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
22 struct module;
23
24 struct cpuidle_device;
25 struct cpuidle_driver;
26
27
28 /****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
31
32 struct 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
42 struct 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
76 struct cpuidle_device_kobj;
77 struct cpuidle_state_kobj;
78 struct cpuidle_driver_kobj;
79
80 struct 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
87 int last_residency;
88 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
89 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
90 struct cpuidle_driver_kobj *kobj_driver;
91 struct cpuidle_device_kobj *kobj_dev;
92 struct list_head device_list;
93
94 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
95 cpumask_t coupled_cpus;
96 struct cpuidle_coupled *coupled;
97 #endif
98 };
99
100 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
101 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
102
103 /**
104 * cpuidle_get_last_residency - retrieves the last state's residency time
105 * @dev: the target CPU
106 */
cpuidle_get_last_residency(struct cpuidle_device * dev)107 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
108 {
109 return dev->last_residency;
110 }
111
112
113 /****************************
114 * CPUIDLE DRIVER INTERFACE *
115 ****************************/
116
117 struct cpuidle_driver {
118 const char *name;
119 struct module *owner;
120 int refcnt;
121
122 /* used by the cpuidle framework to setup the broadcast timer */
123 unsigned int bctimer:1;
124 /* states array must be ordered in decreasing power consumption */
125 struct cpuidle_state states[CPUIDLE_STATE_MAX];
126 int state_count;
127 int safe_state_index;
128
129 /* the driver handles the cpus in cpumask */
130 struct cpumask *cpumask;
131 };
132
133 #ifdef CONFIG_CPU_IDLE
134 extern void disable_cpuidle(void);
135 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
136 struct cpuidle_device *dev);
137
138 extern int cpuidle_select(struct cpuidle_driver *drv,
139 struct cpuidle_device *dev,
140 bool *stop_tick);
141 extern int cpuidle_enter(struct cpuidle_driver *drv,
142 struct cpuidle_device *dev, int index);
143 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
144
145 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
146 extern struct cpuidle_driver *cpuidle_get_driver(void);
147 extern struct cpuidle_driver *cpuidle_driver_ref(void);
148 extern void cpuidle_driver_unref(void);
149 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
150 extern int cpuidle_register_device(struct cpuidle_device *dev);
151 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
152 extern int cpuidle_register(struct cpuidle_driver *drv,
153 const struct cpumask *const coupled_cpus);
154 extern void cpuidle_unregister(struct cpuidle_driver *drv);
155 extern void cpuidle_pause_and_lock(void);
156 extern void cpuidle_resume_and_unlock(void);
157 extern void cpuidle_pause(void);
158 extern void cpuidle_resume(void);
159 extern int cpuidle_enable_device(struct cpuidle_device *dev);
160 extern void cpuidle_disable_device(struct cpuidle_device *dev);
161 extern int cpuidle_play_dead(void);
162
163 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
cpuidle_get_device(void)164 static inline struct cpuidle_device *cpuidle_get_device(void)
165 {return __this_cpu_read(cpuidle_devices); }
166 #else
disable_cpuidle(void)167 static inline void disable_cpuidle(void) { }
cpuidle_not_available(struct cpuidle_driver * drv,struct cpuidle_device * dev)168 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
169 struct cpuidle_device *dev)
170 {return true; }
cpuidle_select(struct cpuidle_driver * drv,struct cpuidle_device * dev,bool * stop_tick)171 static inline int cpuidle_select(struct cpuidle_driver *drv,
172 struct cpuidle_device *dev, bool *stop_tick)
173 {return -ENODEV; }
cpuidle_enter(struct cpuidle_driver * drv,struct cpuidle_device * dev,int index)174 static inline int cpuidle_enter(struct cpuidle_driver *drv,
175 struct cpuidle_device *dev, int index)
176 {return -ENODEV; }
cpuidle_reflect(struct cpuidle_device * dev,int index)177 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
cpuidle_register_driver(struct cpuidle_driver * drv)178 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
179 {return -ENODEV; }
cpuidle_get_driver(void)180 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
cpuidle_driver_ref(void)181 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
cpuidle_driver_unref(void)182 static inline void cpuidle_driver_unref(void) {}
