iommu/amd: Implement iommu_device_group

Just use the amd_iommu_alias_table directly.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/amd_iommu.c

@@ -2773,6 +2773,18 @@ static int amd_iommu_domain_has_cap(struct iommu_domain *domain,
 	return 0;
 }
 
+static int amd_iommu_device_group(struct device *dev, unsigned int *groupid)
+{
+	struct iommu_dev_data *dev_data = dev->archdata.iommu;
+
+	if (!dev_data)
+		return -ENODEV;
+
+	*groupid = amd_iommu_alias_table[dev_data->devid];
+
+	return 0;
+}
+
 static struct iommu_ops amd_iommu_ops = {
 	.domain_init = amd_iommu_domain_init,
 	.domain_destroy = amd_iommu_domain_destroy,
@@ -2782,6 +2794,7 @@ static struct iommu_ops amd_iommu_ops = {
 	.unmap = amd_iommu_unmap,
 	.iova_to_phys = amd_iommu_iova_to_phys,
 	.domain_has_cap = amd_iommu_domain_has_cap,
+	.device_group = amd_iommu_device_group,
 };
 
 /*****************************************************************************