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