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/kobject.h>
  17 #include <linux/completion.h>
  18 #include <linux/hrtimer.h>
  19
  20 #define CPUIDLE_STATE_MAX       8
  21 #define CPUIDLE_NAME_LEN        16
  22 #define CPUIDLE_DESC_LEN        32
  23
  24 struct module;
  25
  26 struct cpuidle_device;
  27 struct cpuidle_driver;
  28
  29
  30 /****************************
  31  * CPUIDLE DEVICE INTERFACE *
  32  ****************************/
  33
  34 struct cpuidle_state_usage {
  35         void            *driver_data;
  36
  37         unsigned long long      disable;
  38         unsigned long long      usage;
  39         unsigned long long      time; /* in US */
  40 };
  41
  42 struct cpuidle_state {
  43         char            name[CPUIDLE_NAME_LEN];
  44         char            desc[CPUIDLE_DESC_LEN];
  45
  46         unsigned int    flags;
  47         unsigned int    exit_latency; /* in US */
  48         int             power_usage; /* in mW */
  49         unsigned int    target_residency; /* in US */
  50
  51         int (*enter)    (struct cpuidle_device *dev,
  52                         struct cpuidle_driver *drv,
  53                         int index);
  54
  55         int (*enter_dead) (struct cpuidle_device *dev, int index);
  56 };
  57
  58 /* Idle State Flags */
  59 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  60
  61 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  62
  63 /**
  64  * cpuidle_get_statedata - retrieves private driver state data
  65  * @st_usage: the state usage statistics
  66  */
  67 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
  68 {
  69         return st_usage->driver_data;
  70 }
  71
  72 /**
  73  * cpuidle_set_statedata - stores private driver state data
  74  * @st_usage: the state usage statistics
  75  * @data: the private data
  76  */
  77 static inline void
  78 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
  79 {
  80         st_usage->driver_data = data;
  81 }
  82
  83 struct cpuidle_state_kobj {
  84         struct cpuidle_state *state;
  85         struct cpuidle_state_usage *state_usage;
  86         struct completion kobj_unregister;
  87         struct kobject kobj;
  88 };
  89
  90 struct cpuidle_device {
  91         unsigned int            registered:1;
  92         unsigned int            enabled:1;
  93         unsigned int            cpu;
  94
  95         int                     last_residency;
  96         int                     state_count;
  97         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  98         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  99
 100         struct list_head        device_list;
 101         struct kobject          kobj;
 102         struct completion       kobj_unregister;
 103 };
 104
 105 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 106
 107 /**
 108  * cpuidle_get_last_residency - retrieves the last state's residency time
 109  * @dev: the target CPU
 110  *
 111  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 112  */
 113 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 114 {
 115         return dev->last_residency;
 116 }
 117
 118
 119 /****************************
 120  * CPUIDLE DRIVER INTERFACE *
 121  ****************************/
 122
 123 struct cpuidle_driver {
 124         const char              *name;
 125         struct module           *owner;
 126
 127         unsigned int            power_specified:1;
 128         /* set to 1 to use the core cpuidle time keeping (for all states). */
 129         unsigned int            en_core_tk_irqen:1;
 130         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 131         int                     state_count;
 132         int                     safe_state_index;
 133 };
 134
 135 #ifdef CONFIG_CPU_IDLE
 136 extern void disable_cpuidle(void);
 137 extern int cpuidle_idle_call(void);
 138 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 139 extern struct cpuidle_driver *cpuidle_get_driver(void);
 140 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 141 extern void cpuidle_driver_unref(void);
 142 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 143 extern int cpuidle_register_device(struct cpuidle_device *dev);
 144 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 145
 146 extern void cpuidle_pause_and_lock(void);
 147 extern void cpuidle_resume_and_unlock(void);
 148 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 149 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 150 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
 151                                 struct cpuidle_driver *drv, int index,
 152                                 int (*enter)(struct cpuidle_device *dev,
 153                                         struct cpuidle_driver *drv, int index));
 154 extern int cpuidle_play_dead(void);
 155
 156 #else
 157 static inline void disable_cpuidle(void) { }
 158 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 159 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 160 {return -ENODEV; }
 161 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 162 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 163 static inline void cpuidle_driver_unref(void) {}
 164 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 165 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 166 {return -ENODEV; }
 167 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 168
 169 static inline void cpuidle_pause_and_lock(void) { }
 170 static inline void cpuidle_resume_and_unlock(void) { }
 171 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 172 {return -ENODEV; }
 173 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 174 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
 175                                 struct cpuidle_driver *drv, int index,
 176                                 int (*enter)(struct cpuidle_device *dev,
 177                                         struct cpuidle_driver *drv, int index))
 178 { return -ENODEV; }
 179 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 180
 181 #endif
 182
 183 /******************************
 184  * CPUIDLE GOVERNOR INTERFACE *
 185  ******************************/
 186
 187 struct cpuidle_governor {
 188         char                    name[CPUIDLE_NAME_LEN];
 189         struct list_head        governor_list;
 190         unsigned int            rating;
 191
 192         int  (*enable)          (struct cpuidle_driver *drv,
 193                                         struct cpuidle_device *dev);
 194         void (*disable)         (struct cpuidle_driver *drv,
 195                                         struct cpuidle_device *dev);
 196
 197         int  (*select)          (struct cpuidle_driver *drv,
 198                                         struct cpuidle_device *dev);
 199         void (*reflect)         (struct cpuidle_device *dev, int index);
 200
 201         struct module           *owner;
 202 };
 203
 204 #ifdef CONFIG_CPU_IDLE
 205
 206 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 207 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 208
 209 #else
 210
 211 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 212 {return 0;}
 213 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 214
 215 #endif
 216
 217 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 218 #define CPUIDLE_DRIVER_STATE_START      1
 219 #else
 220 #define CPUIDLE_DRIVER_STATE_START      0
 221 #endif
 222
 223 #endif /* _LINUX_CPUIDLE_H */