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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
32#define CPUIDLE_STATE_DISABLED_BY_USER BIT(0)
33#define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1)
34
35struct cpuidle_state_usage {
36 unsigned long long disable;
37 unsigned long long usage;
38 u64 time_ns;
39 unsigned long long above; /* Number of times it's been too deep */
40 unsigned long long below; /* Number of times it's been too shallow */
41#ifdef CONFIG_SUSPEND
42 unsigned long long s2idle_usage;
43 unsigned long long s2idle_time; /* in US */
44#endif
45};
46
47struct cpuidle_state {
48 char name[CPUIDLE_NAME_LEN];
49 char desc[CPUIDLE_DESC_LEN];
50
51 u64 exit_latency_ns;
52 u64 target_residency_ns;
53 unsigned int flags;
54 unsigned int exit_latency; /* in US */
55 int power_usage; /* in mW */
56 unsigned int target_residency; /* in US */
57
58 int (*enter) (struct cpuidle_device *dev,
59 struct cpuidle_driver *drv,
60 int index);
61
62 int (*enter_dead) (struct cpuidle_device *dev, int index);
63
64 /*
65 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
66 * suspended, so it must not re-enable interrupts at any point (even
67 * temporarily) or attempt to change states of clock event devices.
68 */
69 void (*enter_s2idle) (struct cpuidle_device *dev,
70 struct cpuidle_driver *drv,
71 int index);
72};
73
74/* Idle State Flags */
75#define CPUIDLE_FLAG_NONE (0x00)
76#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
77#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
78#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
79#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
80#define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
81
82struct cpuidle_device_kobj;
83struct cpuidle_state_kobj;
84struct cpuidle_driver_kobj;
85
86struct cpuidle_device {
87 unsigned int registered:1;
88 unsigned int enabled:1;
89 unsigned int poll_time_limit:1;
90 unsigned int cpu;
91 ktime_t next_hrtimer;
92
93 int last_state_idx;
94 u64 last_residency_ns;
95 u64 poll_limit_ns;
96 u64 forced_idle_latency_limit_ns;
97 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
98 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
99 struct cpuidle_driver_kobj *kobj_driver;
100 struct cpuidle_device_kobj *kobj_dev;
101 struct list_head device_list;
102
103#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
104 cpumask_t coupled_cpus;
105 struct cpuidle_coupled *coupled;
106#endif
107};
108
109DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
110DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
111
112/****************************
113 * CPUIDLE DRIVER INTERFACE *
114 ****************************/
115
116struct cpuidle_driver {
117 const char *name;
118 struct module *owner;
119
120 /* used by the cpuidle framework to setup the broadcast timer */
121 unsigned int bctimer:1;
122 /* states array must be ordered in decreasing power consumption */
123 struct cpuidle_state states[CPUIDLE_STATE_MAX];
124 int state_count;
125 int safe_state_index;
126
127 /* the driver handles the cpus in cpumask */
128 struct cpumask *cpumask;
129
130 /* preferred governor to switch at register time */
131 const char *governor;
132};
133
134#ifdef CONFIG_CPU_IDLE
135extern void disable_cpuidle(void);
136extern bool cpuidle_not_available(struct cpuidle_driver *drv,
137 struct cpuidle_device *dev);
138
139extern int cpuidle_select(struct cpuidle_driver *drv,
140 struct cpuidle_device *dev,
141 bool *stop_tick);
142extern int cpuidle_enter(struct cpuidle_driver *drv,
143 struct cpuidle_device *dev, int index);
144extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
145extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
146 struct cpuidle_device *dev);
147
148extern int cpuidle_register_driver(struct cpuidle_driver *drv);
149extern struct cpuidle_driver *cpuidle_get_driver(void);
150extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
151 bool disable);
152extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
153extern int cpuidle_register_device(struct cpuidle_device *dev);
154extern void cpuidle_unregister_device(struct cpuidle_device *dev);
155extern int cpuidle_register(struct cpuidle_driver *drv,
156 const struct cpumask *const coupled_cpus);
157extern void cpuidle_unregister(struct cpuidle_driver *drv);
158extern void cpuidle_pause_and_lock(void);
159extern void cpuidle_resume_and_unlock(void);
160extern void cpuidle_pause(void);
161extern void cpuidle_resume(void);
162extern int cpuidle_enable_device(struct cpuidle_device *dev);
163extern void cpuidle_disable_device(struct cpuidle_device *dev);
164extern int cpuidle_play_dead(void);
165
166extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
167static inline struct cpuidle_device *cpuidle_get_device(void)
168{return __this_cpu_read(cpuidle_devices); }
169#else
