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linux
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 unsigned long long above; /* Number of times it's been too deep */
37 unsigned long long below; /* Number of times it's been too shallow */
38#ifdef CONFIG_SUSPEND
39 unsigned long long s2idle_usage;
40 unsigned long long s2idle_time; /* in US */
41#endif
42};
43
44struct cpuidle_state {
45 char name[CPUIDLE_NAME_LEN];
46 char desc[CPUIDLE_DESC_LEN];
47
48 unsigned int flags;
49 unsigned int exit_latency; /* in US */
50 int power_usage; /* in mW */
51 unsigned int target_residency; /* in US */
52 bool disabled; /* disabled on all CPUs */
53
54 int (*enter) (struct cpuidle_device *dev,
55 struct cpuidle_driver *drv,
56 int index);
57
58 int (*enter_dead) (struct cpuidle_device *dev, int index);
59
60 /*
61 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
62 * suspended, so it must not re-enable interrupts at any point (even
63 * temporarily) or attempt to change states of clock event devices.
64 */
65 void (*enter_s2idle) (struct cpuidle_device *dev,
66 struct cpuidle_driver *drv,
67 int index);
68};
69
70/* Idle State Flags */
71#define CPUIDLE_FLAG_NONE (0x00)
72#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
73#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
74#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
75
76struct cpuidle_device_kobj;
77struct cpuidle_state_kobj;
78struct cpuidle_driver_kobj;
79
80struct cpuidle_device {
81 unsigned int registered:1;
82 unsigned int enabled:1;
83 unsigned int use_deepest_state:1;
84 unsigned int poll_time_limit:1;
85 unsigned int cpu;
86
87 int last_residency;
88 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
90 struct cpuidle_driver_kobj *kobj_driver;
91 struct cpuidle_device_kobj *kobj_dev;
92 struct list_head device_list;
93
94#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
95 cpumask_t coupled_cpus;
96 struct cpuidle_coupled *coupled;
97#endif
98};
99
100DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
101DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
102
103/****************************
104 * CPUIDLE DRIVER INTERFACE *
105 ****************************/
106
107struct cpuidle_driver {
108 const char *name;
109 struct module *owner;
110 int refcnt;
111
112 /* used by the cpuidle framework to setup the broadcast timer */
113 unsigned int bctimer:1;
114 /* states array must be ordered in decreasing power consumption */
115 struct cpuidle_state states[CPUIDLE_STATE_MAX];
116 int state_count;
117 int safe_state_index;
118
119 /* the driver handles the cpus in cpumask */
120 struct cpumask *cpumask;
121};
122
123#ifdef CONFIG_CPU_IDLE
124extern void disable_cpuidle(void);
125extern bool cpuidle_not_available(struct cpuidle_driver *drv,
126 struct cpuidle_device *dev);
127
128extern int cpuidle_select(struct cpuidle_driver *drv,
129 struct cpuidle_device *dev,
130 bool *stop_tick);
131extern int cpuidle_enter(struct cpuidle_driver *drv,
132 struct cpuidle_device *dev, int index);
133extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
134
135extern int cpuidle_register_driver(struct cpuidle_driver *drv);
136extern struct cpuidle_driver *cpuidle_get_driver(void);
137extern struct cpuidle_driver *cpuidle_driver_ref(void);
138extern void cpuidle_driver_unref(void);
139extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
140extern int cpuidle_register_device(struct cpuidle_device *dev);
141extern void cpuidle_unregister_device(struct cpuidle_device *dev);
142extern int cpuidle_register(struct cpuidle_driver *drv,
143 const struct cpumask *const coupled_cpus);
144extern void cpuidle_unregister(struct cpuidle_driver *drv);
145extern void cpuidle_pause_and_lock(void);
146extern void cpuidle_resume_and_unlock(void);
147extern void cpuidle_pause(void);
148extern void cpuidle_resume(void);
149extern int cpuidle_enable_device(struct cpuidle_device *dev);
150extern void cpuidle_disable_device(struct cpuidle_device *dev);
151extern int cpuidle_play_dead(void);
152
153extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
154static inline struct cpuidle_device *cpuidle_get_device(void)
155{return __this_cpu_read(cpuidle_devices); }
156#else
157static inline void disable_cpuidle(void) { }
158static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
