LXR linux/include/linux/cpuidle.h

   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
  32#define CPUIDLE_STATE_DISABLED_BY_USER          BIT(0)
  33#define CPUIDLE_STATE_DISABLED_BY_DRIVER        BIT(1)
  34
  35struct cpuidle_state_usage {
  36        unsigned long long      disable;
  37        unsigned long long      usage;
  38        u64                     time_ns;
  39        unsigned long long      above; /* Number of times it's been too deep */
  40        unsigned long long      below; /* Number of times it's been too shallow */
  41        unsigned long long      rejected; /* Number of times idle entry was rejected */
  42#ifdef CONFIG_SUSPEND
  43        unsigned long long      s2idle_usage;
  44        unsigned long long      s2idle_time; /* in US */
  45#endif
  46};
  47
  48struct cpuidle_state {
  49        char            name[CPUIDLE_NAME_LEN];
  50        char            desc[CPUIDLE_DESC_LEN];
  51
  52        s64             exit_latency_ns;
  53        s64             target_residency_ns;
  54        unsigned int    flags;
  55        unsigned int    exit_latency; /* in US */
  56        int             power_usage; /* in mW */
  57        unsigned int    target_residency; /* in US */
  58
  59        int (*enter)    (struct cpuidle_device *dev,
  60                        struct cpuidle_driver *drv,
  61                        int index);
  62
  63        int (*enter_dead) (struct cpuidle_device *dev, int index);
  64
  65        /*
  66         * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
  67         * suspended, so it must not re-enable interrupts at any point (even
  68         * temporarily) or attempt to change states of clock event devices.
  69         *
  70         * This callback may point to the same function as ->enter if all of
  71         * the above requirements are met by it.
  72         */
  73        int (*enter_s2idle)(struct cpuidle_device *dev,
  74                            struct cpuidle_driver *drv,
  75                            int index);
  76};
  77
  78/* Idle State Flags */
  79#define CPUIDLE_FLAG_NONE               (0x00)
  80#define CPUIDLE_FLAG_POLLING            BIT(0) /* polling state */
  81#define CPUIDLE_FLAG_COUPLED            BIT(1) /* state applies to multiple cpus */
  82#define CPUIDLE_FLAG_TIMER_STOP         BIT(2) /* timer is stopped on this state */
  83#define CPUIDLE_FLAG_UNUSABLE           BIT(3) /* avoid using this state */
  84#define CPUIDLE_FLAG_OFF                BIT(4) /* disable this state by default */
  85#define CPUIDLE_FLAG_TLB_FLUSHED        BIT(5) /* idle-state flushes TLBs */
  86#define CPUIDLE_FLAG_RCU_IDLE           BIT(6) /* idle-state takes care of RCU */
  87
  88struct cpuidle_device_kobj;
  89struct cpuidle_state_kobj;
  90struct cpuidle_driver_kobj;
  91
  92struct cpuidle_device {
  93        unsigned int            registered:1;
  94        unsigned int            enabled:1;
  95        unsigned int            poll_time_limit:1;
  96        unsigned int            cpu;
  97        ktime_t                 next_hrtimer;
  98
  99        int                     last_state_idx;
 100        u64                     last_residency_ns;
 101        u64                     poll_limit_ns;
 102        u64                     forced_idle_latency_limit_ns;
 103        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
 104        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
 105        struct cpuidle_driver_kobj *kobj_driver;
 106        struct cpuidle_device_kobj *kobj_dev;
 107        struct list_head        device_list;
 108
 109#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 110        cpumask_t               coupled_cpus;
 111        struct cpuidle_coupled  *coupled;
 112#endif
 113};
 114
 115DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 116DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 117
 118/****************************
 119 * CPUIDLE DRIVER INTERFACE *
 120 ****************************/
 121
 122struct cpuidle_driver {
 123        const char              *name;
 124        struct module           *owner;
 125
 126        /* used by the cpuidle framework to setup the broadcast timer */
 127        unsigned int            bctimer:1;
 128        /* states array must be ordered in decreasing power consumption */
 129        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 130        int                     state_count;
 131        int                     safe_state_index;
 132
 133        /* the driver handles the cpus in cpumask */
 134        struct cpumask          *cpumask;
 135
 136        /* preferred governor to switch at register time */
 137        const char              *governor;
 138};
 139
 140#ifdef CONFIG_CPU_IDLE
 141extern void disable_cpuidle(void);
 142extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 143                                  struct cpuidle_device *dev);
 144
 145extern int cpuidle_select(struct cpuidle_driver *drv,
 146                          struct cpuidle_device *dev,
 147                          bool *stop_tick);
 148extern int cpuidle_enter(struct cpuidle_driver *drv,
 149                         struct cpuidle_device *dev, int index);
 150extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 151extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 152                             struct cpuidle_device *dev);
 153
 154extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 155extern struct cpuidle_driver *cpuidle_get_driver(void);
 156extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
 157                                        bool disable);
 158extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 159extern int cpuidle_register_device(struct cpuidle_device *dev);
 160extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 161extern int cpuidle_register(struct cpuidle_driver *drv,
 162                            const struct cpumask *const coupled_cpus);
 163extern void cpuidle_unregister(struct cpuidle_driver *drv);
 164extern void cpuidle_pause_and_lock(void);
 165extern void cpuidle_resume_and_unlock(void);
 166extern void cpuidle_pause(void);
 167extern void cpuidle_resume(void);
 168extern int cpuidle_enable_device(struct cpuidle_device *dev);
 169extern void cpuidle_disable_device(struct cpuidle_device *dev);
 170extern int cpuidle_play_dead(void);
 171
 172extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 173static inline struct cpuidle_device *cpuidle_get_device(void)
 174{return __this_cpu_read(cpuidle_devices); }
 175#else
 176static inline void disable_cpuidle(void) { }
