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-rw-r--r--drivers/cpuidle/cpuidle.c96
-rw-r--r--include/linux/cpuidle.h19
2 files changed, 94 insertions, 21 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 09d05ab..1506d69 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -65,6 +65,26 @@ int cpuidle_play_dead(void)
}
/**
+ * 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
* @drv: cpuidle driver for this cpu
@@ -108,6 +128,51 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
}
/**
+ * cpuidle_select - ask the cpuidle framework to choose an idle state
+ *
+ * @drv: the cpuidle driver
+ * @dev: the cpuidle device
+ *
+ * Returns the index of the idle state.
+ */
+int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+{
+ return cpuidle_curr_governor->select(drv, dev);
+}
+
+/**
+ * cpuidle_enter - enter into the specified idle state
+ *
+ * @drv: the cpuidle driver tied with the cpu
+ * @dev: the cpuidle device
+ * @index: the index in the idle state table
+ *
+ * Returns the index in the idle state, < 0 in case of error.
+ * The error code depends on the backend driver
+ */
+int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+ int index)
+{
+ if (cpuidle_state_is_coupled(dev, drv, index))
+ return cpuidle_enter_state_coupled(dev, drv, index);
+ return cpuidle_enter_state(dev, drv, index);
+}
+
+/**
+ * cpuidle_reflect - tell the underlying governor what was the state
+ * we were in
+ *
+ * @dev : the cpuidle device
+ * @index: the index in the idle state table
+ *
+ */
+void cpuidle_reflect(struct cpuidle_device *dev, int index)
+{
+ if (cpuidle_curr_governor->reflect)
+ cpuidle_curr_governor->reflect(dev, index);
+}
+
+/**
* cpuidle_idle_call - the main idle loop
*
* NOTE: no locks or semaphores should be used here
@@ -116,26 +181,21 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
int cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
- struct cpuidle_driver *drv;
- int next_state, entered_state;
+ struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+ int next_state, entered_state, ret;
bool broadcast;
- if (off || !initialized)
- return -ENODEV;
-
- /* check if the device is ready */
- if (!dev || !dev->enabled)
- return -EBUSY;
-
- drv = cpuidle_get_cpu_driver(dev);
+ ret = cpuidle_enabled(drv, dev);
+ if (ret < 0)
+ return ret;
/* ask the governor for the next state */
- next_state = cpuidle_curr_governor->select(drv, dev);
+ next_state = cpuidle_select(drv, dev);
+
if (need_resched()) {
dev->last_residency = 0;
/* give the governor an opportunity to reflect on the outcome */
- if (cpuidle_curr_governor->reflect)
- cpuidle_curr_governor->reflect(dev, next_state);
+ cpuidle_reflect(dev, next_state);
local_irq_enable();
return 0;
}
@@ -146,14 +206,9 @@ int cpuidle_idle_call(void)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu))
return -EBUSY;
-
trace_cpu_idle_rcuidle(next_state, dev->cpu);
- if (cpuidle_state_is_coupled(dev, drv, next_state))
- entered_state = cpuidle_enter_state_coupled(dev, drv,
- next_state);
- else
- entered_state = cpuidle_enter_state(dev, drv, next_state);
+ entered_state = cpuidle_enter(drv, dev, next_state);
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
@@ -161,8 +216,7 @@ int cpuidle_idle_call(void)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
/* give the governor an opportunity to reflect on the outcome */
- if (cpuidle_curr_governor->reflect)
- cpuidle_curr_governor->reflect(dev, entered_state);
+ cpuidle_reflect(dev, entered_state);
return 0;
}
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 50fcbb0..accc2dd 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -119,6 +119,15 @@ 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,
+ struct cpuidle_device *dev, int index);
+extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
+
extern int cpuidle_idle_call(void);
extern int cpuidle_register_driver(struct cpuidle_driver *drv);
extern struct cpuidle_driver *cpuidle_get_driver(void);
@@ -141,6 +150,16 @@ 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; }
+static inline int cpuidle_enter(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev, int index)
+{return -ENODEV; }
+static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
static inline int cpuidle_idle_call(void) { return -ENODEV; }
static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
{return -ENODEV; }
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