v4.19.13 snapshot.
diff --git a/tools/include/linux/stringify.h b/tools/include/linux/stringify.h
new file mode 100644
index 0000000..60e2c18
--- /dev/null
+++ b/tools/include/linux/stringify.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_STRINGIFY_H
+#define __LINUX_STRINGIFY_H
+
+/* Indirect stringification. Doing two levels allows the parameter to be a
+ * macro itself. For example, compile with -DFOO=bar, __stringify(FOO)
+ * converts to "bar".
+ */
+
+#define __stringify_1(x...) #x
+#define __stringify(x...) __stringify_1(x)
+
+#endif /* !__LINUX_STRINGIFY_H */