Merge branch 'pm-cpuidle'

* pm-cpuidle:
  cpuidle: Measure idle state durations with monotonic clock
  cpuidle: fix a suspicious RCU usage in menu governor
  cpuidle: support multiple drivers
  cpuidle: prepare the cpuidle core to handle multiple drivers
  cpuidle: move driver checking within the lock section
  cpuidle: move driver's refcount to cpuidle
  cpuidle: fixup device.h header in cpuidle.h
  cpuidle / sysfs: move structure declaration into the sysfs.c file
  cpuidle: Get typical recent sleep interval
  cpuidle: Set residency to 0 if target Cstate not enter
  cpuidle: Quickly notice prediction failure in general case
  cpuidle: Quickly notice prediction failure for repeat mode
  cpuidle / sysfs: move kobj initialization in the syfs file
  cpuidle / sysfs: change function parameter

8 files changed, 560 insertions, 166 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index e8086c7..f1a5da4 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -735,31 +735,18 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index)
 {
-	ktime_t  kt1, kt2;
-	s64 idle_time;
 	struct acpi_processor *pr;
 	struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 	struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
 
 	pr = __this_cpu_read(processors);
-	dev->last_residency = 0;
 
 	if (unlikely(!pr))
 		return -EINVAL;
 
-	local_irq_disable();
-
-
 	lapic_timer_state_broadcast(pr, cx, 1);
-	kt1 = ktime_get_real();
 	acpi_idle_do_entry(cx);
-	kt2 = ktime_get_real();
-	idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
-
-	/* Update device last_residency*/
-	dev->last_residency = (int)idle_time;
 
-	local_irq_enable();
 	lapic_timer_state_broadcast(pr, cx, 0);
 
 	return index;
@@ -806,19 +793,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 	struct acpi_processor *pr;
 	struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 	struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
-	ktime_t  kt1, kt2;
-	s64 idle_time_ns;
-	s64 idle_time;
 
 	pr = __this_cpu_read(processors);
-	dev->last_residency = 0;
 
 	if (unlikely(!pr))
 		return -EINVAL;
 
-	local_irq_disable();
-
-
 	if (cx->entry_method != ACPI_CSTATE_FFH) {
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
@@ -829,7 +809,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 
 		if (unlikely(need_resched())) {
 			current_thread_info()->status |= TS_POLLING;
-			local_irq_enable();
 			return -EINVAL;
 		}
 	}
@@ -843,22 +822,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 	if (cx->type == ACPI_STATE_C3)
 		ACPI_FLUSH_CPU_CACHE();
 
-	kt1 = ktime_get_real();
 	/* Tell the scheduler that we are going deep-idle: */
 	sched_clock_idle_sleep_event();
 	acpi_idle_do_entry(cx);
-	kt2 = ktime_get_real();
-	idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
-	idle_time = idle_time_ns;
-	do_div(idle_time, NSEC_PER_USEC);
 
-	/* Update device last_residency*/
-	dev->last_residency = (int)idle_time;
+	sched_clock_idle_wakeup_event(0);
 
-	/* Tell the scheduler how much we idled: */
-	sched_clock_idle_wakeup_event(idle_time_ns);
-
-	local_irq_enable();
 	if (cx->entry_method != ACPI_CSTATE_FFH)
 		current_thread_info()->status |= TS_POLLING;
 
@@ -883,13 +852,8 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	struct acpi_processor *pr;
 	struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 	struct acpi_processor_cx *cx = cpuidle_get_statedata(state_usage);
-	ktime_t  kt1, kt2;
-	s64 idle_time_ns;
-	s64 idle_time;
-
 
 	pr = __this_cpu_read(processors);
-	dev->last_residency = 0;
 
 	if (unlikely(!pr))
 		return -EINVAL;
@@ -899,16 +863,11 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 			return drv->states[drv->safe_state_index].enter(dev,
 						drv, drv->safe_state_index);
 		} else {
-			local_irq_disable();
 			acpi_safe_halt();
-			local_irq_enable();
 			return -EBUSY;
 		}
 	}
 
-	local_irq_disable();
-
-
 	if (cx->entry_method != ACPI_CSTATE_FFH) {
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
@@ -919,7 +878,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 
 		if (unlikely(need_resched())) {
 			current_thread_info()->status |= TS_POLLING;
-			local_irq_enable();
 			return -EINVAL;
 		}
 	}
@@ -934,7 +892,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	 */
 	lapic_timer_state_broadcast(pr, cx, 1);
 
