Merge branch 'suspend-to-idle'

* suspend-to-idle:
  cpuidle / sleep: Use broadcast timer for states that stop local timer
  cpuidle: Clean up fallback handling in cpuidle_idle_call()
  cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() too
  idle / sleep: Avoid excessive disabling and enabling interrupts

drivers/cpuidle/cpuidle.c

@@ -44,6 +44,12 @@ void disable_cpuidle(void)
 	off = 1;
 }
 
+bool cpuidle_not_available(struct cpuidle_driver *drv,
+			   struct cpuidle_device *dev)
+{
+	return off || !initialized || !drv || !dev || !dev->enabled;
+}
+
 /**
  * cpuidle_play_dead - cpu off-lining
  *
@@ -66,13 +72,7 @@ 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,
+static int find_deepest_state(struct cpuidle_driver *drv,
 			      struct cpuidle_device *dev, bool freeze)
 {
 	unsigned int latency_req = 0;
@@ -92,6 +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)
 {
@@ -113,15 +124,14 @@ 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.
+ * 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;
 
 	/*
@@ -129,24 +139,11 @@ void cpuidle_enter_freeze(void)
 	 * 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) {
-		enter_freeze_proper(drv, dev, index);
-		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);
+	index = find_deepest_state(drv, dev, true);
 	if (index >= 0)
-		cpuidle_enter(drv, dev, index);
-	else
-		arch_cpu_idle();
+		enter_freeze_proper(drv, dev, index);
 
-	/* Interrupts are enabled again here. */
-	local_irq_disable();
+	return index;
 }
 
 /**
@@ -205,12 +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 (off || !initialized)
-		return -ENODEV;
-
-	if (!drv || !dev || !dev->enabled)
-		return -EBUSY;
-
 	return cpuidle_curr_governor->select(drv, dev);
 }
 

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

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
@@ -115,30 +119,24 @@ static void cpuidle_idle_call(void)
 	 * until a proper wakeup interrupt happens.
 	 */
 	if (idle_should_freeze()) {
-		cpuidle_enter_freeze();
+		entered_state = cpuidle_enter_freeze(drv, dev);
+		if (entered_state >= 0) {
 			local_irq_enable();
 			goto exit_idle;
 		}
 
+		reflect = false;
+		next_state = cpuidle_find_deepest_state(drv, dev);
+	} else {
+		reflect = true;
 		/*
 		 * 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);
-	if (next_state < 0) {
-use_default:
-		/*
-		 * We can't use the cpuidle framework, let's use the default
-		 * idle routine.
-		 */
-		if (current_clr_polling_and_test())
-			local_irq_enable();
-		else
-			arch_cpu_idle();
-
-		goto exit_idle;
 	}
-
+	/* Fall back to the default arch idle method on errors. */
+	if (next_state < 0)
+		goto use_default;
 
 	/*
 	 * The idle task must be scheduled, it is pointless to
@@ -183,6 +181,7 @@ static void cpuidle_idle_call(void)
 	/*
 	 * Give the governor an opportunity to reflect on the outcome
 	 */
+	if (reflect)
 		cpuidle_reflect(dev, entered_state);
 
 exit_idle:
@@ -196,6 +195,19 @@ static void cpuidle_idle_call(void)
 
 	rcu_idle_exit();
 	start_critical_timings();
+	return;
+
+use_default:
+	/*
+	 * We can't use the cpuidle framework, let's use the default
+	 * idle routine.
+	 */
+	if (current_clr_polling_and_test())
+		local_irq_enable();
+	else
+		arch_cpu_idle();
+
+	goto exit_idle;
 }
 
 /*