @@ int pci_max_pasids(struct pci_dev *pdev) return (1 << FIELD_GET(PCI_PASID_CAP_WIDTH, supported)); } EXPORT_SYMBOL_GPL(pci_max_pasids); + +/** + * pci_pasid_status - Check the PASID status + * @pdev: PCI device structure + * + * Returns a negative value when no PASID capability is present. + * Otherwise the value of the control register is returned. + * Status reported are: + * + * PCI_PASID_CTRL_ENABLE - PASID enabled + * PCI_PASID_CTRL_EXEC - Execute permission enabled + * PCI_PASID_CTRL_PRIV - Privileged mode enabled + */ +int pci_pasid_status(struct pci_dev *pdev) +{ + int pasid; + u16 ctrl; + + if (pdev->is_virtfn) + pdev = pci_physfn(pdev); + + pasid = pdev->pasid_cap; + if (!pasid) + return -EINVAL; + + pci_read_config_word(pdev, pasid + PCI_PASID_CTRL, &ctrl); + + ctrl &= PCI_PASID_CTRL_ENABLE | PCI_PASID_CTRL_EXEC | + PCI_PASID_CTRL_PRIV; + + return ctrl; +} +EXPORT_SYMBOL_GPL(pci_pasid_status); #endif /* CONFIG_PCI_PASID */ |