v4.19.13 snapshot.
diff --git a/tools/testing/radix-tree/linux/cpu.h b/tools/testing/radix-tree/linux/cpu.h
new file mode 100644
index 0000000..a45530d
--- /dev/null
+++ b/tools/testing/radix-tree/linux/cpu.h
@@ -0,0 +1 @@
+#define cpuhp_setup_state_nocalls(a, b, c, d)	(0)