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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_residency;
89 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
90 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
91 struct cpuidle_driver_kobj *kobj_driver;
92 struct cpuidle_device_kobj *kobj_dev;
93 struct list_head device_list;
94
95#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
96 cpumask_t coupled_cpus;
97 struct cpuidle_coupled *coupled;
98#endif
99};
100
101DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
102DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
103
104/****************************
105 * CPUIDLE DRIVER INTERFACE *
106 ****************************/
107
108struct cpuidle_driver {
109 const char *name;
110 struct module *owner;
111 int refcnt;
112
113 /* used by the cpuidle framework to setup the broadcast timer */
114 unsigned int bctimer:1;
115 /* states array must be ordered in decreasing power consumption */
116 struct cpuidle_state states[CPUIDLE_STATE_MAX];
117 int state_count;
118 int safe_state_index;
119
120 /* the driver handles the cpus in cpumask */
121 struct cpumask *cpumask;
122};
123
124#ifdef CONFIG_CPU_IDLE
125extern void disable_cpuidle(void);
126extern bool cpuidle_not_available(struct cpuidle_driver *drv,
127 struct cpuidle_device *dev);
128
129extern int cpuidle_select(struct cpuidle_driver *drv,
130 struct cpuidle_device *dev,
131 bool *stop_tick);
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);
155static inline struct cpuidle_device *cpuidle_get_device(void)
156{return __this_cpu_read(cpuidle_devices); }
157#else
158static inline void disable_cpuidle(void) { }
159static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
160 struct cpuidle_device *dev)
161{return true; }
162static inline int cpuidle_select(struct cpuidle_driver *drv,
163 struct cpuidle_device *dev, bool *stop_tick)
164{return -ENODEV; }
165static inline int cpuidle_enter(struct cpuidle_driver *drv,
166 struct cpuidle_device *dev, int index)
167{return -ENODEV; }
168static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
169static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
170{return -ENODEV; }
171static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
172static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
173static inline void cpuidle_driver_unref(void) {}
174static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
175static inline int cpuidle_register_device(struct cpuidle_device *dev)
176{return -ENODEV; }
177static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
178static inline int cpuidle_register(struct cpuidle_driver *drv,
179 const struct cpumask *const coupled_cpus)
180{return -ENODEV; }
181static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
182static inline void cpuidle_pause_and_lock(void) { }
183static inline void cpuidle_resume_and_unlock(void) { }
184static inline void cpuidle_pause(void) { }
185static inline void cpuidle_resume(void) { }
186static inline int cpuidle_enable_device(struct cpuidle_device *dev)
187{return -ENODEV; }
188static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
189static inline int cpuidle_play_dead(void) {return -ENODEV; }
190static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
191 struct cpuidle_device *dev) {return NULL; }
192static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
193#endif
194
195#ifdef CONFIG_CPU_IDLE
196extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
197 struct cpuidle_device *dev);
198extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
199 struct cpuidle_device *dev);
200extern void cpuidle_use_deepest_state(bool enable);
201#else
202static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
203 struct cpuidle_device *dev)
204{return -ENODEV; }
205static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
206 struct cpuidle_device *dev)
207{return -ENODEV; }
208static inline void cpuidle_use_deepest_state(bool enable)
209{
210}
211#endif
212
213/* kernel/sched/idle.c */
214extern void sched_idle_set_state(struct cpuidle_state *idle_state);
215extern void default_idle_call(void);
216
217#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
218void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
219#else
220static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
221{
222}
223#endif
224
225#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
226void cpuidle_poll_state_init(struct cpuidle_driver *drv);
227#else
228static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
229#endif
230
231/******************************
232 * CPUIDLE GOVERNOR INTERFACE *
233 ******************************/
234
235struct cpuidle_governor {
236 char name[CPUIDLE_NAME_LEN];
237 struct list_head governor_list;
238 unsigned int rating;
239
240 int (*enable) (struct cpuidle_driver *drv,
241 struct cpuidle_device *dev);
242 void (*disable) (struct cpuidle_driver *drv,
243 struct cpuidle_device *dev);
244
245 int (*select) (struct cpuidle_driver *drv,
246 struct cpuidle_device *dev,
247 bool *stop_tick);
248 void (*reflect) (struct cpuidle_device *dev, int index);
249};
250
251#ifdef CONFIG_CPU_IDLE
252extern int cpuidle_register_governor(struct cpuidle_governor *gov);
253extern int cpuidle_governor_latency_req(unsigned int cpu);
254#else
255static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
256{return 0;}
257#endif
258
259#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
260({ \
261 int __ret = 0; \
262 \
263 if (!idx) { \
264 cpu_do_idle(); \
265 return idx; \
266 } \
267 \
268 if (!is_retention) \
269 __ret = cpu_pm_enter(); \
270 if (!__ret) { \
271 __ret = low_level_idle_enter(idx); \
272 if (!is_retention) \
273 cpu_pm_exit(); \
274 } \
275 \
276 __ret ? -1 : idx; \
277})
278
279#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
280 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
281
282#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
283 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
284
285#endif /* _LINUX_CPUIDLE_H */