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 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);
}
--
2.25.0
