2 * cpuidle.h - a generic framework for CPU idle power management
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
8 * This code is licenced under the GPL.
11 #ifndef _LINUX_CPUIDLE_H
12 #define _LINUX_CPUIDLE_H
14 #include <linux/percpu.h>
15 #include <linux/list.h>
16 #include <linux/hrtimer.h>
18 #define CPUIDLE_STATE_MAX 10
19 #define CPUIDLE_NAME_LEN 16
20 #define CPUIDLE_DESC_LEN 32
24 struct cpuidle_device;
25 struct cpuidle_driver;
28 /****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
32 struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
38 struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
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 */
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
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.
59 void (*enter_freeze) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
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 */
68 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
70 struct cpuidle_device_kobj;
71 struct cpuidle_state_kobj;
72 struct cpuidle_driver_kobj;
74 struct cpuidle_device {
75 unsigned int registered:1;
76 unsigned int enabled:1;
77 unsigned int use_deepest_state:1;
81 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
82 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
83 struct cpuidle_driver_kobj *kobj_driver;
84 struct cpuidle_device_kobj *kobj_dev;
85 struct list_head device_list;
87 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
88 cpumask_t coupled_cpus;
89 struct cpuidle_coupled *coupled;
93 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
94 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
97 * cpuidle_get_last_residency - retrieves the last state's residency time
98 * @dev: the target CPU
100 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
102 return dev->last_residency;
106 /****************************
107 * CPUIDLE DRIVER INTERFACE *
108 ****************************/
110 struct cpuidle_driver {
112 struct module *owner;
115 /* used by the cpuidle framework to setup the broadcast timer */
116 unsigned int bctimer:1;
117 /* states array must be ordered in decreasing power consumption */
118 struct cpuidle_state states[CPUIDLE_STATE_MAX];
120 int safe_state_index;
122 /* the driver handles the cpus in cpumask */
123 struct cpumask *cpumask;
126 #ifdef CONFIG_CPU_IDLE
127 extern void disable_cpuidle(void);
128 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
129 struct cpuidle_device *dev);
131 extern int cpuidle_select(struct cpuidle_driver *drv,
132 struct cpuidle_device *dev);
133 extern int cpuidle_enter(struct cpuidle_driver *drv,
134 struct cpuidle_device *dev, int index);
135 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
137 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
138 extern struct cpuidle_driver *cpuidle_get_driver(void);
139 extern struct cpuidle_driver *cpuidle_driver_ref(void);
140 extern void cpuidle_driver_unref(void);
141 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
142 extern int cpuidle_register_device(struct cpuidle_device *dev);
143 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
144 extern int cpuidle_register(struct cpuidle_driver *drv,
145 const struct cpumask *const coupled_cpus);
146 extern void cpuidle_unregister(struct cpuidle_driver *drv);
147 extern void cpuidle_pause_and_lock(void);
148 extern void cpuidle_resume_and_unlock(void);
149 extern void cpuidle_pause(void);
150 extern void cpuidle_resume(void);
151 extern int cpuidle_enable_device(struct cpuidle_device *dev);
152 extern void cpuidle_disable_device(struct cpuidle_device *dev);
153 extern int cpuidle_play_dead(void);
155 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
156 static inline struct cpuidle_device *cpuidle_get_device(void)
157 {return __this_cpu_read(cpuidle_devices); }
159 static inline void disable_cpuidle(void) { }
160 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
161 struct cpuidle_device *dev)
163 static inline int cpuidle_select(struct cpuidle_driver *drv,
164 struct cpuidle_device *dev)
166 static inline int cpuidle_enter(struct cpuidle_driver *drv,
167 struct cpuidle_device *dev, int index)
169 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
170 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
172 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
173 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
174 static inline void cpuidle_driver_unref(void) {}
175 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
176 static inline int cpuidle_register_device(struct cpuidle_device *dev)
178 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
179 static inline int cpuidle_register(struct cpuidle_driver *drv,
180 const struct cpumask *const coupled_cpus)
182 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
183 static inline void cpuidle_pause_and_lock(void) { }
184 static inline void cpuidle_resume_and_unlock(void) { }
185 static inline void cpuidle_pause(void) { }
186 static inline void cpuidle_resume(void) { }
187 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
189 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
190 static inline int cpuidle_play_dead(void) {return -ENODEV; }
191 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
192 struct cpuidle_device *dev) {return NULL; }
193 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
196 #ifdef CONFIG_CPU_IDLE
197 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
198 struct cpuidle_device *dev);
199 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201 extern void cpuidle_use_deepest_state(bool enable);
203 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
204 struct cpuidle_device *dev)
206 static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev)
209 static inline void cpuidle_use_deepest_state(bool enable)
214 /* kernel/sched/idle.c */
215 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
216 extern void default_idle_call(void);
218 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
219 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
221 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
226 /******************************
227 * CPUIDLE GOVERNOR INTERFACE *
228 ******************************/
230 struct cpuidle_governor {
231 char name[CPUIDLE_NAME_LEN];
232 struct list_head governor_list;
235 int (*enable) (struct cpuidle_driver *drv,
236 struct cpuidle_device *dev);
237 void (*disable) (struct cpuidle_driver *drv,
238 struct cpuidle_device *dev);
240 int (*select) (struct cpuidle_driver *drv,
241 struct cpuidle_device *dev);
242 void (*reflect) (struct cpuidle_device *dev, int index);
245 #ifdef CONFIG_CPU_IDLE
246 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
248 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
252 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
253 #define CPUIDLE_DRIVER_STATE_START 1
255 #define CPUIDLE_DRIVER_STATE_START 0
258 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
267 __ret = cpu_pm_enter(); \
269 __ret = low_level_idle_enter(idx); \
276 #endif /* _LINUX_CPUIDLE_H */