LXR linux/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
  24struct module;
  25
  26struct cpuidle_device;
  27struct cpuidle_driver;
  28
  29
  30/****************************
  31 * CPUIDLE DEVICE INTERFACE *
  32 ****************************/
  33
  34struct cpuidle_state_usage {
  35        void            *driver_data;
  36
  37        unsigned long long      usage;
  38        unsigned long long      time; /* in US */
  39};
  40
  41struct cpuidle_state {
  42        char            name[CPUIDLE_NAME_LEN];
  43        char            desc[CPUIDLE_DESC_LEN];
  44
  45        unsigned int    flags;
  46        unsigned int    exit_latency; /* in US */
  47        int             power_usage; /* in mW */
  48        unsigned int    target_residency; /* in US */
  49        unsigned int    disable;
  50
  51        int (*enter)    (struct cpuidle_device *dev,
  52                        struct cpuidle_driver *drv,
  53                        int index);
  54
  55        int (*enter_dead) (struct cpuidle_device *dev, int index);
  56};
  57
  58/* Idle State Flags */
  59#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  60
  61#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  62
  63/**
  64 * cpuidle_get_statedata - retrieves private driver state data
  65 * @st_usage: the state usage statistics
  66 */
  67static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
  68{
  69        return st_usage->driver_data;
  70}
  71
  72/**
  73 * cpuidle_set_statedata - stores private driver state data
  74 * @st_usage: the state usage statistics
  75 * @data: the private data
  76 */
  77static inline void
  78cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
  79{
  80        st_usage->driver_data = data;
  81}
  82
  83struct cpuidle_state_kobj {
  84        struct cpuidle_state *state;
  85        struct cpuidle_state_usage *state_usage;
  86        struct completion kobj_unregister;
  87        struct kobject kobj;
  88};
  89
  90struct cpuidle_device {
  91        unsigned int            registered:1;
  92        unsigned int            enabled:1;
  93        unsigned int            cpu;
  94
  95        int                     last_residency;
  96        int                     state_count;
  97        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  98        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  99
 100        struct list_head        device_list;
 101        struct kobject          kobj;
 102        struct completion       kobj_unregister;
 103};
 104
 105DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
 106
 107/**
 108 * cpuidle_get_last_residency - retrieves the last state's residency time
 109 * @dev: the target CPU
 110 *
 111 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 112 */
 113static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 114{
 115        return dev->last_residency;
 116}
 117
 118
 119/****************************
 120 * CPUIDLE DRIVER INTERFACE *
 121 ****************************/
 122
 123struct cpuidle_driver {
 124        const char              *name;
 125        struct module           *owner;
 126
 127        unsigned int            power_specified:1;
 128        /* set to 1 to use the core cpuidle time keeping (for all states). */
 129        unsigned int            en_core_tk_irqen:1;
 130        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 131        int                     state_count;
 132        int                     safe_state_index;
 133};
 134
 135#ifdef CONFIG_CPU_IDLE
 136extern void disable_cpuidle(void);
 137extern int cpuidle_idle_call(void);
 138extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 139struct cpuidle_driver *cpuidle_get_driver(void);
 140extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 141extern int cpuidle_register_device(struct cpuidle_device *dev);
 142extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 143
 144extern void cpuidle_pause_and_lock(void);
 145extern void cpuidle_resume_and_unlock(void);
 146extern int cpuidle_enable_device(struct cpuidle_device *dev);
 147extern void cpuidle_disable_device(struct cpuidle_device *dev);
 148extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
 149                                struct cpuidle_driver *drv, int index,
 150                                int (*enter)(struct cpuidle_device *dev,
 151                                        struct cpuidle_driver *drv, int index));
 152extern int cpuidle_play_dead(void);
 153
 154#else
 155static inline void disable_cpuidle(void) { }
 156static inline int cpuidle_idle_call(void) { return -ENODEV; }
 157static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 158{return -ENODEV; }
 159static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 160static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 161static inline int cpuidle_register_device(struct cpuidle_device *dev)
 162{return -ENODEV; }
 163static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 164
 165static inline void cpuidle_pause_and_lock(void) { }
 166static inline void cpuidle_resume_and_unlock(void) { }
 167static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 168{return -ENODEV; }
 169static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 170static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
 171                                struct cpuidle_driver *drv, int index,
 172                                int (*enter)(struct cpuidle_device *dev,
 173                                        struct cpuidle_driver *drv, int index))
 174{ return -ENODEV; }
 175static inline int cpuidle_play_dead(void) {return -ENODEV; }
 176
 177#endif
 178
 179/******************************
 180 * CPUIDLE GOVERNOR INTERFACE *
 181 ******************************/
 182
 183struct cpuidle_governor {
 184        char                    name[CPUIDLE_NAME_LEN];
 185        struct list_head        governor_list;
 186        unsigned int            rating;
 187
 188        int  (*enable)          (struct cpuidle_driver *drv,
 189                                        struct cpuidle_device *dev);
 190        void (*disable)         (struct cpuidle_driver *drv,
 191                                        struct cpuidle_device *dev);
 192
 193        int  (*select)          (struct cpuidle_driver *drv,
 194                                        struct cpuidle_device *dev);
 195        void (*reflect)         (struct cpuidle_device *dev, int index);
 196
 197        struct module           *owner;
 198};
 199
 200#ifdef CONFIG_CPU_IDLE
 201
 202extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 203extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 204
 205#ifdef CONFIG_INTEL_IDLE
 206extern int intel_idle_cpu_init(int cpu);
 207#else
 208static inline int intel_idle_cpu_init(int cpu) { return -1; }
 209#endif
 210
 211#else
 212static inline int intel_idle_cpu_init(int cpu) { return -1; }
 213
 214static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 215{return 0;}
 216static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 217
 218#endif
 219
 220#ifdef CONFIG_ARCH_HAS_CPU_RELAX
 221#define CPUIDLE_DRIVER_STATE_START      1
 222#else
 223#define CPUIDLE_DRIVER_STATE_START      0
 224#endif
 225
 226#endif /* _LINUX_CPUIDLE_H */
 227