irqchip: gic: Use mask field in GICC_IAR

Bit[9:0] is interrupt ID field in GICC_IAR. Bit[12:10] is CPU ID field,
and others are reserved.

So we should use GICC_IAR_INT_ID_MASK to get interrupt ID. It's not a good way
to use ~0x1c00 (CPU ID field) to get interrupt ID.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Link: https://lkml.kernel.org/r/1399795571-17231-3-git-send-email-haojian.zhuang@linaro.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 4300b66..f711fb6 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -287,7 +287,7 @@
 
 	do {
 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
-		irqnr = irqstat & ~0x1c00;
+		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
 
 		if (likely(irqnr > 15 && irqnr < 1021)) {
 			irqnr = irq_find_mapping(gic->domain, irqnr);