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         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
  82 struct cpuidle_device_kobj;
  83 struct cpuidle_state_kobj;
  84 struct cpuidle_driver_kobj;
  85
  86 struct 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
 109 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 110 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 111
 112 /****************************
 113  * CPUIDLE DRIVER INTERFACE *
 114  ****************************/
 115
 116 struct 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
 135 extern void disable_cpuidle(void);
 136 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 137                                   struct cpuidle_device *dev);
 138
 139 extern int cpuidle_select(struct cpuidle_driver *drv,
 140                           struct cpuidle_device *dev,
 141                           bool *stop_tick);
 142 extern int cpuidle_enter(struct cpuidle_driver *drv,
 143                          struct cpuidle_device *dev, int index);
 144 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 145 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 146                              struct cpuidle_device *dev);
 147
 148 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 149 extern struct cpuidle_driver *cpuidle_get_driver(void);
 150 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
 151                                         bool disable);
 152 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 153 extern int cpuidle_register_device(struct cpuidle_device *dev);
 154 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 155 extern int cpuidle_register(struct cpuidle_driver *drv,
 156                             const struct cpumask *const coupled_cpus);
 157 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 158 extern void cpuidle_pause_and_lock(void);
 159 extern void cpuidle_resume_and_unlock(void);
 160 extern void cpuidle_pause(void);
 161 extern void cpuidle_resume(void);
 162 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 163 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 164 extern int cpuidle_play_dead(void);
 165
 166 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 167 static inline struct cpuidle_device *cpuidle_get_device(void)
 168 {return __this_cpu_read(cpuidle_devices); }
 169 #else
 170 static inline void disable_cpuidle(void) { }
 171 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 172                                          struct cpuidle_device *dev)
 173 {return true; }
 174 static inline int cpuidle_select(struct cpuidle_driver *drv,
 175                                  struct cpuidle_device *dev, bool *stop_tick)
 176 {return -ENODEV; }
 177 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 178                                 struct cpuidle_device *dev, int index)
 179 {return -ENODEV; }
 180 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 181 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 182                              struct cpuidle_device *dev)
 183 {return 0; }
 184 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 185 {return -ENODEV; }
 186 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 187 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
 188                                                int idx, bool disable) { }
 189 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 190 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 191 {return -ENODEV; }
 192 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 193 static inline int cpuidle_register(struct cpuidle_driver *drv,
 194                                    const struct cpumask *const coupled_cpus)
 195 {return -ENODEV; }
 196 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 197 static inline void cpuidle_pause_and_lock(void) { }
 198 static inline void cpuidle_resume_and_unlock(void) { }
 199 static inline void cpuidle_pause(void) { }
 200 static inline void cpuidle_resume(void) { }
 201 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 202 {return -ENODEV; }
 203 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 204 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 205 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 206         struct cpuidle_device *dev) {return NULL; }
 207 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 208 #endif
 209
 210 #ifdef CONFIG_CPU_IDLE
 211 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 212                                       struct cpuidle_device *dev,
 213                                       u64 latency_limit_ns);
 214 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 215                                 struct cpuidle_device *dev);
 216 extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
 217 #else
 218 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 219                                              struct cpuidle_device *dev,
 220                                              u64 latency_limit_ns)
 221 {return -ENODEV; }
 222 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 223                                        struct cpuidle_device *dev)
 224 {return -ENODEV; }
 225 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
 226 {
 227 }
 228 #endif
 229
 230 /* kernel/sched/idle.c */
 231 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 232 extern void default_idle_call(void);
 233
 234 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 235 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 236 #else
 237 static 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)
 243 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 244 #else
 245 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 246 #endif
 247
 248 /******************************
 249  * CPUIDLE GOVERNOR INTERFACE *
 250  ******************************/
 251
 252 struct 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
 269 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 270 extern s64 cpuidle_governor_latency_req(unsigned int cpu);
 271 #else
 272 static 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 */