v4.19.13 snapshot.
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
new file mode 100644
index 0000000..6c28d28
--- /dev/null
+++ b/arch/arm/mach-imx/headsmp.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+
+diag_reg_offset:
+ .word g_diag_reg - .
+
+ .macro set_diag_reg
+ adr r0, diag_reg_offset
+ ldr r1, [r0]
+ add r1, r1, r0 @ r1 = physical &g_diag_reg
+ ldr r0, [r1]
+ mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
+ .endm
+
+ENTRY(v7_secondary_startup)
+ARM_BE8(setend be) @ go BE8 if entered LE
+ set_diag_reg
+ b secondary_startup
+ENDPROC(v7_secondary_startup)