linux/include/linux/cpuidle.h
<<
>>
Prefs 
   1/*
   2 * cpuidle.h - a generic framework for CPU idle power management
   3 *
   4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
   5 *          Shaohua Li <shaohua.li@intel.com>
   6 *          Adam Belay <abelay@novell.com>
   7 *
   8 * This code is licenced under the GPL.
   9 */
  10
  11#ifndef _LINUX_CPUIDLE_H
  12#define _LINUX_CPUIDLE_H
  13
  14#include <linux/percpu.h>
  15#include <linux/list.h>
  16#include <linux/hrtimer.h>
  17
  18#define CPUIDLE_STATE_MAX       10
  19#define CPUIDLE_NAME_LEN        16
  20#define CPUIDLE_DESC_LEN        32
  21
  22struct module;
  23
  24struct cpuidle_device;
  25struct cpuidle_driver;
  26
  27
  28/****************************
  29 * CPUIDLE DEVICE INTERFACE *
  30 ****************************/
  31
  32struct cpuidle_state_usage {
  33        unsigned long long      disable;
  34        unsigned long long      usage;
  35        unsigned long long      time; /* in US */
  36        unsigned long long      above; /* Number of times it's been too deep */
  37        unsigned long long      below; /* Number of times it's been too shallow */
  38#ifdef CONFIG_SUSPEND
  39        unsigned long long      s2idle_usage;
  40        unsigned long long      s2idle_time; /* in US */
  41#endif
  42};
  43
  44struct cpuidle_state {
  45        char            name[CPUIDLE_NAME_LEN];
  46        char            desc[CPUIDLE_DESC_LEN];
  47
  48        unsigned int    flags;
  49        unsigned int    exit_latency; /* in US */
  50        int             power_usage; /* in mW */
  51        unsigned int    target_residency; /* in US */
  52        bool            disabled; /* disabled on all CPUs */
  53
  54        int (*enter)    (struct cpuidle_device *dev,
  55                        struct cpuidle_driver *drv,
  56                        int index);
  57
  58        int (*enter_dead) (struct cpuidle_device *dev, int index);
  59
  60        /*
  61         * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
  62         * suspended, so it must not re-enable interrupts at any point (even
  63         * temporarily) or attempt to change states of clock event devices.
  64         */
  65        void (*enter_s2idle) (struct cpuidle_device *dev,
  66                              struct cpuidle_driver *drv,
  67                              int index);
  68};
  69
  70/* Idle State Flags */
  71#define CPUIDLE_FLAG_NONE       (0x00)
  72#define CPUIDLE_FLAG_POLLING    BIT(0) /* polling state */
  73#define CPUIDLE_FLAG_COUPLED    BIT(1) /* state applies to multiple cpus */
  74#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
  75
  76struct cpuidle_device_kobj;
  77struct cpuidle_state_kobj;
  78struct cpuidle_driver_kobj;
  79
  80struct cpuidle_device {
  81        unsigned int            registered:1;
  82        unsigned int            enabled:1;
  83        unsigned int            use_deepest_state:1;
  84        unsigned int            poll_time_limit:1;
  85        unsigned int            cpu;
  86        ktime_t                 next_hrtimer;
  87
  88        int                     last_residency;
  89        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  90        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  91        struct cpuidle_driver_kobj *kobj_driver;
  92        struct cpuidle_device_kobj *kobj_dev;
  93        struct list_head        device_list;
  94
  95#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  96        cpumask_t               coupled_cpus;
  97        struct cpuidle_coupled  *coupled;
  98#endif
  99};
 100
 101DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 102DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 103
 104/****************************
 105 * CPUIDLE DRIVER INTERFACE *
 106 ****************************/
 107
 108struct cpuidle_driver {
 109        const char              *name;
 110        struct module           *owner;
 111        int                     refcnt;
 112
 113        /* used by the cpuidle framework to setup the broadcast timer */
 114        unsigned int            bctimer:1;
 115        /* states array must be ordered in decreasing power consumption */
 116        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 117        int                     state_count;
 118        int                     safe_state_index;
 119
 120        /* the driver handles the cpus in cpumask */
 121        struct cpumask          *cpumask;
 122};
 123
 124#ifdef CONFIG_CPU_IDLE
 125extern void disable_cpuidle(void);
 126extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 127                                  struct cpuidle_device *dev);
 128
 129extern int cpuidle_select(struct cpuidle_driver *drv,
 130                          struct cpuidle_device *dev,
 131                          bool *stop_tick);
 132extern int cpuidle_enter(struct cpuidle_driver *drv,
 133                         struct cpuidle_device *dev, int index);
 134extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 135
 136extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 137extern struct cpuidle_driver *cpuidle_get_driver(void);
 138extern struct cpuidle_driver *cpuidle_driver_ref(void);
 139extern void cpuidle_driver_unref(void);
 140extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 141extern int cpuidle_register_device(struct cpuidle_device *dev);
 142extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 143extern int cpuidle_register(struct cpuidle_driver *drv,
 144                            const struct cpumask *const coupled_cpus);
 145extern void cpuidle_unregister(struct cpuidle_driver *drv);
 146extern void cpuidle_pause_and_lock(void);
 147extern void cpuidle_resume_and_unlock(void);
 148extern void cpuidle_pause(void);
 149extern void cpuidle_resume(void);
 150extern int cpuidle_enable_device(struct cpuidle_device *dev);
 151extern void cpuidle_disable_device(struct cpuidle_device *dev);
 152extern int cpuidle_play_dead(void);
 153
 154extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 155static inline struct cpuidle_device *cpuidle_get_device(void)
 156{return __this_cpu_read(cpuidle_devices); }
 157#else