170static inline void disable_cpuidle(void) { }
171static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
172 struct cpuidle_device *dev)
173{return true; }
174static inline int cpuidle_select(struct cpuidle_driver *drv,
175 struct cpuidle_device *dev, bool *stop_tick)
176{return -ENODEV; }
177static inline int cpuidle_enter(struct cpuidle_driver *drv,
178 struct cpuidle_device *dev, int index)
179{return -ENODEV; }
180static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
181static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
182 struct cpuidle_device *dev)
183{return 0; }
184static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
185{return -ENODEV; }
186static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
187static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
188 int idx, bool disable) { }
189static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
190static inline int cpuidle_register_device(struct cpuidle_device *dev)
191{return -ENODEV; }
192static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
193static inline int cpuidle_register(struct cpuidle_driver *drv,
194 const struct cpumask *const coupled_cpus)
195{return -ENODEV; }
196static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
197static inline void cpuidle_pause_and_lock(void) { }
198static inline void cpuidle_resume_and_unlock(void) { }
199static inline void cpuidle_pause(void) { }
200static inline void cpuidle_resume(void) { }
201static inline int cpuidle_enable_device(struct cpuidle_device *dev)
202{return -ENODEV; }
203static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
204static inline int cpuidle_play_dead(void) {return -ENODEV; }
205static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
206 struct cpuidle_device *dev) {return NULL; }
207static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
208#endif
209
210#ifdef CONFIG_CPU_IDLE
211extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
212 struct cpuidle_device *dev,
213 u64 latency_limit_ns);
214extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
215 struct cpuidle_device *dev);
216extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
217#else
218static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
219 struct cpuidle_device *dev,
220 u64 latency_limit_ns)
221{return -ENODEV; }
222static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
223 struct cpuidle_device *dev)
224{return -ENODEV; }
225static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
226{
227}
228#endif
229
230/* kernel/sched/idle.c */
231extern void sched_idle_set_state(struct cpuidle_state *idle_state);
232extern void default_idle_call(void);
233
234#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
235void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
236#else
237static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
238{
239}
240#endif
241
242#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
243void cpuidle_poll_state_init(struct cpuidle_driver *drv);
244#else
245static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
246#endif
247
248/******************************
249 * CPUIDLE GOVERNOR INTERFACE *
250 ******************************/
251
252struct cpuidle_governor {
253 char name[CPUIDLE_NAME_LEN];
254 struct list_head governor_list;
255 unsigned int rating;
256
257 int (*enable) (struct cpuidle_driver *drv,
258 struct cpuidle_device *dev);
259 void (*disable) (struct cpuidle_driver *drv,
260 struct cpuidle_device *dev);
261
262 int (*select) (struct cpuidle_driver *drv,
263 struct cpuidle_device *dev,
264 bool *stop_tick);
265 void (*reflect) (struct cpuidle_device *dev, int index);
266};
267
268#ifdef CONFIG_CPU_IDLE
269extern int cpuidle_register_governor(struct cpuidle_governor *gov);
270extern s64 cpuidle_governor_latency_req(unsigned int cpu);
271#else
272static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
273{return 0;}
274#endif
275
276#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
277 idx, \
278 state, \
279 is_retention) \
280({ \
281 int __ret = 0; \
282 \
283 if (!idx) { \
284 cpu_do_idle(); \
285 return idx; \
286 } \
287 \
288 if (!is_retention) \
289 __ret = cpu_pm_enter(); \
290 if (!__ret) { \
291 __ret = low_level_idle_enter(state); \
292 if (!is_retention) \
293 cpu_pm_exit(); \
294 } \
295 \
296 __ret ? -1 : idx; \
297})
298
299#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
300 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
301
302#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
303 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
304
305#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
306 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
307
308#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
309 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
310
311#endif /* _LINUX_CPUIDLE_H */