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/hrtimer.h>
  17
  18#define CPUIDLE_STATE_MAX       10
  19#define CPUIDLE_NAME_LEN        16
  20#define CPUIDLE_DESC_LEN        32
  21
  22struct module;
  23
  24struct cpuidle_device;
  25struct cpuidle_driver;
  26
  27
  28/****************************
  29 * CPUIDLE DEVICE INTERFACE *
  30 ****************************/
  31
  32struct cpuidle_state_usage {
  33        unsigned long long      disable;
  34        unsigned long long      usage;
  35        unsigned long long      time; /* in US */
  36};
  37
  38struct cpuidle_state {
  39        char            name[CPUIDLE_NAME_LEN];
  40        char            desc[CPUIDLE_DESC_LEN];
  41
  42        unsigned int    flags;
  43        unsigned int    exit_latency; /* in US */
  44        int             power_usage; /* in mW */
  45        unsigned int    target_residency; /* in US */
  46        bool            disabled; /* disabled on all CPUs */
  47
  48        int (*enter)    (struct cpuidle_device *dev,
  49                        struct cpuidle_driver *drv,
  50                        int index);
  51
  52        int (*enter_dead) (struct cpuidle_device *dev, int index);
  53};
  54
  55/* Idle State Flags */
  56#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
  57#define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  58#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  59
  60#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  61
  62struct cpuidle_device_kobj;
  63struct cpuidle_state_kobj;
  64struct cpuidle_driver_kobj;
  65
  66struct cpuidle_device {
  67        unsigned int            registered:1;
  68        unsigned int            enabled:1;
  69        unsigned int            cpu;
  70
  71        int                     last_residency;
  72        int                     state_count;
  73        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  74        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  75        struct cpuidle_driver_kobj *kobj_driver;
  76        struct cpuidle_device_kobj *kobj_dev;
  77        struct list_head        device_list;
  78
  79#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  80        int                     safe_state_index;
  81        cpumask_t               coupled_cpus;
  82        struct cpuidle_coupled  *coupled;
  83#endif
  84};
  85
  86DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  87DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  88
  89/**
  90 * cpuidle_get_last_residency - retrieves the last state's residency time
  91 * @dev: the target CPU
  92 *
  93 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
  94 */
  95static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
  96{
  97        return dev->last_residency;
  98}
  99
 100
 101/****************************
 102 * CPUIDLE DRIVER INTERFACE *
 103 ****************************/
 104
 105struct cpuidle_driver {
 106        const char              *name;
 107        struct module           *owner;
 108        int                     refcnt;
 109
 110        /* used by the cpuidle framework to setup the broadcast timer */
 111        unsigned int            bctimer:1;
 112        /* states array must be ordered in decreasing power consumption */
 113        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 114        int                     state_count;
 115        int                     safe_state_index;
 116
 117        /* the driver handles the cpus in cpumask */
 118        struct cpumask          *cpumask;
 119};
 120
 121#ifdef CONFIG_CPU_IDLE
 122extern void disable_cpuidle(void);
 123
 124extern int cpuidle_select(struct cpuidle_driver *drv,
 125                          struct cpuidle_device *dev);
 126extern int cpuidle_enter(struct cpuidle_driver *drv,
 127                         struct cpuidle_device *dev, int index);
 128extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 129
 130extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 131extern struct cpuidle_driver *cpuidle_get_driver(void);
 132extern struct cpuidle_driver *cpuidle_driver_ref(void);
 133extern void cpuidle_driver_unref(void);
 134extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 135extern int cpuidle_register_device(struct cpuidle_device *dev);
 136extern void cpuidle_unregister_device(struct cpuidle_device *dev);
 137extern int cpuidle_register(struct cpuidle_driver *drv,
 138                            const struct cpumask *const coupled_cpus);
 139extern void cpuidle_unregister(struct cpuidle_driver *drv);
 140extern void cpuidle_pause_and_lock(void);
 141extern void cpuidle_resume_and_unlock(void);
 142extern void cpuidle_pause(void);
 143extern void cpuidle_resume(void);
 144extern int cpuidle_enable_device(struct cpuidle_device *dev);
 145extern void cpuidle_disable_device(struct cpuidle_device *dev);
 146extern int cpuidle_play_dead(void);
 147extern void cpuidle_use_deepest_state(bool enable);
 148
 149extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 150#else
 151static inline void disable_cpuidle(void) { }
 152static inline int cpuidle_select(struct cpuidle_driver *drv,
 153                                 struct cpuidle_device *dev)
 154{return -ENODEV; }
 155static inline int cpuidle_enter(struct cpuidle_driver *drv,
 156                                struct cpuidle_device *dev, int index)
 157{return -ENODEV; }
 158static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 159static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 160{return -ENODEV; }
 161static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 162static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 163static inline void cpuidle_driver_unref(void) {}
 164static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 165static inline int cpuidle_register_device(struct cpuidle_device *dev)
 166{return -ENODEV; }
 167static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 168static inline int cpuidle_register(struct cpuidle_driver *drv,
 169                                   const struct cpumask *const coupled_cpus)
 170{return -ENODEV; }
 171static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 172static inline void cpuidle_pause_and_lock(void) { }
 173static inline void cpuidle_resume_and_unlock(void) { }
 174static inline void cpuidle_pause(void) { }
 175static inline void cpuidle_resume(void) { }
 176static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 177{return -ENODEV; }
 178static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 179static inline int cpuidle_play_dead(void) {return -ENODEV; }
 180static inline void cpuidle_use_deepest_state(bool enable) {}
 181static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 182        struct cpuidle_device *dev) {return NULL; }
 183#endif
 184
 185#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 186void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 187#else
 188static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 189{
 190}
 191#endif
 192
 193/******************************
 194 * CPUIDLE GOVERNOR INTERFACE *
 195 ******************************/
 196
 197struct cpuidle_governor {
 198        char                    name[CPUIDLE_NAME_LEN];
 199        struct list_head        governor_list;
 200        unsigned int            rating;
 201
 202        int  (*enable)          (struct cpuidle_driver *drv,
 203                                        struct cpuidle_device *dev);
 204        void (*disable)         (struct cpuidle_driver *drv,
 205                                        struct cpuidle_device *dev);
 206
 207        int  (*select)          (struct cpuidle_driver *drv,
 208                                        struct cpuidle_device *dev);
 209        void (*reflect)         (struct cpuidle_device *dev, int index);
 210
 211        struct module           *owner;
 212};
 213
 214#ifdef CONFIG_CPU_IDLE
 215extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 216#else
 217static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 218{return 0;}
 219#endif
 220
 221#ifdef CONFIG_ARCH_HAS_CPU_RELAX
 222#define CPUIDLE_DRIVER_STATE_START      1
 223#else
 224#define CPUIDLE_DRIVER_STATE_START      0
 225#endif
 226
 227#endif /* _LINUX_CPUIDLE_H */
 228