 158static inline void disable_cpuidle(void) { }
 159static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 160                                         struct cpuidle_device *dev)
 161{return true; }
 162static inline int cpuidle_select(struct cpuidle_driver *drv,
 163                                 struct cpuidle_device *dev, bool *stop_tick)
 164{return -ENODEV; }
 165static inline int cpuidle_enter(struct cpuidle_driver *drv,
 166                                struct cpuidle_device *dev, int index)
 167{return -ENODEV; }
 168static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 169static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 170{return -ENODEV; }
 171static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 172static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 173static inline void cpuidle_driver_unref(void) {}
 174static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 175static inline int cpuidle_register_device(struct cpuidle_device *dev)
 176{return -ENODEV; }
 177static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 178static inline int cpuidle_register(struct cpuidle_driver *drv,
 179                                   const struct cpumask *const coupled_cpus)
 180{return -ENODEV; }
 181static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 182static inline void cpuidle_pause_and_lock(void) { }
 183static inline void cpuidle_resume_and_unlock(void) { }
 184static inline void cpuidle_pause(void) { }
 185static inline void cpuidle_resume(void) { }
 186static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 187{return -ENODEV; }
 188static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 189static inline int cpuidle_play_dead(void) {return -ENODEV; }
 190static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 191        struct cpuidle_device *dev) {return NULL; }
 192static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 193#endif
 194
 195#ifdef CONFIG_CPU_IDLE
 196extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 197                                      struct cpuidle_device *dev);
 198extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 199                                struct cpuidle_device *dev);
 200extern void cpuidle_use_deepest_state(bool enable);
 201#else
 202static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 203                                             struct cpuidle_device *dev)
 204{return -ENODEV; }
 205static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 206                                       struct cpuidle_device *dev)
 207{return -ENODEV; }
 208static inline void cpuidle_use_deepest_state(bool enable)
 209{
 210}
 211#endif
 212
 213/* kernel/sched/idle.c */
 214extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 215extern void default_idle_call(void);
 216
 217#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 218void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 219#else
 220static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 221{
 222}
 223#endif
 224
 225#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 226void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 227#else
 228static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 229#endif
 230
 231/******************************
 232 * CPUIDLE GOVERNOR INTERFACE *
 233 ******************************/
 234
 235struct cpuidle_governor {
 236        char                    name[CPUIDLE_NAME_LEN];
 237        struct list_head        governor_list;
 238        unsigned int            rating;
 239
 240        int  (*enable)          (struct cpuidle_driver *drv,
 241                                        struct cpuidle_device *dev);
 242        void (*disable)         (struct cpuidle_driver *drv,
 243                                        struct cpuidle_device *dev);
 244
 245        int  (*select)          (struct cpuidle_driver *drv,
 246                                        struct cpuidle_device *dev,
 247                                        bool *stop_tick);
 248        void (*reflect)         (struct cpuidle_device *dev, int index);
 249};
 250
 251#ifdef CONFIG_CPU_IDLE
 252extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 253extern int cpuidle_governor_latency_req(unsigned int cpu);
 254#else
 255static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 256{return 0;}
 257#endif
 258
 259#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
 260({                                                                      \
 261        int __ret = 0;                                                  \
 262                                                                        \
 263        if (!idx) {                                                     \
 264                cpu_do_idle();                                          \
 265                return idx;                                             \
 266        }                                                               \
 267                                                                        \
 268        if (!is_retention)                                              \
 269                __ret =  cpu_pm_enter();                                \
 270        if (!__ret) {                                                   \
 271                __ret = low_level_idle_enter(idx);                      \
 272                if (!is_retention)                                      \
 273                        cpu_pm_exit();                                  \
 274        }                                                               \
 275                                                                        \
 276        __ret ? -1 : idx;                                               \
 277})
 278
 279#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 280        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
 281
 282#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx)      \
 283        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
 284
 285#endif /* _LINUX_CPUIDLE_H */
 286
Hosted by Missing Link Electronics. The original LXR software by the LXR community, this experimental version by lxr@linux.no.