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_s2idle 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_s2idle) (struct cpuidle_device *dev,
  60                               struct cpuidle_driver *drv,
  61                               int index);
  62 };
  63
  64 /* Idle State Flags */
  65 #define CPUIDLE_FLAG_NONE       (0x00)
  66 #define CPUIDLE_FLAG_POLLING    (0x01) /* polling state */
  67 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  68 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  69
  70 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  71
  72 struct cpuidle_device_kobj;
  73 struct cpuidle_state_kobj;
  74 struct cpuidle_driver_kobj;
  75
  76 struct cpuidle_device {
  77         unsigned int            registered:1;
  78         unsigned int            enabled:1;
  79         unsigned int            use_deepest_state:1;
  80         unsigned int            cpu;
  81
  82         int                     last_residency;
  83         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  84         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  85         struct cpuidle_driver_kobj *kobj_driver;
  86         struct cpuidle_device_kobj *kobj_dev;
  87         struct list_head        device_list;
  88
  89 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  90         cpumask_t               coupled_cpus;
  91         struct cpuidle_coupled  *coupled;
  92 #endif
  93 };
  94
  95 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  96 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  97
  98 /**
  99  * cpuidle_get_last_residency - retrieves the last state's residency time
 100  * @dev: the target CPU
 101  */
 102 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 103 {
 104         return dev->last_residency;
 105 }
 106
 107
 108 /****************************
 109  * CPUIDLE DRIVER INTERFACE *
 110  ****************************/
 111
 112 struct cpuidle_driver {
 113         const char              *name;
 114         struct module           *owner;
 115         int                     refcnt;
 116
 117         /* used by the cpuidle framework to setup the broadcast timer */
 118         unsigned int            bctimer:1;
 119         /* states array must be ordered in decreasing power consumption */
 120         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 121         int                     state_count;
 122         int                     safe_state_index;
 123
 124         /* the driver handles the cpus in cpumask */
 125         struct cpumask          *cpumask;
 126 };
 127
 128 #ifdef CONFIG_CPU_IDLE
 129 extern void disable_cpuidle(void);
 130 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 131                                   struct cpuidle_device *dev);
 132
 133 extern int cpuidle_select(struct cpuidle_driver *drv,
 134                           struct cpuidle_device *dev,
 135                           bool *stop_tick);
 136 extern int cpuidle_enter(struct cpuidle_driver *drv,
 137                          struct cpuidle_device *dev, int index);
 138 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 139
 140 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 141 extern struct cpuidle_driver *cpuidle_get_driver(void);
 142 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 143 extern void cpuidle_driver_unref(void);
 144 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 145 extern int cpuidle_register_device(struct cpuidle_device *dev);
 146 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 147 extern int cpuidle_register(struct cpuidle_driver *drv,
 148                             const struct cpumask *const coupled_cpus);
 149 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 150 extern void cpuidle_pause_and_lock(void);
 151 extern void cpuidle_resume_and_unlock(void);
 152 extern void cpuidle_pause(void);
 153 extern void cpuidle_resume(void);
 154 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 155 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 156 extern int cpuidle_play_dead(void);
 157
 158 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 159 static inline struct cpuidle_device *cpuidle_get_device(void)
 160 {return __this_cpu_read(cpuidle_devices); }
 161 extern unsigned int cpuidle_get_target_residency(int cpu, int state);
 162 #else
 163 static inline void disable_cpuidle(void) { }
 164 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 165                                          struct cpuidle_device *dev)
 166 {return true; }
 167 static inline int cpuidle_select(struct cpuidle_driver *drv,
 168                                  struct cpuidle_device *dev, bool *stop_tick)
 169 {return -ENODEV; }
 170 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 171                                 struct cpuidle_device *dev, int index)
 172 {return -ENODEV; }
 173 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 174 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 175 {return -ENODEV; }
 176 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 177 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 178 static inline void cpuidle_driver_unref(void) {}
 179 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 180 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 181 {return -ENODEV; }
 182 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 183 static inline int cpuidle_register(struct cpuidle_driver *drv,
 184                                    const struct cpumask *const coupled_cpus)
 185 {return -ENODEV; }
 186 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 187 static inline void cpuidle_pause_and_lock(void) { }
 188 static inline void cpuidle_resume_and_unlock(void) { }
 189 static inline void cpuidle_pause(void) { }
 190 static inline void cpuidle_resume(void) { }
 191 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 192 {return -ENODEV; }
 193 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 194 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 195 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 196         struct cpuidle_device *dev) {return NULL; }
 197 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 198 static inline unsigned int cpuidle_get_target_residency(int cpu, int state) {return UINT_MAX;}
 199 #endif
 200
 201 #ifdef CONFIG_CPU_IDLE
 202 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 203                                       struct cpuidle_device *dev);
 204 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 205                                 struct cpuidle_device *dev);
 206 extern void cpuidle_use_deepest_state(bool enable);
 207 #else
 208 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 209                                              struct cpuidle_device *dev)
 210 {return -ENODEV; }
 211 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 212                                        struct cpuidle_device *dev)
 213 {return -ENODEV; }
 214 static inline void cpuidle_use_deepest_state(bool enable)
 215 {
 216 }
 217 #endif
 218
 219 /* kernel/sched/idle.c */
 220 extern void sched_idle_set_state(struct cpuidle_state *idle_state, int index);
 221 extern void default_idle_call(void);
 222
 223 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 224 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 225 #else
 226 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 227 {
 228 }
 229 #endif
 230
 231 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 232 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 233 #else
 234 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 235 #endif
 236
 237 /******************************
 238  * CPUIDLE GOVERNOR INTERFACE *
 239  ******************************/
 240
 241 struct cpuidle_governor {
 242         char                    name[CPUIDLE_NAME_LEN];
 243         struct list_head        governor_list;
 244         unsigned int            rating;
 245
 246         int  (*enable)          (struct cpuidle_driver *drv,
 247                                         struct cpuidle_device *dev);
 248         void (*disable)         (struct cpuidle_driver *drv,
 249                                         struct cpuidle_device *dev);
 250
 251         int  (*select)          (struct cpuidle_driver *drv,
 252                                         struct cpuidle_device *dev,
 253                                         bool *stop_tick);
 254         void (*reflect)         (struct cpuidle_device *dev, int index);
 255 };
 256
 257 #ifdef CONFIG_CPU_IDLE
 258 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 259 #else
 260 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 261 {return 0;}
 262 #endif
 263
 264 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 265 ({                                                              \
 266         int __ret;                                              \
 267                                                                 \
 268         if (!idx) {                                             \
 269                 cpu_do_idle();                                  \
 270                 return idx;                                     \
 271         }                                                       \
 272                                                                 \
 273         __ret = cpu_pm_enter();                                 \
 274         if (!__ret) {                                           \
 275                 __ret = low_level_idle_enter(idx);              \
 276                 cpu_pm_exit();                                  \
 277         }                                                       \
 278                                                                 \
 279         __ret ? -1 : idx;                                       \
 280 })
 281
 282 #endif /* _LINUX_CPUIDLE_H */