diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 71773d0fb769..e453bbd09445 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -172,6 +172,15 @@ static bool pci_iommuv2_capable(struct pci_dev *pdev) return true; } +static bool pdev_pri_erratum(struct pci_dev *pdev, u32 erratum) +{ + struct iommu_dev_data *dev_data; + + dev_data = get_dev_data(&pdev->dev); + + return dev_data->errata & (1 << erratum) ? true : false; +} + /* * In this function the list of preallocated protection domains is traversed to * find the domain for a specific device @@ -1934,9 +1943,33 @@ static void pdev_iommuv2_disable(struct pci_dev *pdev) pci_disable_pasid(pdev); } +/* FIXME: Change generic reset-function to do the same */ +static int pri_reset_while_enabled(struct pci_dev *pdev) +{ + u16 control; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + control |= PCI_PRI_RESET; + pci_write_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, control); + + return 0; +} + static int pdev_iommuv2_enable(struct pci_dev *pdev) { - int ret; + bool reset_enable; + int reqs, ret; + + /* FIXME: Hardcode number of outstanding requests for now */ + reqs = 32; + if (pdev_pri_erratum(pdev, AMD_PRI_DEV_ERRATUM_LIMIT_REQ_ONE)) + reqs = 1; + reset_enable = pdev_pri_erratum(pdev, AMD_PRI_DEV_ERRATUM_ENABLE_RESET); /* Only allow access to user-accessible pages */ ret = pci_enable_pasid(pdev, 0); @@ -1948,11 +1981,17 @@ static int pdev_iommuv2_enable(struct pci_dev *pdev) if (ret) goto out_err; - /* FIXME: Hardcode number of outstanding requests for now */ - ret = pci_enable_pri(pdev, 32); + /* Enable PRI */ + ret = pci_enable_pri(pdev, reqs); if (ret) goto out_err; + if (reset_enable) { + ret = pri_reset_while_enabled(pdev); + if (ret) + goto out_err; + } + ret = pci_enable_ats(pdev, PAGE_SHIFT); if (ret) goto out_err; @@ -3481,3 +3520,15 @@ struct iommu_domain *amd_iommu_get_v2_domain(struct pci_dev *pdev) return domain->iommu_domain; } EXPORT_SYMBOL(amd_iommu_get_v2_domain); + +void amd_iommu_enable_device_erratum(struct pci_dev *pdev, u32 erratum) +{ + struct iommu_dev_data *dev_data; + + if (!amd_iommu_v2_supported()) + return; + + dev_data = get_dev_data(&pdev->dev); + dev_data->errata |= (1 << erratum); +} +EXPORT_SYMBOL(amd_iommu_enable_device_erratum); diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index c39988fbcbbb..6ad8b10b3130 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -404,6 +404,7 @@ struct iommu_dev_data { } ats; /* ATS state */ bool pri_tlp; /* PASID TLB required for PPR completions */ + u32 errata; /* Bitmap for errata to apply */ }; /* diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h index a6863a2dec1f..4152c3073db4 100644 --- a/include/linux/amd-iommu.h +++ b/include/linux/amd-iommu.h @@ -26,6 +26,24 @@ extern int amd_iommu_detect(void); + +/** + * amd_iommu_enable_device_erratum() - Enable erratum workaround for device + * in the IOMMUv2 driver + * @pdev: The PCI device the workaround is necessary for + * @erratum: The erratum workaround to enable + * + * Possible values for the erratum number are for now: + * - AMD_PRI_DEV_ERRATUM_ENABLE_RESET - Reset PRI capability when PRI + * is enabled + * - AMD_PRI_DEV_ERRATUM_LIMIT_REQ_ONE - Limit number of outstanding PRI + * requests to one + */ +#define AMD_PRI_DEV_ERRATUM_ENABLE_RESET 0 +#define AMD_PRI_DEV_ERRATUM_LIMIT_REQ_ONE 1 + +extern void amd_iommu_enable_device_erratum(struct pci_dev *pdev, u32 erratum); + #else static inline int amd_iommu_detect(void) { return -ENODEV; }