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Release 4.14 drivers/cpuidle/cpuidle.c

Directory: drivers/cpuidle
/*
 * 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/clockchips.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/notifier.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 <linux/suspend.h>
#include <linux/tick.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 int enabled_devices;

static int off __read_mostly;

static int initialized __read_mostly;


int cpuidle_disabled(void) { return off; }

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Len Brown10100.00%1100.00%
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void disable_cpuidle(void) { off = 1; }

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Len Brown11100.00%1100.00%
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bool cpuidle_not_available(struct cpuidle_driver *drv, struct cpuidle_device *dev) { return off || !initialized || !drv || !dev || !dev->enabled; }

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Rafael J. Wysocki32100.00%1100.00%
Total32100.00%1100.00%

/** * 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 >= 0; i--) if (drv->states[i].enter_dead) return drv->states[i].enter_dead(dev, i); return -ENODEV; }

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Boris Ostrovsky6271.26%120.00%
Daniel Lezcano1517.24%240.00%
Toshi Kani910.34%120.00%
Rafael J. Wysocki11.15%120.00%
Total87100.00%5100.00%


static int find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev, unsigned int max_latency, unsigned int forbidden_flags, bool s2idle) { unsigned int latency_req = 0; int i, ret = 0; for (i = 1; 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 || s->exit_latency > max_latency || (s->flags & forbidden_flags) || (s2idle && !s->enter_s2idle)) continue; latency_req = s->exit_latency; ret = i; } return ret; }

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Rafael J. Wysocki136100.00%6100.00%
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/** * cpuidle_use_deepest_state - Set/clear governor override flag. * @enable: New value of the flag. * * Set/unset the current CPU to use the deepest idle state (override governors * going forward if set). */
void cpuidle_use_deepest_state(bool enable) { struct cpuidle_device *dev; preempt_disable(); dev = cpuidle_get_device(); if (dev) dev->use_deepest_state = enable; preempt_enable(); }

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Jacob jun Pan3088.24%150.00%
Li Fei411.76%150.00%
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/** * 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, UINT_MAX, 0, false); }

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#ifdef CONFIG_SUSPEND
static void enter_s2idle_proper(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { /* * trace_suspend_resume() called by tick_freeze() for the last CPU * executing it contains RCU usage regarded as invalid in the idle * context, so tell RCU about that. */ RCU_NONIDLE(tick_freeze()); /* * The state used here cannot be a "coupled" one, because the "coupled" * cpuidle mechanism enables interrupts and doing that with timekeeping * suspended is generally unsafe. */ stop_critical_timings(); drv->states[index].enter_s2idle(dev, drv, index); WARN_ON(!irqs_disabled()); /* * timekeeping_resume() that will be called by tick_unfreeze() for the * first CPU executing it calls functions containing RCU read-side * critical sections, so tell RCU about that. */ RCU_NONIDLE(tick_unfreeze()); start_critical_timings(); }

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Rafael J. Wysocki5790.48%375.00%
Lucas Stach69.52%125.00%
Total63100.00%4100.00%

/** * cpuidle_enter_s2idle - 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_s2idle callback, find the deepest of * them and enter it with frozen tick. */
int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) { int index; /* * Find the deepest state with ->enter_s2idle present, which guarantees * that interrupts won't be enabled when it exits and allows the tick to * be frozen safely. */ index = find_deepest_state(drv, dev, UINT_MAX, 0, true); if (index > 0) enter_s2idle_proper(drv, dev, index); return index; }

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Rafael J. Wysocki5198.08%583.33%
Sudeep Holla11.92%116.67%
Total52100.00%6100.00%

#endif /* CONFIG_SUSPEND */ /** * cpuidle_enter_state - enter the state and update stats * @dev: cpuidle device for this cpu * @drv: cpuidle driver for this cpu * @index: index into the states table in @drv 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]; bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); ktime_t time_start, time_end; s64 diff; /* * Tell the time framework to switch to a broadcast timer because our * local timer will be shut down. If a local timer is used from another * CPU as a broadcast timer, this call may fail if it is not available. */ if (broadcast && tick_broadcast_enter()) { index = find_deepest_state(drv, dev, target_state->exit_latency, CPUIDLE_FLAG_TIMER_STOP, false); if (index < 0) { default_idle_call(); return -EBUSY; } target_state = &drv->states[index]; } /* Take note of the planned idle state. */ sched_idle_set_state(target_state); trace_cpu_idle_rcuidle(index, dev->cpu); time_start = ns_to_ktime(local_clock()); stop_critical_timings(); entered_state = target_state->enter(dev, drv, index); start_critical_timings(); sched_clock_idle_wakeup_event(); time_end = ns_to_ktime(local_clock()); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); /* The cpu is no longer idle or about to enter idle. */ sched_idle_set_state(NULL); if (broadcast) { if (WARN_ON_ONCE(!irqs_disabled())) local_irq_disable(); tick_broadcast_exit(); } if (!cpuidle_state_is_coupled(drv, index)) local_irq_enable(); diff = ktime_us_delta(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; } return entered_state; }

