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         int                     state_count;
  81         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  82         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  83         struct cpuidle_driver_kobj *kobj_driver;
  84         struct cpuidle_device_kobj *kobj_dev;
  85         struct list_head        device_list;
  86
  87 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  88         int                     safe_state_index;
  89         cpumask_t               coupled_cpus;
  90         struct cpuidle_coupled  *coupled;
  91 #endif
  92 };
  93
  94 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  95 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  96
  97 /**
  98  * cpuidle_get_last_residency - retrieves the last state's residency time
  99  * @dev: the target CPU
 100  */
 101 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 102 {
 103         return dev->last_residency;
 104 }
 105
 106
 107 /****************************
 108  * CPUIDLE DRIVER INTERFACE *
 109  ****************************/
 110
 111 struct cpuidle_driver {
 112         const char              *name;
 113         struct module           *owner;
 114         int                     refcnt;
 115
 116         /* used by the cpuidle framework to setup the broadcast timer */
 117         unsigned int            bctimer:1;
 118         /* states array must be ordered in decreasing power consumption */
 119         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 120         int                     state_count;
 121         int                     safe_state_index;
 122
 123         /* the driver handles the cpus in cpumask */
 124         struct cpumask          *cpumask;
 125 };
 126
 127 #ifdef CONFIG_CPU_IDLE
 128 extern void disable_cpuidle(void);
 129 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 130                                   struct cpuidle_device *dev);
 131
 132 extern int cpuidle_select(struct cpuidle_driver *drv,
 133                           struct cpuidle_device *dev);
 134 extern int cpuidle_enter(struct cpuidle_driver *drv,
 135                          struct cpuidle_device *dev, int index);
 136 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 137
 138 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 139 extern struct cpuidle_driver *cpuidle_get_driver(void);
 140 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 141 extern void cpuidle_driver_unref(void);
 142 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 143 extern int cpuidle_register_device(struct cpuidle_device *dev);
 144 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 145 extern int cpuidle_register(struct cpuidle_driver *drv,
 146                             const struct cpumask *const coupled_cpus);
 147 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 148 extern void cpuidle_pause_and_lock(void);
 149 extern void cpuidle_resume_and_unlock(void);
 150 extern void cpuidle_pause(void);
 151 extern void cpuidle_resume(void);
 152 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 153 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 154 extern int cpuidle_play_dead(void);
 155 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 156                                       struct cpuidle_device *dev);
 157 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 158                                 struct cpuidle_device *dev);
 159
 160 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 161 #else
 162 static inline void disable_cpuidle(void) { }
 163 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 164                                          struct cpuidle_device *dev)
 165 {return true; }
 166 static inline int cpuidle_select(struct cpuidle_driver *drv,
 167                                  struct cpuidle_device *dev)
 168 {return -ENODEV; }
 169 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 170                                 struct cpuidle_device *dev, int index)
 171 {return -ENODEV; }
 172 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 173 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 174 {return -ENODEV; }
 175 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 176 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 177 static inline void cpuidle_driver_unref(void) {}
 178 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 179 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 180 {return -ENODEV; }
 181 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 182 static inline int cpuidle_register(struct cpuidle_driver *drv,
 183                                    const struct cpumask *const coupled_cpus)
 184 {return -ENODEV; }
 185 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 186 static inline void cpuidle_pause_and_lock(void) { }
 187 static inline void cpuidle_resume_and_unlock(void) { }
 188 static inline void cpuidle_pause(void) { }
 189 static inline void cpuidle_resume(void) { }
 190 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 191 {return -ENODEV; }
 192 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 193 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 194 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 195                                              struct cpuidle_device *dev)
 196 {return -ENODEV; }
 197 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 198                                        struct cpuidle_device *dev)
 199 {return -ENODEV; }
 200 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 201         struct cpuidle_device *dev) {return NULL; }
 202 #endif
 203
 204 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 205 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 206 #else
 207 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 208 {
 209 }
 210 #endif
 211
 212 /******************************
 213  * CPUIDLE GOVERNOR INTERFACE *
 214  ******************************/
 215
 216 struct cpuidle_governor {
 217         char                    name[CPUIDLE_NAME_LEN];
 218         struct list_head        governor_list;
 219         unsigned int            rating;
 220
 221         int  (*enable)          (struct cpuidle_driver *drv,
 222                                         struct cpuidle_device *dev);
 223         void (*disable)         (struct cpuidle_driver *drv,
 224                                         struct cpuidle_device *dev);
 225
 226         int  (*select)          (struct cpuidle_driver *drv,
 227                                         struct cpuidle_device *dev);
 228         void (*reflect)         (struct cpuidle_device *dev, int index);
 229
 230         struct module           *owner;
 231 };
 232
 233 #ifdef CONFIG_CPU_IDLE
 234 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 235 #else
 236 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 237 {return 0;}
 238 #endif
 239
 240 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 241 #define CPUIDLE_DRIVER_STATE_START      1
 242 #else
 243 #define CPUIDLE_DRIVER_STATE_START      0
 244 #endif
 245
 246 #endif /* _LINUX_CPUIDLE_H */