v4.19.13 snapshot.
diff --git a/include/linux/kobj_map.h b/include/linux/kobj_map.h
new file mode 100644
index 0000000..c9919f8
--- /dev/null
+++ b/include/linux/kobj_map.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * kobj_map.h
+ */
+
+#ifndef _KOBJ_MAP_H_
+#define _KOBJ_MAP_H_
+
+#include <linux/mutex.h>
+
+typedef struct kobject *kobj_probe_t(dev_t, int *, void *);
+struct kobj_map;
+
+int kobj_map(struct kobj_map *, dev_t, unsigned long, struct module *,
+ kobj_probe_t *, int (*)(dev_t, void *), void *);
+void kobj_unmap(struct kobj_map *, dev_t, unsigned long);
+struct kobject *kobj_lookup(struct kobj_map *, dev_t, int *);
+struct kobj_map *kobj_map_init(kobj_probe_t *, struct mutex *);
+
+#endif /* _KOBJ_MAP_H_ */