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_COUPLED    (0x02) /* state applies to multiple cpus */
  57 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  58
  59 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  60
  61 struct cpuidle_device_kobj;
  62 struct cpuidle_state_kobj;
  63 struct cpuidle_driver_kobj;
  64
  65 struct cpuidle_device {
  66         unsigned int            registered:1;
  67         unsigned int            enabled:1;
  68         unsigned int            cpu;
  69
  70         int                     last_residency;
  71         int                     state_count;
  72         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  73         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  74         struct cpuidle_driver_kobj *kobj_driver;
  75         struct cpuidle_device_kobj *kobj_dev;
  76         struct list_head        device_list;
  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 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  87
  88 /**
  89  * cpuidle_get_last_residency - retrieves the last state's residency time
  90  * @dev: the target CPU
  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         /* used by the cpuidle framework to setup the broadcast timer */
 108         unsigned int            bctimer: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         /* the driver handles the cpus in cpumask */
 115         struct cpumask          *cpumask;
 116 };
 117
 118 #ifdef CONFIG_CPU_IDLE
 119 extern void disable_cpuidle(void);
 120
 121 extern int cpuidle_select(struct cpuidle_driver *drv,
 122                           struct cpuidle_device *dev);
 123 extern int cpuidle_enter(struct cpuidle_driver *drv,
 124                          struct cpuidle_device *dev, int index);
 125 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 126
 127 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 128 extern struct cpuidle_driver *cpuidle_get_driver(void);
 129 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 130 extern void cpuidle_driver_unref(void);
 131 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 132 extern int cpuidle_register_device(struct cpuidle_device *dev);
 133 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 134 extern int cpuidle_register(struct cpuidle_driver *drv,
 135                             const struct cpumask *const coupled_cpus);
 136 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 137 extern void cpuidle_pause_and_lock(void);
 138 extern void cpuidle_resume_and_unlock(void);
 139 extern void cpuidle_pause(void);
 140 extern void cpuidle_resume(void);
 141 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 142 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 143 extern int cpuidle_play_dead(void);
 144 extern void cpuidle_use_deepest_state(bool enable);
 145
 146 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 147 #else
 148 static inline void disable_cpuidle(void) { }
 149 static inline int cpuidle_select(struct cpuidle_driver *drv,
 150                                  struct cpuidle_device *dev)
 151 {return -ENODEV; }
 152 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 153                                 struct cpuidle_device *dev, int index)
 154 {return -ENODEV; }
 155 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 156 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 157 {return -ENODEV; }
 158 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 159 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 160 static inline void cpuidle_driver_unref(void) {}
 161 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 162 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 163 {return -ENODEV; }
 164 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 165 static inline int cpuidle_register(struct cpuidle_driver *drv,
 166                                    const struct cpumask *const coupled_cpus)
 167 {return -ENODEV; }
 168 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 169 static inline void cpuidle_pause_and_lock(void) { }
 170 static inline void cpuidle_resume_and_unlock(void) { }
 171 static inline void cpuidle_pause(void) { }
 172 static inline void cpuidle_resume(void) { }
 173 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 174 {return -ENODEV; }
 175 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 176 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 177 static inline void cpuidle_use_deepest_state(bool enable) {}
 178 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 179         struct cpuidle_device *dev) {return NULL; }
 180 #endif
 181
 182 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 183 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 184 #else
 185 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 186 {
 187 }
 188 #endif
 189
 190 /******************************
 191  * CPUIDLE GOVERNOR INTERFACE *
 192  ******************************/
 193
 194 struct cpuidle_governor {
 195         char                    name[CPUIDLE_NAME_LEN];
 196         struct list_head        governor_list;
 197         unsigned int            rating;
 198
 199         int  (*enable)          (struct cpuidle_driver *drv,
 200                                         struct cpuidle_device *dev);
 201         void (*disable)         (struct cpuidle_driver *drv,
 202                                         struct cpuidle_device *dev);
 203
 204         int  (*select)          (struct cpuidle_driver *drv,
 205                                         struct cpuidle_device *dev);
 206         void (*reflect)         (struct cpuidle_device *dev, int index);
 207
 208         struct module           *owner;
 209 };
 210
 211 #ifdef CONFIG_CPU_IDLE
 212 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 213 #else
 214 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 215 {return 0;}
 216 #endif
 217
 218 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 219 #define CPUIDLE_DRIVER_STATE_START      1
 220 #else
 221 #define CPUIDLE_DRIVER_STATE_START      0
 222 #endif
 223
 224 #endif /* _LINUX_CPUIDLE_H */