include/linux/cpuidle.h

   1 /*
   2  * cpuidle.h - a generic framework for CPU idle power management
   3  *
   4  * (C) 2007 Venkatesh Pallipadi <[email protected]>
   5  *          Shaohua Li <[email protected]>
   6  *          Adam Belay <[email protected]>
   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
  22 struct module;
  23
  24 struct cpuidle_device;
  25 struct 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
  35 struct 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
  47 struct 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          * This callback may point to the same function as ->enter if all of
  70          * the above requirements are met by it.
  71          */
  72         int (*enter_s2idle)(struct cpuidle_device *dev,
  73                             struct cpuidle_driver *drv,
  74                             int index);
  75 };
  76
  77 /* Idle State Flags */
  78 #define CPUIDLE_FLAG_NONE               (0x00)
  79 #define CPUIDLE_FLAG_POLLING            BIT(0) /* polling state */
  80 #define CPUIDLE_FLAG_COUPLED            BIT(1) /* state applies to multiple cpus */
  81 #define CPUIDLE_FLAG_TIMER_STOP         BIT(2) /* timer is stopped on this state */
  82 #define CPUIDLE_FLAG_UNUSABLE           BIT(3) /* avoid using this state */
  83 #define CPUIDLE_FLAG_OFF                BIT(4) /* disable this state by default */
  84 #define CPUIDLE_FLAG_TLB_FLUSHED        BIT(5) /* idle-state flushes TLBs */
  85 #define CPUIDLE_FLAG_RCU_IDLE           BIT(6) /* idle-state takes care of RCU */
  86
  87 struct cpuidle_device_kobj;
  88 struct cpuidle_state_kobj;
  89 struct cpuidle_driver_kobj;
  90
  91 struct cpuidle_device {
  92         unsigned int            registered:1;
  93         unsigned int            enabled:1;
  94         unsigned int            poll_time_limit:1;
  95         unsigned int            cpu;
  96         ktime_t                 next_hrtimer;
  97
  98         int                     last_state_idx;
  99         u64                     last_residency_ns;
 100         u64                     poll_limit_ns;
 101         u64                     forced_idle_latency_limit_ns;
 102         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
 103         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
 104         struct cpuidle_driver_kobj *kobj_driver;
 105         struct cpuidle_device_kobj *kobj_dev;
 106         struct list_head        device_list;
 107
 108 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 109         cpumask_t               coupled_cpus;
 110         struct cpuidle_coupled  *coupled;
 111 #endif
 112 };
 113
 114 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 115 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 116
 117 /****************************
 118  * CPUIDLE DRIVER INTERFACE *
 119  ****************************/
 120
 121 struct cpuidle_driver {
 122         const char              *name;
 123         struct module           *owner;
 124
 125         /* used by the cpuidle framework to setup the broadcast timer */
 126         unsigned int            bctimer:1;
 127         /* states array must be ordered in decreasing power consumption */
 128         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 129         int                     state_count;
 130         int                     safe_state_index;
 131
 132         /* the driver handles the cpus in cpumask */
 133         struct cpumask          *cpumask;
 134
 135         /* preferred governor to switch at register time */
 136         const char              *governor;
 137 };
 138
 139 #ifdef CONFIG_CPU_IDLE
 140 extern void disable_cpuidle(void);
 141 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 142                                   struct cpuidle_device *dev);
 143
 144 extern int cpuidle_select(struct cpuidle_driver *drv,
 145                           struct cpuidle_device *dev,
 146                           bool *stop_tick);
 147 extern int cpuidle_enter(struct cpuidle_driver *drv,
 148                          struct cpuidle_device *dev, int index);
 149 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 150 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 151                              struct cpuidle_device *dev);
 152
 153 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 154 extern struct cpuidle_driver *cpuidle_get_driver(void);
 155 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
 156                                         bool disable);
 157 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 158 extern int cpuidle_register_device(struct cpuidle_device *dev);
 159 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 160 extern int cpuidle_register(struct cpuidle_driver *drv,
 161                             const struct cpumask *const coupled_cpus);
 162 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 163 extern void cpuidle_pause_and_lock(void);
 164 extern void cpuidle_resume_and_unlock(void);
 165 extern void cpuidle_pause(void);
 166 extern void cpuidle_resume(void);
 167 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 168 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 169 extern int cpuidle_play_dead(void);
 170
 171 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 172 static inline struct cpuidle_device *cpuidle_get_device(void)
 173 {return __this_cpu_read(cpuidle_devices); }
 174 #else
 175 static inline void disable_cpuidle(void) { }
 176 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 177                                          struct cpuidle_device *dev)
 178 {return true; }
 179 static inline int cpuidle_select(struct cpuidle_driver *drv,
 180                                  struct cpuidle_device *dev, bool *stop_tick)
 181 {return -ENODEV; }
 182 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 183                                 struct cpuidle_device *dev, int index)
 184 {return -ENODEV; }
 185 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 186 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 187                              struct cpuidle_device *dev)
