1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d14413916f93..8309e634977e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1248,6 +1248,25 @@ void iommu_group_remove_device(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(iommu_group_remove_device);
 
+#if IS_ENABLED(CONFIG_LOCKDEP) && IS_ENABLED(CONFIG_IOMMU_API)
+/**
+ * iommu_group_mutex_assert - Check device group mutex lock
+ * @dev: the device that has group param set
+ *
+ * This function is called by an iommu driver to check whether it holds
+ * group mutex lock for the given device or not.
+ *
+ * Note that this function must be called after device group param is set.
+ */
+void iommu_group_mutex_assert(struct device *dev)
+{
+	struct iommu_group *group = dev->iommu_group;
+
+	lockdep_assert_held(&group->mutex);
+}
+EXPORT_SYMBOL_GPL(iommu_group_mutex_assert);
+#endif
+
 static struct device *iommu_group_first_dev(struct iommu_group *group)
 {
 	lockdep_assert_held(&group->mutex);