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 struct cpuidle_state_usage {
  33         unsigned long long      disable;
  34         unsigned long long      usage;
  35         unsigned long long      time; /* in US */
  36         unsigned long long      above; /* Number of times it's been too deep */
  37         unsigned long long      below; /* Number of times it's been too shallow */
  38 #ifdef CONFIG_SUSPEND
  39         unsigned long long      s2idle_usage;
  40         unsigned long long      s2idle_time; /* in US */
  41 #endif
  42 };
  43
  44 struct cpuidle_state {
  45         char            name[CPUIDLE_NAME_LEN];
  46         char            desc[CPUIDLE_DESC_LEN];
  47
  48         unsigned int    flags;
  49         unsigned int    exit_latency; /* in US */
  50         int             power_usage; /* in mW */
  51         unsigned int    target_residency; /* in US */
  52         bool            disabled; /* disabled on all CPUs */
  53
  54         int (*enter)    (struct cpuidle_device *dev,
  55                         struct cpuidle_driver *drv,
  56                         int index);
  57
  58         int (*enter_dead) (struct cpuidle_device *dev, int index);
  59
  60         /*
  61          * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
  62          * suspended, so it must not re-enable interrupts at any point (even
  63          * temporarily) or attempt to change states of clock event devices.
  64          */
  65         void (*enter_s2idle) (struct cpuidle_device *dev,
  66                               struct cpuidle_driver *drv,
  67                               int index);
  68 };
  69
  70 /* Idle State Flags */
  71 #define CPUIDLE_FLAG_NONE       (0x00)
  72 #define CPUIDLE_FLAG_POLLING    (0x01) /* polling state */
  73 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  74 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  75
  76 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  77
  78 struct cpuidle_device_kobj;
  79 struct cpuidle_state_kobj;
  80 struct cpuidle_driver_kobj;
  81
  82 struct cpuidle_device {
  83         unsigned int            registered:1;
  84         unsigned int            enabled:1;
  85         unsigned int            use_deepest_state:1;
  86         unsigned int            poll_time_limit:1;
  87         unsigned int            cpu;
  88
  89         int                     last_residency;
  90         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  91         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  92         struct cpuidle_driver_kobj *kobj_driver;
  93         struct cpuidle_device_kobj *kobj_dev;
  94         struct list_head        device_list;
  95
  96 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  97         cpumask_t               coupled_cpus;
  98         struct cpuidle_coupled  *coupled;
  99 #endif
 100 };
 101
 102 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 103 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 104
 105 /****************************
 106  * CPUIDLE DRIVER INTERFACE *
 107  ****************************/
 108
 109 struct cpuidle_driver {
 110         const char              *name;
 111         struct module           *owner;
 112         int                     refcnt;
 113
 114         /* used by the cpuidle framework to setup the broadcast timer */
 115         unsigned int            bctimer:1;
 116         /* states array must be ordered in decreasing power consumption */
 117         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 118         int                     state_count;
 119         int                     safe_state_index;
 120
 121         /* the driver handles the cpus in cpumask */
 122         struct cpumask          *cpumask;
 123 };
 124
 125 #ifdef CONFIG_CPU_IDLE
 126 extern void disable_cpuidle(void);
 127 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 128                                   struct cpuidle_device *dev);
 129
 130 extern int cpuidle_select(struct cpuidle_driver *drv,
 131                           struct cpuidle_device *dev,
 132                           bool *stop_tick);
 133 extern int cpuidle_enter(struct cpuidle_driver *drv,
 134                          struct cpuidle_device *dev, int index);
 135 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 136
 137 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 138 extern struct cpuidle_driver *cpuidle_get_driver(void);
 139 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 140 extern void cpuidle_driver_unref(void);
 141 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 142 extern int cpuidle_register_device(struct cpuidle_device *dev);
 143 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 144 extern int cpuidle_register(struct cpuidle_driver *drv,
 145                             const struct cpumask *const coupled_cpus);
 146 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 147 extern void cpuidle_pause_and_lock(void);
 148 extern void cpuidle_resume_and_unlock(void);
 149 extern void cpuidle_pause(void);
 150 extern void cpuidle_resume(void);
 151 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 152 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 153 extern int cpuidle_play_dead(void);
 154
 155 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 156 static inline struct cpuidle_device *cpuidle_get_device(void)
 157 {return __this_cpu_read(cpuidle_devices); }
 158 #else
 159 static inline void disable_cpuidle(void) { }
 160 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 161                                          struct cpuidle_device *dev)
 162 {return true; }
 163 static inline int cpuidle_select(struct cpuidle_driver *drv,
