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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 (0x01) /* polling state */
73#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
74#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
75
76#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
77
78struct cpuidle_device_kobj;
79struct cpuidle_state_kobj;
80struct cpuidle_driver_kobj;
81
82struct cpuidle_device {
83 unsigned int registered:1;
84 unsigned int enabled:1;
85 unsigned int use_deepest_state:1;
86 unsigned int poll_time_limit:1;
87 unsigned int cpu;
88
89 int last_residency;
90 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
91 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
92 struct cpuidle_driver_kobj *kobj_driver;
93 struct cpuidle_device_kobj *kobj_dev;
94 struct list_head device_list;
95
96#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
97 cpumask_t coupled_cpus;
98 struct cpuidle_coupled *coupled;
99#endif
100};
101
102DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
103DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
104
105/****************************
106 * CPUIDLE DRIVER INTERFACE *
107 ****************************/
108
109struct cpuidle_driver {
110 const char *name;
111 struct module *owner;
112 int refcnt;
113
114 /* used by the cpuidle framework to setup the broadcast timer */
115 unsigned int bctimer:1;
116 /* states array must be ordered in decreasing power consumption */
117 struct cpuidle_state states[CPUIDLE_STATE_MAX];
118 int state_count;
119 int safe_state_index;
120
121 /* the driver handles the cpus in cpumask */
122 struct cpumask *cpumask;
123};
124
125#ifdef CONFIG_CPU_IDLE
126extern void disable_cpuidle(void);
127extern bool cpuidle_not_available(struct cpuidle_driver *drv,
128 struct cpuidle_device *dev);
129
130extern int cpuidle_select(struct cpuidle_driver *drv,
131 struct cpuidle_device *dev,
132 bool *stop_tick);
133extern int cpuidle_enter(struct cpuidle_driver *drv,
134 struct cpuidle_device *dev, int index);
135extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
136
137extern int cpuidle_register_driver(struct cpuidle_driver *drv);
138extern struct cpuidle_driver *cpuidle_get_driver(void);
139extern struct cpuidle_driver *cpuidle_driver_ref(void);
140extern void cpuidle_driver_unref(void);
141extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
142extern int cpuidle_register_device(struct cpuidle_device *dev);
143extern void cpuidle_unregister_device(struct cpuidle_device *dev);
144extern int cpuidle_register(struct cpuidle_driver *drv,
145 const struct cpumask *const coupled_cpus);
146extern void cpuidle_unregister(struct cpuidle_driver *drv);
147extern void cpuidle_pause_and_lock(void);
148extern void cpuidle_resume_and_unlock(void);
149extern void cpuidle_pause(void);
150extern void cpuidle_resume(void);
151extern int cpuidle_enable_device(struct cpuidle_device *dev);
152extern void cpuidle_disable_device(struct cpuidle_device *dev);
153extern int cpuidle_play_dead(void);
154
155extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
156static inline struct cpuidle_device *cpuidle_get_device(void)
157{return __this_cpu_read(cpuidle_devices); }
158#else
159static inline void disable_cpuidle(void) { }
160static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
161 struct cpuidle_device *dev)
162{return true; }
163static inline int cpuidle_select(struct cpuidle_driver *drv,
164 struct cpuidle_device *dev, bool *stop_tick)
165{return -ENODEV; }
166static inline int cpuidle_enter(struct cpuidle_driver *drv,
167 struct cpuidle_device *dev, int index)
168{return -ENODEV; }
169static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
170static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
171{return -ENODEV; }
172static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
173static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
174static inline void cpuidle_driver_unref(void) {}
175static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
176static inline int cpuidle_register_device(struct cpuidle_device *dev)
177{return -ENODEV; }
178static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
179static inline int cpuidle_register(struct cpuidle_driver *drv,
180 const struct cpumask *const coupled_cpus)
181{return -ENODEV; }
182static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
183static inline void cpuidle_pause_and_lock(void) { }
184static inline void cpuidle_resume_and_unlock(void) { }
185static inline void cpuidle_pause(void) { }
186static inline void cpuidle_resume(void) { }
187static inline int cpuidle_enable_device(struct cpuidle_device *dev)
188{return -ENODEV; }
189static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
190static inline int cpuidle_play_dead(void) {return -ENODEV; }
191static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
192 struct cpuidle_device *dev) {return NULL; }
193static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
194#endif
195
196#ifdef CONFIG_CPU_IDLE
197extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
198 struct cpuidle_device *dev);
199extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201extern void cpuidle_use_deepest_state(bool enable);
202#else
203static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
204 struct cpuidle_device *dev)
205{return -ENODEV; }
206static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev)
208{return -ENODEV; }
209static inline void cpuidle_use_deepest_state(bool enable)
210{
211}
212#endif
213
214/* kernel/sched/idle.c */
215extern void sched_idle_set_state(struct cpuidle_state *idle_state);
216extern void default_idle_call(void);
217
218#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
219void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
220#else
221static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
222{
223}
224#endif
225
226#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
227void cpuidle_poll_state_init(struct cpuidle_driver *drv);
228#else
229static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
230#endif
231
232/******************************
233 * CPUIDLE GOVERNOR INTERFACE *
234 ******************************/
235
236struct cpuidle_governor {
237 char name[CPUIDLE_NAME_LEN];
238 struct list_head governor_list;
239 unsigned int rating;
240
241 int (*enable) (struct cpuidle_driver *drv,
242 struct cpuidle_device *dev);
243 void (*disable) (struct cpuidle_driver *drv,
244 struct cpuidle_device *dev);
245
246 int (*select) (struct cpuidle_driver *drv,
247 struct cpuidle_device *dev,
248 bool *stop_tick);
249 void (*reflect) (struct cpuidle_device *dev, int index);
250};
251
252#ifdef CONFIG_CPU_IDLE
253extern int cpuidle_register_governor(struct cpuidle_governor *gov);
254extern int cpuidle_governor_latency_req(unsigned int cpu);
255#else
256static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
257{return 0;}
258#endif
259
260#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
261({ \
262 int __ret = 0; \
263 \
264 if (!idx) { \
265 cpu_do_idle(); \
266 return idx; \
267 } \
268 \
269 if (!is_retention) \
270 __ret = cpu_pm_enter(); \
271 if (!__ret) { \
272 __ret = low_level_idle_enter(idx); \
273 if (!is_retention) \
274 cpu_pm_exit(); \
275 } \
276 \
277 __ret ? -1 : idx; \
278})
279
280#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
281 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
282
283#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
284 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
285
286#endif /* _LINUX_CPUIDLE_H */