iommu/amd: Add amd_iommu_device_info() function
This function can be used to find out which features
necessary for IOMMUv2 usage are available on a given device.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index d5074f4..03944e7 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3565,3 +3565,46 @@
dev_data->errata |= (1 << erratum);
}
EXPORT_SYMBOL(amd_iommu_enable_device_erratum);
+
+int amd_iommu_device_info(struct pci_dev *pdev,
+ struct amd_iommu_device_info *info)
+{
+ int max_pasids;
+ int pos;
+
+ if (pdev == NULL || info == NULL)
+ return -EINVAL;
+
+ if (!amd_iommu_v2_supported())
+ return -EINVAL;
+
+ memset(info, 0, sizeof(*info));
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS);
+ if (pos)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+ if (pos)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PRI_SUP;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+ if (pos) {
+ int features;
+
+ max_pasids = 1 << (9 * (amd_iommu_max_glx_val + 1));
+ max_pasids = min(max_pasids, (1 << 20));
+
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
+ info->max_pasids = min(pci_max_pasids(pdev), max_pasids);
+
+ features = pci_pasid_features(pdev);
+ if (features & PCI_PASID_CAP_EXEC)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_EXEC_SUP;
+ if (features & PCI_PASID_CAP_PRIV)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PRIV_SUP;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(amd_iommu_device_info);