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>

1 files changed, 26 insertions, 0 deletions

diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 06688c42167d..c03c281ae6ee 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -119,6 +119,32 @@ typedef int (*amd_iommu_invalid_ppr_cb)(struct pci_dev *pdev,
 extern int amd_iommu_set_invalid_ppr_cb(struct pci_dev *pdev,
                                         amd_iommu_invalid_ppr_cb cb);
 
+/**
+ * amd_iommu_device_info() - Get information about IOMMUv2 support of a
+ *                           PCI device
+ * @pdev: PCI device to query information from
+ * @info: A pointer to an amd_iommu_device_info structure which will contain
+ *        the information about the PCI device
+ *
+ * Returns 0 on success, negative value on error
+ */
+
+#define AMD_IOMMU_DEVICE_FLAG_ATS_SUP     0x1    /* ATS feature supported */
+#define AMD_IOMMU_DEVICE_FLAG_PRI_SUP     0x2    /* PRI feature supported */
+#define AMD_IOMMU_DEVICE_FLAG_PASID_SUP   0x4    /* PASID context supported */
+#define AMD_IOMMU_DEVICE_FLAG_EXEC_SUP    0x8    /* Device may request execution
+                                                    on memory pages */
+#define AMD_IOMMU_DEVICE_FLAG_PRIV_SUP   0x10    /* Device may request
+                                                    super-user privileges */
+
+struct amd_iommu_device_info {
+        int max_pasids;
+        u32 flags;
+};
+
+extern int amd_iommu_device_info(struct pci_dev *pdev,
+                                 struct amd_iommu_device_info *info);
+
 #else
 
 static inline int amd_iommu_detect(void) { return -ENODEV; }