-	kt1 = ktime_get_real();
 	/*
 	 * disable bus master
 	 * bm_check implies we need ARB_DIS
@@ -965,18 +922,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 		c3_cpu_count--;
 		raw_spin_unlock(&c3_lock);
 	}
-	kt2 = ktime_get_real();
-	idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
-	idle_time = idle_time_ns;
-	do_div(idle_time, NSEC_PER_USEC);
-
-	/* Update device last_residency*/
-	dev->last_residency = (int)idle_time;
 
-	/* Tell the scheduler how much we idled: */
-	sched_clock_idle_wakeup_event(idle_time_ns);
+	sched_clock_idle_wakeup_event(0);
 
-	local_irq_enable();
 	if (cx->entry_method != ACPI_CSTATE_FFH)
 		current_thread_info()->status |= TS_POLLING;
 
@@ -987,6 +935,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 struct cpuidle_driver acpi_idle_driver = {
 	.name =		"acpi_idle",
 	.owner =	THIS_MODULE,
+	.en_core_tk_irqen = 1,
 };
 
 /**
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index a76b689..234ae65 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -9,6 +9,15 @@ config CPU_IDLE
 
 	  If you're using an ACPI-enabled platform, you should say Y here.
 
+config CPU_IDLE_MULTIPLE_DRIVERS
+        bool "Support multiple cpuidle drivers"
+        depends on CPU_IDLE
+        default n
+        help
+         Allows the cpuidle framework to use different drivers for each CPU.
+         This is useful if you have a system with different CPU latencies and
+         states. If unsure say N.
+
 config CPU_IDLE_GOV_LADDER
 	bool
 	depends on CPU_IDLE
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 7f15b85..8df53dd 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -68,7 +68,7 @@ static cpuidle_enter_t cpuidle_enter_ops;
 int cpuidle_play_dead(void)
 {
 	struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
-	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 	int i, dead_state = -1;
 	int power_usage = -1;
 
@@ -109,8 +109,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
 		/* 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].time += dev->last_residency;
 		dev->states_usage[entered_state].usage++;
 	} else {
 		dev->last_residency = 0;
@@ -128,7 +127,7 @@ 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 = cpuidle_get_driver();
+	struct cpuidle_driver *drv;
 	int next_state, entered_state;
 
 	if (off)
@@ -141,9 +140,15 @@ int cpuidle_idle_call(void)
 	if (!dev || !dev->enabled)
 		return -EBUSY;
 
+	drv = cpuidle_get_cpu_driver(dev);
+
 	/* ask the governor for the next state */
 	next_state = cpuidle_curr_governor->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);
 		local_irq_enable();
 		return 0;
 	}
@@ -308,15 +313,19 @@ static void poll_idle_init(struct cpuidle_driver *drv) {}
 int cpuidle_enable_device(struct cpuidle_device *dev)
 {
 	int ret, i;
-	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_driver *drv;
 
 	if (!dev)
 		return -EINVAL;
 
 	if (dev->enabled)
 		return 0;
+
+	drv = cpuidle_get_cpu_driver(dev);
+
 	if (!drv || !cpuidle_curr_governor)
 		return -EIO;
+
 	if (!dev->state_count)
 		dev->state_count = drv->state_count;
 
@@ -331,7 +340,8 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 
 	poll_idle_init(drv);
 
-	if ((ret = cpuidle_add_state_sysfs(dev)))
+	ret = cpuidle_add_device_sysfs(dev);
+	if (ret)
 		return ret;
 
 	if (cpuidle_curr_governor->enable &&
@@ -352,7 +362,7 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 	return 0;
 
 fail_sysfs:
-	cpuidle_remove_state_sysfs(dev);
+	cpuidle_remove_device_sysfs(dev);
 
 	return ret;
 }
@@ -368,17 +378,20 @@ EXPORT_SYMBOL_GPL(cpuidle_enable_device);
  */
 void cpuidle_disable_device(struct cpuidle_device *dev)
 {
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+
 	if (!dev || !dev->enabled)
 		return;
-	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
+
+	if (!drv || !cpuidle_curr_governor)
 		return;
 
 	dev->enabled = 0;
 
 	if (cpuidle_curr_governor->disable)
-		cpuidle_curr_governor->disable(cpuidle_get_driver(), dev);
+		cpuidle_curr_governor->disable(drv, dev);
 
-	cpuidle_remove_state_sysfs(dev);
+	cpuidle_remove_device_sysfs(dev);
 	enabled_devices--;
 }
 
