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