diff options
Diffstat (limited to 'drivers/pci/ats.c')
| -rw-r--r-- | drivers/pci/ats.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index bf892a025d4..f727a09eb72 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -7,6 +7,7 @@ * PCI Express I/O Virtualization (IOV) support. * Address Translation Service 1.0 * Page Request Interface added by Joerg Roedel <joerg.roedel@amd.com> + * PASID support added by Joerg Roedel <joerg.roedel@amd.com> */ #include <linux/pci-ats.h> @@ -323,3 +324,115 @@ int pci_pri_status(struct pci_dev *pdev) } EXPORT_SYMBOL_GPL(pci_pri_status); #endif /* CONFIG_PCI_PRI */ + +#ifdef CONFIG_PCI_PASID +/** + * pci_enable_pasid - Enable the PASID capability + * @pdev: PCI device structure + * @features: Features to enable + * + * Returns 0 on success, negative value on error. This function checks + * whether the features are actually supported by the device and returns + * an error if not. + */ +int pci_enable_pasid(struct pci_dev *pdev, int features) +{ + u16 control, supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, &control); + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + if (!(supported & PCI_PASID_ENABLE)) + return -EINVAL; + + supported &= PCI_PASID_EXEC | PCI_PASID_PRIV; + + /* User wants to enable anything unsupported? */ + if ((supported & features) != features) + return -EINVAL; + + control = PCI_PASID_ENABLE | features; + + pci_write_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, control); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_enable_pasid); + +/** + * pci_disable_pasid - Disable the PASID capability + * @pdev: PCI device structure + * + */ +void pci_disable_pasid(struct pci_dev *pdev) +{ + u16 control = 0; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return; + + pci_write_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, control); +} +EXPORT_SYMBOL_GPL(pci_disable_pasid); + +/** + * pci_pasid_features - Check which PASID features are supported + * @pdev: PCI device structure + * + * Returns a negative value when no PASI capability is present. + * Otherwise is returns a bitmask with supported features. Current + * features reported are: + * PCI_PASID_ENABLE - PASID capability can be enabled + * PCI_PASID_EXEC - Execute permission supported + * PCI_PASID_PRIV - Priviledged mode supported + */ +int pci_pasid_features(struct pci_dev *pdev) +{ + u16 supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + supported &= PCI_PASID_ENABLE | PCI_PASID_EXEC | PCI_PASID_PRIV; + + return supported; +} +EXPORT_SYMBOL_GPL(pci_pasid_features); + +#define PASID_NUMBER_SHIFT 8 +#define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT) +/** + * pci_max_pasid - Get maximum number of PASIDs supported by device + * @pdev: PCI device structure + * + * Returns negative value when PASID capability is not present. + * Otherwise it returns the numer of supported PASIDs. + */ +int pci_max_pasids(struct pci_dev *pdev) +{ + u16 supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT; + + return (1 << supported); +} +EXPORT_SYMBOL_GPL(pci_max_pasids); +#endif /* CONFIG_PCI_PASID */ |