@@ -394,17 +407,14 @@ EXPORT_SYMBOL_GPL(cpuidle_disable_device);
 static int __cpuidle_register_device(struct cpuidle_device *dev)
 {
 	int ret;
-	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
-	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 
-	if (!try_module_get(cpuidle_driver->owner))
+	if (!try_module_get(drv->owner))
 		return -EINVAL;
 
-	init_completion(&dev->kobj_unregister);
-
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
-	ret = cpuidle_add_sysfs(cpu_dev);
+	ret = cpuidle_add_sysfs(dev);
 	if (ret)
 		goto err_sysfs;
 
@@ -416,12 +426,11 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 	return 0;
 
 err_coupled:
-	cpuidle_remove_sysfs(cpu_dev);
-	wait_for_completion(&dev->kobj_unregister);
+	cpuidle_remove_sysfs(dev);
 err_sysfs:
 	list_del(&dev->device_list);
 	per_cpu(cpuidle_devices, dev->cpu) = NULL;
-	module_put(cpuidle_driver->owner);
+	module_put(drv->owner);
 	return ret;
 }
 
@@ -460,8 +469,7 @@ EXPORT_SYMBOL_GPL(cpuidle_register_device);
  */
 void cpuidle_unregister_device(struct cpuidle_device *dev)
 {
-	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
-	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 
 	if (dev->registered == 0)
 		return;
@@ -470,16 +478,15 @@ void cpuidle_unregister_device(struct cpuidle_device *dev)
 
 	cpuidle_disable_device(dev);
 
-	cpuidle_remove_sysfs(cpu_dev);
+	cpuidle_remove_sysfs(dev);
 	list_del(&dev->device_list);
-	wait_for_completion(&dev->kobj_unregister);
 	per_cpu(cpuidle_devices, dev->cpu) = NULL;
 
 	cpuidle_coupled_unregister_device(dev);
 
 	cpuidle_resume_and_unlock();
 
-	module_put(cpuidle_driver->owner);
+	module_put(drv->owner);
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
index 76e7f69..ee97e96 100644
--- a/drivers/cpuidle/cpuidle.h
+++ b/drivers/cpuidle/cpuidle.h
@@ -5,8 +5,6 @@
 #ifndef __DRIVER_CPUIDLE_H
 #define __DRIVER_CPUIDLE_H
 
-#include <linux/device.h>
-
 /* For internal use only */
 extern struct cpuidle_governor *cpuidle_curr_governor;
 extern struct list_head cpuidle_governors;
@@ -25,12 +23,15 @@ extern void cpuidle_uninstall_idle_handler(void);
 extern int cpuidle_switch_governor(struct cpuidle_governor *gov);
 
 /* sysfs */
+
+struct device;
+
 extern int cpuidle_add_interface(struct device *dev);
 extern void cpuidle_remove_interface(struct device *dev);
-extern int cpuidle_add_state_sysfs(struct cpuidle_device *device);
-extern void cpuidle_remove_state_sysfs(struct cpuidle_device *device);
-extern int cpuidle_add_sysfs(struct device *dev);
-extern void cpuidle_remove_sysfs(struct device *dev);
+extern int cpuidle_add_device_sysfs(struct cpuidle_device *device);
+extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device);
+extern int cpuidle_add_sysfs(struct cpuidle_device *dev);
+extern void cpuidle_remove_sysfs(struct cpuidle_device *dev);
 
 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 bool cpuidle_state_is_coupled(struct cpuidle_device *dev,
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 87db387..3af841f 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -14,9 +14,10 @@
 
 #include "cpuidle.h"
 
-static struct cpuidle_driver *cpuidle_curr_driver;
 DEFINE_SPINLOCK(cpuidle_driver_lock);
-int cpuidle_driver_refcount;
+
+static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu);
+static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu);
 
 static void set_power_states(struct cpuidle_driver *drv)
 {
@@ -40,11 +41,15 @@ static void set_power_states(struct cpuidle_driver *drv)
 		drv->states[i].power_usage = -1 - i;
 }
 
-/**
- * cpuidle_register_driver - registers a driver
- * @drv: the driver
- */
-int cpuidle_register_driver(struct cpuidle_driver *drv)
+static void __cpuidle_driver_init(struct cpuidle_driver *drv)
+{
+	drv->refcnt = 0;
+
+	if (!drv->power_specified)
+		set_power_states(drv);
+}
+
+static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu)
 {
 	if (!drv || !drv->state_count)
 		return -EINVAL;
@@ -52,31 +57,145 @@ int cpuidle_register_driver(struct cpuidle_driver *drv)
 	if (cpuidle_disabled())
 		return -ENODEV;
 
