Enable PASID for PCI devices that support it. Initialize PASID early in add_device() because it must be enabled before ATS. Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> --- drivers/iommu/arm-smmu-v3.c | 62 ++++++++++++++++++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index b2b7ba9c4e32..f42454512e87 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2634,6 +2634,53 @@ static void arm_smmu_disable_ats(struct arm_smmu_master *master) atomic_dec(&smmu_domain->nr_ats_masters); } +static int arm_smmu_enable_pasid(struct arm_smmu_master *master) +{ + int ret; + int features; + int num_pasids; + struct pci_dev *pdev; + + if (!dev_is_pci(master->dev)) + return -ENODEV; + + pdev = to_pci_dev(master->dev); + + features = pci_pasid_features(pdev); + if (features < 0) + return features; + + num_pasids = pci_max_pasids(pdev); + if (num_pasids <= 0) + return num_pasids; + + ret = pci_enable_pasid(pdev, features); + if (ret) { + dev_err(&pdev->dev, "Failed to enable PASID\n"); + return ret; + } + + master->ssid_bits = min_t(u8, ilog2(num_pasids), + master->smmu->ssid_bits); + return 0; +} + +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) +{ + struct pci_dev *pdev; + + if (!dev_is_pci(master->dev)) + return; + + pdev = to_pci_dev(master->dev); + + if (!pdev->pasid_enabled) + return; + + master->ssid_bits = 0; + pci_disable_pasid(pdev); +} + static void arm_smmu_detach_dev(struct arm_smmu_master *master) { unsigned long flags; @@ -2842,13 +2889,23 @@ static int arm_smmu_add_device(struct device *dev) master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); + /* + * Note that PASID must be enabled before, and disabled after ATS: + * PCI Express Base 4.0r1.0 - 10.5.1.3 ATS Control Register + * + * Behavior is undefined if this bit is Set and the value of the PASID + * Enable, Execute Requested Enable, or Privileged Mode Requested bits + * are changed. + */ + arm_smmu_enable_pasid(master); + if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB)) master->ssid_bits = min_t(u8, master->ssid_bits, CTXDESC_LINEAR_CDMAX); ret = iommu_device_link(&smmu->iommu, dev); if (ret) - goto err_free_master; + goto err_disable_pasid; group = iommu_group_get_for_dev(dev); if (IS_ERR(group)) { @@ -2861,6 +2918,8 @@ static int arm_smmu_add_device(struct device *dev) err_unlink: iommu_device_unlink(&smmu->iommu, dev); +err_disable_pasid: + arm_smmu_disable_pasid(master); err_free_master: kfree(master); fwspec->iommu_priv = NULL; @@ -2881,6 +2940,7 @@ static void arm_smmu_remove_device(struct device *dev) arm_smmu_detach_dev(master); iommu_group_remove_device(dev); iommu_device_unlink(&smmu->iommu, dev); + arm_smmu_disable_pasid(master); kfree(master); iommu_fwspec_free(dev); } -- 2.24.1