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 /* Idle State Flags */
  56 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  57 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  58 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  59
  60 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  61
  62 struct cpuidle_device_kobj;
  63 struct cpuidle_state_kobj;
  64 struct cpuidle_driver_kobj;
  65
  66 struct cpuidle_device {
  67         unsigned int            registered:1;
  68         unsigned int            enabled:1;
  69         unsigned int            cpu;
  70
  71         int                     last_residency;
  72         int                     state_count;
  73         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  74         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  75         struct cpuidle_driver_kobj *kobj_driver;
  76         struct cpuidle_device_kobj *kobj_dev;
  77         struct list_head        device_list;
  78
  79 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  80         int                     safe_state_index;
  81         cpumask_t               coupled_cpus;
  82         struct cpuidle_coupled  *coupled;
  83 #endif
  84 };
  85
  86 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  87 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  88
  89 /**
  90  * cpuidle_get_last_residency - retrieves the last state's residency time
  91  * @dev: the target CPU
  92  *
  93  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
  94  */
  95 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  96 {
  97         return dev->last_residency;
  98 }
  99
 100
 101 /****************************
 102  * CPUIDLE DRIVER INTERFACE *
 103  ****************************/
 104
 105 struct cpuidle_driver {
 106         const char              *name;
 107         struct module           *owner;
 108         int                     refcnt;
 109
 110         /* used by the cpuidle framework to setup the broadcast timer */
 111         unsigned int            bctimer:1;
 112         /* states array must be ordered in decreasing power consumption */
 113         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 114         int                     state_count;
 115         int                     safe_state_index;
 116
 117         /* the driver handles the cpus in cpumask */
 118         struct cpumask          *cpumask;
 119 };
 120
 121 #ifdef CONFIG_CPU_IDLE
 122 extern void disable_cpuidle(void);
 123
 124 extern int cpuidle_select(struct cpuidle_driver *drv,
 125                           struct cpuidle_device *dev);
 126 extern int cpuidle_enter(struct cpuidle_driver *drv,
 127                          struct cpuidle_device *dev, int index);
 128 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 129
 130 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 131 extern struct cpuidle_driver *cpuidle_get_driver(void);
 132 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 133 extern void cpuidle_driver_unref(void);
 134 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 135 extern int cpuidle_register_device(struct cpuidle_device *dev);
 136 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 137 extern int cpuidle_register(struct cpuidle_driver *drv,
 138                             const struct cpumask *const coupled_cpus);
 139 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 140 extern void cpuidle_pause_and_lock(void);
 141 extern void cpuidle_resume_and_unlock(void);
 142 extern void cpuidle_pause(void);
 143 extern void cpuidle_resume(void);
 144 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 145 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 146 extern int cpuidle_play_dead(void);
 147 extern void cpuidle_use_deepest_state(bool enable);
 148
 149 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 150 #else
 151 static inline void disable_cpuidle(void) { }
 152 static inline int cpuidle_select(struct cpuidle_driver *drv,
 153                                  struct cpuidle_device *dev)
 154 {return -ENODEV; }
 155 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 156                                 struct cpuidle_device *dev, int index)
 157 {return -ENODEV; }
 158 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 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 static inline int cpuidle_register(struct cpuidle_driver *drv,
 169                                    const struct cpumask *const coupled_cpus)
 170 {return -ENODEV; }
 171 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 172 static inline void cpuidle_pause_and_lock(void) { }
 173 static inline void cpuidle_resume_and_unlock(void) { }
 174 static inline void cpuidle_pause(void) { }
 175 static inline void cpuidle_resume(void) { }
 176 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 177 {return -ENODEV; }
 178 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 179 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 180 static inline void cpuidle_use_deepest_state(bool enable) {}
 181 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 182         struct cpuidle_device *dev) {return NULL; }
 183 #endif
 184
 185 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 186 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 187 #else
 188 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 189 {
 190 }
 191 #endif
 192
 193 /******************************
 194  * CPUIDLE GOVERNOR INTERFACE *
 195  ******************************/
 196
 197 struct cpuidle_governor {
 198         char                    name[CPUIDLE_NAME_LEN];
 199         struct list_head        governor_list;
 200         unsigned int            rating;
 201
 202         int  (*enable)          (struct cpuidle_driver *drv,
 203                                         struct cpuidle_device *dev);
 204         void (*disable)         (struct cpuidle_driver *drv,
 205                                         struct cpuidle_device *dev);
 206
 207         int  (*select)          (struct cpuidle_driver *drv,
 208                                         struct cpuidle_device *dev);
 209         void (*reflect)         (struct cpuidle_device *dev, int index);
 210
 211         struct module           *owner;
 212 };
 213
 214 #ifdef CONFIG_CPU_IDLE
 215 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 216 #else
 217 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 218 {return 0;}
 219 #endif
 220
 221 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 222 #define CPUIDLE_DRIVER_STATE_START      1
 223 #else
 224 #define CPUIDLE_DRIVER_STATE_START      0
 225 #endif
 226
 227 #endif /* _LINUX_CPUIDLE_H */