-	spin_lock(&cpuidle_driver_lock);
-	if (cpuidle_curr_driver) {
-		spin_unlock(&cpuidle_driver_lock);
+	if (__cpuidle_get_cpu_driver(cpu))
 		return -EBUSY;
+
+	__cpuidle_driver_init(drv);
+
+	__cpuidle_set_cpu_driver(drv, cpu);
+
+	return 0;
+}
+
+static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu)
+{
+	if (drv != __cpuidle_get_cpu_driver(cpu))
+		return;
+
+	if (!WARN_ON(drv->refcnt > 0))
+		__cpuidle_set_cpu_driver(NULL, cpu);
+}
+
+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
+
+static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);
+
+static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
+{
+	per_cpu(cpuidle_drivers, cpu) = drv;
+}
+
+static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
+{
+	return per_cpu(cpuidle_drivers, cpu);
+}
+
+static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv)
+{
+	int cpu;
+	for_each_present_cpu(cpu)
+		__cpuidle_unregister_driver(drv, cpu);
+}
+
+static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv)
+{
+	int ret = 0;
+	int i, cpu;
+
+	for_each_present_cpu(cpu) {
+		ret = __cpuidle_register_driver(drv, cpu);
+		if (ret)
+			break;
 	}
 
-	if (!drv->power_specified)
-		set_power_states(drv);
+	if (ret)
+		for_each_present_cpu(i) {
+			if (i == cpu)
+				break;
+			__cpuidle_unregister_driver(drv, i);
+		}
 
-	cpuidle_curr_driver = drv;
 
+	return ret;
+}
+
+int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu)
+{
+	int ret;
+
+	spin_lock(&cpuidle_driver_lock);
+	ret = __cpuidle_register_driver(drv, cpu);
 	spin_unlock(&cpuidle_driver_lock);
 
-	return 0;
+	return ret;
+}
+
+void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu)
+{
+	spin_lock(&cpuidle_driver_lock);
+	__cpuidle_unregister_driver(drv, cpu);
+	spin_unlock(&cpuidle_driver_lock);
+}
+
+/**
+ * cpuidle_register_driver - registers a driver
+ * @drv: the driver
+ */
+int cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+	int ret;
+
+	spin_lock(&cpuidle_driver_lock);
+	ret = __cpuidle_register_all_cpu_driver(drv);
+	spin_unlock(&cpuidle_driver_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(cpuidle_register_driver);
 
 /**
- * cpuidle_get_driver - return the current driver
+ * cpuidle_unregister_driver - unregisters a driver
+ * @drv: the driver
  */
-struct cpuidle_driver *cpuidle_get_driver(void)
+void cpuidle_unregister_driver(struct cpuidle_driver *drv)
+{
+	spin_lock(&cpuidle_driver_lock);
+	__cpuidle_unregister_all_cpu_driver(drv);
+	spin_unlock(&cpuidle_driver_lock);
+}
+EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
+
+#else
+
+static struct cpuidle_driver *cpuidle_curr_driver;
+
+static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
+{
+	cpuidle_curr_driver = drv;
+}
+
+static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
 {
 	return cpuidle_curr_driver;
 }
-EXPORT_SYMBOL_GPL(cpuidle_get_driver);
+
+/**
+ * cpuidle_register_driver - registers a driver
+ * @drv: the driver
+ */
+int cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+	int ret, cpu;
+
+	cpu = get_cpu();
+	spin_lock(&cpuidle_driver_lock);
+	ret = __cpuidle_register_driver(drv, cpu);
+	spin_unlock(&cpuidle_driver_lock);
+	put_cpu();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cpuidle_register_driver);
 
 /**
  * cpuidle_unregister_driver - unregisters a driver
@@ -84,20 +203,50 @@ EXPORT_SYMBOL_GPL(cpuidle_get_driver);
  */
 void cpuidle_unregister_driver(struct cpuidle_driver *drv)
 {
-	if (drv != cpuidle_curr_driver) {
-		WARN(1, "invalid cpuidle_unregister_driver(%s)\n",
-			drv->name);
-		return;
-	}
+	int cpu;
 
