1 files changed, 326 insertions, 176 deletions

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index a5071084337..cb7019977c5 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -8,105 +8,198 @@
  * This code is licenced under the GPL.
  */
 
+#include <linux/clockchips.h>
 #include <linux/kernel.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
 #include <linux/notifier.h>
-#include <linux/pm_qos_params.h>
+#include <linux/pm_qos.h>
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/ktime.h>
 #include <linux/hrtimer.h>
+#include <linux/module.h>
 #include <trace/events/power.h>
 
 #include "cpuidle.h"
 
 DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
+DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 
 DEFINE_MUTEX(cpuidle_lock);
 LIST_HEAD(cpuidle_detected_devices);
-static void (*pm_idle_old)(void);
 
 static int enabled_devices;
+static int off __read_mostly;
+static int initialized __read_mostly;
+static bool use_deepest_state __read_mostly;
 
-#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
-static void cpuidle_kick_cpus(void)
+int cpuidle_disabled(void)
 {
-	cpu_idle_wait();
+	return off;
 }
-#elif defined(CONFIG_SMP)
-# error "Arch needs cpu_idle_wait() equivalent here"
-#else /* !CONFIG_ARCH_HAS_CPU_IDLE_WAIT && !CONFIG_SMP */
-static void cpuidle_kick_cpus(void) {}
-#endif
+void disable_cpuidle(void)
+{
+	off = 1;
+}
+
+/**
+ * cpuidle_play_dead - cpu off-lining
+ *
+ * Returns in case of an error or no driver
+ */
+int cpuidle_play_dead(void)
+{
+	struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+	int i;
+
+	if (!drv)
+		return -ENODEV;
+
+	/* Find lowest-power state that supports long-term idle */
+	for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--)
+		if (drv->states[i].enter_dead)
+			return drv->states[i].enter_dead(dev, i);
 
-static int __cpuidle_register_device(struct cpuidle_device *dev);
+	return -ENODEV;
+}
 
 /**
- * cpuidle_idle_call - the main idle loop
+ * cpuidle_use_deepest_state - Enable/disable the "deepest idle" mode.
+ * @enable: Whether enable or disable the feature.
+ *
+ * If the "deepest idle" mode is enabled, cpuidle will ignore the governor and
+ * always use the state with the greatest exit latency (out of the states that
+ * are not disabled).
  *
- * NOTE: no locks or semaphores should be used here
+ * This function can only be called after cpuidle_pause() to avoid races.
  */
-static void cpuidle_idle_call(void)
+void cpuidle_use_deepest_state(bool enable)
 {
-	struct cpuidle_device *dev = __get_cpu_var(cpuidle_devices);
-	struct cpuidle_state *target_state;
-	int next_state;
-
-	/* check if the device is ready */
-	if (!dev || !dev->enabled) {
-		if (pm_idle_old)
-			pm_idle_old();
-		else
-#if defined(CONFIG_ARCH_HAS_DEFAULT_IDLE)
-			default_idle();
-#else
-			local_irq_enable();
-#endif
-		return;
+	use_deepest_state = enable;
+}
+
+/**
+ * cpuidle_find_deepest_state - Find the state of the greatest exit latency.
+ * @drv: cpuidle driver for a given CPU.
+ * @dev: cpuidle device for a given CPU.
+ */
+static int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
+				      struct cpuidle_device *dev)
+{
+	unsigned int latency_req = 0;
+	int i, ret = CPUIDLE_DRIVER_STATE_START - 1;
+
+	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
+		struct cpuidle_state *s = &drv->states[i];
+		struct cpuidle_state_usage *su = &dev->states_usage[i];
+
+		if (s->disabled || su->disable || s->exit_latency <= latency_req)
+			continue;
+
+		latency_req = s->exit_latency;
+		ret = i;
 	}
+	return ret;
+}
 
-#if 0
-	/* shows regressions, re-enable for 2.6.29 */
-	/*
-	 * run any timers that can be run now, at this point
-	 * before calculating the idle duration etc.
-	 */
-	hrtimer_peek_ahead_timers();
-#endif
+/**
+ * cpuidle_enter_state - enter the state and update stats
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ * @next_state: index into drv->states of the state to enter
+ */
+int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+			int index)
+{
+	int entered_state;
+
+	struct cpuidle_state *target_state = &drv->states[index];
+	ktime_t time_start, time_end;
+	s64 diff;
 
