[ARM SMP] Add Realview MPcore SMP support

Add SMP support for the MPcore tile fitted to the Realview ARM
platform.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/arch-realview/entry-macro.S b/include/asm-arm/arch-realview/entry-macro.S
index 2712ba7..4df469b 100644
--- a/include/asm-arm/arch-realview/entry-macro.S
+++ b/include/asm-arm/arch-realview/entry-macro.S
@@ -47,3 +47,17 @@
 		cmpcs	\irqnr, \irqnr
 
 		.endm
+
+		/* We assume that irqstat (the raw value of the IRQ acknowledge
+		 * register) is preserved from the macro above.
+		 * If there is an IPI, we immediately signal end of interrupt on the
+		 * controller, since this requires the original irqstat value which
+		 * we won't easily be able to recreate later.
+		 */
+
+		.macro test_for_ipi, irqnr, irqstat, base, tmp
+		bic	\irqnr, \irqstat, #0x1c00
+		cmp	\irqnr, #16
+		strcc	\irqstat, [\base, #GIC_CPU_EOI]
+		cmpcs	\irqnr, \irqnr
+		.endm