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 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
44 struct 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
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 ktime_t next_hrtimer;
87
88 int last_state_idx;
89 int last_residency;
90 u64 poll_limit_ns;
91 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
92 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
93 struct cpuidle_driver_kobj *kobj_driver;
94 struct cpuidle_device_kobj *kobj_dev;
95 struct list_head device_list;
96
97 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
98 cpumask_t coupled_cpus;
99 struct cpuidle_coupled *coupled;
100 #endif
101 };
102
103 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
104 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
105
106 /****************************
107 * CPUIDLE DRIVER INTERFACE *
108 ****************************/
109
110 struct cpuidle_driver {
111 const char *name;
112 struct module *owner;
113 int refcnt;
114
115 /* used by the cpuidle framework to setup the broadcast timer */
116 unsigned int bctimer:1;
117 /* states array must be ordered in decreasing power consumption */
118 struct cpuidle_state states[CPUIDLE_STATE_MAX];
119 int state_count;
120 int safe_state_index;
121
122 /* the driver handles the cpus in cpumask */
123 struct cpumask *cpumask;
124
125 /* preferred governor to switch at register time */
126 const char *governor;
127 };
128
129 #ifdef CONFIG_CPU_IDLE
130 extern void disable_cpuidle(void);
131 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
132 struct cpuidle_device *dev);
133
134 extern int cpuidle_select(struct cpuidle_driver *drv,
135 struct cpuidle_device *dev,
136 bool *stop_tick);
137 extern int cpuidle_enter(struct cpuidle_driver *drv,
138 struct cpuidle_device *dev, int index);
139 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
140 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
141 struct cpuidle_device *dev);
142
143 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
144 extern struct cpuidle_driver *cpuidle_get_driver(void);
145 extern struct cpuidle_driver *cpuidle_driver_ref(void);
146 extern void cpuidle_driver_unref(void);
147 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
148 extern int cpuidle_register_device(struct cpuidle_device *dev);
149 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
150 extern int cpuidle_register(struct cpuidle_driver *drv,
151 const struct cpumask *const coupled_cpus);
152 extern void cpuidle_unregister(struct cpuidle_driver *drv);
153 extern void cpuidle_pause_and_lock(void);
154 extern void cpuidle_resume_and_unlock(void);
155 extern void cpuidle_pause(void);
156 extern void cpuidle_resume(void);
157 extern int cpuidle_enable_device(struct cpuidle_device *dev);
158 extern void cpuidle_disable_device(struct cpuidle_device *dev);
159 extern int cpuidle_play_dead(void);
160
161 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
cpuidle_get_device(void)162 static inline struct cpuidle_device *cpuidle_get_device(void)
163 {return __this_cpu_read(cpuidle_devices); }
164 #else
disable_cpuidle(void)165 static inline void disable_cpuidle(void) { }
cpuidle_not_available(struct cpuidle_driver * drv,struct cpuidle_device * dev)166 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
167 struct cpuidle_device *dev)
168 {return true; }
cpuidle_select(struct cpuidle_driver * drv,struct cpuidle_device * dev,bool * stop_tick)169 static inline int cpuidle_select(struct cpuidle_driver *drv,
170 struct cpuidle_device *dev, bool *stop_tick)
171 {return -ENODEV; }
cpuidle_enter(struct cpuidle_driver * drv,struct cpuidle_device * dev,int index)172 static inline int cpuidle_enter(struct cpuidle_driver *drv,
173 struct cpuidle_device *dev, int index)
174 {return -ENODEV; }
cpuidle_reflect(struct cpuidle_device * dev,int index)175 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
cpuidle_poll_time(struct cpuidle_driver * drv,struct cpuidle_device * dev)176 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
177 struct cpuidle_device *dev)
178 {return 0; }
cpuidle_register_driver(struct cpuidle_driver * drv)179 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
180 {return -ENODEV; }
cpuidle_get_driver(void)181 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
cpuidle_driver_ref(void)182 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
cpuidle_driver_unref(void)183 static inline void cpuidle_driver_unref(void) {}
cpuidle_unregister_driver(struct cpuidle_driver * drv)184 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
