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       10
  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        unsigned long long      disable;
  36        unsigned long long      usage;
  37        unsigned long long      time; /* in US */
  38};
  39
  40struct cpuidle_state {
  41        char            name[CPUIDLE_NAME_LEN];
  42        char            desc[CPUIDLE_DESC_LEN];
  43
  44        unsigned int    flags;
  45        unsigned int    exit_latency; /* in US */
  46        int             power_usage; /* in mW */
  47        unsigned int    target_residency; /* in US */
  48        bool            disabled; /* disabled on all CPUs */
  49
  50        int (*enter)    (struct cpuidle_device *dev,
  51                        struct cpuidle_driver *drv,
  52                        int index);
  53
  54        int (*enter_dead) (struct cpuidle_device *dev, int index);
  55};
  56
  57/* Idle State Flags */
  58#define CPUIDLE_FLAG_TIME_INVALID       (0x01) /* is residency time measurable? */
  59#define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  60#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  61
  62#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  63
  64struct cpuidle_device {
  65        unsigned int            registered:1;
  66        unsigned int            enabled:1;
  67        unsigned int            cpu;
  68
  69        int                     last_residency;
  70        int                     state_count;
  71        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  72        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  73        struct cpuidle_driver_kobj *kobj_driver;
  74        struct list_head        device_list;
  75        struct kobject          kobj;
  76        struct completion       kobj_unregister;
  77
  78#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  79        int                     safe_state_index;
  80        cpumask_t               coupled_cpus;
  81        struct cpuidle_coupled  *coupled;
  82#endif
  83};
  84
  85DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  86
  87/**
  88 * cpuidle_get_last_residency - retrieves the last state's residency time
  89 * @dev: the target CPU
  90 *
  91 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_INVALID is set
  92 */
  93static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  94{
  95        return dev->last_residency;
  96}
  97
  98
  99/****************************
 100 * CPUIDLE DRIVER INTERFACE *
 101 ****************************/
 102
 103struct cpuidle_driver {
 104        const char              *name;
 105        struct module           *owner;
 106        int                     refcnt;
 107
 108        /* used by the cpuidle framework to setup the broadcast timer */
 109        unsigned int            bctimer:1;
 110        /* states array must be ordered in decreasing power consumption */
 111        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 112        int                     state_count;
 113        int                     safe_state_index;
 114
 115        /* the driver handles the cpus in cpumask */
 116        struct cpumask       *cpumask;
 117};
 118
 119#ifdef CONFIG_CPU_IDLE
 120extern void disable_cpuidle(void);
 121extern int cpuidle_idle_call(void);
 122extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 123extern struct cpuidle_driver *cpuidle_get_driver(void);
 124extern struct cpuidle_driver *cpuidle_driver_ref(void);
 125extern void cpuidle_driver_unref(void);
 126extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 127extern int cpuidle_register_device(struct cpuidle_device *dev);
 128extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 129extern int cpuidle_register(struct cpuidle_driver *drv,
 130                            const struct cpumask *const coupled_cpus);
 131extern void cpuidle_unregister(struct cpuidle_driver *drv);
 132extern void cpuidle_pause_and_lock(void);
 133extern void cpuidle_resume_and_unlock(void);
 134extern void cpuidle_pause(void);
 135extern void cpuidle_resume(void);
 136extern int cpuidle_enable_device(struct cpuidle_device *dev);
 137extern void cpuidle_disable_device(struct cpuidle_device *dev);
 138extern int cpuidle_play_dead(void);
 139
 140extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 141#else
 142static inline void disable_cpuidle(void) { }
 143static inline int cpuidle_idle_call(void) { return -ENODEV; }
 144static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 145{return -ENODEV; }
 146static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 147static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 148static inline void cpuidle_driver_unref(void) {}
 149static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 150static inline int cpuidle_register_device(struct cpuidle_device *dev)
 151{return -ENODEV; }
 152static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 153static inline int cpuidle_register(struct cpuidle_driver *drv,
 154                                   const struct cpumask *const coupled_cpus)
 155{return -ENODEV; }
 156static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 157static inline void cpuidle_pause_and_lock(void) { }
 158static inline void cpuidle_resume_and_unlock(void) { }
 159static inline void cpuidle_pause(void) { }
 160static inline void cpuidle_resume(void) { }
 161static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 162{return -ENODEV; }
 163static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 164static inline int cpuidle_play_dead(void) {return -ENODEV; }
 165#endif
 166
 167#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 168void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 169#else
 170static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 171{
 172}
 173#endif
 174
 175/******************************
 176 * CPUIDLE GOVERNOR INTERFACE *
 177 ******************************/
 178
 179struct cpuidle_governor {
 180        char                    name[CPUIDLE_NAME_LEN];
 181        struct list_head        governor_list;
 182        unsigned int            rating;
 183
 184        int  (*enable)          (struct cpuidle_driver *drv,
 185                                        struct cpuidle_device *dev);
 186        void (*disable)         (struct cpuidle_driver *drv,
 187                                        struct cpuidle_device *dev);
 188
 189        int  (*select)          (struct cpuidle_driver *drv,
 190                                        struct cpuidle_device *dev);
 191        void (*reflect)         (struct cpuidle_device *dev, int index);
 192
 193        struct module           *owner;
 194};
 195
 196#ifdef CONFIG_CPU_IDLE
 197
 198extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 199extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 200
 201#else
 202
 203static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 204{return 0;}
 205static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
 206
 207#endif
 208
 209#ifdef CONFIG_ARCH_HAS_CPU_RELAX
 210#define CPUIDLE_DRIVER_STATE_START      1
 211#else
 212#define CPUIDLE_DRIVER_STATE_START      0
 213#endif
 214
 215#endif /* _LINUX_CPUIDLE_H */
 216