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         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
  61 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  62
  63 struct cpuidle_device {
  64         unsigned int            registered:1;
  65         unsigned int            enabled:1;
  66         unsigned int            cpu;
  67
  68         int                     last_residency;
  69         int                     state_count;
  70         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  71         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  72         struct cpuidle_driver_kobj *kobj_driver;
  73         struct list_head        device_list;
  74         struct kobject          kobj;
  75         struct completion       kobj_unregister;
  76
  77 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  78         int                     safe_state_index;
  79         cpumask_t               coupled_cpus;
  80         struct cpuidle_coupled  *coupled;
  81 #endif
  82 };
  83
  84 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  85
  86 /**
  87  * cpuidle_get_last_residency - retrieves the last state's residency time
  88  * @dev: the target CPU
  89  *
  90  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
  91  */
  92 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  93 {
  94         return dev->last_residency;
  95 }
  96
  97
  98 /****************************
  99  * CPUIDLE DRIVER INTERFACE *
 100  ****************************/
 101
 102 struct cpuidle_driver {
 103         const char              *name;
 104         struct module           *owner;
 105         int                     refcnt;
 106
 107         /* set to 1 to use the core cpuidle time keeping (for all states). */
 108         unsigned int            en_core_tk_irqen:1;
 109         /* states array must be ordered in decreasing power consumption */
 110         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 111         int                     state_count;
 112         int                     safe_state_index;
 113 };
 114
 115 #ifdef CONFIG_CPU_IDLE
 116 extern void disable_cpuidle(void);
 117 extern int cpuidle_idle_call(void);
 118 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 119 extern struct cpuidle_driver *cpuidle_get_driver(void);
 120 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 121 extern void cpuidle_driver_unref(void);
 122 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 123 extern int cpuidle_register_device(struct cpuidle_device *dev);
 124 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 125
 126 extern void cpuidle_pause_and_lock(void);
 127 extern void cpuidle_resume_and_unlock(void);
 128 extern void cpuidle_pause(void);
 129 extern void cpuidle_resume(void);
 130 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 131 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 132 extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
 133                                 struct cpuidle_driver *drv, int index,
 134                                 int (*enter)(struct cpuidle_device *dev,
 135                                         struct cpuidle_driver *drv, int index));
 136 extern int cpuidle_play_dead(void);
 137
 138 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 139 extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
 140 extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
 141
 142 #else
 143 static inline void disable_cpuidle(void) { }
 144 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 145 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 146 {return -ENODEV; }
 147 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 148 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 149 static inline void cpuidle_driver_unref(void) {}
 150 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 151 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 152 {return -ENODEV; }
 153 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 154
 155 static inline void cpuidle_pause_and_lock(void) { }
 156 static inline void cpuidle_resume_and_unlock(void) { }
 157 static inline void cpuidle_pause(void) { }
 158 static inline void cpuidle_resume(void) { }
 159 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 160 {return -ENODEV; }
 161 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 162 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
 163                                 struct cpuidle_driver *drv, int index,
 164                                 int (*enter)(struct cpuidle_device *dev,
 165                                         struct cpuidle_driver *drv, int index))
 166 { return -ENODEV; }
 167 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 168 #endif
 169
 170 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 171 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 172 #else
 173 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 174 {
 175 }
 176 #endif
 177
 178 /******************************
 179  * CPUIDLE GOVERNOR INTERFACE *
 180  ******************************/
 181
 182 struct cpuidle_governor {
 183         char                    name[CPUIDLE_NAME_LEN];
 184         struct list_head        governor_list;
 185         unsigned int            rating;
 186
 187         int  (*enable)          (struct cpuidle_driver *drv,
 188                                         struct cpuidle_device *dev);
 189         void (*disable)         (struct cpuidle_driver *drv,
 190                                         struct cpuidle_device *dev);
 191
 192         int  (*select)          (struct cpuidle_driver *drv,
 193                                         struct cpuidle_device *dev);
 194         void (*reflect)         (struct cpuidle_device *dev, int index);
 195
 196         struct module           *owner;
 197 };
 198
 199 #ifdef CONFIG_CPU_IDLE
 200
 201 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 202 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 203
 204 #else
 205
 206 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 207 {return 0;}
 208 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 209
 210 #endif
 211
 212 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 213 #define CPUIDLE_DRIVER_STATE_START      1
 214 #else
 215 #define CPUIDLE_DRIVER_STATE_START      0
 216 #endif
 217
 218 #endif /* _LINUX_CPUIDLE_H */