cpuidle_register_device(struct cpuidle_device * dev)185 static inline int cpuidle_register_device(struct cpuidle_device *dev)
186 {return -ENODEV; }
cpuidle_unregister_device(struct cpuidle_device * dev)187 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
cpuidle_register(struct cpuidle_driver * drv,const struct cpumask * const coupled_cpus)188 static inline int cpuidle_register(struct cpuidle_driver *drv,
189 const struct cpumask *const coupled_cpus)
190 {return -ENODEV; }
cpuidle_unregister(struct cpuidle_driver * drv)191 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
cpuidle_pause_and_lock(void)192 static inline void cpuidle_pause_and_lock(void) { }
cpuidle_resume_and_unlock(void)193 static inline void cpuidle_resume_and_unlock(void) { }
cpuidle_pause(void)194 static inline void cpuidle_pause(void) { }
cpuidle_resume(void)195 static inline void cpuidle_resume(void) { }
cpuidle_enable_device(struct cpuidle_device * dev)196 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
197 {return -ENODEV; }
cpuidle_disable_device(struct cpuidle_device * dev)198 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
cpuidle_play_dead(void)199 static inline int cpuidle_play_dead(void) {return -ENODEV; }
cpuidle_get_cpu_driver(struct cpuidle_device * dev)200 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
201 struct cpuidle_device *dev) {return NULL; }
cpuidle_get_device(void)202 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
203 #endif
204
205 #ifdef CONFIG_CPU_IDLE
206 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
209 struct cpuidle_device *dev);
210 extern void cpuidle_use_deepest_state(bool enable);
211 #else
cpuidle_find_deepest_state(struct cpuidle_driver * drv,struct cpuidle_device * dev)212 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
213 struct cpuidle_device *dev)
214 {return -ENODEV; }
cpuidle_enter_s2idle(struct cpuidle_driver * drv,struct cpuidle_device * dev)215 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
216 struct cpuidle_device *dev)
217 {return -ENODEV; }
cpuidle_use_deepest_state(bool enable)218 static inline void cpuidle_use_deepest_state(bool enable)
219 {
220 }
221 #endif
222
223 /* kernel/sched/idle.c */
224 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
225 extern void default_idle_call(void);
226
227 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
228 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
229 #else
cpuidle_coupled_parallel_barrier(struct cpuidle_device * dev,atomic_t * a)230 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
231 {
232 }
233 #endif
234
235 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
236 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
237 #else
cpuidle_poll_state_init(struct cpuidle_driver * drv)238 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
239 #endif
240
241 /******************************
242 * CPUIDLE GOVERNOR INTERFACE *
243 ******************************/
244
245 struct cpuidle_governor {
246 char name[CPUIDLE_NAME_LEN];
247 struct list_head governor_list;
248 unsigned int rating;
249
250 int (*enable) (struct cpuidle_driver *drv,
251 struct cpuidle_device *dev);
252 void (*disable) (struct cpuidle_driver *drv,
253 struct cpuidle_device *dev);
254
255 int (*select) (struct cpuidle_driver *drv,
256 struct cpuidle_device *dev,
257 bool *stop_tick);
258 void (*reflect) (struct cpuidle_device *dev, int index);
259 };
260
261 #ifdef CONFIG_CPU_IDLE
262 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
263 extern int cpuidle_governor_latency_req(unsigned int cpu);
264 #else
cpuidle_register_governor(struct cpuidle_governor * gov)265 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
266 {return 0;}
267 #endif
268
269 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
270 idx, \
271 state, \
272 is_retention) \
273 ({ \
274 int __ret = 0; \
275 \
276 if (!idx) { \
277 cpu_do_idle(); \
278 return idx; \
279 } \
280 \
281 if (!is_retention) \
282 __ret = cpu_pm_enter(); \
283 if (!__ret) { \
284 __ret = low_level_idle_enter(state); \
285 if (!is_retention) \
286 cpu_pm_exit(); \
287 } \
288 \
289 __ret ? -1 : idx; \
290 })
291
292 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
293 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
294
295 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
296 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
297
298 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
299 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
300
301 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
302 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
303
304 #endif /* _LINUX_CPUIDLE_H */
305