cpuidle_unregister_driver(struct cpuidle_driver * drv)183 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
cpuidle_register_device(struct cpuidle_device * dev)184 static inline int cpuidle_register_device(struct cpuidle_device *dev)
185 {return -ENODEV; }
cpuidle_unregister_device(struct cpuidle_device * dev)186 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
cpuidle_register(struct cpuidle_driver * drv,const struct cpumask * const coupled_cpus)187 static inline int cpuidle_register(struct cpuidle_driver *drv,
188 const struct cpumask *const coupled_cpus)
189 {return -ENODEV; }
cpuidle_unregister(struct cpuidle_driver * drv)190 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
cpuidle_pause_and_lock(void)191 static inline void cpuidle_pause_and_lock(void) { }
cpuidle_resume_and_unlock(void)192 static inline void cpuidle_resume_and_unlock(void) { }
cpuidle_pause(void)193 static inline void cpuidle_pause(void) { }
cpuidle_resume(void)194 static inline void cpuidle_resume(void) { }
cpuidle_enable_device(struct cpuidle_device * dev)195 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
196 {return -ENODEV; }
cpuidle_disable_device(struct cpuidle_device * dev)197 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
cpuidle_play_dead(void)198 static inline int cpuidle_play_dead(void) {return -ENODEV; }
cpuidle_get_cpu_driver(struct cpuidle_device * dev)199 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
200 struct cpuidle_device *dev) {return NULL; }
cpuidle_get_device(void)201 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
202 #endif
203
204 #ifdef CONFIG_CPU_IDLE
205 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
206 struct cpuidle_device *dev);
207 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
208 struct cpuidle_device *dev);
209 extern void cpuidle_use_deepest_state(bool enable);
210 #else
cpuidle_find_deepest_state(struct cpuidle_driver * drv,struct cpuidle_device * dev)211 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
212 struct cpuidle_device *dev)
213 {return -ENODEV; }
cpuidle_enter_s2idle(struct cpuidle_driver * drv,struct cpuidle_device * dev)214 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
215 struct cpuidle_device *dev)
216 {return -ENODEV; }
cpuidle_use_deepest_state(bool enable)217 static inline void cpuidle_use_deepest_state(bool enable)
218 {
219 }
220 #endif
221
222 /* kernel/sched/idle.c */
223 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
224 extern void default_idle_call(void);
225
226 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
227 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
228 #else
cpuidle_coupled_parallel_barrier(struct cpuidle_device * dev,atomic_t * a)229 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
230 {
231 }
232 #endif
233
234 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
235 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
236 #else
cpuidle_poll_state_init(struct cpuidle_driver * drv)237 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
238 #endif
239
240 /******************************
241 * CPUIDLE GOVERNOR INTERFACE *
242 ******************************/
243
244 struct cpuidle_governor {
245 char name[CPUIDLE_NAME_LEN];
246 struct list_head governor_list;
247 unsigned int rating;
248
249 int (*enable) (struct cpuidle_driver *drv,
250 struct cpuidle_device *dev);
251 void (*disable) (struct cpuidle_driver *drv,
252 struct cpuidle_device *dev);
253
254 int (*select) (struct cpuidle_driver *drv,
255 struct cpuidle_device *dev,
256 bool *stop_tick);
257 void (*reflect) (struct cpuidle_device *dev, int index);
258 };
259
260 #ifdef CONFIG_CPU_IDLE
261 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
262 extern int cpuidle_governor_latency_req(unsigned int cpu);
263 #else
cpuidle_register_governor(struct cpuidle_governor * gov)264 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
265 {return 0;}
266 #endif
267
268 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
269 ({ \
270 int __ret = 0; \
271 \
272 if (!idx) { \
273 cpu_do_idle(); \
274 return idx; \
275 } \
276 \
277 if (!is_retention) \
278 __ret = cpu_pm_enter(); \
279 if (!__ret) { \
280 __ret = low_level_idle_enter(idx); \
281 if (!is_retention) \
282 cpu_pm_exit(); \
283 } \
284 \
285 __ret ? -1 : idx; \
286 })
287
288 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
289 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
290
291 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
292 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
293
294 #endif /* _LINUX_CPUIDLE_H */
295