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
  19 #define CPUIDLE_STATE_MAX       8
  20 #define CPUIDLE_NAME_LEN        16
  21 #define CPUIDLE_DESC_LEN        32
  22
  23 struct module;
  24
  25 struct cpuidle_device;
  26
  27
  28 /****************************
  29  * CPUIDLE DEVICE INTERFACE *
  30  ****************************/
  31
  32 struct cpuidle_state {
  33         char            name[CPUIDLE_NAME_LEN];
  34         char            desc[CPUIDLE_DESC_LEN];
  35         void            *driver_data;
  36
  37         unsigned int    flags;
  38         unsigned int    exit_latency; /* in US */
  39         unsigned int    power_usage; /* in mW */
  40         unsigned int    target_residency; /* in US */
  41
  42         unsigned long long      usage;
  43         unsigned long long      time; /* in US */
  44
  45         int (*enter)    (struct cpuidle_device *dev,
  46                          struct cpuidle_state *state);
  47 };
  48
  49 /* Idle State Flags */
  50 #define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  51 #define CPUIDLE_FLAG_IGNORE     (0x100) /* ignore during this idle period */
  52
  53 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  54
  55 /**
  56  * cpuidle_get_statedata - retrieves private driver state data
  57  * @state: the state
  58  */
  59 static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
  60 {
  61         return state->driver_data;
  62 }
  63
  64 /**
  65  * cpuidle_set_statedata - stores private driver state data
  66  * @state: the state
  67  * @data: the private data
  68  */
  69 static inline void
  70 cpuidle_set_statedata(struct cpuidle_state *state, void *data)
  71 {
  72         state->driver_data = data;
  73 }
  74
  75 struct cpuidle_state_kobj {
  76         struct cpuidle_state *state;
  77         struct completion kobj_unregister;
  78         struct kobject kobj;
  79 };
  80
  81 struct cpuidle_device {
  82         unsigned int            registered:1;
  83         unsigned int            enabled:1;
  84         unsigned int            power_specified:1;
  85         unsigned int            cpu;
  86
  87         int                     last_residency;
  88         int                     state_count;
  89         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
  90         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  91         struct cpuidle_state    *last_state;
  92
  93         struct list_head        device_list;
  94         struct kobject          kobj;
  95         struct completion       kobj_unregister;
  96         void                    *governor_data;
  97         struct cpuidle_state    *safe_state;
  98
  99         int (*prepare)          (struct cpuidle_device *dev);
 100 };
 101
 102 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 103
 104 /**
 105  * cpuidle_get_last_residency - retrieves the last state's residency time
 106  * @dev: the target CPU
 107  *
 108  * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 109  */
 110 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 111 {
 112         return dev->last_residency;
 113 }
 114
 115
 116 /****************************
 117  * CPUIDLE DRIVER INTERFACE *
 118  ****************************/
 119
 120 struct cpuidle_driver {
 121         char                    name[CPUIDLE_NAME_LEN];
 122         struct module           *owner;
 123 };
 124
 125 #ifdef CONFIG_CPU_IDLE
 126 extern void disable_cpuidle(void);
 127 extern int cpuidle_idle_call(void);
 128
 129 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 130 struct cpuidle_driver *cpuidle_get_driver(void);
 131 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 132 extern int cpuidle_register_device(struct cpuidle_device *dev);
 133 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 134
 135 extern void cpuidle_pause_and_lock(void);
 136 extern void cpuidle_resume_and_unlock(void);
 137 extern int cpuidle_enable_device(struct cpuidle_device *dev);
 138 extern void cpuidle_disable_device(struct cpuidle_device *dev);
 139
 140 #else
 141 static inline void disable_cpuidle(void) { }
 142 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 143
 144 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 145 {return -ENODEV; }
 146 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 147 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 148 static inline int cpuidle_register_device(struct cpuidle_device *dev)
 149 {return -ENODEV; }
 150 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 151
 152 static inline void cpuidle_pause_and_lock(void) { }
 153 static inline void cpuidle_resume_and_unlock(void) { }
 154 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 155 {return -ENODEV; }
 156 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 157
 158 #endif
 159
 160 /******************************
 161  * CPUIDLE GOVERNOR INTERFACE *
 162  ******************************/
 163
 164 struct cpuidle_governor {
 165         char                    name[CPUIDLE_NAME_LEN];
 166         struct list_head        governor_list;
 167         unsigned int            rating;
 168
 169         int  (*enable)          (struct cpuidle_device *dev);
 170         void (*disable)         (struct cpuidle_device *dev);
 171
 172         int  (*select)          (struct cpuidle_device *dev);
 173         void (*reflect)         (struct cpuidle_device *dev);
 174
 175         struct module           *owner;
 176 };
 177
 178 #ifdef CONFIG_CPU_IDLE
 179
 180 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 181 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 182
 183 #else
 184
 185 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 186 {return 0;}
 187 static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 188
 189 #endif
 190
 191 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
 192 #define CPUIDLE_DRIVER_STATE_START      1
 193 #else
 194 #define CPUIDLE_DRIVER_STATE_START      0
 195 #endif
 196
 197 #endif /* _LINUX_CPUIDLE_H */