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