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          * CPUs execute ->enter_freeze with the local tick or entire timekeeping
  56          * suspended, so it must not re-enable interrupts at any point (even
  57          * temporarily) or attempt to change states of clock event devices.
  58          */
  59         void (*enter_freeze) (struct cpuidle_device *dev,
  60                               struct cpuidle_driver *drv,
  61                               int index);
  62 };
  63
  64 /* Idle State Flags */
  65 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  66 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  67
  68 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  69
  70 struct cpuidle_device_kobj;
  71 struct cpuidle_state_kobj;
  72 struct cpuidle_driver_kobj;
  73
  74 struct cpuidle_device {
  75         unsigned int            registered:1;
  76         unsigned int            enabled:1;
  77         unsigned int            cpu;
  78
  79         int                     last_residency;
  80         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  81         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  82         struct cpuidle_driver_kobj *kobj_driver;
  83         struct cpuidle_device_kobj *kobj_dev;
  84         struct list_head        device_list;
  85
  86 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  87         int                     safe_state_index;
  88         cpumask_t               coupled_cpus;
  89         struct cpuidle_coupled  *coupled;
  90 #endif
  91 };
  92
  93 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  94 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  95
  96 /**
  97  * cpuidle_get_last_residency - retrieves the last state's residency time
  98  * @dev: the target CPU
  99  */
 100 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 101 {
 102         return dev->last_residency;
 103 }
 104
 105
 106 /****************************
 107  * CPUIDLE DRIVER INTERFACE *
 108  ****************************/
 109
 110 struct cpuidle_driver {
 111         const char              *name;
 112         struct module           *owner;
 113         int                     refcnt;
 114
 115         /* used by the cpuidle framework to setup the broadcast timer */
 116         unsigned int            bctimer:1;
 117         /* states array must be ordered in decreasing power consumption */
 118         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 119         int                     state_count;
 120         int                     safe_state_index;
 121
 122         /* the driver handles the cpus in cpumask */
 123         struct cpumask          *cpumask;
 124 };
 125
 126 #ifdef CONFIG_CPU_IDLE
 127 extern void disable_cpuidle(void);
 128 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 129                                   struct cpuidle_device *dev);
 130
 131 extern int cpuidle_select(struct cpuidle_driver *drv,
 132                           struct cpuidle_device *dev);
 133 extern int cpuidle_enter(struct cpuidle_driver *drv,
 134                          struct cpuidle_device *dev, int index);
 135 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 136
 137 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 138 extern struct cpuidle_driver *cpuidle_get_driver(void);
 139 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 140 extern void cpuidle_driver_unref(void);
 141 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 142 extern int cpuidle_register_device(struct cpuidle_device *dev);
 143 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 144 extern int cpuidle_register(struct cpuidle_driver *drv,
 145                             const struct cpumask *const coupled_cpus);
 146 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 147 extern void cpuidle_pause_and_lock(void);
 148 extern void cpuidle_resume_and_unlock(void);
 149 extern void cpuidle_pause(void);
 150 extern void cpuidle_resume(void);
 151 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 152 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 153 extern int cpuidle_play_dead(void);
 154 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 155                                       struct cpuidle_device *dev);
 156 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 157                                 struct cpuidle_device *dev);
 158
 159 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 160 #else
 161 static inline void disable_cpuidle(void) { }
 162 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 163                                          struct cpuidle_device *dev)
 164 {return true; }
 165 static inline int cpuidle_select(struct cpuidle_driver *drv,
 166                                  struct cpuidle_device *dev)
 167 {return -ENODEV; }
 168 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 169                                 struct cpuidle_device *dev, int index)
 170 {return -ENODEV; }
 171 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 172 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 173 {return -ENODEV; }
 174 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 175 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 176 static inline void cpuidle_driver_unref(void) {}
 177 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 178 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 179 {return -ENODEV; }
 180 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 181 static inline int cpuidle_register(struct cpuidle_driver *drv,
 182                                    const struct cpumask *const coupled_cpus)
 183 {return -ENODEV; }
 184 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 185 static inline void cpuidle_pause_and_lock(void) { }
 186 static inline void cpuidle_resume_and_unlock(void) { }
 187 static inline void cpuidle_pause(void) { }
 188 static inline void cpuidle_resume(void) { }
 189 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 190 {return -ENODEV; }
 191 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 192 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 193 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 194                                              struct cpuidle_device *dev)
 195 {return -ENODEV; }
 196 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 197                                        struct cpuidle_device *dev)
 198 {return -ENODEV; }
 199 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 200         struct cpuidle_device *dev) {return NULL; }
 201 #endif
 202
 203 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 204 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 205 #else
 206 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 207 {
 208 }
 209 #endif
 210
 211 /******************************
 212  * CPUIDLE GOVERNOR INTERFACE *
 213  ******************************/
 214
 215 struct cpuidle_governor {
 216         char                    name[CPUIDLE_NAME_LEN];
 217         struct list_head        governor_list;
 218         unsigned int            rating;
 219
 220         int  (*enable)          (struct cpuidle_driver *drv,
 221                                         struct cpuidle_device *dev);
 222         void (*disable)         (struct cpuidle_driver *drv,
 223                                         struct cpuidle_device *dev);
 224
 225         int  (*select)          (struct cpuidle_driver *drv,
 226                                         struct cpuidle_device *dev);
 227         void (*reflect)         (struct cpuidle_device *dev, int index);
 228
 229         struct module           *owner;
 230 };
 231
 232 #ifdef CONFIG_CPU_IDLE
 233 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 234 #else
 235 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 236 {return 0;}
 237 #endif
 238
 239 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 240 #define CPUIDLE_DRIVER_STATE_START      1
 241 #else
 242 #define CPUIDLE_DRIVER_STATE_START      0
 243 #endif
 244
 245 #endif /* _LINUX_CPUIDLE_H */