+	cpu = get_cpu();
 	spin_lock(&cpuidle_driver_lock);
+	__cpuidle_unregister_driver(drv, cpu);
+	spin_unlock(&cpuidle_driver_lock);
+	put_cpu();
+}
+EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
+#endif
+
+/**
+ * cpuidle_get_driver - return the current driver
+ */
+struct cpuidle_driver *cpuidle_get_driver(void)
+{
+	struct cpuidle_driver *drv;
+	int cpu;
 
-	if (!WARN_ON(cpuidle_driver_refcount > 0))
-		cpuidle_curr_driver = NULL;
+	cpu = get_cpu();
+	drv = __cpuidle_get_cpu_driver(cpu);
+	put_cpu();
 
+	return drv;
+}
+EXPORT_SYMBOL_GPL(cpuidle_get_driver);
+
+/**
+ * cpuidle_get_cpu_driver - return the driver tied with a cpu
+ */
+struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver *drv;
+
+	if (!dev)
+		return NULL;
+
+	spin_lock(&cpuidle_driver_lock);
+	drv = __cpuidle_get_cpu_driver(dev->cpu);
 	spin_unlock(&cpuidle_driver_lock);
+
+	return drv;
 }
-EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
+EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
 
 struct cpuidle_driver *cpuidle_driver_ref(void)
 {
@@ -105,8 +254,8 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
 
 	spin_lock(&cpuidle_driver_lock);
 
-	drv = cpuidle_curr_driver;
-	cpuidle_driver_refcount++;
+	drv = cpuidle_get_driver();
+	drv->refcnt++;
 
 	spin_unlock(&cpuidle_driver_lock);
 	return drv;
@@ -114,10 +263,12 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
 
 void cpuidle_driver_unref(void)
 {
+	struct cpuidle_driver *drv = cpuidle_get_driver();
+
 	spin_lock(&cpuidle_driver_lock);
 
-	if (!WARN_ON(cpuidle_driver_refcount <= 0))
-		cpuidle_driver_refcount--;
+	if (drv && !WARN_ON(drv->refcnt <= 0))
+		drv->refcnt--;
 
 	spin_unlock(&cpuidle_driver_lock);
 }
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 5b1f2c3..bd40b94 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -28,6 +28,13 @@
 #define MAX_INTERESTING 50000
 #define STDDEV_THRESH 400
 
+/* 60 * 60 > STDDEV_THRESH * INTERVALS = 400 * 8 */
+#define MAX_DEVIATION 60
+
+static DEFINE_PER_CPU(struct hrtimer, menu_hrtimer);
+static DEFINE_PER_CPU(int, hrtimer_status);
+/* menu hrtimer mode */
+enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL};
 
 /*
  * Concepts and ideas behind the menu governor
@@ -109,6 +116,13 @@
  *
  */
 
+/*
+ * The C-state residency is so long that is is worthwhile to exit
+ * from the shallow C-state and re-enter into a deeper C-state.
+ */
+static unsigned int perfect_cstate_ms __read_mostly = 30;
+module_param(perfect_cstate_ms, uint, 0000);
+
 struct menu_device {
 	int		last_state_idx;
 	int             needs_update;
@@ -191,40 +205,102 @@ static u64 div_round64(u64 dividend, u32 divisor)
 	return div_u64(dividend + (divisor / 2), divisor);
 }
 
+/* Cancel the hrtimer if it is not triggered yet */
+void menu_hrtimer_cancel(void)
+{
+	int cpu = smp_processor_id();
+	struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
+
+	/* The timer is still not time out*/
+	if (per_cpu(hrtimer_status, cpu)) {
+		hrtimer_cancel(hrtmr);
+		per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
+	}
+}
+EXPORT_SYMBOL_GPL(menu_hrtimer_cancel);
+
+/* Call back for hrtimer is triggered */
+static enum hrtimer_restart menu_hrtimer_notify(struct hrtimer *hrtimer)
+{
+	int cpu = smp_processor_id();
+	struct menu_device *data = &per_cpu(menu_devices, cpu);
+
+	/* In general case, the expected residency is much larger than
+	 *  deepest C-state target residency, but prediction logic still
+	 *  predicts a small predicted residency, so the prediction
+	 *  history is totally broken if the timer is triggered.
+	 *  So reset the correction factor.
+	 */
+	if (per_cpu(hrtimer_status, cpu) == MENU_HRTIMER_GENERAL)
+		data->correction_factor[data->bucket] = RESOLUTION * DECAY;
+
+	per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
+
+	return HRTIMER_NORESTART;
+}
+
 /*
  * Try detecting repeating patterns by keeping track of the last 8
  * intervals, and checking if the standard deviation of that set
  * of points is below a threshold. If it is... then use the
  * average of these 8 points as the estimated value.
  */
-static void detect_repeating_patterns(struct menu_device *data)
+static u32 get_typical_interval(struct menu_device *data)
 {
-	int i;
-	uint64_t avg = 0;
-	uint64_t stddev = 0; /* contains the square of the std deviation */
-
-	/* first calculate average and standard deviation of the past */
-	for (i = 0; i < INTERVALS; i++)
-		avg += data->intervals[i];
-	avg = avg / INTERVALS;
+	int i = 0, divisor = 0;
+	uint64_t max = 0, avg = 0, stddev = 0;
+	int64_t thresh = LLONG_MAX; /* Discard outliers above this value. */
+	unsigned int ret = 0;
 
