linux-kernel - [PATCHv4 1/4] cpuidle: refactor out cpuidle_enter

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Date:	Mon,  7 May 2012 17:57:39 -0700
From:	Colin Cross <ccross@...roid.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-arm-kernel@...ts.infradead.org,
	linux-pm@...ts.linux-foundation.org, Kevin Hilman <khilman@...com>,
	Len Brown <len.brown@...el.com>,
	Trinabh Gupta <g.trinabh@...il.com>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	Deepthi Dharwar <deepthi@...ux.vnet.ibm.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Kay Sievers <kay.sievers@...y.org>,
	Santosh Shilimkar <santosh.shilimkar@...com>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Amit Kucheria <amit.kucheria@...aro.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Arnd Bergmann <arnd.bergmann@...aro.org>,
	Russell King <linux@....linux.org.uk>,
	"Rafael J. Wysocki" <rjw@...k.pl>, Colin Cross <ccross@...roid.com>
Subject: [PATCHv4 1/4] cpuidle: refactor out cpuidle_enter_state

Split the code to enter a state and update the stats into a helper
function, cpuidle_enter_state, and export it.  This function will
be called by the coupled state code to handle entering the safe
state and the final coupled state.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@...com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@...com>
Reviewed-by: Kevin Hilman <khilman@...com>
Tested-by: Kevin Hilman <khilman@...com>
Signed-off-by: Colin Cross <ccross@...roid.com>
---
 drivers/cpuidle/cpuidle.c |   42 +++++++++++++++++++++++++++++-------------
 drivers/cpuidle/cpuidle.h |    2 ++
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 2f0083a..3e3e3e4 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -103,6 +103,34 @@ int cpuidle_play_dead(void)
 }
 
 /**
+ * cpuidle_enter_state - enter the state and update stats
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ * @next_state: index into drv->states of the state to enter
+ */
+int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+		int next_state)
+{
+	int entered_state;
+
+	entered_state = cpuidle_enter_ops(dev, drv, next_state);
+
+	if (entered_state >= 0) {
+		/* Update cpuidle counters */
+		/* This can be moved to within driver enter routine
+		 * but that results in multiple copies of same code.
+		 */
+		dev->states_usage[entered_state].time +=
+				(unsigned long long)dev->last_residency;
+		dev->states_usage[entered_state].usage++;
+	} else {
+		dev->last_residency = 0;
+	}
+
+	return entered_state;
+}
+
+/**
  * cpuidle_idle_call - the main idle loop
  *
  * NOTE: no locks or semaphores should be used here
@@ -143,23 +171,11 @@ int cpuidle_idle_call(void)
 	trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
 	trace_cpu_idle_rcuidle(next_state, dev->cpu);
 
-	entered_state = cpuidle_enter_ops(dev, drv, next_state);
+	entered_state = cpuidle_enter_state(dev, drv, next_state);
 
 	trace_power_end_rcuidle(dev->cpu);
 	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
 
-	if (entered_state >= 0) {
-		/* Update cpuidle counters */
-		/* This can be moved to within driver enter routine
-		 * but that results in multiple copies of same code.
-		 */
-		dev->states_usage[entered_state].time +=
-				(unsigned long long)dev->last_residency;
-		dev->states_usage[entered_state].usage++;
-	} else {
-		dev->last_residency = 0;
-	}
-
 	/* give the governor an opportunity to reflect on the outcome */
 	if (cpuidle_curr_governor->reflect)
 		cpuidle_curr_governor->reflect(dev, entered_state);
diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
index 7db1866..d8a3ccc 100644
--- a/drivers/cpuidle/cpuidle.h
+++ b/drivers/cpuidle/cpuidle.h
@@ -14,6 +14,8 @@
 extern struct mutex cpuidle_lock;
 extern spinlock_t cpuidle_driver_lock;
 extern int cpuidle_disabled(void);
+extern int cpuidle_enter_state(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state);
 
 /* idle loop */
 extern void cpuidle_install_idle_handler(void);
-- 
1.7.7.3

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