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Diffstat (limited to 'include/linux/cpuidle.h')
| -rw-r--r-- | include/linux/cpuidle.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h new file mode 100644 index 000000000..3183aeb7f --- /dev/null +++ b/include/linux/cpuidle.h @@ -0,0 +1,352 @@ +/* + * cpuidle.h - a generic framework for CPU idle power management + * + * (C) 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. + */ + +#ifndef _LINUX_CPUIDLE_H +#define _LINUX_CPUIDLE_H + +#include <linux/percpu.h> +#include <linux/list.h> +#include <linux/hrtimer.h> +#include <linux/context_tracking.h> + +#define CPUIDLE_STATE_MAX 10 +#define CPUIDLE_NAME_LEN 16 +#define CPUIDLE_DESC_LEN 32 + +struct module; + +struct cpuidle_device; +struct cpuidle_driver; + + +/**************************** + * CPUIDLE DEVICE INTERFACE * + ****************************/ + +#define CPUIDLE_STATE_DISABLED_BY_USER BIT(0) +#define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1) + +struct cpuidle_state_usage { + unsigned long long disable; + unsigned long long usage; + u64 time_ns; + unsigned long long above; /* Number of times it's been too deep */ + unsigned long long below; /* Number of times it's been too shallow */ + unsigned long long rejected; /* Number of times idle entry was rejected */ +#ifdef CONFIG_SUSPEND + unsigned long long s2idle_usage; + unsigned long long s2idle_time; /* in US */ +#endif +}; + +struct cpuidle_state { + char name[CPUIDLE_NAME_LEN]; + char desc[CPUIDLE_DESC_LEN]; + + s64 exit_latency_ns; + s64 target_residency_ns; + unsigned int flags; + unsigned int exit_latency; /* in US */ + int power_usage; /* in mW */ + unsigned int target_residency; /* in US */ + + int (*enter) (struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index); + + int (*enter_dead) (struct cpuidle_device *dev, int index); + + /* + * CPUs execute ->enter_s2idle with the local tick or entire timekeeping + * suspended, so it must not re-enable interrupts at any point (even + * temporarily) or attempt to change states of clock event devices. + * + * This callback may point to the same function as ->enter if all of + * the above requirements are met by it. + */ + int (*enter_s2idle)(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index); +}; + +/* Idle State Flags */ +#define CPUIDLE_FLAG_NONE (0x00) +#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */ +#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */ +#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */ +#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */ +#define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ +#define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */ +#define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */ + +struct cpuidle_device_kobj; +struct cpuidle_state_kobj; +struct cpuidle_driver_kobj; + +struct cpuidle_device { + unsigned int registered:1; + unsigned int enabled:1; + unsigned int poll_time_limit:1; + unsigned int cpu; + ktime_t next_hrtimer; + + int last_state_idx; + u64 last_residency_ns; + u64 poll_limit_ns; + u64 forced_idle_latency_limit_ns; + struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; + struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; + struct cpuidle_driver_kobj *kobj_driver; + struct cpuidle_device_kobj *kobj_dev; + struct list_head device_list; + +#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED + cpumask_t coupled_cpus; + struct cpuidle_coupled *coupled; +#endif +}; + +DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); +DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); + +static __always_inline void ct_cpuidle_enter(void) +{ + lockdep_assert_irqs_disabled(); + /* + * Idle is allowed to (temporary) enable IRQs. It + * will return with IRQs disabled. + * + * Trace IRQs enable here, then switch off RCU, and have + * arch_cpu_idle() use raw_local_irq_enable(). Note that + * ct_idle_enter() relies on lockdep IRQ state, so switch that + * last -- this is very similar to the entry code. + */ + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(); + instrumentation_end(); + ct_idle_enter(); + lockdep_hardirqs_on(_RET_IP_); +} + +static __always_inline void ct_cpuidle_exit(void) +{ + /* + * Carefully undo the above. + */ + lockdep_hardirqs_off(_RET_IP_); + ct_idle_exit(); + instrumentation_begin(); +} + +/**************************** + * CPUIDLE DRIVER INTERFACE * + ****************************/ + +struct cpuidle_driver { + const char *name; + struct module *owner; + + /* used by the cpuidle framework to setup the broadcast timer */ + unsigned int bctimer:1; + /* states array must be ordered in decreasing power consumption */ + struct cpuidle_state states[CPUIDLE_STATE_MAX]; + int state_count; + int safe_state_index; + + /* the driver handles the cpus in cpumask */ + struct cpumask *cpumask; + + /* preferred governor to switch at register time */ + const char *governor; +}; + +#ifdef CONFIG_CPU_IDLE +extern void disable_cpuidle(void); +extern bool cpuidle_not_available(struct cpuidle_driver *drv, + struct cpuidle_device *dev); + +extern int cpuidle_select(struct cpuidle_driver *drv, + struct cpuidle_device *dev, + bool *stop_tick); +extern int cpuidle_enter(struct cpuidle_driver *drv, + struct cpuidle_device *dev, int index); +extern void cpuidle_reflect(struct cpuidle_device *dev, int index); +extern u64 cpuidle_poll_time(struct cpuidle_driver *drv, + struct cpuidle_device *dev); + +extern int cpuidle_register_driver(struct cpuidle_driver *drv); +extern struct cpuidle_driver *cpuidle_get_driver(void); +extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, + bool disable); +extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); +extern int cpuidle_register_device(struct cpuidle_device *dev); +extern void cpuidle_unregister_device(struct cpuidle_device *dev); +extern int cpuidle_register(struct cpuidle_driver *drv, + const struct cpumask *const coupled_cpus); +extern void cpuidle_unregister(struct cpuidle_driver *drv); +extern void cpuidle_pause_and_lock(void); +extern void cpuidle_resume_and_unlock(void); +extern void cpuidle_pause(void); +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 struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); +static inline struct cpuidle_device *cpuidle_get_device(void) +{return __this_cpu_read(cpuidle_devices); } +#else +static inline void disable_cpuidle(void) { } +static inline bool cpuidle_not_available(struct cpuidle_driver *drv, + struct cpuidle_device *dev) +{return true; } +static inline int cpuidle_select(struct cpuidle_driver *drv, + struct cpuidle_device *dev, bool *stop_tick) +{return -ENODEV; } +static inline int cpuidle_enter(struct cpuidle_driver *drv, + struct cpuidle_device *dev, int index) +{return -ENODEV; } +static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } +static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv, + struct cpuidle_device *dev) +{return 0; } +static inline int cpuidle_register_driver(struct cpuidle_driver *drv) +{return -ENODEV; } +static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } +static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, + int idx, bool disable) { } +static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } +static inline int cpuidle_register_device(struct cpuidle_device *dev) +{return -ENODEV; } +static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { } +static inline int cpuidle_register(struct cpuidle_driver *drv, + const struct cpumask *const coupled_cpus) +{return -ENODEV; } +static inline void cpuidle_unregister(struct cpuidle_driver *drv) { } +static inline void cpuidle_pause_and_lock(void) { } +static inline void cpuidle_resume_and_unlock(void) { } +static inline void cpuidle_pause(void) { } +static inline void cpuidle_resume(void) { } +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 struct cpuidle_driver *cpuidle_get_cpu_driver( + struct cpuidle_device *dev) {return NULL; } +static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } +#endif + +#ifdef CONFIG_CPU_IDLE +extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, + struct cpuidle_device *dev, + u64 latency_limit_ns); +extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, + struct cpuidle_device *dev); +extern void cpuidle_use_deepest_state(u64 latency_limit_ns); +#else +static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, + struct cpuidle_device *dev, + u64 latency_limit_ns) +{return -ENODEV; } +static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, + struct cpuidle_device *dev) +{return -ENODEV; } +static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) +{ +} +#endif + +/* kernel/sched/idle.c */ +extern void sched_idle_set_state(struct cpuidle_state *idle_state); +extern void default_idle_call(void); + +#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED +void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a); +#else +static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a) +{ +} +#endif + +#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) +void cpuidle_poll_state_init(struct cpuidle_driver *drv); +#else +static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} +#endif + +/****************************** + * CPUIDLE GOVERNOR INTERFACE * + ******************************/ + +struct cpuidle_governor { + char name[CPUIDLE_NAME_LEN]; + struct list_head governor_list; + unsigned int rating; + + int (*enable) (struct cpuidle_driver *drv, + struct cpuidle_device *dev); + void (*disable) (struct cpuidle_driver *drv, + struct cpuidle_device *dev); + + int (*select) (struct cpuidle_driver *drv, + struct cpuidle_device *dev, + bool *stop_tick); + void (*reflect) (struct cpuidle_device *dev, int index); +}; + +extern int cpuidle_register_governor(struct cpuidle_governor *gov); +extern s64 cpuidle_governor_latency_req(unsigned int cpu); + +#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ + idx, \ + state, \ + is_retention, is_rcu) \ +({ \ + int __ret = 0; \ + \ + if (!idx) { \ + cpu_do_idle(); \ + return idx; \ + } \ + \ + if (!is_retention) \ + __ret = cpu_pm_enter(); \ + if (!__ret) { \ + if (!is_rcu) \ + ct_cpuidle_enter(); \ + __ret = low_level_idle_enter(state); \ + if (!is_rcu) \ + ct_cpuidle_exit(); \ + if (!is_retention) \ + cpu_pm_exit(); \ + } \ + \ + __ret ? -1 : idx; \ +}) + +#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0, 0) + +#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1, 0) + +#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 0) + +#define CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(low_level_idle_enter, idx, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 1) + +#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 0) + +#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(low_level_idle_enter, idx, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 1) + +#endif /* _LINUX_CPUIDLE_H */ |