| /* |
| * 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/percpu-defs.h" |
| #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 <linux/mmu_context.h> |
| #include <linux/context_tracking.h> |
| #include <trace/events/power.h> |
| #include <trace/hooks/cpuidle.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; |
| } |
| 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 |
| * |
| * 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; |
| } |
| |
| static int find_deepest_state(struct cpuidle_driver *drv, |
| struct cpuidle_device *dev, |
| u64 max_latency_ns, |
| unsigned int forbidden_flags, |
| bool s2idle) |
| { |
| u64 latency_req = 0; |
| int i, ret = 0; |
| |
| for (i = 1; i < drv->state_count; i++) { |
| struct cpuidle_state *s = &drv->states[i]; |
| |
| if (dev->states_usage[i].disable || |
| s->exit_latency_ns <= latency_req || |
| s->exit_latency_ns > max_latency_ns || |
| (s->flags & forbidden_flags) || |
| (s2idle && !s->enter_s2idle)) |
| continue; |
| |
| latency_req = s->exit_latency_ns; |
| ret = i; |
| } |
| return ret; |
| } |
| |
| /** |
| * cpuidle_use_deepest_state - Set/unset governor override mode. |
| * @latency_limit_ns: Idle state exit latency limit (or no override if 0). |
| * |
| * If @latency_limit_ns is nonzero, set the current CPU to use the deepest idle |
| * state with exit latency within @latency_limit_ns (override governors going |
| * forward), or do not override governors if it is zero. |
| */ |
| void cpuidle_use_deepest_state(u64 latency_limit_ns) |
| { |
| struct cpuidle_device *dev; |
| |
| preempt_disable(); |
| dev = cpuidle_get_device(); |
| if (dev) |
| dev->forced_idle_latency_limit_ns = latency_limit_ns; |
| preempt_enable(); |
| } |
| |
| /** |
| * cpuidle_find_deepest_state - Find the deepest available idle state. |
| * @drv: cpuidle driver for the given CPU. |
| * @dev: cpuidle device for the given CPU. |
| * @latency_limit_ns: Idle state exit latency limit |
| * |
| * Return: the index of the deepest available idle state. |
| */ |
| int cpuidle_find_deepest_state(struct cpuidle_driver *drv, |
| struct cpuidle_device *dev, |
| u64 latency_limit_ns) |
| { |
| return find_deepest_state(drv, dev, latency_limit_ns, 0, false); |
| } |
| |
| #ifdef CONFIG_SUSPEND |
| static void enter_s2idle_proper(struct cpuidle_driver *drv, |
| struct cpuidle_device *dev, int index) |
| { |
| ktime_t time_start, time_end; |
| struct cpuidle_state *target_state = &drv->states[index]; |
| |
| time_start = ns_to_ktime(local_clock()); |
| |
| 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(); |
| if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
| ct_idle_enter(); |
| target_state->enter_s2idle(dev, drv, index); |
| if (WARN_ON_ONCE(!irqs_disabled())) |
| local_irq_disable(); |
| if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
| ct_idle_exit(); |
| tick_unfreeze(); |
| start_critical_timings(); |
| |
| time_end = ns_to_ktime(local_clock()); |
| |
| dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); |
| dev->states_usage[index].s2idle_usage++; |
| } |
| |
| /** |
| * 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, U64_MAX, 0, true); |
| if (index > 0) { |
| enter_s2idle_proper(drv, dev, index); |
| local_irq_enable(); |
| } |
| return index; |
| } |
| #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; |
| bool broadcast; |
| ktime_t time_start, time_end; |
| |
| /* |
| * The vendor hook may modify index, which means target_state and |
| * broadcast must be assigned after the vendor hook. |
| */ |
| trace_android_vh_cpu_idle_enter(&index, dev); |
| if (index < 0) |
| return index; |
| |
| target_state = &drv->states[index]; |
| broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
| |
| /* |
| * 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_ns, |
| CPUIDLE_FLAG_TIMER_STOP, false); |
| if (index < 0) { |
| default_idle_call(); |
| return -EBUSY; |
| } |
| target_state = &drv->states[index]; |
| broadcast = false; |
| } |
| |
| if (target_state->flags & CPUIDLE_FLAG_TLB_FLUSHED) |
| leave_mm(dev->cpu); |
| |
| /* Take note of the planned idle state. */ |
| sched_idle_set_state(target_state); |
| |
| trace_cpu_idle(index, dev->cpu); |
| time_start = ns_to_ktime(local_clock()); |
| |
| stop_critical_timings(); |
| if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
| ct_idle_enter(); |
| entered_state = target_state->enter(dev, drv, index); |
| if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) |
| ct_idle_exit(); |
| start_critical_timings(); |
| |
| sched_clock_idle_wakeup_event(); |
| time_end = ns_to_ktime(local_clock()); |
| trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu); |
| trace_android_vh_cpu_idle_exit(entered_state, dev); |
| |
| /* 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(); |
| |
| if (entered_state >= 0) { |
| s64 diff, delay = drv->states[entered_state].exit_latency_ns; |
| int i; |
| |
| /* |
| * Update cpuidle counters |
| * This can be moved to within driver enter routine, |
| * but that results in multiple copies of same code. |
| */ |
| diff = ktime_sub(time_end, time_start); |
| |
| dev->last_residency_ns = diff; |
| dev->states_usage[entered_state].time_ns += diff; |
| dev->states_usage[entered_state].usage++; |
| |
| if (diff < drv->states[entered_state].target_residency_ns) { |
| for (i = entered_state - 1; i >= 0; i--) { |
| if (dev->states_usage[i].disable) |
| continue; |
| |
| /* Shallower states are enabled, so update. */ |
| dev->states_usage[entered_state].above++; |
| trace_cpu_idle_miss(dev->cpu, entered_state, false); |
| break; |
| } |
| } else if (diff > delay) { |
