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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};
37
38struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
41
42 unsigned int flags;
43 unsigned int exit_latency; /* in US */
44 int power_usage; /* in mW */
45 unsigned int target_residency; /* in US */
46 bool disabled; /* disabled on all CPUs */
47
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
50 int index);
51
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
53
54 /*
55 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
56 * suspended, so it must not re-enable interrupts at any point (even
57 * temporarily) or attempt to change states of clock event devices.
58 */
59 void (*enter_s2idle) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
61 int index);
62};
63
64/* Idle State Flags */
65#define CPUIDLE_FLAG_NONE (0x00)
66#define CPUIDLE_FLAG_POLLING (0x01) /* polling state */
67#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
68#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
69
70#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
71
72struct cpuidle_device_kobj;
73struct cpuidle_state_kobj;
74struct cpuidle_driver_kobj;
75
76struct cpuidle_device {
77 unsigned int registered:1;
78 unsigned int enabled:1;
79 unsigned int use_deepest_state:1;
80 unsigned int cpu;
81
82 int last_residency;
83 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
84 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
85 struct cpuidle_driver_kobj *kobj_driver;
86 struct cpuidle_device_kobj *kobj_dev;
87 struct list_head device_list;
88
89#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
90 cpumask_t coupled_cpus;
91 struct cpuidle_coupled *coupled;
92#endif
93};
94
95DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
96DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
97
98/**
99 * cpuidle_get_last_residency - retrieves the last state's residency time
100 * @dev: the target CPU
101 */
102static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
103{
104 return dev->last_residency;
105}
106
107
108/****************************
109 * CPUIDLE DRIVER INTERFACE *
110 ****************************/
111
112struct cpuidle_driver {
113 const char *name;
114 struct module *owner;
115 int refcnt;
116
117 /* used by the cpuidle framework to setup the broadcast timer */
118 unsigned int bctimer:1;
119 /* states array must be ordered in decreasing power consumption */
120 struct cpuidle_state states[CPUIDLE_STATE_MAX];
121 int state_count;
122 int safe_state_index;
123
124 /* the driver handles the cpus in cpumask */
125 struct cpumask *cpumask;
126};
127
128#ifdef CONFIG_CPU_IDLE
129extern void disable_cpuidle(void);
130extern bool cpuidle_not_available(struct cpuidle_driver *drv,
131 struct cpuidle_device *dev);
132
133extern int cpuidle_select(struct cpuidle_driver *drv,
134 struct cpuidle_device *dev);
135extern int cpuidle_enter(struct cpuidle_driver *drv,
136 struct cpuidle_device *dev, int index);
137extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
138
139extern int cpuidle_register_driver(struct cpuidle_driver *drv);
140extern struct cpuidle_driver *cpuidle_get_driver(void);
141extern struct cpuidle_driver *cpuidle_driver_ref(void);
142extern void cpuidle_driver_unref(void);
143extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
144extern int cpuidle_register_device(struct cpuidle_device *dev);
145extern void cpuidle_unregister_device(struct cpuidle_device *dev);
146extern int cpuidle_register(struct cpuidle_driver *drv,
147 const struct cpumask *const coupled_cpus);
148extern void cpuidle_unregister(struct cpuidle_driver *drv);
149extern void cpuidle_pause_and_lock(void);
150extern void cpuidle_resume_and_unlock(void);
151extern void cpuidle_pause(void);
152extern void cpuidle_resume(void);
153extern int cpuidle_enable_device(struct cpuidle_device *dev);
154extern void cpuidle_disable_device(struct cpuidle_device *dev);
155extern int cpuidle_play_dead(void);
156
157extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
158static inline struct cpuidle_device *cpuidle_get_device(void)
159{return __this_cpu_read(cpuidle_devices); }
160#else
161static inline void disable_cpuidle(void) { }
162static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
163 struct cpuidle_device *dev)
164{return true; }
165static inline int cpuidle_select(struct cpuidle_driver *drv,
166 struct cpuidle_device *dev)
167{return -ENODEV; }
168static inline int cpuidle_enter(struct cpuidle_driver *drv,
169 struct cpuidle_device *dev, int index)
170{return -ENODEV; }
171static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
172static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
173{return -ENODEV; }
174static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
175static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
176static inline void cpuidle_driver_unref(void) {}
177static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
178static inline int cpuidle_register_device(struct cpuidle_device *dev)
179{return -ENODEV; }
180static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
181static inline int cpuidle_register(struct cpuidle_driver *drv,
182 const struct cpumask *const coupled_cpus)
183{return -ENODEV; }
184static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
185static inline void cpuidle_pause_and_lock(void) { }
186static inline void cpuidle_resume_and_unlock(void) { }
187static inline void cpuidle_pause(void) { }
188static inline void cpuidle_resume(void) { }
189static inline int cpuidle_enable_device(struct cpuidle_device *dev)
190{return -ENODEV; }
191static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
192static inline int cpuidle_play_dead(void) {return -ENODEV; }
193static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
194 struct cpuidle_device *dev) {return NULL; }
195static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
196#endif
197
198#ifdef CONFIG_CPU_IDLE
199extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
202 struct cpuidle_device *dev);
203extern void cpuidle_use_deepest_state(bool enable);
204#else
205static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
206 struct cpuidle_device *dev)
207{return -ENODEV; }
208static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
209 struct cpuidle_device *dev)
210{return -ENODEV; }
211static inline void cpuidle_use_deepest_state(bool enable)
212{
213}
214#endif
215
216/* kernel/sched/idle.c */
217extern void sched_idle_set_state(struct cpuidle_state *idle_state);
218extern void default_idle_call(void);
219
220#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
221void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
222#else
223static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
224{
225}
226#endif
227
228#ifdef CONFIG_ARCH_HAS_CPU_RELAX
229void cpuidle_poll_state_init(struct cpuidle_driver *drv);
230#else
231static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
232#endif
233
234/******************************
235 * CPUIDLE GOVERNOR INTERFACE *
236 ******************************/
237
238struct cpuidle_governor {
239 char name[CPUIDLE_NAME_LEN];
240 struct list_head governor_list;
241 unsigned int rating;
242
243 int (*enable) (struct cpuidle_driver *drv,
244 struct cpuidle_device *dev);
245 void (*disable) (struct cpuidle_driver *drv,
246 struct cpuidle_device *dev);
247
248 int (*select) (struct cpuidle_driver *drv,
249 struct cpuidle_device *dev);
250 void (*reflect) (struct cpuidle_device *dev, int index);
251};
252
253#ifdef CONFIG_CPU_IDLE
254extern int cpuidle_register_governor(struct cpuidle_governor *gov);
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) \
261({ \
262 int __ret; \
263 \
264 if (!idx) { \
265 cpu_do_idle(); \
266 return idx; \
267 } \
268 \
269 __ret = cpu_pm_enter(); \
270 if (!__ret) { \
271 __ret = low_level_idle_enter(idx); \
272 cpu_pm_exit(); \
273 } \
274 \
275 __ret ? -1 : idx; \
276})
277
278#endif /* _LINUX_CPUIDLE_H */