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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 ktime_t next_hrtimer;
87
88 int last_state_idx;
89 int last_residency;
90 u64 poll_limit_ns;
91 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
92 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
93 struct cpuidle_driver_kobj *kobj_driver;
94 struct cpuidle_device_kobj *kobj_dev;
95 struct list_head device_list;
96
97#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
98 cpumask_t coupled_cpus;
99 struct cpuidle_coupled *coupled;
100#endif
101};
102
103DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
104DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
105
106/****************************
107 * CPUIDLE DRIVER INTERFACE *
108 ****************************/
109
110struct cpuidle_driver {
111 const char *name;
112 struct module *owner;
113 int refcnt;
114
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];
119 int state_count;
120 int safe_state_index;
121
122 /* the driver handles the cpus in cpumask */
123 struct cpumask *cpumask;
124
125 /* preferred governor to switch at register time */
126 const char *governor;
127};
128
129#ifdef CONFIG_CPU_IDLE
130extern void disable_cpuidle(void);
131extern bool cpuidle_not_available(struct cpuidle_driver *drv,
132 struct cpuidle_device *dev);
133
134extern int cpuidle_select(struct cpuidle_driver *drv,
135 struct cpuidle_device *dev,
136 bool *stop_tick);
137extern int cpuidle_enter(struct cpuidle_driver *drv,
138 struct cpuidle_device *dev, int index);
139extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
140extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
141 struct cpuidle_device *dev);
142
143extern int cpuidle_register_driver(struct cpuidle_driver *drv);
144extern struct cpuidle_driver *cpuidle_get_driver(void);
145extern struct cpuidle_driver *cpuidle_driver_ref(void);
146extern void cpuidle_driver_unref(void);
147extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
148extern int cpuidle_register_device(struct cpuidle_device *dev);
149extern void cpuidle_unregister_device(struct cpuidle_device *dev);
150extern int cpuidle_register(struct cpuidle_driver *drv,
151 const struct cpumask *const coupled_cpus);
152extern void cpuidle_unregister(struct cpuidle_driver *drv);
153extern void cpuidle_pause_and_lock(void);
154extern void cpuidle_resume_and_unlock(void);
155extern void cpuidle_pause(void);
156extern void cpuidle_resume(void);
157extern int cpuidle_enable_device(struct cpuidle_device *dev);
158extern void cpuidle_disable_device(struct cpuidle_device *dev);
159extern int cpuidle_play_dead(void);
160
161extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
162static inline struct cpuidle_device *cpuidle_get_device(void)
163{return __this_cpu_read(cpuidle_devices); }
164#else
165static inline void disable_cpuidle(void) { }
166static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
167 struct cpuidle_device *dev)
168{return true; }
169static inline int cpuidle_select(struct cpuidle_driver *drv,
170 struct cpuidle_device *dev, bool *stop_tick)
171{return -ENODEV; }
172static inline int cpuidle_enter(struct cpuidle_driver *drv,
173 struct cpuidle_device *dev, int index)
174{return -ENODEV; }
175static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
176static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
177 struct cpuidle_device *dev)
178{return 0; }
179static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
180{return -ENODEV; }
181static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
182static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
183static inline void cpuidle_driver_unref(void) {}
184static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
185static inline int cpuidle_register_device(struct cpuidle_device *dev)
186{return -ENODEV; }
187static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
188static inline int cpuidle_register(struct cpuidle_driver *drv,
189 const struct cpumask *const coupled_cpus)
190{return -ENODEV; }
191static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
192static inline void cpuidle_pause_and_lock(void) { }
193static inline void cpuidle_resume_and_unlock(void) { }
194static inline void cpuidle_pause(void) { }
195static inline void cpuidle_resume(void) { }
196static inline int cpuidle_enable_device(struct cpuidle_device *dev)
197{return -ENODEV; }
198static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
199static inline int cpuidle_play_dead(void) {return -ENODEV; }
200static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
201 struct cpuidle_device *dev) {return NULL; }
202static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
203#endif
204
205#ifdef CONFIG_CPU_IDLE
206extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
209 struct cpuidle_device *dev);
210extern void cpuidle_use_deepest_state(bool enable);
211#else
212static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
213 struct cpuidle_device *dev)
214{return -ENODEV; }
215static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
216 struct cpuidle_device *dev)
217{return -ENODEV; }
218static inline void cpuidle_use_deepest_state(bool enable)
219{
220}
221#endif
222
223/* kernel/sched/idle.c */
224extern void sched_idle_set_state(struct cpuidle_state *idle_state);
225extern void default_idle_call(void);
226
227#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
228void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
229#else
230static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
231{
232}
233#endif
234
235#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
236void cpuidle_poll_state_init(struct cpuidle_driver *drv);
237#else
238static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
239#endif
240
241/******************************
242 * CPUIDLE GOVERNOR INTERFACE *
243 ******************************/
244
245struct cpuidle_governor {
246 char name[CPUIDLE_NAME_LEN];
247 struct list_head governor_list;
248 unsigned int rating;
249
250 int (*enable) (struct cpuidle_driver *drv,
251 struct cpuidle_device *dev);
252 void (*disable) (struct cpuidle_driver *drv,
253 struct cpuidle_device *dev);
254
255 int (*select) (struct cpuidle_driver *drv,
256 struct cpuidle_device *dev,
257 bool *stop_tick);
258 void (*reflect) (struct cpuidle_device *dev, int index);
259};
260
261#ifdef CONFIG_CPU_IDLE
262extern int cpuidle_register_governor(struct cpuidle_governor *gov);
263extern int cpuidle_governor_latency_req(unsigned int cpu);
264#else
265static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
266{return 0;}
267#endif
268
269#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
270 idx, \
271 state, \
272 is_retention) \
273({ \
274 int __ret = 0; \
275 \
276 if (!idx) { \
277 cpu_do_idle(); \
278 return idx; \
279 } \
280 \
281 if (!is_retention) \
282 __ret = cpu_pm_enter(); \
283 if (!__ret) { \
284 __ret = low_level_idle_enter(state); \
285 if (!is_retention) \
286 cpu_pm_exit(); \
287 } \
288 \
289 __ret ? -1 : idx; \
290})
291
292#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
293 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
294
295#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
296 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
297
298#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
299 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
300
301#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
302 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
303
304#endif /* _LINUX_CPUIDLE_H */