 188 {return 0; }
 189 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 190 {return -ENODEV; }
 191 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 192 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
 193                                                int idx, bool disable) { }
 194 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 195 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 196 {return -ENODEV; }
 197 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 198 static inline int cpuidle_register(struct cpuidle_driver *drv,
 199                                    const struct cpumask *const coupled_cpus)
 200 {return -ENODEV; }
 201 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 202 static inline void cpuidle_pause_and_lock(void) { }
 203 static inline void cpuidle_resume_and_unlock(void) { }
 204 static inline void cpuidle_pause(void) { }
 205 static inline void cpuidle_resume(void) { }
 206 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 207 {return -ENODEV; }
 208 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 209 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 210 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 211         struct cpuidle_device *dev) {return NULL; }
 212 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 213 #endif
 214
 215 #ifdef CONFIG_CPU_IDLE
 216 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 217                                       struct cpuidle_device *dev,
 218                                       u64 latency_limit_ns);
 219 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 220                                 struct cpuidle_device *dev);
 221 extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
 222 #else
 223 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 224                                              struct cpuidle_device *dev,
 225                                              u64 latency_limit_ns)
 226 {return -ENODEV; }
 227 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 228                                        struct cpuidle_device *dev)
 229 {return -ENODEV; }
 230 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
 231 {
 232 }
 233 #endif
 234
 235 /* kernel/sched/idle.c */
 236 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 237 extern void default_idle_call(void);
 238
 239 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 240 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 241 #else
 242 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 243 {
 244 }
 245 #endif
 246
 247 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 248 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 249 #else
 250 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 251 #endif
 252
 253 /******************************
 254  * CPUIDLE GOVERNOR INTERFACE *
 255  ******************************/
 256
 257 struct cpuidle_governor {
 258         char                    name[CPUIDLE_NAME_LEN];
 259         struct list_head        governor_list;
 260         unsigned int            rating;
 261
 262         int  (*enable)          (struct cpuidle_driver *drv,
 263                                         struct cpuidle_device *dev);
 264         void (*disable)         (struct cpuidle_driver *drv,
 265                                         struct cpuidle_device *dev);
 266
 267         int  (*select)          (struct cpuidle_driver *drv,
 268                                         struct cpuidle_device *dev,
 269                                         bool *stop_tick);
 270         void (*reflect)         (struct cpuidle_device *dev, int index);
 271 };
 272
 273 #ifdef CONFIG_CPU_IDLE
 274 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 275 extern s64 cpuidle_governor_latency_req(unsigned int cpu);
 276 #else
 277 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 278 {return 0;}
 279 #endif
 280
 281 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter,                   \
 282                                 idx,                                    \
 283                                 state,                                  \
 284                                 is_retention)                           \
 285 ({                                                                      \
 286         int __ret = 0;                                                  \
 287                                                                         \
 288         if (!idx) {                                                     \
 289                 cpu_do_idle();                                          \
 290                 return idx;                                             \
 291         }                                                               \
 292                                                                         \
 293         if (!is_retention)                                              \
 294                 __ret =  cpu_pm_enter();                                \
 295         if (!__ret) {                                                   \
 296                 __ret = low_level_idle_enter(state);                    \
 297                 if (!is_retention)                                      \
 298                         cpu_pm_exit();                                  \
 299         }                                                               \
 300                                                                         \
 301         __ret ? -1 : idx;                                               \
 302 })
 303
 304 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 305         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
 306
 307 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx)      \
 308         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
 309
 310 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state)   \
 311         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
 312
 313 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
 314         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
 315
 316 #endif /* _LINUX_CPUIDLE_H */