-	/* if the avg is beyond the known next tick, it's worthless */
-	if (avg > data->expected_us)
-		return;
+again:
 
-	for (i = 0; i < INTERVALS; i++)
-		stddev += (data->intervals[i] - avg) *
-			  (data->intervals[i] - avg);
-
-	stddev = stddev / INTERVALS;
+	/* first calculate average and standard deviation of the past */
+	max = avg = divisor = stddev = 0;
+	for (i = 0; i < INTERVALS; i++) {
+		int64_t value = data->intervals[i];
+		if (value <= thresh) {
+			avg += value;
+			divisor++;
+			if (value > max)
+				max = value;
+		}
+	}
+	do_div(avg, divisor);
 
+	for (i = 0; i < INTERVALS; i++) {
+		int64_t value = data->intervals[i];
+		if (value <= thresh) {
+			int64_t diff = value - avg;
+			stddev += diff * diff;
+		}
+	}
+	do_div(stddev, divisor);
+	stddev = int_sqrt(stddev);
 	/*
-	 * now.. if stddev is small.. then assume we have a
-	 * repeating pattern and predict we keep doing this.
+	 * If we have outliers to the upside in our distribution, discard
+	 * those by setting the threshold to exclude these outliers, then
+	 * calculate the average and standard deviation again. Once we get
+	 * down to the bottom 3/4 of our samples, stop excluding samples.
+	 *
+	 * This can deal with workloads that have long pauses interspersed
+	 * with sporadic activity with a bunch of short pauses.
+	 *
+	 * The typical interval is obtained when standard deviation is small
+	 * or standard deviation is small compared to the average interval.
 	 */
-
-	if (avg && stddev < STDDEV_THRESH)
+	if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
+							|| stddev <= 20) {
 		data->predicted_us = avg;
+		ret = 1;
+		return ret;
+
+	} else if ((divisor * 4) > INTERVALS * 3) {
+		/* Exclude the max interval */
+		thresh = max - 1;
+		goto again;
+	}
+
+	return ret;
 }
 
 /**
@@ -240,6 +316,9 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	int i;
 	int multiplier;
 	struct timespec t;
+	int repeat = 0, low_predicted = 0;
+	int cpu = smp_processor_id();
+	struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
 
 	if (data->needs_update) {
 		menu_update(drv, dev);
@@ -274,7 +353,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
 					 RESOLUTION * DECAY);
 
-	detect_repeating_patterns(data);
+	repeat = get_typical_interval(data);
 
 	/*
 	 * We want to default to C1 (hlt), not to busy polling
@@ -295,8 +374,10 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 
 		if (s->disabled || su->disable)
 			continue;
-		if (s->target_residency > data->predicted_us)
+		if (s->target_residency > data->predicted_us) {
+			low_predicted = 1;
 			continue;
+		}
 		if (s->exit_latency > latency_req)
 			continue;
 		if (s->exit_latency * multiplier > data->predicted_us)
@@ -309,6 +390,44 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		}
 	}
 