-	/*
-	 * Call the device's prepare function before calling the
-	 * governor's select function.  ->prepare gives the device's
-	 * cpuidle driver a chance to update any dynamic information
-	 * of its cpuidle states for the current idle period, e.g.
-	 * state availability, latencies, residencies, etc.
-	 */
-	if (dev->prepare)
-		dev->prepare(dev);
-
-	/* ask the governor for the next state */
-	next_state = cpuidle_curr_governor->select(dev);
-	if (need_resched()) {
+	time_start = ktime_get();
+
+	entered_state = target_state->enter(dev, drv, index);
+
+	time_end = ktime_get();
+
+	if (!cpuidle_state_is_coupled(dev, drv, entered_state))
 		local_irq_enable();
-		return;
+
+	diff = ktime_to_us(ktime_sub(time_end, time_start));
+	if (diff > INT_MAX)
+		diff = INT_MAX;
+
+	dev->last_residency = (int) diff;
+
+	if (entered_state >= 0) {
+		/* Update cpuidle counters */
+		/* This can be moved to within driver enter routine
+		 * but that results in multiple copies of same code.
+		 */
+		dev->states_usage[entered_state].time += dev->last_residency;
+		dev->states_usage[entered_state].usage++;
+	} else {
+		dev->last_residency = 0;
 	}
 
-	target_state = &dev->states[next_state];
+	return entered_state;
+}
 
-	/* enter the state and update stats */
-	dev->last_state = target_state;
-	dev->last_residency = target_state->enter(dev, target_state);
-	if (dev->last_state)
-		target_state = dev->last_state;
+/**
+ * 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)
+{
+	if (off || !initialized)
+		return -ENODEV;
 
-	target_state->time += (unsigned long long)dev->last_residency;
-	target_state->usage++;
+	if (!drv || !dev || !dev->enabled)
+		return -EBUSY;
 
-	/* give the governor an opportunity to reflect on the outcome */
-	if (cpuidle_curr_governor->reflect)
-		cpuidle_curr_governor->reflect(dev);
-	trace_power_end(smp_processor_id());
+	if (unlikely(use_deepest_state))
+		return cpuidle_find_deepest_state(drv, 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 && !unlikely(use_deepest_state))
+		cpuidle_curr_governor->reflect(dev, index);
 }
 
 /**
@@ -114,10 +207,10 @@ static void cpuidle_idle_call(void)
  */
 void cpuidle_install_idle_handler(void)
 {
-	if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
+	if (enabled_devices) {
 		/* Make sure all changes finished before we switch to new idle */
 		smp_wmb();
-		pm_idle = cpuidle_idle_call;
+		initialized = 1;
 	}
 }
 
@@ -126,9 +219,9 @@ void cpuidle_install_idle_handler(void)
  */
 void cpuidle_uninstall_idle_handler(void)
 {
-	if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
-		pm_idle = pm_idle_old;
-		cpuidle_kick_cpus();
+	if (enabled_devices) {
+		initialized = 0;
+		kick_all_cpus_sync();
 	}
 }
 
@@ -154,6 +247,22 @@ void cpuidle_resume_and_unlock(void)
 
 EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
 
+/* Currently used in suspend/resume path to suspend cpuidle */
+void cpuidle_pause(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_uninstall_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
+/* Currently used in suspend/resume path to resume cpuidle */
+void cpuidle_resume(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_install_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
 /**
  * cpuidle_enable_device - enables idle PM for a CPU
  * @dev: the CPU
@@ -163,35 +272,34 @@ EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
  */
 int cpuidle_enable_device(struct cpuidle_device *dev)
 {
-	int ret, i;
+	int ret;
+	struct cpuidle_driver *drv;
+
+	if (!dev)
+		return -EINVAL;
 
 	if (dev->enabled)
 		return 0;
-	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
+
+	drv = cpuidle_get_cpu_driver(dev);
+
+	if (!drv || !cpuidle_curr_governor)
 		return -EIO;
-	if (!dev->state_count)
+
+	if (!dev->registered)
 		return -EINVAL;
 
-	if (dev->registered == 0) {
-		ret = __cpuidle_register_device(dev);
-		if (ret)
-			return ret;
-	}
+	if (!dev->state_count)
+		dev->state_count = drv->state_count;
 
-	if ((ret = cpuidle_add_state_sysfs(dev)))
+	ret = cpuidle_add_device_sysfs(dev);
+	if (ret)
 		return ret;
 
 	if (cpuidle_curr_governor->enable &&
-	    (ret = cpuidle_curr_governor->enable(dev)))
+	    (ret = cpuidle_curr_governor->enable(drv, dev)))
 		goto fail_sysfs;
 
