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
  88 /**
  89  * cpuidle_get_last_residency - retrieves the last state's residency time
  90  * @dev: the target CPU
  91  *
  92  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
  93  */
  94 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  95 {
  96         return dev->last_residency;
  97 }
  98
  99
 100 /****************************
 101  * CPUIDLE DRIVER INTERFACE *
 102  ****************************/
 103
 104 struct cpuidle_driver {
 105         const char              *name;
 106         struct module           *owner;
 107         int                     refcnt;
 108
 109         /* used by the cpuidle framework to setup the broadcast timer */
 110         unsigned int            bctimer:1;
 111         /* states array must be ordered in decreasing power consumption */
 112         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 113         int                     state_count;
 114         int                     safe_state_index;
 115
 116         /* the driver handles the cpus in cpumask */
 117         struct cpumask          *cpumask;
 118 };
 119
 120 #ifdef CONFIG_CPU_IDLE
 121 extern void disable_cpuidle(void);
 122 extern int cpuidle_idle_call(void);
 123 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 124 extern struct cpuidle_driver *cpuidle_get_driver(void);
 125 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 126 extern void cpuidle_driver_unref(void);
 127 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 128 extern int cpuidle_register_device(struct cpuidle_device *dev);
 129 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 130 extern int cpuidle_register(struct cpuidle_driver *drv,
 131                             const struct cpumask *const coupled_cpus);
 132 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 133 extern void cpuidle_pause_and_lock(void);
 134 extern void cpuidle_resume_and_unlock(void);
 135 extern void cpuidle_pause(void);
 136 extern void cpuidle_resume(void);
 137 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 138 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 139 extern int cpuidle_play_dead(void);
 140
 141 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 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 static inline int cpuidle_register(struct cpuidle_driver *drv,
 155                                    const struct cpumask *const coupled_cpus)
 156 {return -ENODEV; }
 157 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 158 static inline void cpuidle_pause_and_lock(void) { }
 159 static inline void cpuidle_resume_and_unlock(void) { }
 160 static inline void cpuidle_pause(void) { }
 161 static inline void cpuidle_resume(void) { }
 162 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 163 {return -ENODEV; }
 164 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 165 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 166 #endif
 167
 168 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 169 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 170 #else
 171 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 172 {
 173 }
 174 #endif
 175
 176 /******************************
 177  * CPUIDLE GOVERNOR INTERFACE *
 178  ******************************/
 179
 180 struct cpuidle_governor {
 181         char                    name[CPUIDLE_NAME_LEN];
 182         struct list_head        governor_list;
 183         unsigned int            rating;
 184
 185         int  (*enable)          (struct cpuidle_driver *drv,
 186                                         struct cpuidle_device *dev);
 187         void (*disable)         (struct cpuidle_driver *drv,
 188                                         struct cpuidle_device *dev);
 189
 190         int  (*select)          (struct cpuidle_driver *drv,
 191                                         struct cpuidle_device *dev);
 192         void (*reflect)         (struct cpuidle_device *dev, int index);
 193
 194         struct module           *owner;
 195 };
 196
 197 #ifdef CONFIG_CPU_IDLE
 198 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 199 #else
 200 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 201 {return 0;}
 202 #endif
 203
 204 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 205 #define CPUIDLE_DRIVER_STATE_START      1
 206 #else
 207 #define CPUIDLE_DRIVER_STATE_START      0
 208 #endif
 209
 210 #endif /* _LINUX_CPUIDLE_H */