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
  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         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
  48 struct 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
  88 struct cpuidle_device_kobj;
  89 struct cpuidle_state_kobj;
  90 struct cpuidle_driver_kobj;
  91
  92 struct 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
 115 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 116 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 117
 118 /****************************
 119  * CPUIDLE DRIVER INTERFACE *
 120  ****************************/
 121
 122 struct 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
 141 extern void disable_cpuidle(void);
 142 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 143                                   struct cpuidle_device *dev);
 144
 145 extern int cpuidle_select(struct cpuidle_driver *drv,
 146                           struct cpuidle_device *dev,
 147                           bool *stop_tick);
 148 extern int cpuidle_enter(struct cpuidle_driver *drv,
 149                          struct cpuidle_device *dev, int index);
 150 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 151 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 152                              struct cpuidle_device *dev);
 153
 154 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 155 extern struct cpuidle_driver *cpuidle_get_driver(void);
 156 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
 157                                         bool disable);
 158 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 159 extern int cpuidle_register_device(struct cpuidle_device *dev);
 160 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 161 extern int cpuidle_register(struct cpuidle_driver *drv,
 162                             const struct cpumask *const coupled_cpus);
 163 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 164 extern void cpuidle_pause_and_lock(void);
 165 extern void cpuidle_resume_and_unlock(void);
 166 extern void cpuidle_pause(void);
 167 extern void cpuidle_resume(void);
 168 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 169 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 170 extern int cpuidle_play_dead(void);
 171
 172 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 173 static inline struct cpuidle_device *cpuidle_get_device(void)
 174 {return __this_cpu_read(cpuidle_devices); }
 175 #else
 176 static inline void disable_cpuidle(void) { }
 177 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 178                                          struct cpuidle_device *dev)
 179 {return true; }
 180 static inline int cpuidle_select(struct cpuidle_driver *drv,
 181                                  struct cpuidle_device *dev, bool *stop_tick)
 182 {return -ENODEV; }
 183 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 184                                 struct cpuidle_device *dev, int index)
 185 {return -ENODEV; }
 186 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 187 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
 188                              struct cpuidle_device *dev)
 189 {return 0; }
 190 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 191 {return -ENODEV; }
 192 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 193 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
 194                                                int idx, bool disable) { }
 195 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 196 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 197 {return -ENODEV; }
 198 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 199 static inline int cpuidle_register(struct cpuidle_driver *drv,
 200                                    const struct cpumask *const coupled_cpus)
 201 {return -ENODEV; }
 202 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 203 static inline void cpuidle_pause_and_lock(void) { }
 204 static inline void cpuidle_resume_and_unlock(void) { }
 205 static inline void cpuidle_pause(void) { }
 206 static inline void cpuidle_resume(void) { }
 207 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 208 {return -ENODEV; }
 209 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 210 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 211 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 212         struct cpuidle_device *dev) {return NULL; }
 213 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 214 #endif
 215
 216 #ifdef CONFIG_CPU_IDLE
 217 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 218                                       struct cpuidle_device *dev,
 219                                       u64 latency_limit_ns);
 220 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 221                                 struct cpuidle_device *dev);
 222 extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
 223 #else
 224 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 225                                              struct cpuidle_device *dev,
 226                                              u64 latency_limit_ns)
 227 {return -ENODEV; }
 228 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 229                                        struct cpuidle_device *dev)
 230 {return -ENODEV; }
 231 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
 232 {
 233 }
 234 #endif
 235
 236 /* kernel/sched/idle.c */
 237 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 238 extern void default_idle_call(void);
 239
 240 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 241 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 242 #else
 243 static 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)
 249 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 250 #else
 251 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 252 #endif
 253
 254 /******************************
 255  * CPUIDLE GOVERNOR INTERFACE *
 256  ******************************/
 257
 258 struct 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
 274 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 275 extern 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 */