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 #define CPUIDLE_STATE_DISABLED_BY_USER BIT(0)
33 #define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1)
34
35 struct cpuidle_state_usage {
36 unsigned long long disable;
37 unsigned long long usage;
38 u64 time_ns;
39 unsigned long long above; /* Number of times it's been too deep */
40 unsigned long long below; /* Number of times it's been too shallow */
41 unsigned long long rejected; /* Number of times idle entry was rejected */
42 #ifdef CONFIG_SUSPEND
43 unsigned long long s2idle_usage;
44 unsigned long long s2idle_time; /* in US */
45 #endif
46 };
47
48 struct cpuidle_state {
49 char name[CPUIDLE_NAME_LEN];
50 char desc[CPUIDLE_DESC_LEN];
51
52 s64 exit_latency_ns;
53 s64 target_residency_ns;
54 unsigned int flags;
55 unsigned int exit_latency; /* in US */
56 int power_usage; /* in mW */
57 unsigned int target_residency; /* in US */
58
59 int (*enter) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
61 int index);
62
63 int (*enter_dead) (struct cpuidle_device *dev, int index);
64
65 /*
66 * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
67 * suspended, so it must not re-enable interrupts at any point (even
68 * temporarily) or attempt to change states of clock event devices.
69 *
70 * This callback may point to the same function as ->enter if all of
71 * the above requirements are met by it.
72 */
73 int (*enter_s2idle)(struct cpuidle_device *dev,
74 struct cpuidle_driver *drv,
75 int index);
76 };
77
78 /* Idle State Flags */
79 #define CPUIDLE_FLAG_NONE (0x00)
80 #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
81 #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
82 #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
83 #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
84 #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
85 #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */
86 #define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */
87
88 struct cpuidle_device_kobj;
89 struct cpuidle_state_kobj;
90 struct cpuidle_driver_kobj;
91
92 struct cpuidle_device {
93 unsigned int registered:1;
94 unsigned int enabled:1;
95 unsigned int poll_time_limit:1;
96 unsigned int cpu;
97 ktime_t next_hrtimer;
98
99 int last_state_idx;
100 u64 last_residency_ns;
101 u64 poll_limit_ns;
102 u64 forced_idle_latency_limit_ns;
103 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
104 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
105 struct cpuidle_driver_kobj *kobj_driver;
106 struct cpuidle_device_kobj *kobj_dev;
107 struct list_head device_list;
108
109 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
110 cpumask_t coupled_cpus;
111 struct cpuidle_coupled *coupled;
112 #endif
113 };
114
115 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
116 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
117
118 /****************************
119 * CPUIDLE DRIVER INTERFACE *
120 ****************************/
121
122 struct cpuidle_driver {
123 const char *name;
124 struct module *owner;
125
126 /* used by the cpuidle framework to setup the broadcast timer */
127 unsigned int bctimer:1;
128 /* states array must be ordered in decreasing power consumption */
129 struct cpuidle_state states[CPUIDLE_STATE_MAX];
130 int state_count;
131 int safe_state_index;
132
133 /* the driver handles the cpus in cpumask */
134 struct cpumask *cpumask;
135
136 /* preferred governor to switch at register time */
137 const char *governor;
138 };
139
140 #ifdef CONFIG_CPU_IDLE
141 extern void disable_cpuidle(void);
142 extern bool cpuidle_not_available(struct cpuidle_driver *drv,
143 struct cpuidle_device *dev);
144
145 extern int cpuidle_select(struct cpuidle_driver *drv,
146 struct cpuidle_device *dev,
147 bool *stop_tick);
148 extern int cpuidle_enter(struct cpuidle_driver *drv,
149 struct cpuidle_device *dev, int index);
150 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
151 extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
152 struct cpuidle_device *dev);
153
154 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
155 extern struct cpuidle_driver *cpuidle_get_driver(void);
156 extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
157 bool disable);
158 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
159 extern int cpuidle_register_device(struct cpuidle_device *dev);
160 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
161 extern int cpuidle_register(struct cpuidle_driver *drv,
162 const struct cpumask *const coupled_cpus);
163 extern void cpuidle_unregister(struct cpuidle_driver *drv);
164 extern void cpuidle_pause_and_lock(void);
165 extern void cpuidle_resume_and_unlock(void);
166 extern void cpuidle_pause(void);
167 extern void cpuidle_resume(void);
168 extern int cpuidle_enable_device(struct cpuidle_device *dev);
169 extern void cpuidle_disable_device(struct cpuidle_device *dev);
170 extern int cpuidle_play_dead(void);
171
172 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
cpuidle_get_device(void)173 static inline struct cpuidle_device *cpuidle_get_device(void)
174 {return __this_cpu_read(cpuidle_devices); }
175 #else
disable_cpuidle(void)176 static inline void disable_cpuidle(void) { }
cpuidle_not_available(struct cpuidle_driver * drv,struct cpuidle_device * dev)177 static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
