[PATCHv2 1/5] cpuidle: refactor out cpuidle_enter_state

From: Colin Cross
Date: Wed Mar 14 2012 - 14:30:26 EST


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.

Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
---
drivers/cpuidle/cpuidle.c | 44 ++++++++++++++++++++++++++++++--------------
drivers/cpuidle/cpuidle.h | 2 ++
2 files changed, 32 insertions(+), 14 deletions(-)

v2:
* fixed kerneldoc comment format

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 59f4261..1453830 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -54,6 +54,35 @@ static void cpuidle_kick_cpus(void) {}
static int __cpuidle_register_device(struct cpuidle_device *dev);

/**
+ * 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;
+ struct cpuidle_state *target_state;
+
+ target_state = &drv->states[next_state];
+
+ entered_state = target_state->enter(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++;
+ }
+
+ return entered_state;
+}
+
+/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
@@ -63,7 +92,6 @@ int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_driver *drv = cpuidle_get_driver();
- struct cpuidle_state *target_state;
int next_state, entered_state;

if (off)
@@ -92,26 +120,14 @@ int cpuidle_idle_call(void)
return 0;
}

- target_state = &drv->states[next_state];
-
trace_power_start(POWER_CSTATE, next_state, dev->cpu);
trace_cpu_idle(next_state, dev->cpu);

- entered_state = target_state->enter(dev, drv, next_state);
+ entered_state = cpuidle_enter_state(dev, drv, next_state);

trace_power_end(dev->cpu);
trace_cpu_idle(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++;
- }
-
/* 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 list_head cpuidle_detected_devices;
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);
--
1.7.9.2

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