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-rw-r--r--drivers/cpuidle/cpuidle.c62
-rw-r--r--include/linux/cpuidle.h17
-rw-r--r--kernel/sched/idle.c30
3 files changed, 58 insertions, 51 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 8b3e132..080bd2d 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -44,8 +44,8 @@ void disable_cpuidle(void)
off = 1;
}
-static bool cpuidle_not_available(struct cpuidle_driver *drv,
- struct cpuidle_device *dev)
+bool cpuidle_not_available(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
{
return off || !initialized || !drv || !dev || !dev->enabled;
}
@@ -72,14 +72,8 @@ int cpuidle_play_dead(void)
return -ENODEV;
}
-/**
- * cpuidle_find_deepest_state - Find deepest state meeting specific conditions.
- * @drv: cpuidle driver for the given CPU.
- * @dev: cpuidle device for the given CPU.
- * @freeze: Whether or not the state should be suitable for suspend-to-idle.
- */
-static int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
- struct cpuidle_device *dev, bool freeze)
+static int find_deepest_state(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev, bool freeze)
{
unsigned int latency_req = 0;
int i, ret = freeze ? -1 : CPUIDLE_DRIVER_STATE_START - 1;
@@ -98,6 +92,17 @@ static int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
return ret;
}
+/**
+ * cpuidle_find_deepest_state - Find the deepest available idle state.
+ * @drv: cpuidle driver for the given CPU.
+ * @dev: cpuidle device for the given CPU.
+ */
+int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{
+ return find_deepest_state(drv, dev, false);
+}
+
static void enter_freeze_proper(struct cpuidle_driver *drv,
struct cpuidle_device *dev, int index)
{
@@ -119,46 +124,26 @@ static void enter_freeze_proper(struct cpuidle_driver *drv,
/**
* cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle.
+ * @drv: cpuidle driver for the given CPU.
+ * @dev: cpuidle device for the given CPU.
*
* If there are states with the ->enter_freeze callback, find the deepest of
- * them and enter it with frozen tick. Otherwise, find the deepest state
- * available and enter it normally.
- *
- * Returns with enabled interrupts.
+ * them and enter it with frozen tick.
*/
-void cpuidle_enter_freeze(void)
+int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
- struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
- struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
int index;
- if (cpuidle_not_available(drv, dev))
- goto fallback;
-
/*
* Find the deepest state with ->enter_freeze present, which guarantees
* that interrupts won't be enabled when it exits and allows the tick to
* be frozen safely.
*/
- index = cpuidle_find_deepest_state(drv, dev, true);
- if (index >= 0) {
+ index = find_deepest_state(drv, dev, true);
+ if (index >= 0)
enter_freeze_proper(drv, dev, index);
- local_irq_enable();
- return;
- }
- /*
- * It is not safe to freeze the tick, find the deepest state available
- * at all and try to enter it normally.
- */
- index = cpuidle_find_deepest_state(drv, dev, false);
- if (index >= 0) {
- cpuidle_enter(drv, dev, index);
- return;
- }
-
- fallback:
- arch_cpu_idle();
+ return index;
}
/**
@@ -217,9 +202,6 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
*/
int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
- if (cpuidle_not_available(drv, dev))
- return -ENODEV;
-
return cpuidle_curr_governor->select(drv, dev);
}
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index f551a92..306178d 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -126,6 +126,8 @@ struct cpuidle_driver {
#ifdef CONFIG_CPU_IDLE
extern void disable_cpuidle(void);
+extern bool cpuidle_not_available(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev);
extern int cpuidle_select(struct cpuidle_driver *drv,
struct cpuidle_device *dev);
@@ -150,11 +152,17 @@ extern void cpuidle_resume(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);
extern int cpuidle_play_dead(void);
-extern void cpuidle_enter_freeze(void);
+extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev);
+extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev);
extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
#else
static inline void disable_cpuidle(void) { }
+static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{return true; }
static inline int cpuidle_select(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
{return -ENODEV; }
@@ -183,7 +191,12 @@ static inline int cpuidle_enable_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
static inline int cpuidle_play_dead(void) {return -ENODEV; }
-static inline void cpuidle_enter_freeze(void) { }
+static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{return -ENODEV; }
+static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{return -ENODEV; }
static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
struct cpuidle_device *dev) {return NULL; }
#endif
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 84b93b6..80014a1 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -82,6 +82,7 @@ static void cpuidle_idle_call(void)
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
int next_state, entered_state;
unsigned int broadcast;
+ bool reflect;
/*
* Check if the idle task must be rescheduled. If it is the
@@ -105,6 +106,9 @@ static void cpuidle_idle_call(void)
*/
rcu_idle_enter();
+ if (cpuidle_not_available(drv, dev))
+ goto use_default;
+
/*
* Suspend-to-idle ("freeze") is a system state in which all user space
* has been frozen, all I/O devices have been suspended and the only
@@ -115,15 +119,22 @@ static void cpuidle_idle_call(void)
* until a proper wakeup interrupt happens.
*/
if (idle_should_freeze()) {
- cpuidle_enter_freeze();
- goto exit_idle;
- }
+ entered_state = cpuidle_enter_freeze(drv, dev);
+ if (entered_state >= 0) {
+ local_irq_enable();
+ goto exit_idle;
+ }
- /*
- * Ask the cpuidle framework to choose a convenient idle state.
- * Fall back to the default arch idle method on errors.
- */
- next_state = cpuidle_select(drv, dev);
+ reflect = false;
+ next_state = cpuidle_find_deepest_state(drv, dev);
+ } else {
+ reflect = true;
+ /*
+ * Ask the cpuidle framework to choose a convenient idle state.
+ */
+ next_state = cpuidle_select(drv, dev);
+ }
+ /* Fall back to the default arch idle method on errors. */
if (next_state < 0)
goto use_default;
@@ -170,7 +181,8 @@ static void cpuidle_idle_call(void)
/*
* Give the governor an opportunity to reflect on the outcome
*/
- cpuidle_reflect(dev, entered_state);
+ if (reflect)
+ cpuidle_reflect(dev, entered_state);
exit_idle:
__current_set_polling();
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