 164                                  struct cpuidle_device *dev, bool *stop_tick)
 165 {return -ENODEV; }
 166 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 167                                 struct cpuidle_device *dev, int index)
 168 {return -ENODEV; }
 169 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 170 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 171 {return -ENODEV; }
 172 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 173 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 174 static inline void cpuidle_driver_unref(void) {}
 175 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 176 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 177 {return -ENODEV; }
 178 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 179 static inline int cpuidle_register(struct cpuidle_driver *drv,
 180                                    const struct cpumask *const coupled_cpus)
 181 {return -ENODEV; }
 182 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 183 static inline void cpuidle_pause_and_lock(void) { }
 184 static inline void cpuidle_resume_and_unlock(void) { }
 185 static inline void cpuidle_pause(void) { }
 186 static inline void cpuidle_resume(void) { }
 187 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 188 {return -ENODEV; }
 189 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 190 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 191 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 192         struct cpuidle_device *dev) {return NULL; }
 193 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 194 #endif
 195
 196 #ifdef CONFIG_CPU_IDLE
 197 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 198                                       struct cpuidle_device *dev);
 199 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 200                                 struct cpuidle_device *dev);
 201 extern void cpuidle_use_deepest_state(bool enable);
 202 #else
 203 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 204                                              struct cpuidle_device *dev)
 205 {return -ENODEV; }
 206 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 207                                        struct cpuidle_device *dev)
 208 {return -ENODEV; }
 209 static inline void cpuidle_use_deepest_state(bool enable)
 210 {
 211 }
 212 #endif
 213
 214 /* kernel/sched/idle.c */
 215 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 216 extern void default_idle_call(void);
 217
 218 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 219 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 220 #else
 221 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 222 {
 223 }
 224 #endif
 225
 226 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 227 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 228 #else
 229 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 230 #endif
 231
 232 /******************************
 233  * CPUIDLE GOVERNOR INTERFACE *
 234  ******************************/
 235
 236 struct cpuidle_governor {
 237         char                    name[CPUIDLE_NAME_LEN];
 238         struct list_head        governor_list;
 239         unsigned int            rating;
 240
 241         int  (*enable)          (struct cpuidle_driver *drv,
 242                                         struct cpuidle_device *dev);
 243         void (*disable)         (struct cpuidle_driver *drv,
 244                                         struct cpuidle_device *dev);
 245
 246         int  (*select)          (struct cpuidle_driver *drv,
 247                                         struct cpuidle_device *dev,
 248                                         bool *stop_tick);
 249         void (*reflect)         (struct cpuidle_device *dev, int index);
 250 };
 251
 252 #ifdef CONFIG_CPU_IDLE
 253 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 254 extern int cpuidle_governor_latency_req(unsigned int cpu);
 255 #else
 256 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 257 {return 0;}
 258 #endif
 259
 260 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
 261 ({                                                                      \
 262         int __ret = 0;                                                  \
 263                                                                         \
 264         if (!idx) {                                                     \
 265                 cpu_do_idle();                                          \
 266                 return idx;                                             \
 267         }                                                               \
 268                                                                         \
 269         if (!is_retention)                                              \
 270                 __ret =  cpu_pm_enter();                                \
 271         if (!__ret) {                                                   \
 272                 __ret = low_level_idle_enter(idx);                      \
 273                 if (!is_retention)                                      \
 274                         cpu_pm_exit();                                  \
 275         }                                                               \
 276                                                                         \
 277         __ret ? -1 : idx;                                               \
 278 })
 279
 280 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 281         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
 282
 283 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx)      \
 284         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
 285
 286 #endif /* _LINUX_CPUIDLE_H */