-	for (i = 0; i < dev->state_count; i++) {
-		dev->states[i].usage = 0;
-		dev->states[i].time = 0;
-	}
-	dev->last_residency = 0;
-	dev->last_state = NULL;
-
 	smp_wmb();
 
 	dev->enabled = 1;
@@ -200,7 +308,7 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 	return 0;
 
 fail_sysfs:
-	cpuidle_remove_state_sysfs(dev);
+	cpuidle_remove_device_sysfs(dev);
 
 	return ret;
 }
@@ -216,60 +324,39 @@ EXPORT_SYMBOL_GPL(cpuidle_enable_device);
  */
 void cpuidle_disable_device(struct cpuidle_device *dev)
 {
-	if (!dev->enabled)
+	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(dev);
+		cpuidle_curr_governor->disable(drv, dev);
 
-	cpuidle_remove_state_sysfs(dev);
+	cpuidle_remove_device_sysfs(dev);
 	enabled_devices--;
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_disable_device);
 
-#ifdef CONFIG_ARCH_HAS_CPU_RELAX
-static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st)
+static void __cpuidle_unregister_device(struct cpuidle_device *dev)
 {
-	ktime_t	t1, t2;
-	s64 diff;
-	int ret;
-
-	t1 = ktime_get();
-	local_irq_enable();
-	while (!need_resched())
-		cpu_relax();
-
-	t2 = ktime_get();
-	diff = ktime_to_us(ktime_sub(t2, t1));
-	if (diff > INT_MAX)
-		diff = INT_MAX;
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 
-	ret = (int) diff;
-	return ret;
+	list_del(&dev->device_list);
+	per_cpu(cpuidle_devices, dev->cpu) = NULL;
+	module_put(drv->owner);
 }
 
-static void poll_idle_init(struct cpuidle_device *dev)
+static void __cpuidle_device_init(struct cpuidle_device *dev)
 {
-	struct cpuidle_state *state = &dev->states[0];
-
-	cpuidle_set_statedata(state, NULL);
-
-	snprintf(state->name, CPUIDLE_NAME_LEN, "C0");
-	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
-	state->exit_latency = 0;
-	state->target_residency = 0;
-	state->power_usage = -1;
-	state->flags = CPUIDLE_FLAG_POLL;
-	state->enter = poll_idle;
+	memset(dev->states_usage, 0, sizeof(dev->states_usage));
+	dev->last_residency = 0;
 }
-#else
-static void poll_idle_init(struct cpuidle_device *dev) {}
-#endif /* CONFIG_ARCH_HAS_CPU_RELAX */
 
 /**
  * __cpuidle_register_device - internal register function called before register
@@ -281,47 +368,21 @@ static void poll_idle_init(struct cpuidle_device *dev) {}
 static int __cpuidle_register_device(struct cpuidle_device *dev)
 {
 	int ret;
-	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
-	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 
-	if (!sys_dev)
-		return -EINVAL;
-	if (!try_module_get(cpuidle_driver->owner))
+	if (!try_module_get(drv->owner))
 		return -EINVAL;
 
-	init_completion(&dev->kobj_unregister);
-
-	poll_idle_init(dev);
-
-	/*
-	 * cpuidle driver should set the dev->power_specified bit
-	 * before registering the device if the driver provides
-	 * power_usage numbers.
-	 *
-	 * For those devices whose ->power_specified is not set,
-	 * we fill in power_usage with decreasing values as the
-	 * cpuidle code has an implicit assumption that state Cn
-	 * uses less power than C(n-1).
-	 *
-	 * With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned
-	 * an power value of -1.  So we use -2, -3, etc, for other
-	 * c-states.
-	 */
-	if (!dev->power_specified) {
-		int i;
-		for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++)
-			dev->states[i].power_usage = -1 - i;
-	}
-
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
-	if ((ret = cpuidle_add_sysfs(sys_dev))) {
-		module_put(cpuidle_driver->owner);
-		return ret;
-	}
 
-	dev->registered = 1;
-	return 0;
+	ret = cpuidle_coupled_register_device(dev);
+	if (ret)
+		__cpuidle_unregister_device(dev);
+	else
+		dev->registered = 1;
+
+	return ret;
 }
 
 /**
@@ -330,22 +391,42 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
  */
 int cpuidle_register_device(struct cpuidle_device *dev)
 {
-	int ret;
+	int ret = -EBUSY;
+
+	if (!dev)
+		return -EINVAL;
 
 	mutex_lock(&cpuidle_lock);
 