159 struct cpuidle_device *dev)
160{return true; }
161static inline int cpuidle_select(struct cpuidle_driver *drv,
162 struct cpuidle_device *dev, bool *stop_tick)
163{return -ENODEV; }
164static inline int cpuidle_enter(struct cpuidle_driver *drv,
165 struct cpuidle_device *dev, int index)
166{return -ENODEV; }
167static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
168static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
169{return -ENODEV; }
170static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
171static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
172static inline void cpuidle_driver_unref(void) {}
173static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
174static inline int cpuidle_register_device(struct cpuidle_device *dev)
175{return -ENODEV; }
176static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
177static inline int cpuidle_register(struct cpuidle_driver *drv,
178 const struct cpumask *const coupled_cpus)
179{return -ENODEV; }
180static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
181static inline void cpuidle_pause_and_lock(void) { }
182static inline void cpuidle_resume_and_unlock(void) { }
183static inline void cpuidle_pause(void) { }
184static inline void cpuidle_resume(void) { }
185static inline int cpuidle_enable_device(struct cpuidle_device *dev)
186{return -ENODEV; }
187static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
188static inline int cpuidle_play_dead(void) {return -ENODEV; }
189static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
190 struct cpuidle_device *dev) {return NULL; }
191static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
192#endif
193
194#ifdef CONFIG_CPU_IDLE
195extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
196 struct cpuidle_device *dev);
197extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
198 struct cpuidle_device *dev);
199extern void cpuidle_use_deepest_state(bool enable);
200#else
201static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
202 struct cpuidle_device *dev)
203{return -ENODEV; }
204static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev)
206{return -ENODEV; }
207static inline void cpuidle_use_deepest_state(bool enable)
208{
209}
210#endif
211
212/* kernel/sched/idle.c */
213extern void sched_idle_set_state(struct cpuidle_state *idle_state);
214extern void default_idle_call(void);
215
216#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
217void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
218#else
219static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
220{
221}
222#endif
223
224#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
225void cpuidle_poll_state_init(struct cpuidle_driver *drv);
226#else
227static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
228#endif
229
230/******************************
231 * CPUIDLE GOVERNOR INTERFACE *
232 ******************************/
233
234struct cpuidle_governor {
235 char name[CPUIDLE_NAME_LEN];
236 struct list_head governor_list;
237 unsigned int rating;
238
239 int (*enable) (struct cpuidle_driver *drv,
240 struct cpuidle_device *dev);
241 void (*disable) (struct cpuidle_driver *drv,
242 struct cpuidle_device *dev);
243
244 int (*select) (struct cpuidle_driver *drv,
245 struct cpuidle_device *dev,
246 bool *stop_tick);
247 void (*reflect) (struct cpuidle_device *dev, int index);
248};
249
250#ifdef CONFIG_CPU_IDLE
251extern int cpuidle_register_governor(struct cpuidle_governor *gov);
252extern int cpuidle_governor_latency_req(unsigned int cpu);
253#else
254static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
255{return 0;}
256#endif
257
258#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
259({ \
260 int __ret = 0; \
261 \
262 if (!idx) { \
263 cpu_do_idle(); \
264 return idx; \
265 } \
266 \
267 if (!is_retention) \
268 __ret = cpu_pm_enter(); \
269 if (!__ret) { \
270 __ret = low_level_idle_enter(idx); \
271 if (!is_retention) \
272 cpu_pm_exit(); \
273 } \
274 \
275 __ret ? -1 : idx; \
276})
277
278#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
279 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
280
281#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
282 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
283
284#endif /* _LINUX_CPUIDLE_H */