ARM: imx: replicate the diagnostic register of boot cpu into secondary cores

The diagnostic register holds the errata bits.  Mostly bootloader
does not bring up secondary cores, so that when errata bits are set
in bootloader, they are set only for boot cpu.  But on a SMP
configuration, it should be equally done on every single core.
Set up the diagnostic register for secondary cores by replicating
the register from boot cpu.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
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