+	/* not deepest C-state chosen for low predicted residency */
+	if (low_predicted) {
+		unsigned int timer_us = 0;
+		unsigned int perfect_us = 0;
+
+		/*
+		 * Set a timer to detect whether this sleep is much
+		 * longer than repeat mode predicted.  If the timer
+		 * triggers, the code will evaluate whether to put
+		 * the CPU into a deeper C-state.
+		 * The timer is cancelled on CPU wakeup.
+		 */
+		timer_us = 2 * (data->predicted_us + MAX_DEVIATION);
+
+		perfect_us = perfect_cstate_ms * 1000;
+
+		if (repeat && (4 * timer_us < data->expected_us)) {
+			RCU_NONIDLE(hrtimer_start(hrtmr,
+				ns_to_ktime(1000 * timer_us),
+				HRTIMER_MODE_REL_PINNED));
+			/* In repeat case, menu hrtimer is started */
+			per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_REPEAT;
+		} else if (perfect_us < data->expected_us) {
+			/*
+			 * The next timer is long. This could be because
+			 * we did not make a useful prediction.
+			 * In that case, it makes sense to re-enter
+			 * into a deeper C-state after some time.
+			 */
+			RCU_NONIDLE(hrtimer_start(hrtmr,
+				ns_to_ktime(1000 * timer_us),
+				HRTIMER_MODE_REL_PINNED));
+			/* In general case, menu hrtimer is started */
+			per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_GENERAL;
+		}
+
+	}
+
 	return data->last_state_idx;
 }
 
@@ -399,6 +518,9 @@ static int menu_enable_device(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev)
 {
 	struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
+	struct hrtimer *t = &per_cpu(menu_hrtimer, dev->cpu);
+	hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	t->function = menu_hrtimer_notify;
 
 	memset(data, 0, sizeof(struct menu_device));
 
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 5f809e3..3409429 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/cpu.h>
 #include <linux/capability.h>
+#include <linux/device.h>
 
 #include "cpuidle.h"
 
@@ -297,6 +298,13 @@ static struct attribute *cpuidle_state_default_attrs[] = {
 	NULL
 };
 
+struct cpuidle_state_kobj {
+	struct cpuidle_state *state;
+	struct cpuidle_state_usage *state_usage;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
@@ -356,17 +364,17 @@ static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 }
 
 /**
- * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
+ * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
  * @device: the target device
  */
-int cpuidle_add_state_sysfs(struct cpuidle_device *device)
+static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 {
 	int i, ret = -ENOMEM;
 	struct cpuidle_state_kobj *kobj;
-	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 
 	/* state statistics */
-	for (i = 0; i < device->state_count; i++) {
+	for (i = 0; i < drv->state_count; i++) {
 		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 		if (!kobj)
 			goto error_state;
@@ -374,8 +382,8 @@ int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 		kobj->state_usage = &device->states_usage[i];
 		init_completion(&kobj->kobj_unregister);
 
-		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
-					   "state%d", i);
+		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
+					   &device->kobj, "state%d", i);
 		if (ret) {
 			kfree(kobj);
 			goto error_state;
@@ -393,10 +401,10 @@ error_state:
 }
 
 /**
- * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
+ * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
  * @device: the target device
  */
-void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
+static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 {
 	int i;
 
@@ -404,17 +412,179 @@ void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 		cpuidle_free_state_kobj(device, i);
 }
 
