ARM: SMP: provide individual IPI interrupt statistics

This separates out the individual IPI interrupt counts from the
total IPI count, which allows better visibility of what IPIs are
being used for.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/hardirq.h

@@ -5,13 +5,15 @@
 #include <linux/threads.h>
 #include <asm/irq.h>
 
+#define NR_IPI	5
+
 typedef struct {
 	unsigned int __softirq_pending;
 #ifdef CONFIG_LOCAL_TIMERS
 	unsigned int local_timer_irqs;
 #endif
 #ifdef CONFIG_SMP
-	unsigned int ipi_irqs;
+	unsigned int ipi_irqs[NR_IPI];
 #endif
 } ____cacheline_aligned irq_cpustat_t;