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 #ifdef CONFIG_SUSPEND
  37         unsigned long long      s2idle_usage;
  38         unsigned long long      s2idle_time; /* in US */
  39 #endif
  40 };
  41
  42 struct cpuidle_state {
  43         char            name[CPUIDLE_NAME_LEN];
  44         char            desc[CPUIDLE_DESC_LEN];
  45
  46         unsigned int    flags;
  47         unsigned int    exit_latency; /* in US */
  48         int             power_usage; /* in mW */
  49         unsigned int    target_residency; /* in US */
  50         bool            disabled; /* disabled on all CPUs */
  51
  52         int (*enter)    (struct cpuidle_device *dev,
  53                         struct cpuidle_driver *drv,
  54                         int index);
  55
  56         int (*enter_dead) (struct cpuidle_device *dev, int index);
  57
  58         /*
  59          * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
  60          * suspended, so it must not re-enable interrupts at any point (even
  61          * temporarily) or attempt to change states of clock event devices.
  62          */
  63         void (*enter_s2idle) (struct cpuidle_device *dev,
  64                               struct cpuidle_driver *drv,
  65                               int index);
  66 };
  67
  68 /* Idle State Flags */
  69 #define CPUIDLE_FLAG_NONE       (0x00)
  70 #define CPUIDLE_FLAG_POLLING    (0x01) /* polling state */
  71 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  72 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  73
  74 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  75
  76 struct cpuidle_device_kobj;
  77 struct cpuidle_state_kobj;
  78 struct cpuidle_driver_kobj;
  79
  80 struct cpuidle_device {
  81         unsigned int            registered:1;
  82         unsigned int            enabled:1;
  83         unsigned int            use_deepest_state:1;
  84         unsigned int            cpu;
  85
  86         int                     last_residency;
  87         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  88         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  89         struct cpuidle_driver_kobj *kobj_driver;
  90         struct cpuidle_device_kobj *kobj_dev;
  91         struct list_head        device_list;
  92
  93 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  94         cpumask_t               coupled_cpus;
  95         struct cpuidle_coupled  *coupled;
  96 #endif
  97 };
  98
  99 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 100 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 101
 102 /**
 103  * cpuidle_get_last_residency - retrieves the last state's residency time
 104  * @dev: the target CPU
 105  */
 106 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 107 {
 108         return dev->last_residency;
 109 }
 110
 111
 112 /****************************
 113  * CPUIDLE DRIVER INTERFACE *
 114  ****************************/
 115
 116 struct cpuidle_driver {
 117         const char              *name;
 118         struct module           *owner;
 119         int                     refcnt;
 120
 121         /* used by the cpuidle framework to setup the broadcast timer */
 122         unsigned int            bctimer:1;
 123         /* states array must be ordered in decreasing power consumption */
 124         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 125         int                     state_count;
 126         int                     safe_state_index;
 127
 128         /* the driver handles the cpus in cpumask */
 129         struct cpumask          *cpumask;
 130 };
 131
 132 #ifdef CONFIG_CPU_IDLE
 133 extern void disable_cpuidle(void);
 134 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 135                                   struct cpuidle_device *dev);
 136
 137 extern int cpuidle_select(struct cpuidle_driver *drv,
 138                           struct cpuidle_device *dev,
 139                           bool *stop_tick);
 140 extern int cpuidle_enter(struct cpuidle_driver *drv,
 141                          struct cpuidle_device *dev, int index);
 142 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 143
 144 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 145 extern struct cpuidle_driver *cpuidle_get_driver(void);
 146 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 147 extern void cpuidle_driver_unref(void);
 148 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 149 extern int cpuidle_register_device(struct cpuidle_device *dev);
 150 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 151 extern int cpuidle_register(struct cpuidle_driver *drv,
 152                             const struct cpumask *const coupled_cpus);
 153 extern void cpuidle_unregister(struct cpuidle_driver *drv);
 154 extern void cpuidle_pause_and_lock(void);
 155 extern void cpuidle_resume_and_unlock(void);
 156 extern void cpuidle_pause(void);
 157 extern void cpuidle_resume(void);
 158 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 159 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 160 extern int cpuidle_play_dead(void);
 161
 162 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 163 static inline struct cpuidle_device *cpuidle_get_device(void)
 164 {return __this_cpu_read(cpuidle_devices); }
 165 #else
 166 static inline void disable_cpuidle(void) { }
 167 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 168                                          struct cpuidle_device *dev)
 169 {return true; }
 170 static inline int cpuidle_select(struct cpuidle_driver *drv,
 171                                  struct cpuidle_device *dev, bool *stop_tick)
 172 {return -ENODEV; }