 177static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 178                                         struct cpuidle_device *dev)
 179{return true; }
 180static inline int cpuidle_select(struct cpuidle_driver *drv,
 181                                 struct cpuidle_device *dev, bool *stop_tick)
 182{return -ENODEV; }
 183static inline int cpuidle_enter(struct cpuidle_driver *drv,
 184                                struct cpuidle_device *dev, int index)
 185{return -ENODEV; }
 186static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 187static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 188                             struct cpuidle_device *dev)
 189{return 0; }
 190static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 191{return -ENODEV; }
 192static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 193static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
 194                                               int idx, bool disable) { }
 195static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 196static inline int cpuidle_register_device(struct cpuidle_device *dev)
 197{return -ENODEV; }
 198static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 199static inline int cpuidle_register(struct cpuidle_driver *drv,
 200                                   const struct cpumask *const coupled_cpus)
 201{return -ENODEV; }
 202static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 203static inline void cpuidle_pause_and_lock(void) { }
 204static inline void cpuidle_resume_and_unlock(void) { }
 205static inline void cpuidle_pause(void) { }
 206static inline void cpuidle_resume(void) { }
 207static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 208{return -ENODEV; }
 209static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 210static inline int cpuidle_play_dead(void) {return -ENODEV; }
 211static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 212        struct cpuidle_device *dev) {return NULL; }
 213static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 214#endif
 215
 216#ifdef CONFIG_CPU_IDLE
 217extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 218                                      struct cpuidle_device *dev,
 219                                      u64 latency_limit_ns);
 220extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 221                                struct cpuidle_device *dev);
 222extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
 223#else
 224static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 225                                             struct cpuidle_device *dev,
 226                                             u64 latency_limit_ns)
 227{return -ENODEV; }
 228static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 229                                       struct cpuidle_device *dev)
 230{return -ENODEV; }
 231static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
 232{
 233}
 234#endif
 235
 236/* kernel/sched/idle.c */
 237extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 238extern void default_idle_call(void);
 239
 240#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 241void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 242#else
 243static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 244{
 245}
 246#endif
 247
 248#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 249void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 250#else
 251static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 252#endif
 253
 254/******************************
 255 * CPUIDLE GOVERNOR INTERFACE *
 256 ******************************/
 257
 258struct cpuidle_governor {
 259        char                    name[CPUIDLE_NAME_LEN];
 260        struct list_head        governor_list;
 261        unsigned int            rating;
 262
 263        int  (*enable)          (struct cpuidle_driver *drv,
 264                                        struct cpuidle_device *dev);
 265        void (*disable)         (struct cpuidle_driver *drv,
 266                                        struct cpuidle_device *dev);
 267
 268        int  (*select)          (struct cpuidle_driver *drv,
 269                                        struct cpuidle_device *dev,
 270                                        bool *stop_tick);
 271        void (*reflect)         (struct cpuidle_device *dev, int index);
 272};
 273
 274extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 275extern s64 cpuidle_governor_latency_req(unsigned int cpu);
 276
 277#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter,                   \
 278                                idx,                                    \
 279                                state,                                  \
 280                                is_retention)                           \
 281({                                                                      \
 282        int __ret = 0;                                                  \
 283                                                                        \
 284        if (!idx) {                                                     \
 285                cpu_do_idle();                                          \
 286                return idx;                                             \
 287        }                                                               \
 288                                                                        \
 289        if (!is_retention)                                              \
 290                __ret =  cpu_pm_enter();                                \
 291        if (!__ret) {                                                   \
 292                __ret = low_level_idle_enter(state);                    \
 293                if (!is_retention)                                      \
 294                        cpu_pm_exit();                                  \
 295        }                                                               \
 296                                                                        \
 297        __ret ? -1 : idx;                                               \
 298})
 299
 300#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 301        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
 302
 303#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx)      \
 304        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
 305
 306#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state)   \
 307        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
 308
 309#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
 310        __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
 311
 312#endif /* _LINUX_CPUIDLE_H */
 313