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       10
  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         unsigned long long      disable;
  36         unsigned long long      usage;
  37         unsigned long long      time; /* in US */
  38 };
  39
  40 struct cpuidle_state {
  41         char            name[CPUIDLE_NAME_LEN];
  42         char            desc[CPUIDLE_DESC_LEN];
  43
  44         unsigned int    flags;
  45         unsigned int    exit_latency; /* in US */
  46         int             power_usage; /* in mW */
  47         unsigned int    target_residency; /* in US */
  48         bool            disabled; /* disabled on all CPUs */
  49
  50         int (*enter)    (struct cpuidle_device *dev,
  51                         struct cpuidle_driver *drv,
  52                         int index);
  53
  54         int (*enter_dead) (struct cpuidle_device *dev, int index);
  55 };
  56
  57 /* Idle State Flags */
  58 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  59 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  60 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  61
  62 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  63
  64 struct cpuidle_device {
  65         unsigned int            registered:1;
  66         unsigned int            enabled:1;
  67         unsigned int            cpu;
  68
  69         int                     last_residency;
  70         int                     state_count;
  71         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  72         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  73         struct cpuidle_driver_kobj *kobj_driver;
  74         struct list_head        device_list;
  75         struct kobject          kobj;
  76         struct completion       kobj_unregister;
  77
  78 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  79         int                     safe_state_index;
  80         cpumask_t               coupled_cpus;
  81         struct cpuidle_coupled  *coupled;
  82 #endif
  83 };
  84
  85 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  86
  87 /**
  88  * cpuidle_get_last_residency - retrieves the last state's residency time
  89  * @dev: the target CPU
  90  *
  91  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
  92  */
  93 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  94 {
  95         return dev->last_residency;
  96 }
  97
  98
  99 /****************************
 100  * CPUIDLE DRIVER INTERFACE *
 101  ****************************/
 102
 103 struct cpuidle_driver {
 104         const char              *name;
 105         struct module           *owner;
 106         int                     refcnt;
 107
 108         /* used by the cpuidle framework to setup the broadcast timer */
 109         unsigned int            bctimer:1;
 110         /* states array must be ordered in decreasing power consumption */
 111         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 112         int                     state_count;
 113         int                     safe_state_index;
 114 };
 115
 116 #ifdef CONFIG_CPU_IDLE
 117 extern void disable_cpuidle(void);
 118 extern int cpuidle_idle_call(void);
 119 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 120 extern struct cpuidle_driver *cpuidle_get_driver(void);
 121 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 122 extern void cpuidle_driver_unref(void);
 123 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 124 extern int cpuidle_register_device(struct cpuidle_device *dev);
 125 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 126 extern int cpuidle_register(struct cpuidle_driver *drv,
 127                             const struct cpumask *const coupled_cpus);
 128 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 129 extern void cpuidle_pause_and_lock(void);
 130 extern void cpuidle_resume_and_unlock(void);
 131 extern void cpuidle_pause(void);
 132 extern void cpuidle_resume(void);
 133 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 134 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 135 extern int cpuidle_play_dead(void);
 136
 137 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 138 extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
 139 extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
 140
 141 #else
 142 static inline void disable_cpuidle(void) { }
 143 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 144 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 145 {return -ENODEV; }
 146 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 147 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 148 static inline void cpuidle_driver_unref(void) {}
 149 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 150 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 151 {return -ENODEV; }
 152 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 153 static inline int cpuidle_register(struct cpuidle_driver *drv,
 154                                    const struct cpumask *const coupled_cpus)
 155 {return -ENODEV; }
 156 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 157 static inline void cpuidle_pause_and_lock(void) { }
 158 static inline void cpuidle_resume_and_unlock(void) { }
 159 static inline void cpuidle_pause(void) { }
 160 static inline void cpuidle_resume(void) { }
 161 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 162 {return -ENODEV; }
 163 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 164 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 165 #endif
 166
 167 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 168 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 169 #else
 170 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 171 {
 172 }
 173 #endif
 174
 175 /******************************
 176  * CPUIDLE GOVERNOR INTERFACE *
 177  ******************************/
 178
 179 struct cpuidle_governor {
 180         char                    name[CPUIDLE_NAME_LEN];
 181         struct list_head        governor_list;
 182         unsigned int            rating;
 183
 184         int  (*enable)          (struct cpuidle_driver *drv,
 185                                         struct cpuidle_device *dev);
 186         void (*disable)         (struct cpuidle_driver *drv,
 187                                         struct cpuidle_device *dev);
 188
 189         int  (*select)          (struct cpuidle_driver *drv,
 190                                         struct cpuidle_device *dev);
 191         void (*reflect)         (struct cpuidle_device *dev, int index);
 192
 193         struct module           *owner;
 194 };
 195
 196 #ifdef CONFIG_CPU_IDLE
 197
 198 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 199 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 200
 201 #else
 202
 203 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 204 {return 0;}
 205 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 206
 207 #endif
 208
 209 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 210 #define CPUIDLE_DRIVER_STATE_START      1
 211 #else
 212 #define CPUIDLE_DRIVER_STATE_START      0
 213 #endif
 214
 215 #endif /* _LINUX_CPUIDLE_H */