1 files changed, 441 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
new file mode 100644
index 00000000..bf509245
--- /dev/null
+++ b/drivers/cpuidle/cpuidle.c
@@ -0,0 +1,441 @@
+/*
+ * cpuidle.c - core cpuidle infrastructure
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *               Shaohua Li <shaohua.li@intel.com>
+ *               Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/pm_qos_params.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <trace/events/power.h>
+
+#include "cpuidle.h"
+
+DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
+
+DEFINE_MUTEX(cpuidle_lock);
+LIST_HEAD(cpuidle_detected_devices);
+static void (*pm_idle_old)(void);
+
+static int enabled_devices;
+
+#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
+static void cpuidle_kick_cpus(void)
+{
+	cpu_idle_wait();
+}
+#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
+
+static int __cpuidle_register_device(struct cpuidle_device *dev);
+
+/**
+ * cpuidle_idle_call - the main idle loop
+ *
+ * NOTE: no locks or semaphores should be used here
+ */
+static void cpuidle_idle_call(void)
+{
+	struct cpuidle_device *dev = __this_cpu_read(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;
+	}
+
+#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
+
+	/*
+	 * 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()) {
+		local_irq_enable();
+		return;
+	}
+
+	target_state = &dev->states[next_state];
+
+	/* enter the state and update stats */
+	dev->last_state = target_state;
+
+	trace_power_start(POWER_CSTATE, next_state, dev->cpu);
+	trace_cpu_idle(next_state, dev->cpu);
+
+	dev->last_residency = target_state->enter(dev, target_state);
+
+	trace_power_end(dev->cpu);
+	trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
+
+	if (dev->last_state)
+		target_state = dev->last_state;
+
+	target_state->time += (unsigned long long)dev->last_residency;
+	target_state->usage++;
+
+	/* give the governor an opportunity to reflect on the outcome */
+	if (cpuidle_curr_governor->reflect)
+		cpuidle_curr_governor->reflect(dev);
+}
+
+/**
+ * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
+ */
+void cpuidle_install_idle_handler(void)
+{
+	if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
+		/* Make sure all changes finished before we switch to new idle */
+		smp_wmb();
+		pm_idle = cpuidle_idle_call;
+	}
+}
+
+/**
+ * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
+ */
+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();
+	}
+}
+
+/**
+ * cpuidle_pause_and_lock - temporarily disables CPUIDLE
+ */
+void cpuidle_pause_and_lock(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_uninstall_idle_handler();
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock);
+
+/**
+ * cpuidle_resume_and_unlock - resumes CPUIDLE operation
+ */
+void cpuidle_resume_and_unlock(void)
+{
+	cpuidle_install_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
+
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st)
+{
+	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;
+
+	ret = (int) diff;
+	return ret;
+}
+
+static void poll_idle_init(struct cpuidle_device *dev)
+{
+	struct cpuidle_state *state = &dev->states[0];
+
+	cpuidle_set_statedata(state, NULL);
+
+	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+	state->exit_latency = 0;
+	state->target_residency = 0;
+	state->power_usage = -1;
+	state->flags = 0;
+	state->enter = poll_idle;
+}
+#else
+static void poll_idle_init(struct cpuidle_device *dev) {}
+#endif /* CONFIG_ARCH_HAS_CPU_RELAX */
+
+/**
+ * cpuidle_enable_device - enables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+int cpuidle_enable_device(struct cpuidle_device *dev)
+{
+	int ret, i;
+
+	if (dev->enabled)
+		return 0;
+	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
+		return -EIO;
+	if (!dev->state_count)
+		return -EINVAL;
+
+	if (dev->registered == 0) {
+		ret = __cpuidle_register_device(dev);
+		if (ret)
+			return ret;
+	}
+
+	poll_idle_init(dev);
+
+	if ((ret = cpuidle_add_state_sysfs(dev)))
+		return ret;
+
+	if (cpuidle_curr_governor->enable &&
+	    (ret = cpuidle_curr_governor->enable(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;
+
+	enabled_devices++;
+	return 0;
+
+fail_sysfs:
+	cpuidle_remove_state_sysfs(dev);
+
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_enable_device);
+
+/**
+ * cpuidle_disable_device - disables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+void cpuidle_disable_device(struct cpuidle_device *dev)
+{
+	if (!dev->enabled)
+		return;
+	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
+		return;
+
+	dev->enabled = 0;
+
+	if (cpuidle_curr_governor->disable)
+		cpuidle_curr_governor->disable(dev);
+
+	cpuidle_remove_state_sysfs(dev);
+	enabled_devices--;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_disable_device);
+
+/**
+ * __cpuidle_register_device - internal register function called before register
+ * and enable routines
+ * @dev: the cpu
+ *
+ * cpuidle_lock mutex must be held before this is called
+ */
+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();
+
+	if (!sys_dev)
+		return -EINVAL;
+	if (!try_module_get(cpuidle_driver->owner))
+		return -EINVAL;
+
+	init_completion(&dev->kobj_unregister);
+
+	/*
+	 * 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;
+}
+
+/**
+ * cpuidle_register_device - registers a CPU's idle PM feature
+ * @dev: the cpu
+ */
+int cpuidle_register_device(struct cpuidle_device *dev)
+{
+	int ret;
+
+	mutex_lock(&cpuidle_lock);
+
+	if ((ret = __cpuidle_register_device(dev))) {
+		mutex_unlock(&cpuidle_lock);
+		return ret;
+	}
+
+	cpuidle_enable_device(dev);
+	cpuidle_install_idle_handler();
+
+	mutex_unlock(&cpuidle_lock);
+
+	return 0;
+
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_device);
+
+/**
+ * cpuidle_unregister_device - unregisters a CPU's idle PM feature
+ * @dev: the cpu
+ */
+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)
+		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_resume_and_unlock();
+
+	module_put(cpuidle_driver->owner);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
+
+#ifdef CONFIG_SMP
+
+static void smp_callback(void *v)
+{
+	/* we already woke the CPU up, nothing more to do */
+}
+
+/*
+ * This function gets called when a part of the kernel has a new latency
+ * requirement.  This means we need to get all processors out of their C-state,
+ * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
+ * wakes them all right up.
+ */
+static int cpuidle_latency_notify(struct notifier_block *b,
+		unsigned long l, void *v)
+{
+	smp_call_function(smp_callback, NULL, 1);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpuidle_latency_notifier = {
+	.notifier_call = cpuidle_latency_notify,
+};
+
+static inline void latency_notifier_init(struct notifier_block *n)
+{
+	pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n);
+}
+
+#else /* CONFIG_SMP */
+
+#define latency_notifier_init(x) do { } while (0)
+
+#endif /* CONFIG_SMP */
+
+/**
+ * cpuidle_init - core initializer
+ */
+static int __init cpuidle_init(void)
+{
+	int ret;
+
+	pm_idle_old = pm_idle;
+
+	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
+	if (ret)
+		return ret;
+
+	latency_notifier_init(&cpuidle_latency_notifier);
+
+	return 0;
+}
+
+core_initcall(cpuidle_init);