File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
new file mode 100644
index 0000000..b5e9768
--- /dev/null
+++ b/arch/arm/mach-imx/headsmp.S
@@ -0,0 +1,30 @@
+/*
+ * 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>
+
+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)
+	set_diag_reg
+	b	secondary_startup
+ENDPROC(v7_secondary_startup)