diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
index 67b9c48..627f16f 100644
--- a/arch/arm/mach-imx/headsmp.S
+++ b/arch/arm/mach-imx/headsmp.S
@@ -18,8 +18,20 @@
 	.section ".text.head", "ax"
 
 #ifdef CONFIG_SMP
+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)
 	bl	v7_invalidate_l1
+	set_diag_reg
 	b	secondary_startup
 ENDPROC(v7_secondary_startup)
 #endif