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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#ifdef CONFIG_SUSPEND
37 unsigned long long s2idle_usage;
38 unsigned long long s2idle_time; /* in US */
39#endif
40};
41
42struct cpuidle_state {
43 char name[CPUIDLE_NAME_LEN];
44 char desc[CPUIDLE_DESC_LEN];
45
46 unsigned int flags;
47 unsigned int exit_latency; /* in US */
48 int power_usage; /* in mW */
49 unsigned int target_residency; /* in US */
50 bool disabled; /* disabled on all CPUs */
51
52 int (*enter) (struct cpuidle_device *dev,
53 struct cpuidle_driver *drv,
54 int index);
55
56 int (*enter_dead) (struct cpuidle_device *dev, int index);
57
58 /*
59 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
60 * suspended, so it must not re-enable interrupts at any point (even
61 * temporarily) or attempt to change states of clock event devices.
62 */
63 void (*enter_s2idle) (struct cpuidle_device *dev,
64 struct cpuidle_driver *drv,
65 int index);
66};
67
68/* Idle State Flags */
69#define CPUIDLE_FLAG_NONE (0x00)
70#define CPUIDLE_FLAG_POLLING (0x01) /* polling state */
71#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
72#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
73
74#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
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 cpu;
85
86 int last_residency;
87 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
88 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
89 struct cpuidle_driver_kobj *kobj_driver;
90 struct cpuidle_device_kobj *kobj_dev;
91 struct list_head device_list;
92
93#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
94 cpumask_t coupled_cpus;
95 struct cpuidle_coupled *coupled;
96#endif
97};
98
99DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
100DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
101
102/**
103 * cpuidle_get_last_residency - retrieves the last state's residency time
104 * @dev: the target CPU
105 */
106static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
107{
108 return dev->last_residency;
109}
110
111
112/****************************
113 * CPUIDLE DRIVER INTERFACE *
114 ****************************/
115
116struct cpuidle_driver {
117 const char *name;
118 struct module *owner;
119 int refcnt;
120
121 /* used by the cpuidle framework to setup the broadcast timer */
122 unsigned int bctimer:1;
123 /* states array must be ordered in decreasing power consumption */
124 struct cpuidle_state states[CPUIDLE_STATE_MAX];
125 int state_count;
126 int safe_state_index;
127
128 /* the driver handles the cpus in cpumask */
129 struct cpumask *cpumask;
130};
131
132#ifdef CONFIG_CPU_IDLE
133extern void disable_cpuidle(void);
134extern bool cpuidle_not_available(struct cpuidle_driver *drv,
135 struct cpuidle_device *dev);
136
137extern int cpuidle_select(struct cpuidle_driver *drv,
138 struct cpuidle_device *dev,
139 bool *stop_tick);
140extern int cpuidle_enter(struct cpuidle_driver *drv,
141 struct cpuidle_device *dev, int index);
142extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
143
144extern int cpuidle_register_driver(struct cpuidle_driver *drv);
145extern struct cpuidle_driver *cpuidle_get_driver(void);
146extern struct cpuidle_driver *cpuidle_driver_ref(void);
147extern void cpuidle_driver_unref(void);
148extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
149extern int cpuidle_register_device(struct cpuidle_device *dev);
150extern void cpuidle_unregister_device(struct cpuidle_device *dev);
151extern int cpuidle_register(struct cpuidle_driver *drv,
152 const struct cpumask *const coupled_cpus);
153extern void cpuidle_unregister(struct cpuidle_driver *drv);
154extern void cpuidle_pause_and_lock(void);
155extern void cpuidle_resume_and_unlock(void);
156extern void cpuidle_pause(void);
157extern void cpuidle_resume(void);
158extern int cpuidle_enable_device(struct cpuidle_device *dev);
159extern void cpuidle_disable_device(struct cpuidle_device *dev);
160extern int cpuidle_play_dead(void);
161
162extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
163static inline struct cpuidle_device *cpuidle_get_device(void)
164{return __this_cpu_read(cpuidle_devices); }
165#else
166static inline void disable_cpuidle(void) { }
167static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
168 struct cpuidle_device *dev)
169{return true; }
170static inline int cpuidle_select(struct cpuidle_driver *drv,
171 struct cpuidle_device *dev, bool *stop_tick)
172{return -ENODEV; }
173static inline int cpuidle_enter(struct cpuidle_driver *drv,
174 struct cpuidle_device *dev, int index)
175{return -ENODEV; }
176static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
177static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
178{return -ENODEV; }
179static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
180static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
181static inline void cpuidle_driver_unref(void) {}
182static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
183static inline int cpuidle_register_device(struct cpuidle_device *dev)
184{return -ENODEV; }
185static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
186static inline int cpuidle_register(struct cpuidle_driver *drv,
187 const struct cpumask *const coupled_cpus)
188{return -ENODEV; }
189static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
190static inline void cpuidle_pause_and_lock(void) { }
191static inline void cpuidle_resume_and_unlock(void) { }
192static inline void cpuidle_pause(void) { }
193static inline void cpuidle_resume(void) { }
194static inline int cpuidle_enable_device(struct cpuidle_device *dev)
195{return -ENODEV; }
196static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
197static inline int cpuidle_play_dead(void) {return -ENODEV; }
198static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
199 struct cpuidle_device *dev) {return NULL; }
200static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
201#endif
202
203#ifdef CONFIG_CPU_IDLE
204extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208extern void cpuidle_use_deepest_state(bool enable);
209#else
210static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
211 struct cpuidle_device *dev)
212{return -ENODEV; }
213static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
214 struct cpuidle_device *dev)
215{return -ENODEV; }
216static inline void cpuidle_use_deepest_state(bool enable)
217{
218}
219#endif
220
221/* kernel/sched/idle.c */
222extern void sched_idle_set_state(struct cpuidle_state *idle_state);
223extern void default_idle_call(void);
224
225#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
226void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
227#else
228static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
229{
230}
231#endif
232
233#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
234void cpuidle_poll_state_init(struct cpuidle_driver *drv);
235#else
236static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
237#endif
238
239/******************************
240 * CPUIDLE GOVERNOR INTERFACE *
241 ******************************/
242
243struct cpuidle_governor {
244 char name[CPUIDLE_NAME_LEN];
245 struct list_head governor_list;
246 unsigned int rating;
247
248 int (*enable) (struct cpuidle_driver *drv,
249 struct cpuidle_device *dev);
250 void (*disable) (struct cpuidle_driver *drv,
251 struct cpuidle_device *dev);
252
253 int (*select) (struct cpuidle_driver *drv,
254 struct cpuidle_device *dev,
255 bool *stop_tick);
256 void (*reflect) (struct cpuidle_device *dev, int index);
257};
258
259#ifdef CONFIG_CPU_IDLE
260extern int cpuidle_register_governor(struct cpuidle_governor *gov);
261#else
262static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
263{return 0;}
264#endif
265
266#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
267({ \
268 int __ret = 0; \
269 \
270 if (!idx) { \
271 cpu_do_idle(); \
272 return idx; \
273 } \
274 \
275 if (!is_retention) \
276 __ret = cpu_pm_enter(); \
277 if (!__ret) { \
278 __ret = low_level_idle_enter(idx); \
279 if (!is_retention) \
280 cpu_pm_exit(); \
281 } \
282 \
283 __ret ? -1 : idx; \
284})
285
286#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
287 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
288
289#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
290 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
291
292#endif /* _LINUX_CPUIDLE_H */