 173 static inline int cpuidle_enter(struct cpuidle_driver *drv,
 174                                 struct cpuidle_device *dev, int index)
 175 {return -ENODEV; }
 176 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 177 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 178 {return -ENODEV; }
 179 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 180 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 181 static inline void cpuidle_driver_unref(void) {}
 182 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 183 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 184 {return -ENODEV; }
 185 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 186 static inline int cpuidle_register(struct cpuidle_driver *drv,
 187                                    const struct cpumask *const coupled_cpus)
 188 {return -ENODEV; }
 189 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 190 static inline void cpuidle_pause_and_lock(void) { }
 191 static inline void cpuidle_resume_and_unlock(void) { }
 192 static inline void cpuidle_pause(void) { }
 193 static inline void cpuidle_resume(void) { }
 194 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 195 {return -ENODEV; }
 196 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 197 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 198 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 199         struct cpuidle_device *dev) {return NULL; }
 200 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 201 #endif
 202
 203 #ifdef CONFIG_CPU_IDLE
 204 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 205                                       struct cpuidle_device *dev);
 206 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 207                                 struct cpuidle_device *dev);
 208 extern void cpuidle_use_deepest_state(bool enable);
 209 #else
 210 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 211                                              struct cpuidle_device *dev)
 212 {return -ENODEV; }
 213 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
 214                                        struct cpuidle_device *dev)
 215 {return -ENODEV; }
 216 static inline void cpuidle_use_deepest_state(bool enable)
 217 {
 218 }
 219 #endif
 220
 221 /* kernel/sched/idle.c */
 222 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 223 extern void default_idle_call(void);
 224
 225 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 226 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 227 #else
 228 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 229 {
 230 }
 231 #endif
 232
 233 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
 234 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
 235 #else
 236 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
 237 #endif
 238
 239 /******************************
 240  * CPUIDLE GOVERNOR INTERFACE *
 241  ******************************/
 242
 243 struct cpuidle_governor {
 244         char                    name[CPUIDLE_NAME_LEN];
 245         struct list_head        governor_list;
 246         unsigned int            rating;
 247
 248         int  (*enable)          (struct cpuidle_driver *drv,
 249                                         struct cpuidle_device *dev);
 250         void (*disable)         (struct cpuidle_driver *drv,
 251                                         struct cpuidle_device *dev);
 252
 253         int  (*select)          (struct cpuidle_driver *drv,
 254                                         struct cpuidle_device *dev,
 255                                         bool *stop_tick);
 256         void (*reflect)         (struct cpuidle_device *dev, int index);
 257 };
 258
 259 #ifdef CONFIG_CPU_IDLE
 260 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 261 extern int cpuidle_governor_latency_req(unsigned int cpu);
 262 #else
 263 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 264 {return 0;}
 265 #endif
 266
 267 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
 268 ({                                                                      \
 269         int __ret = 0;                                                  \
 270                                                                         \
 271         if (!idx) {                                                     \
 272                 cpu_do_idle();                                          \
 273                 return idx;                                             \
 274         }                                                               \
 275                                                                         \
 276         if (!is_retention)                                              \
 277                 __ret =  cpu_pm_enter();                                \
 278         if (!__ret) {                                                   \
 279                 __ret = low_level_idle_enter(idx);                      \
 280                 if (!is_retention)                                      \
 281                         cpu_pm_exit();                                  \
 282         }                                                               \
 283                                                                         \
 284         __ret ? -1 : idx;                                               \
 285 })
 286
 287 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)        \
 288         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
 289
 290 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx)      \
 291         __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
 292
 293 #endif /* _LINUX_CPUIDLE_H */