| for (i = entered_state + 1; i < drv->state_count; i++) { |
| if (dev->states_usage[i].disable) |
| continue; |
| |
| /* |
| * Update if a deeper state would have been a |
| * better match for the observed idle duration. |
| */ |
| if (diff - delay >= drv->states[i].target_residency_ns) { |
| dev->states_usage[entered_state].below++; |
| trace_cpu_idle_miss(dev->cpu, entered_state, true); |
| } |
| |
| break; |
| } |
| } |
| } else { |
| dev->last_residency_ns = 0; |
| dev->states_usage[index].rejected++; |
| } |
| |
| return entered_state; |
| } |
| |
| /** |
| * cpuidle_select - ask the cpuidle framework to choose an idle state |
| * |
| * @drv: the cpuidle driver |
| * @dev: the cpuidle device |
| * @stop_tick: indication on whether or not to stop the tick |
| * |
| * Returns the index of the idle state. The return value must not be negative. |
| * |
| * The memory location pointed to by @stop_tick is expected to be written the |
| * 'false' boolean value if the scheduler tick should not be stopped before |
| * entering the returned state. |
| */ |
| int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
| bool *stop_tick) |
| { |
| return cpuidle_curr_governor->select(drv, dev, stop_tick); |
| } |
| |
| /** |
| * 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) |
| { |
| int ret = 0; |
| |
| /* |
| * Store the next hrtimer, which becomes either next tick or the next |
| * timer event, whatever expires first. Additionally, to make this data |
| * useful for consumers outside cpuidle, we rely on that the governor's |
| * ->select() callback have decided, whether to stop the tick or not. |
| */ |
| WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); |
| |
| if (cpuidle_state_is_coupled(drv, index)) |
| ret = cpuidle_enter_state_coupled(dev, drv, index); |
| else |
| ret = cpuidle_enter_state(dev, drv, index); |
| |
| WRITE_ONCE(dev->next_hrtimer, 0); |
| return ret; |
| } |
| |
| /** |
| * 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); |
| } |
| |
| /* |
| * Min polling interval of 10usec is a guess. It is assuming that |
| * for most users, the time for a single ping-pong workload like |
| * perf bench pipe would generally complete within 10usec but |
| * this is hardware dependant. Actual time can be estimated with |
| * |
| * perf bench sched pipe -l 10000 |
| * |
| * Run multiple times to avoid cpufreq effects. |
| */ |
| #define CPUIDLE_POLL_MIN 10000 |
| #define CPUIDLE_POLL_MAX (TICK_NSEC / 16) |
| |
| /** |
| * cpuidle_poll_time - return amount of time to poll for, |
| * governors can override dev->poll_limit_ns if necessary |
| * |
| * @drv: the cpuidle driver tied with the cpu |
| * @dev: the cpuidle device |
| * |
| */ |
| u64 cpuidle_poll_time(struct cpuidle_driver *drv, |
| struct cpuidle_device *dev) |
| { |
| int i; |
| u64 limit_ns; |
| |
| BUILD_BUG_ON(CPUIDLE_POLL_MIN > CPUIDLE_POLL_MAX); |
| |
| if (dev->poll_limit_ns) |
| return dev->poll_limit_ns; |
| |
| limit_ns = CPUIDLE_POLL_MAX; |
| for (i = 1; i < drv->state_count; i++) { |
| u64 state_limit; |
| |
| if (dev->states_usage[i].disable) |
| continue; |
| |
| state_limit = drv->states[i].target_residency_ns; |
| if (state_limit < CPUIDLE_POLL_MIN) |
| continue; |
| |
| limit_ns = min_t(u64, state_limit, CPUIDLE_POLL_MAX); |
| break; |
| } |
| |
| dev->poll_limit_ns = limit_ns; |
| |
| return dev->poll_limit_ns; |
| } |
| |
| /** |
| * 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; |
| } |
| } |
| |
| /** |
| * 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(); |
| } |
| |
| /** |
| * 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); |
| |
| /* 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 |
| * |
| * 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; |
| |
| if (!cpuidle_curr_governor) |
| return -EIO; |
| |
| drv = cpuidle_get_cpu_driver(dev); |
| |
| if (!drv) |
| 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); |
| if (ret) |
| goto fail_sysfs; |
| } |
| |
| smp_wmb(); |
| |
| dev->enabled = 1; |
| |
| enabled_devices++; |
| return 0; |
| |
| fail_sysfs: |
| cpuidle_remove_device_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) |
| { |
| 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--; |
| } |
| |
| 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; |
| } |
| |
| static void __cpuidle_device_init(struct cpuidle_device *dev) |
| { |
| memset(dev->states_usage, 0, sizeof(dev->states_usage)); |
| dev->last_residency_ns = 0; |
| dev->next_hrtimer = 0; |
| } |
| |
| /** |
| * __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) |
| { |
| struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
| int i, ret; |
| |
| if (!try_module_get(drv->owner)) |
| return -EINVAL; |
| |
| for (i = 0; i < drv->state_count; i++) { |
| if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE) |
| dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; |
| |
| if (drv->states[i].flags & CPUIDLE_FLAG_OFF) |
| dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; |
| } |
| |
| 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; |
| } |
| |
| /** |
| * 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; |
| } |
| |
| 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(); |
| } |
| |
| 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); |
| |
| /** |
| * cpuidle_init - core initializer |
| */ |
| static int __init cpuidle_init(void) |
| { |
| if (cpuidle_disabled()) |
| return -ENODEV; |
| |
| return cpuidle_add_interface(cpu_subsys.dev_root); |
| } |
| |
| module_param(off, int, 0444); |
| module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); |
| core_initcall(cpuidle_init); |