-	if ((ret = __cpuidle_register_device(dev))) {
-		mutex_unlock(&cpuidle_lock);
-		return ret;
-	}
+	if (dev->registered)
+		goto out_unlock;
+
+	__cpuidle_device_init(dev);
+
+	ret = __cpuidle_register_device(dev);
+	if (ret)
+		goto out_unlock;
+
+	ret = cpuidle_add_sysfs(dev);
+	if (ret)
+		goto out_unregister;
+
+	ret = cpuidle_enable_device(dev);
+	if (ret)
+		goto out_sysfs;
 
-	cpuidle_enable_device(dev);
 	cpuidle_install_idle_handler();
 
+out_unlock:
 	mutex_unlock(&cpuidle_lock);
 
-	return 0;
+	return ret;
 
+out_sysfs:
+	cpuidle_remove_sysfs(dev);
+out_unregister:
+	__cpuidle_unregister_device(dev);
+	goto out_unlock;
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_register_device);
@@ -356,28 +437,95 @@ EXPORT_SYMBOL_GPL(cpuidle_register_device);
  */
 void cpuidle_unregister_device(struct cpuidle_device *dev)
 {
-	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
-	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
-
-	if (dev->registered == 0)
+	if (!dev || dev->registered == 0)
 		return;
 
 	cpuidle_pause_and_lock();
 
 	cpuidle_disable_device(dev);
 
-	cpuidle_remove_sysfs(sys_dev);
-	list_del(&dev->device_list);
-	wait_for_completion(&dev->kobj_unregister);
-	per_cpu(cpuidle_devices, dev->cpu) = NULL;
+	cpuidle_remove_sysfs(dev);
 
-	cpuidle_resume_and_unlock();
+	__cpuidle_unregister_device(dev);
 
-	module_put(cpuidle_driver->owner);
+	cpuidle_coupled_unregister_device(dev);
+
+	cpuidle_resume_and_unlock();
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
 
+/**
+ * cpuidle_unregister: unregister a driver and the devices. This function
+ * can be used only if the driver has been previously registered through
+ * the cpuidle_register function.
+ *
+ * @drv: a valid pointer to a struct cpuidle_driver
+ */
+void cpuidle_unregister(struct cpuidle_driver *drv)
+{
+	int cpu;
+	struct cpuidle_device *device;
+
+	for_each_cpu(cpu, drv->cpumask) {
+		device = &per_cpu(cpuidle_dev, cpu);
+		cpuidle_unregister_device(device);
+	}
+
+	cpuidle_unregister_driver(drv);
+}
+EXPORT_SYMBOL_GPL(cpuidle_unregister);
+
+/**
+ * cpuidle_register: registers the driver and the cpu devices with the
+ * coupled_cpus passed as parameter. This function is used for all common
+ * initialization pattern there are in the arch specific drivers. The
+ * devices is globally defined in this file.
+ *
+ * @drv         : a valid pointer to a struct cpuidle_driver
+ * @coupled_cpus: a cpumask for the coupled states
+ *
+ * Returns 0 on success, < 0 otherwise
+ */
+int cpuidle_register(struct cpuidle_driver *drv,
+		     const struct cpumask *const coupled_cpus)
+{
+	int ret, cpu;
+	struct cpuidle_device *device;
+
+	ret = cpuidle_register_driver(drv);
+	if (ret) {
+		pr_err("failed to register cpuidle driver\n");
+		return ret;
+	}
+
+	for_each_cpu(cpu, drv->cpumask) {
+		device = &per_cpu(cpuidle_dev, cpu);
+		device->cpu = cpu;
+
+#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
+		/*
+		 * On multiplatform for ARM, the coupled idle states could be
+		 * enabled in the kernel even if the cpuidle driver does not
+		 * use it. Note, coupled_cpus is a struct copy.
+		 */
+		if (coupled_cpus)
+			device->coupled_cpus = *coupled_cpus;
+#endif
+		ret = cpuidle_register_device(device);
+		if (!ret)
+			continue;
+
+		pr_err("Failed to register cpuidle device for cpu%d\n", cpu);
+
+		cpuidle_unregister(drv);
+		break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cpuidle_register);
+
 #ifdef CONFIG_SMP
 
 static void smp_callback(void *v)
@@ -420,9 +568,10 @@ static int __init cpuidle_init(void)
 {
 	int ret;
 
-	pm_idle_old = pm_idle;
+	if (cpuidle_disabled())
+		return -ENODEV;
 
-	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
+	ret = cpuidle_add_interface(cpu_subsys.dev_root);
 	if (ret)
 		return ret;
 
@@ -431,4 +580,5 @@ static int __init cpuidle_init(void)
 	return 0;
 }
 
+module_param(off, int, 0444);
 core_initcall(cpuidle_init);