[PATCH v2] arm: add cpu_idle tracepoints to arch_cpu_idle

[jszhang@marvell.com (Jisheng Zhang)]

Currently, if cpuidle is disabled or not supported, powertop reports
zero wakeups and zero events. This is due to the cpu_idle tracepoints
are missing.

This patch is to make cpu_idle tracepoints always available even if
cpuidle is disabled or not supported.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
 Since v1:
   - ignore arm_pm_idle.
 arch/arm/kernel/process.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 7a7c4ce..83d2dc5 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -28,6 +28,7 @@
 #include <linux/random.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/leds.h>
+#include <trace/events/power.h>
 
 #include <asm/processor.h>
 #include <asm/thread_notify.h>
@@ -66,11 +67,15 @@ void (*arm_pm_idle)(void);
 
 void arch_cpu_idle(void)
 {
-	if (arm_pm_idle)
+	if (arm_pm_idle) {
 		arm_pm_idle();
-	else
+		local_irq_enable();
+	} else {
+		trace_cpu_idle_rcuidle(1, smp_processor_id());
 		cpu_do_idle();
-	local_irq_enable();
+		local_irq_enable();
+		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+	}
 }
 
 void arch_cpu_idle_prepare(void)
-- 
2.5.1