diff options
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 49 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 4 | ||||
| -rw-r--r-- | include/linux/suspend.h | 16 | ||||
| -rw-r--r-- | kernel/power/suspend.c | 43 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 16 |
5 files changed, 96 insertions, 32 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 125150d..23a8d6c 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -19,6 +19,7 @@ #include <linux/ktime.h> #include <linux/hrtimer.h> #include <linux/module.h> +#include <linux/suspend.h> #include <trace/events/power.h> #include "cpuidle.h" @@ -32,7 +33,6 @@ LIST_HEAD(cpuidle_detected_devices); static int enabled_devices; static int off __read_mostly; static int initialized __read_mostly; -static bool use_deepest_state __read_mostly; int cpuidle_disabled(void) { @@ -66,24 +66,9 @@ int cpuidle_play_dead(void) } /** - * 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). - * - * This function can only be called after cpuidle_pause() to avoid races. - */ -void cpuidle_use_deepest_state(bool enable) -{ - 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. + * cpuidle_find_deepest_state - Find deepest state meeting specific conditions. + * @drv: cpuidle driver for the given CPU. + * @dev: cpuidle device for the given CPU. */ static int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) @@ -105,6 +90,27 @@ static int cpuidle_find_deepest_state(struct cpuidle_driver *drv, } /** + * cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle. + * + * Find the deepest state available and enter it. + */ +void cpuidle_enter_freeze(void) +{ + struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + int index; + + index = cpuidle_find_deepest_state(drv, dev); + if (index >= 0) + cpuidle_enter(drv, dev, index); + else + arch_cpu_idle(); + + /* Interrupts are enabled again here. */ + local_irq_disable(); +} + +/** * cpuidle_enter_state - enter the state and update stats * @dev: cpuidle device for this cpu * @drv: cpuidle driver for this cpu @@ -166,9 +172,6 @@ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) if (!drv || !dev || !dev->enabled) return -EBUSY; - if (unlikely(use_deepest_state)) - return cpuidle_find_deepest_state(drv, dev); - return cpuidle_curr_governor->select(drv, dev); } @@ -200,7 +203,7 @@ int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, */ void cpuidle_reflect(struct cpuidle_device *dev, int index) { - if (cpuidle_curr_governor->reflect && !unlikely(use_deepest_state)) + if (cpuidle_curr_governor->reflect) cpuidle_curr_governor->reflect(dev, index); } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index ab70f3b..f63aabf 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -141,7 +141,7 @@ extern void cpuidle_resume(void); extern int cpuidle_enable_device(struct cpuidle_device *dev); extern void cpuidle_disable_device(struct cpuidle_device *dev); extern int cpuidle_play_dead(void); -extern void cpuidle_use_deepest_state(bool enable); +extern void cpuidle_enter_freeze(void); extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); #else @@ -174,7 +174,7 @@ static inline int cpuidle_enable_device(struct cpuidle_device *dev) {return -ENODEV; } static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } static inline int cpuidle_play_dead(void) {return -ENODEV; } -static inline void cpuidle_use_deepest_state(bool enable) {} +static inline void cpuidle_enter_freeze(void) { } static inline struct cpuidle_driver *cpuidle_get_cpu_driver( struct cpuidle_device *dev) {return NULL; } #endif diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 3388c1b..5efe743 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -201,6 +201,21 @@ struct platform_freeze_ops { */ extern void suspend_set_ops(const struct platform_suspend_ops *ops); extern int suspend_valid_only_mem(suspend_state_t state); + +/* Suspend-to-idle state machnine. */ +enum freeze_state { + FREEZE_STATE_NONE, /* Not suspended/suspending. */ + FREEZE_STATE_ENTER, /* Enter suspend-to-idle. */ + FREEZE_STATE_WAKE, /* Wake up from suspend-to-idle. */ +}; + +extern enum freeze_state __read_mostly suspend_freeze_state; + +static inline bool idle_should_freeze(void) +{ + return unlikely(suspend_freeze_state == FREEZE_STATE_ENTER); +} + extern void freeze_set_ops(const struct platform_freeze_ops *ops); extern void freeze_wake(void); @@ -228,6 +243,7 @@ extern int pm_suspend(suspend_state_t state); static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {} static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; } +static inline bool idle_should_freeze(void) { return false; } static inline void freeze_set_ops(const struct platform_freeze_ops *ops) {} static inline void freeze_wake(void) {} #endif /* !CONFIG_SUSPEND */ diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index c347e3c..b7d6b3a 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -37,7 +37,9 @@ const char *pm_states[PM_SUSPEND_MAX]; static const struct platform_suspend_ops *suspend_ops; static const struct platform_freeze_ops *freeze_ops; static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head); -static bool suspend_freeze_wake; + +enum freeze_state __read_mostly suspend_freeze_state; +static DEFINE_SPINLOCK(suspend_freeze_lock); void freeze_set_ops(const struct platform_freeze_ops *ops) { @@ -48,22 +50,49 @@ void freeze_set_ops(const struct platform_freeze_ops *ops) static void freeze_begin(void) { - suspend_freeze_wake = false; + suspend_freeze_state = FREEZE_STATE_NONE; } static void freeze_enter(void) { - cpuidle_use_deepest_state(true); + spin_lock_irq(&suspend_freeze_lock); + if (pm_wakeup_pending()) + goto out; + + suspend_freeze_state = FREEZE_STATE_ENTER; + spin_unlock_irq(&suspend_freeze_lock); + + get_online_cpus(); cpuidle_resume(); - wait_event(suspend_freeze_wait_head, suspend_freeze_wake); + + /* Push all the CPUs into the idle loop. */ + wake_up_all_idle_cpus(); + pr_debug("PM: suspend-to-idle\n"); + /* Make the current CPU wait so it can enter the idle loop too. */ + wait_event(suspend_freeze_wait_head, + suspend_freeze_state == FREEZE_STATE_WAKE); + pr_debug("PM: resume from suspend-to-idle\n"); + cpuidle_pause(); - cpuidle_use_deepest_state(false); + put_online_cpus(); + + spin_lock_irq(&suspend_freeze_lock); + + out: + suspend_freeze_state = FREEZE_STATE_NONE; + spin_unlock_irq(&suspend_freeze_lock); } void freeze_wake(void) { - suspend_freeze_wake = true; - wake_up(&suspend_freeze_wait_head); + unsigned long flags; + + spin_lock_irqsave(&suspend_freeze_lock, flags); + if (suspend_freeze_state > FREEZE_STATE_NONE) { + suspend_freeze_state = FREEZE_STATE_WAKE; + wake_up(&suspend_freeze_wait_head); + } + spin_unlock_irqrestore(&suspend_freeze_lock, flags); } EXPORT_SYMBOL_GPL(freeze_wake); diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index aaf1c1d..94b2d7b 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -7,6 +7,7 @@ #include <linux/tick.h> #include <linux/mm.h> #include <linux/stackprotector.h> +#include <linux/suspend.h> #include <asm/tlb.h> @@ -105,6 +106,21 @@ static void cpuidle_idle_call(void) rcu_idle_enter(); /* + * Suspend-to-idle ("freeze") is a system state in which all user space + * has been frozen, all I/O devices have been suspended and the only + * activity happens here and in iterrupts (if any). In that case bypass + * the cpuidle governor and go stratight for the deepest idle state + * available. Possibly also suspend the local tick and the entire + * timekeeping to prevent timer interrupts from kicking us out of idle + * until a proper wakeup interrupt happens. + */ + if (idle_should_freeze()) { + cpuidle_enter_freeze(); + local_irq_enable(); + goto exit_idle; + } + + /* * Ask the cpuidle framework to choose a convenient idle state. * Fall back to the default arch idle method on errors. */ |
