ARM: SMP: provide accessors for irq_stat data

Provide __inc_irq_stat() and __get_irq_stat() to increment and
read the irq stat counters.
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

@@ -14,6 +14,9 @@ typedef struct {
 
 #include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
 
+#define __inc_irq_stat(cpu, member)	__IRQ_STAT(cpu, member)++
+#define __get_irq_stat(cpu, member)	__IRQ_STAT(cpu, member)
+
 #if NR_IRQS > 512
 #define HARDIRQ_BITS	10
 #elif NR_IRQS > 256

arch/arm/kernel/smp.c

@@ -423,7 +423,7 @@ asmlinkage void __exception do_local_timer(struct pt_regs *regs)
 	int cpu = smp_processor_id();
 
 	if (local_timer_ack()) {
-		irq_stat[cpu].local_timer_irqs++;
+		__inc_irq_stat(cpu, local_timer_irqs);
 		ipi_timer();
 	}
 
@@ -437,7 +437,7 @@ void show_local_irqs(struct seq_file *p)
 	seq_printf(p, "LOC: ");
 
 	for_each_present_cpu(cpu)
-		seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs);
+		seq_printf(p, "%10u ", __get_irq_stat(cpu, local_timer_irqs));
 
 	seq_putc(p, '\n');
 }