v4.19.13 snapshot.
diff --git a/arch/m68k/include/asm/hwtest.h b/arch/m68k/include/asm/hwtest.h
new file mode 100644
index 0000000..f8d6462
--- /dev/null
+++ b/arch/m68k/include/asm/hwtest.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Routines to test for presence/absence of hardware registers:
+ * see arch/m68k/mm/hwtest.c.
+ * -- PMM <pmaydell@chiark.greenend.org.uk> 05/1998
+ *
+ * Removed __init from decls. We might want them in modules, and
+ * the code is tiny anyway. 16/5/98 pb
+ */
+
+#ifndef __ASM_HWTEST_H
+#define __ASM_HWTEST_H
+
+extern int hwreg_present(volatile void *regp);
+extern int hwreg_write(volatile void *regp, unsigned short val);
+
+#endif