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Rafael J. Wysocki9834.75%430.77%
Colin Cross7426.24%17.69%
Daniel Lezcano6322.34%323.08%
Sandeep Tripathy186.38%17.69%
Shreyas B. Prabhu113.90%17.69%
Paul Burton93.19%17.69%
Lucas Stach62.13%17.69%
Peter Zijlstra31.06%17.69%
Total282100.00%13100.00%

/** * 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. The return value must not be negative. */
int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { return cpuidle_curr_governor->select(drv, dev); }

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Len Brown1248.00%240.00%
Daniel Lezcano728.00%120.00%
Deepthi Dharwar520.00%120.00%
Kevin Hilman14.00%120.00%
Total25100.00%5100.00%

/** * 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(drv, index)) return cpuidle_enter_state_coupled(dev, drv, index); return cpuidle_enter_state(dev, drv, index); }

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Daniel Lezcano2757.45%228.57%
Colin Cross1429.79%228.57%
Len Brown36.38%114.29%
Deepthi Dharwar24.26%114.29%
Preeti U. Murthy12.13%114.29%
Total47100.00%7100.00%

/** * 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 && index >= 0) cpuidle_curr_governor->reflect(dev, index); }

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Len Brown1443.75%120.00%
Daniel Lezcano1237.50%120.00%
Rafael J. Wysocki412.50%120.00%
Deepthi Dharwar13.12%120.00%
Thomas Renninger13.12%120.00%
Total32100.00%5100.00%

/** * cpuidle_install_idle_handler - installs the cpuidle idle loop handler */
void cpuidle_install_idle_handler(void) { if (enabled_devices) { /* Make sure all changes finished before we switch to new idle */ smp_wmb(); initialized = 1; } }

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Len Brown21100.00%2100.00%
Total21100.00%2100.00%

/** * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler */
void cpuidle_uninstall_idle_handler(void) { if (enabled_devices) { initialized = 0; wake_up_all_idle_cpus(); } /* * Make sure external observers (such as the scheduler) * are done looking at pointed idle states. */ synchronize_rcu(); }

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Len Brown1979.17%250.00%
Daniel Lezcano416.67%125.00%
Chuansheng Liu14.17%125.00%
Total24100.00%4100.00%

/** * cpuidle_pause_and_lock - temporarily disables CPUIDLE */
void cpuidle_pause_and_lock(void) { mutex_lock(&cpuidle_lock); cpuidle_uninstall_idle_handler(); }

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Len Brown16100.00%1100.00%
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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); }

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Len Brown16100.00%1100.00%
Total16100.00%1100.00%

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); }

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Preeti U. Murthy22100.00%1100.00%
Total22100.00%1100.00%

/* 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); }

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Preeti U. Murthy22100.00%1100.00%
Total22100.00%1100.00%

/** * 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; 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->registered) return -EINVAL; ret = cpuidle_add_device_sysfs(dev); if (ret) return ret; if (cpuidle_curr_governor->enable && (ret = cpuidle_curr_governor->enable(drv, dev))) goto fail_sysfs; smp_wmb(); dev->enabled = 1; enabled_devices++; return 0; fail_sysfs: cpuidle_remove_device_sysfs(dev); return ret; }

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Len Brown9171.65%116.67%
Daniel Lezcano1914.96%233.33%
Srivatsa S. Bhat97.09%116.67%
Robert Lee75.51%116.67%
Deepthi Dharwar10.79%116.67%
Total127100.00%6100.00%

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) { struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); if (!dev || !dev->enabled) return; if (!drv || !cpuidle_curr_governor) return; dev->enabled = 0; if (cpuidle_curr_governor->disable) cpuidle_curr_governor->disable(drv, dev); cpuidle_remove_device_sysfs(dev); enabled_devices--; }

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Len Brown5275.36%125.00%
Daniel Lezcano1318.84%125.00%
Srivatsa S. Bhat34.35%125.00%
Deepthi Dharwar11.45%125.00%
Total69100.00%4100.00%

EXPORT_SYMBOL_GPL(cpuidle_disable_device);
static void __cpuidle_unregister_device(struct cpuidle_device *dev) { struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); list_del(&dev->device_list); per_cpu(cpuidle_devices, dev->cpu) = NULL; module_put(drv->owner); dev->registered = 0; }

