cpuidle: Combine cpuidle_enabled() with cpuidle_select()

Since both cpuidle_enabled() and cpuidle_select() are only called by
cpuidle_idle_call(), it is not really useful to keep them separate
and combining them will help to avoid complicating cpuidle_idle_call()
even further if governors are changed to return error codes sometimes.

This code modification shouldn't lead to any functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 8236746e46bb9d5afa313aff7d17f72fd1ec2326..f38359f64cc6bea50783fc603da274c0fff43fbd 100644 (file)
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -64,26 +64,6 @@ int cpuidle_play_dead(void)
        return -ENODEV;
 }
 
-/**
- * cpuidle_enabled - check if the cpuidle framework is ready
- * @dev: cpuidle device for this cpu
- * @drv: cpuidle driver for this cpu
- *
- * Return 0 on success, otherwise:
- * -NODEV : the cpuidle framework is not available
- * -EBUSY : the cpuidle framework is not initialized
- */
-int cpuidle_enabled(struct cpuidle_driver *drv, struct cpuidle_device *dev)
-{
-       if (off || !initialized)
-               return -ENODEV;
-
-       if (!drv || !dev || !dev->enabled)
-               return -EBUSY;
-
-       return 0;
-}
-
 /**
  * cpuidle_enter_state - enter the state and update stats
  * @dev: cpuidle device for this cpu
@@ -138,6 +118,12 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
  */
 int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
+       if (off || !initialized)
+               return -ENODEV;
+
+       if (!drv || !dev || !dev->enabled)
+               return -EBUSY;
+
        return cpuidle_curr_governor->select(drv, dev);
 }
 

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index b0238cba440b4d80606b40db4effb5ebcea110a5..a8d5bd391a267524e935dd1f04a1f1bff6d32e4f 100644 (file)
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -120,8 +120,6 @@ struct cpuidle_driver {
 #ifdef CONFIG_CPU_IDLE
 extern void disable_cpuidle(void);
 
-extern int cpuidle_enabled(struct cpuidle_driver *drv,
-                         struct cpuidle_device *dev);
 extern int cpuidle_select(struct cpuidle_driver *drv,
                          struct cpuidle_device *dev);
 extern int cpuidle_enter(struct cpuidle_driver *drv,
@@ -149,9 +147,6 @@ extern int cpuidle_play_dead(void);
 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 #else
 static inline void disable_cpuidle(void) { }
-static inline int cpuidle_enabled(struct cpuidle_driver *drv,
-                                 struct cpuidle_device *dev)
-{return -ENODEV; }
 static inline int cpuidle_select(struct cpuidle_driver *drv,
                                 struct cpuidle_device *dev)
 {return -ENODEV; }

diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 8f4390a079c77d18cb9253c5266b3c7af2f24273..a8f12247ce7c015dc334fbbda54fee98039a0a88 100644 (file)
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -101,19 +101,13 @@ static int cpuidle_idle_call(void)
        rcu_idle_enter();
 
        /*
-        * Check if the cpuidle framework is ready, otherwise fallback
-        * to the default arch specific idle method
+        * Ask the cpuidle framework to choose a convenient idle state.
+        * Fall back to the default arch specific idle method on errors.
         */
-       ret = cpuidle_enabled(drv, dev);
-
-       if (!ret) {
-               /*
-                * Ask the governor to choose an idle state it thinks
-                * it is convenient to go to. There is *always* a
-                * convenient idle state
-                */
-               next_state = cpuidle_select(drv, dev);
+       next_state = cpuidle_select(drv, dev);
 
+       ret = next_state;
+       if (ret >= 0) {
                /*
                 * The idle task must be scheduled, it is pointless to
                 * go to idle, just update no idle residency and get
@@ -140,7 +134,7 @@ static int cpuidle_idle_call(void)
                                        CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
                                        &dev->cpu);
 
-                       if (!ret) {
+                       if (ret >= 0) {
                                trace_cpu_idle_rcuidle(next_state, dev->cpu);
 
                                /*
@@ -175,7 +169,7 @@ static int cpuidle_idle_call(void)
         * We can't use the cpuidle framework, let's use the default
         * idle routine
         */
-       if (ret)
+       if (ret < 0)
                arch_cpu_idle();
 
        __current_set_polling();