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         * CPUs execute ->enter_freeze with the local tick or entire timekeeping
  56         * suspended, so it must not re-enable interrupts at any point (even
  57         * temporarily) or attempt to change states of clock event devices.
  58         */
  59        void (*enter_freeze) (struct cpuidle_device *dev,
  60                              struct cpuidle_driver *drv,
  61                              int index);
  62};
  63
  64/* Idle State Flags */
  65#define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
  66#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
  67
  68#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  69
  70struct cpuidle_device_kobj;
  71struct cpuidle_state_kobj;
  72struct cpuidle_driver_kobj;
  73
  74struct cpuidle_device {
  75        unsigned int            registered:1;
  76        unsigned int            enabled:1;
  77        unsigned int            cpu;
  78
  79        int                     last_residency;
  80        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
  81        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
  82        struct cpuidle_driver_kobj *kobj_driver;
  83        struct cpuidle_device_kobj *kobj_dev;
  84        struct list_head        device_list;
  85
  86#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
  87        cpumask_t               coupled_cpus;
  88        struct cpuidle_coupled  *coupled;
  89#endif
  90};
  91
  92DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
  93DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
  94
  95/**
  96 * cpuidle_get_last_residency - retrieves the last state's residency time
  97 * @dev: the target CPU
  98 */
  99static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 100{
 101        return dev->last_residency;
 102}
 103
 104
 105/****************************
 106 * CPUIDLE DRIVER INTERFACE *
 107 ****************************/
 108
 109struct cpuidle_driver {
 110        const char              *name;
 111        struct module           *owner;
 112        int                     refcnt;
 113
 114        /* used by the cpuidle framework to setup the broadcast timer */
 115        unsigned int            bctimer:1;
 116        /* states array must be ordered in decreasing power consumption */
 117        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
 118        int                     state_count;
 119        int                     safe_state_index;
 120
 121        /* the driver handles the cpus in cpumask */
 122        struct cpumask          *cpumask;
 123};
 124
 125#ifdef CONFIG_CPU_IDLE
 126extern void disable_cpuidle(void);
 127extern bool cpuidle_not_available(struct cpuidle_driver *drv,
 128                                  struct cpuidle_device *dev);
 129
 130extern int cpuidle_select(struct cpuidle_driver *drv,
 131                          struct cpuidle_device *dev);
 132extern int cpuidle_enter(struct cpuidle_driver *drv,
 133                         struct cpuidle_device *dev, int index);
 134extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 135
 136extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 137extern struct cpuidle_driver *cpuidle_get_driver(void);
 138extern struct cpuidle_driver *cpuidle_driver_ref(void);
 139extern void cpuidle_driver_unref(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);
 143extern int cpuidle_register(struct cpuidle_driver *drv,
 144                            const struct cpumask *const coupled_cpus);
 145extern void cpuidle_unregister(struct cpuidle_driver *drv);
 146extern void cpuidle_pause_and_lock(void);
 147extern void cpuidle_resume_and_unlock(void);
 148extern void cpuidle_pause(void);
 149extern void cpuidle_resume(void);
 150extern int cpuidle_enable_device(struct cpuidle_device *dev);
 151extern void cpuidle_disable_device(struct cpuidle_device *dev);
 152extern int cpuidle_play_dead(void);
 153
 154extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 155#else
 156static inline void disable_cpuidle(void) { }
 157static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
 158                                         struct cpuidle_device *dev)
 159{return true; }
 160static inline int cpuidle_select(struct cpuidle_driver *drv,
 161                                 struct cpuidle_device *dev)
 162{return -ENODEV; }
 163static inline int cpuidle_enter(struct cpuidle_driver *drv,
 164                                struct cpuidle_device *dev, int index)
 165{return -ENODEV; }
 166static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 167static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 168{return -ENODEV; }
 169static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 170static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
 171static inline void cpuidle_driver_unref(void) {}
 172static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 173static inline int cpuidle_register_device(struct cpuidle_device *dev)
 174{return -ENODEV; }
 175static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 176static inline int cpuidle_register(struct cpuidle_driver *drv,
 177                                   const struct cpumask *const coupled_cpus)
 178{return -ENODEV; }
 179static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
 180static inline void cpuidle_pause_and_lock(void) { }
 181static inline void cpuidle_resume_and_unlock(void) { }
 182static inline void cpuidle_pause(void) { }
 183static inline void cpuidle_resume(void) { }
 184static inline int cpuidle_enable_device(struct cpuidle_device *dev)
 185{return -ENODEV; }
 186static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 187static inline int cpuidle_play_dead(void) {return -ENODEV; }
 188static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 189        struct cpuidle_device *dev) {return NULL; }
 190#endif
 191
 192#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
 193extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 194                                      struct cpuidle_device *dev);
 195extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 196                                struct cpuidle_device *dev);
 197#else
 198static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 199                                             struct cpuidle_device *dev)
 200{return -ENODEV; }
 201static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 202                                       struct cpuidle_device *dev)
 203{return -ENODEV; }
 204#endif
 205
 206/* kernel/sched/idle.c */
 207extern void sched_idle_set_state(struct cpuidle_state *idle_state);
 208extern void default_idle_call(void);
 209
 210#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 211void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
 212#else
 213static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
 214{
 215}
 216#endif
 217
 218/******************************
 219 * CPUIDLE GOVERNOR INTERFACE *
 220 ******************************/
 221
 222struct cpuidle_governor {
 223        char                    name[CPUIDLE_NAME_LEN];
 224        struct list_head        governor_list;
 225        unsigned int            rating;
 226
 227        int  (*enable)          (struct cpuidle_driver *drv,
 228                                        struct cpuidle_device *dev);
 229        void (*disable)         (struct cpuidle_driver *drv,
 230                                        struct cpuidle_device *dev);
 231
 232        int  (*select)          (struct cpuidle_driver *drv,
 233                                        struct cpuidle_device *dev);
 234        void (*reflect)         (struct cpuidle_device *dev, int index);
 235
 236        struct module           *owner;
 237};
 238
 239#ifdef CONFIG_CPU_IDLE
 240extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 241#else
 242static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 243{return 0;}
 244#endif
 245
 246#ifdef CONFIG_ARCH_HAS_CPU_RELAX
 247#define CPUIDLE_DRIVER_STATE_START      1
 248#else
 249#define CPUIDLE_DRIVER_STATE_START      0
 250#endif
 251
 252#endif /* _LINUX_CPUIDLE_H */
 253