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Dave Gerlach611.32%150.00%
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static void __cpuidle_device_init(struct cpuidle_device *dev) { memset(dev->states_usage, 0, sizeof(dev->states_usage)); dev->last_residency = 0; }

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Daniel Lezcano3296.97%150.00%
Viresh Kumar13.03%150.00%
Total33100.00%2100.00%

/** * __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 cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); if (!try_module_get(drv->owner)) return -EINVAL; per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); ret = cpuidle_coupled_register_device(dev); if (ret) __cpuidle_unregister_device(dev); else dev->registered = 1; return ret; }

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Len Brown5665.12%222.22%
Venkatesh Pallipadi1618.60%111.11%
Daniel Lezcano910.47%333.33%
Colin Cross33.49%222.22%
Viresh Kumar22.33%111.11%
Total86100.00%9100.00%

/** * cpuidle_register_device - registers a CPU's idle PM feature * @dev: the cpu */
int cpuidle_register_device(struct cpuidle_device *dev) { int ret = -EBUSY; if (!dev) return -EINVAL; mutex_lock(&cpuidle_lock); 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_install_idle_handler(); out_unlock: mutex_unlock(&cpuidle_lock); return ret; out_sysfs: cpuidle_remove_sysfs(dev); out_unregister: __cpuidle_unregister_device(dev); goto out_unlock; }

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Daniel Lezcano7261.02%457.14%
Len Brown1916.10%114.29%
Venkatesh Pallipadi1815.25%114.29%
Srivatsa S. Bhat97.63%114.29%
Total118100.00%7100.00%

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) { if (!dev || dev->registered == 0) return; cpuidle_pause_and_lock(); cpuidle_disable_device(dev); cpuidle_remove_sysfs(dev); __cpuidle_unregister_device(dev); cpuidle_coupled_unregister_device(dev); cpuidle_resume_and_unlock(); }

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Len Brown2960.42%116.67%
Venkatesh Pallipadi918.75%116.67%
Colin Cross510.42%116.67%
Konrad Rzeszutek Wilk36.25%116.67%
Daniel Lezcano24.17%233.33%
Total48100.00%6100.00%

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); }

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Daniel Lezcano46100.00%2100.00%
Total46100.00%2100.00%

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; }

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Daniel Lezcano11799.15%266.67%
Viresh Kumar10.85%133.33%
Total118100.00%3100.00%

EXPORT_SYMBOL_GPL(cpuidle_register); #ifdef CONFIG_SMP /* * 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) { wake_up_all_idle_cpus(); return NOTIFY_OK; }

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Len Brown2392.00%150.00%
Chuansheng Liu28.00%150.00%
Total25100.00%2100.00%

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); }

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Mark Gross1684.21%150.00%
Len Brown315.79%150.00%
Total19100.00%2100.00%

#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; if (cpuidle_disabled()) return -ENODEV; ret = cpuidle_add_interface(cpu_subsys.dev_root); if (ret) return ret; latency_notifier_init(&cpuidle_latency_notifier); return 0; }

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Len Brown4291.30%266.67%
Kay Sievers48.70%133.33%
Total46100.00%3100.00%

module_param(off, int, 0444); core_initcall(cpuidle_init);

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Len Brown57529.49%56.67%
Daniel Lezcano51026.15%1621.33%
Rafael J. Wysocki42221.64%1722.67%
Colin Cross964.92%34.00%
Boris Ostrovsky623.18%11.33%
Venkatesh Pallipadi482.46%22.67%
Preeti U. Murthy472.41%22.67%
Jacob jun Pan331.69%11.33%
Srivatsa S. Bhat211.08%22.67%
Sandeep Tripathy180.92%11.33%
Mark Gross160.82%11.33%
Lucas Stach120.62%11.33%
Shreyas B. Prabhu110.56%11.33%
Deepthi Dharwar100.51%22.67%
Toshi Kani100.51%11.33%
Paul Burton90.46%11.33%
Robert Lee70.36%11.33%
Dave Gerlach60.31%11.33%
Arjan van de Ven60.31%22.67%
Kay Sievers40.21%11.33%
Li Fei40.21%11.33%
Viresh Kumar40.21%34.00%
Paul Gortmaker30.15%11.33%
Ingo Molnar30.15%11.33%
Chuansheng Liu30.15%11.33%
Peter Zijlstra30.15%11.33%
Konrad Rzeszutek Wilk30.15%11.33%
Jean Pihet10.05%11.33%
Kevin Hilman10.05%11.33%
Sudeep Holla10.05%11.33%
Thomas Renninger10.05%11.33%
Total1950100.00%75100.00%
Directory: drivers/cpuidle
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