From: Jean-Philippe Brucker Date: Mon, 24 Feb 2020 17:58:42 +0100 Subject: iommu/arm-smmu-v3: Add support for PCI PASID Git-commit: 058c59a047d61601abf503563bbea818ee645c09 Patch-mainline: v5.7-rc1 References: bsc#1175713 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 Reviewed-by: Jonathan Cameron Signed-off-by: Jean-Philippe Brucker Signed-off-by: Will Deacon Acked-by: Joerg Roedel --- 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 aa3ac2a03807..6b76df37025e 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2628,6 +2628,53 @@ 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; @@ -2831,13 +2878,23 @@ 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)) { @@ -2850,6 +2907,8 @@ 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; @@ -2870,6 +2929,7 @@ 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); }