+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
+#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
+#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
+
+#define define_one_driver_ro(_name, show)                       \
+	static struct cpuidle_driver_attr attr_driver_##_name = \
+		__ATTR(_name, 0644, show, NULL)
+
+struct cpuidle_driver_kobj {
+	struct cpuidle_driver *drv;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+struct cpuidle_driver_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct cpuidle_driver *, char *);
+	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
+};
+
+static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
+{
+	ssize_t ret;
+
+	spin_lock(&cpuidle_driver_lock);
+	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
+	spin_unlock(&cpuidle_driver_lock);
+
+	return ret;
+}
+
+static void cpuidle_driver_sysfs_release(struct kobject *kobj)
+{
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	complete(&driver_kobj->kobj_unregister);
+}
+
+static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute * attr,
+				   char * buf)
+{
+	int ret = -EIO;
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+	if (dattr->show)
+		ret = dattr->show(driver_kobj->drv, buf);
+
+	return ret;
+}
+
+static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
+				    const char *buf, size_t size)
+{
+	int ret = -EIO;
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+	if (dattr->store)
+		ret = dattr->store(driver_kobj->drv, buf, size);
+
+	return ret;
+}
+
+define_one_driver_ro(name, show_driver_name);
+
+static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
+	.show = cpuidle_driver_show,
+	.store = cpuidle_driver_store,
+};
+
+static struct attribute *cpuidle_driver_default_attrs[] = {
+	&attr_driver_name.attr,
+	NULL
+};
+
+static struct kobj_type ktype_driver_cpuidle = {
+	.sysfs_ops = &cpuidle_driver_sysfs_ops,
+	.default_attrs = cpuidle_driver_default_attrs,
+	.release = cpuidle_driver_sysfs_release,
+};
+
+/**
+ * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
+ * @device: the target device
+ */
+static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver_kobj *kdrv;
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+	int ret;
+
+	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
+	if (!kdrv)
+		return -ENOMEM;
+
+	kdrv->drv = drv;
+	init_completion(&kdrv->kobj_unregister);
+
+	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
+				   &dev->kobj, "driver");
+	if (ret) {
+		kfree(kdrv);
+		return ret;
+	}
+
+	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
+	dev->kobj_driver = kdrv;
+
+	return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
+ * @device: the target device
+ */
+static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
+	kobject_put(&kdrv->kobj);
+	wait_for_completion(&kdrv->kobj_unregister);
+	kfree(kdrv);
+}
+#else
+static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
+{
+	return 0;
+}
+
+static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+	;
+}
+#endif
+
+/**
+ * cpuidle_add_device_sysfs - adds device specific sysfs attributes
+ * @device: the target device
+ */
+int cpuidle_add_device_sysfs(struct cpuidle_device *device)
+{
+	int ret;
+
+	ret = cpuidle_add_state_sysfs(device);
+	if (ret)
+		return ret;
+
+	ret = cpuidle_add_driver_sysfs(device);
+	if (ret)
+		cpuidle_remove_state_sysfs(device);
+	return ret;
+}
+
+/**
+ * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
+ * @device : the target device
+ */
+void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
+{
+	cpuidle_remove_driver_sysfs(device);
+	cpuidle_remove_state_sysfs(device);
+}
+
 /**
  * cpuidle_add_sysfs - creates a sysfs instance for the target device
  * @dev: the target device
  */
-int cpuidle_add_sysfs(struct device *cpu_dev)
+int cpuidle_add_sysfs(struct cpuidle_device *dev)
 {
-	int cpu = cpu_dev->id;
-	struct cpuidle_device *dev;
+	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 	int error;
 
-	dev = per_cpu(cpuidle_devices, cpu);
+	init_completion(&dev->kobj_unregister);
+
 	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 				     "cpuidle");
 	if (!error)
@@ -426,11 +596,8 @@ int cpuidle_add_sysfs(struct device *cpu_dev)
  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
  * @dev: the target device
  */
-void cpuidle_remove_sysfs(struct device *cpu_dev)
+void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 {
-	int cpu = cpu_dev->id;
-	struct cpuidle_device *dev;
-
-	dev = per_cpu(cpuidle_devices, cpu);
 	kobject_put(&dev->kobj);
+	wait_for_completion(&dev->kobj_unregister);
 }
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index b0f6b4c..c49c04d 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -56,7 +56,6 @@
 #include <linux/kernel.h>
 #include <linux/cpuidle.h>
 #include <linux/clockchips.h>
-#include <linux/hrtimer.h>	/* ktime_get_real() */
 #include <trace/events/power.h>
 #include <linux/sched.h>
 #include <linux/notifier.h>
@@ -72,6 +71,7 @@
 static struct cpuidle_driver intel_idle_driver = {
 	.name = "intel_idle",
 	.owner = THIS_MODULE,
+	.en_core_tk_irqen = 1,
 };
 /* intel_idle.max_cstate=0 disables driver */
 static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1;
@@ -281,8 +281,6 @@ static int intel_idle(struct cpuidle_device *dev,
 	struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
 	unsigned long eax = (unsigned long)cpuidle_get_statedata(state_usage);
 	unsigned int cstate;
-	ktime_t kt_before, kt_after;
-	s64 usec_delta;
 	int cpu = smp_processor_id();
 
 	cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
@@ -297,8 +295,6 @@ static int intel_idle(struct cpuidle_device *dev,
 	if (!(lapic_timer_reliable_states & (1 << (cstate))))
 		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
 
-	kt_before = ktime_get_real();
-
 	stop_critical_timings();
 	if (!need_resched()) {
 
@@ -310,17 +306,9 @@ static int intel_idle(struct cpuidle_device *dev,
 
 	start_critical_timings();
 
-	kt_after = ktime_get_real();
-	usec_delta = ktime_to_us(ktime_sub(kt_after, kt_before));
-
-	local_irq_enable();
-
 	if (!(lapic_timer_reliable_states & (1 << (cstate))))
 		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
 
-	/* Update cpuidle counters */
-	dev->last_residency = (int)usec_delta;
-
 	return index;
 }