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 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
99 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
100 DECLARE_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 */
cpuidle_get_last_residency(struct cpuidle_device * dev)106 static 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
116 struct 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
133 extern void disable_cpuidle(void);
134 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
135 struct cpuidle_device *dev);
136
137 extern int cpuidle_select(struct cpuidle_driver *drv,
138 struct cpuidle_device *dev,
139 bool *stop_tick);
140 extern int cpuidle_enter(struct cpuidle_driver *drv,
141 struct cpuidle_device *dev, int index);
142 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
143
144 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
145 extern struct cpuidle_driver *cpuidle_get_driver(void);
146 extern struct cpuidle_driver *cpuidle_driver_ref(void);
147 extern void cpuidle_driver_unref(void);
148 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
149 extern int cpuidle_register_device(struct cpuidle_device *dev);
150 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
151 extern int cpuidle_register(struct cpuidle_driver *drv,
152 const struct cpumask *const coupled_cpus);
153 extern void cpuidle_unregister(struct cpuidle_driver *drv);
154 extern void cpuidle_pause_and_lock(void);
155 extern void cpuidle_resume_and_unlock(void);
156 extern void cpuidle_pause(void);
157 extern void cpuidle_resume(void);
158 extern int cpuidle_enable_device(struct cpuidle_device *dev);
159 extern void cpuidle_disable_device(struct cpuidle_device *dev);
160 extern int cpuidle_play_dead(void);
161
162 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
cpuidle_get_device(void)163 static inline struct cpuidle_device *cpuidle_get_device(void)
164 {return __this_cpu_read(cpuidle_devices); }
165 #else
disable_cpuidle(void)166 static inline void disable_cpuidle(void) { }
cpuidle_not_available(struct cpuidle_driver * drv,struct cpuidle_device * dev)167 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
168 struct cpuidle_device *dev)
169 {return true; }
cpuidle_select(struct cpuidle_driver * drv,struct cpuidle_device * dev,bool * stop_tick)170 static inline int cpuidle_select(struct cpuidle_driver *drv,
171 struct cpuidle_device *dev, bool *stop_tick)
172 {return -ENODEV; }
cpuidle_enter(struct cpuidle_driver * drv,struct cpuidle_device * dev,int index)173 static inline int cpuidle_enter(struct cpuidle_driver *drv,
174 struct cpuidle_device *dev, int index)
175 {return -ENODEV; }
cpuidle_reflect(struct cpuidle_device * dev,int index)176 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
cpuidle_register_driver(struct cpuidle_driver * drv)177 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
178 {return -ENODEV; }
cpuidle_get_driver(void)179 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
cpuidle_driver_ref(void)180 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
cpuidle_driver_unref(void)181 static inline void cpuidle_driver_unref(void) {}
cpuidle_unregister_driver(struct cpuidle_driver * drv)182 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
cpuidle_register_device(struct cpuidle_device * dev)183 static inline int cpuidle_register_device(struct cpuidle_device *dev)
184 {return -ENODEV; }
cpuidle_unregister_device(struct cpuidle_device * dev)185 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
cpuidle_register(struct cpuidle_driver * drv,const struct cpumask * const coupled_cpus)186 static inline int cpuidle_register(struct cpuidle_driver *drv,
187 const struct cpumask *const coupled_cpus)
188 {return -ENODEV; }
cpuidle_unregister(struct cpuidle_driver * drv)189 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
cpuidle_pause_and_lock(void)190 static inline void cpuidle_pause_and_lock(void) { }
cpuidle_resume_and_unlock(void)191 static inline void cpuidle_resume_and_unlock(void) { }
cpuidle_pause(void)192 static inline void cpuidle_pause(void) { }
cpuidle_resume(void)193 static inline void cpuidle_resume(void) { }
cpuidle_enable_device(struct cpuidle_device * dev)194 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
195 {return -ENODEV; }
cpuidle_disable_device(struct cpuidle_device * dev)196 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
cpuidle_play_dead(void)197 static inline int cpuidle_play_dead(void) {return -ENODEV; }
cpuidle_get_cpu_driver(struct cpuidle_device * dev)198 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
199 struct cpuidle_device *dev) {return NULL; }
cpuidle_get_device(void)200 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
201 #endif
202
203 #ifdef CONFIG_CPU_IDLE
204 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208 extern void cpuidle_use_deepest_state(bool enable);
209 #else
cpuidle_find_deepest_state(struct cpuidle_driver * drv,struct cpuidle_device * dev)210 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
211 struct cpuidle_device *dev)
212 {return -ENODEV; }
cpuidle_enter_s2idle(struct cpuidle_driver * drv,struct cpuidle_device * dev)213 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
214 struct cpuidle_device *dev)
215 {return -ENODEV; }
cpuidle_use_deepest_state(bool enable)216 static inline void cpuidle_use_deepest_state(bool enable)
217 {
218 }
219 #endif
220
221 /* kernel/sched/idle.c */
222 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
223 extern void default_idle_call(void);
224
225 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
226 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
227 #else
cpuidle_coupled_parallel_barrier(struct cpuidle_device * dev,atomic_t * a)228 static 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)
234 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
235 #else
cpuidle_poll_state_init(struct cpuidle_driver * drv)236 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
237 #endif
238
239 /******************************
240 * CPUIDLE GOVERNOR INTERFACE *
241 ******************************/
242
243 struct 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
260 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
261 extern int cpuidle_governor_latency_req(unsigned int cpu);
262 #else
cpuidle_register_governor(struct cpuidle_governor * gov)263 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
264 {return 0;}
265 #endif
266
267 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
268 ({ \
269 int __ret = 0; \
270 \
271 if (!idx) { \
272 cpu_do_idle(); \
273 return idx; \
274 } \
275 \
276 if (!is_retention) \
277 __ret = cpu_pm_enter(); \
278 if (!__ret) { \
279 __ret = low_level_idle_enter(idx); \
280 if (!is_retention) \
281 cpu_pm_exit(); \
282 } \
283 \
284 __ret ? -1 : idx; \
285 })
286
287 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
288 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
289
290 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
291 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
292
293 #endif /* _LINUX_CPUIDLE_H */
294
