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/kobject.h>
  17 #include <linux/completion.h>
  18 #include <linux/hrtimer.h>
  19
  20 #define CPUIDLE_STATE_MAX       8
  21 #define CPUIDLE_NAME_LEN        16
  22 #define CPUIDLE_DESC_LEN        32
  23
  24 struct module;
  25
  26 struct cpuidle_device;
  27 struct cpuidle_driver;
  28
  29
  30 /****************************
  31  * CPUIDLE DEVICE INTERFACE *
  32  ****************************/
  33
  34 struct cpuidle_state_usage {
  35         void            *driver_data;
  36
  37         unsigned long long      disable;
  38         unsigned long long      usage;
  39         unsigned long long      time; /* in US */
  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 /* Idle State Flags */
  60 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  61 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  62
  63 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  64
  65 /**
  66  * cpuidle_get_statedata - retrieves private driver state data
  67  * @st_usage: the state usage statistics
  68  */
  69 static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
  70 {
  71         return st_usage->driver_data;
  72 }
  73
  74 /**
  75  * cpuidle_set_statedata - stores private driver state data
  76  * @st_usage: the state usage statistics
  77  * @data: the private data
  78  */
  79 static inline void
  80 cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
  81 {
  82         st_usage->driver_data = data;
  83 }
  84
  85 struct cpuidle_state_kobj {
  86         struct cpuidle_state *state;
  87         struct cpuidle_state_usage *state_usage;
  88         struct completion kobj_unregister;
  89         struct kobject kobj;
  90 };
  91
  92 struct cpuidle_device {
  93         unsigned int            registered:1;
  94         unsigned int            enabled:1;
  95         unsigned int            cpu;
  96
  97         int                     last_residency;
  98         int                     state_count;
  99         struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
 100         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
 101
 102         struct list_head        device_list;
 103         struct kobject          kobj;
 104         struct completion       kobj_unregister;
 105
 106 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 107         int                     safe_state_index;
 108         cpumask_t               coupled_cpus;
 109         struct cpuidle_coupled  *coupled;
 110 #endif
 111 };
 112
 113 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 114
 115 /**
 116  * cpuidle_get_last_residency - retrieves the last state's residency time
 117  * @dev: the target CPU
 118  *
 119  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 120  */
 121 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 122 {
 123         return dev->last_residency;
 124 }
 125
 126
 127 /****************************
 128  * CPUIDLE DRIVER INTERFACE *
 129  ****************************/
 130
 131 struct cpuidle_driver {
 132         const char              *name;
 133         struct module           *owner;
 134
 135         unsigned int            power_specified:1;
 136         /* set to 1 to use the core cpuidle time keeping (for all states). */
 137         unsigned int            en_core_tk_irqen:1;
 138         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 139         int                     state_count;
 140         int                     safe_state_index;
 141 };
 142
 143 #ifdef CONFIG_CPU_IDLE
 144 extern void disable_cpuidle(void);
 145 extern int cpuidle_idle_call(void);
 146 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 147 extern struct cpuidle_driver *cpuidle_get_driver(void);
 148 extern struct cpuidle_driver *cpuidle_driver_ref(void);
 149 extern void cpuidle_driver_unref(void);
 150 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 151 extern int cpuidle_register_device(struct cpuidle_device *dev);
 152 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 153
 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_wrap_enter(struct cpuidle_device *dev,
 161                                 struct cpuidle_driver *drv, int index,
 162                                 int (*enter)(struct cpuidle_device *dev,
 163                                         struct cpuidle_driver *drv, int index));
 164 extern int cpuidle_play_dead(void);
 165
 166 #else
 167 static inline void disable_cpuidle(void) { }
 168 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 169 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 170 {return -ENODEV; }
 171 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 172 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 173 static inline void cpuidle_driver_unref(void) {}
 174 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 175 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 176 {return -ENODEV; }
 177 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 178
 179 static inline void cpuidle_pause_and_lock(void) { }
 180 static inline void cpuidle_resume_and_unlock(void) { }
 181 static inline void cpuidle_pause(void) { }
 182 static inline void cpuidle_resume(void) { }
 183 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 184 {return -ENODEV; }
 185 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 186 static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
 187                                 struct cpuidle_driver *drv, int index,
 188                                 int (*enter)(struct cpuidle_device *dev,
 189                                         struct cpuidle_driver *drv, int index))
 190 { return -ENODEV; }
 191 static inline int cpuidle_play_dead(void) {return -ENODEV; }
 192
 193 #endif
 194
 195 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 196 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 197 #endif
 198
 199 /******************************
 200  * CPUIDLE GOVERNOR INTERFACE *
 201  ******************************/
 202
 203 struct cpuidle_governor {
 204         char                    name[CPUIDLE_NAME_LEN];
 205         struct list_head        governor_list;
 206         unsigned int            rating;
 207
 208         int  (*enable)          (struct cpuidle_driver *drv,
 209                                         struct cpuidle_device *dev);
 210         void (*disable)         (struct cpuidle_driver *drv,
 211                                         struct cpuidle_device *dev);
 212
 213         int  (*select)          (struct cpuidle_driver *drv,
 214                                         struct cpuidle_device *dev);
 215         void (*reflect)         (struct cpuidle_device *dev, int index);
 216
 217         struct module           *owner;
 218 };
 219
 220 #ifdef CONFIG_CPU_IDLE
 221
 222 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 223 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 224
 225 #else
 226
 227 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 228 {return 0;}
 229 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 230
 231 #endif
 232
 233 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 234 #define CPUIDLE_DRIVER_STATE_START      1
 235 #else
 236 #define CPUIDLE_DRIVER_STATE_START      0
 237 #endif
 238
 239 #endif /* _LINUX_CPUIDLE_H */