178 struct cpuidle_device *dev)
179 {return true; }
cpuidle_select(struct cpuidle_driver * drv,struct cpuidle_device * dev,bool * stop_tick)180 static inline int cpuidle_select(struct cpuidle_driver *drv,
181 struct cpuidle_device *dev, bool *stop_tick)
182 {return -ENODEV; }
cpuidle_enter(struct cpuidle_driver * drv,struct cpuidle_device * dev,int index)183 static inline int cpuidle_enter(struct cpuidle_driver *drv,
184 struct cpuidle_device *dev, int index)
185 {return -ENODEV; }
cpuidle_reflect(struct cpuidle_device * dev,int index)186 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
cpuidle_poll_time(struct cpuidle_driver * drv,struct cpuidle_device * dev)187 static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
188 struct cpuidle_device *dev)
189 {return 0; }
cpuidle_register_driver(struct cpuidle_driver * drv)190 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
191 {return -ENODEV; }
cpuidle_get_driver(void)192 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
cpuidle_driver_state_disabled(struct cpuidle_driver * drv,int idx,bool disable)193 static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
194 int idx, bool disable) { }
cpuidle_unregister_driver(struct cpuidle_driver * drv)195 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
cpuidle_register_device(struct cpuidle_device * dev)196 static inline int cpuidle_register_device(struct cpuidle_device *dev)
197 {return -ENODEV; }
cpuidle_unregister_device(struct cpuidle_device * dev)198 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
cpuidle_register(struct cpuidle_driver * drv,const struct cpumask * const coupled_cpus)199 static inline int cpuidle_register(struct cpuidle_driver *drv,
200 const struct cpumask *const coupled_cpus)
201 {return -ENODEV; }
cpuidle_unregister(struct cpuidle_driver * drv)202 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
cpuidle_pause_and_lock(void)203 static inline void cpuidle_pause_and_lock(void) { }
cpuidle_resume_and_unlock(void)204 static inline void cpuidle_resume_and_unlock(void) { }
cpuidle_pause(void)205 static inline void cpuidle_pause(void) { }
cpuidle_resume(void)206 static inline void cpuidle_resume(void) { }
cpuidle_enable_device(struct cpuidle_device * dev)207 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
208 {return -ENODEV; }
cpuidle_disable_device(struct cpuidle_device * dev)209 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
cpuidle_play_dead(void)210 static inline int cpuidle_play_dead(void) {return -ENODEV; }
cpuidle_get_cpu_driver(struct cpuidle_device * dev)211 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
212 struct cpuidle_device *dev) {return NULL; }
cpuidle_get_device(void)213 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
214 #endif
215
216 #ifdef CONFIG_CPU_IDLE
217 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
218 struct cpuidle_device *dev,
219 u64 latency_limit_ns);
220 extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
221 struct cpuidle_device *dev);
222 extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
223 #else
cpuidle_find_deepest_state(struct cpuidle_driver * drv,struct cpuidle_device * dev,u64 latency_limit_ns)224 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
225 struct cpuidle_device *dev,
226 u64 latency_limit_ns)
227 {return -ENODEV; }
cpuidle_enter_s2idle(struct cpuidle_driver * drv,struct cpuidle_device * dev)228 static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
229 struct cpuidle_device *dev)
230 {return -ENODEV; }
cpuidle_use_deepest_state(u64 latency_limit_ns)231 static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
232 {
233 }
234 #endif
235
236 /* kernel/sched/idle.c */
237 extern void sched_idle_set_state(struct cpuidle_state *idle_state);
238 extern void default_idle_call(void);
239
240 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
241 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
242 #else
cpuidle_coupled_parallel_barrier(struct cpuidle_device * dev,atomic_t * a)243 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
244 {
245 }
246 #endif
247
248 #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
249 void cpuidle_poll_state_init(struct cpuidle_driver *drv);
250 #else
cpuidle_poll_state_init(struct cpuidle_driver * drv)251 static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
252 #endif
253
254 /******************************
255 * CPUIDLE GOVERNOR INTERFACE *
256 ******************************/
257
258 struct cpuidle_governor {
259 char name[CPUIDLE_NAME_LEN];
260 struct list_head governor_list;
261 unsigned int rating;
262
263 int (*enable) (struct cpuidle_driver *drv,
264 struct cpuidle_device *dev);
265 void (*disable) (struct cpuidle_driver *drv,
266 struct cpuidle_device *dev);
267
268 int (*select) (struct cpuidle_driver *drv,
269 struct cpuidle_device *dev,
270 bool *stop_tick);
271 void (*reflect) (struct cpuidle_device *dev, int index);
272 };
273
274 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
275 extern s64 cpuidle_governor_latency_req(unsigned int cpu);
276
277 #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
278 idx, \
279 state, \
280 is_retention) \
281 ({ \
282 int __ret = 0; \
283 \
284 if (!idx) { \
285 cpu_do_idle(); \
286 return idx; \
287 } \
288 \
289 if (!is_retention) \
290 __ret = cpu_pm_enter(); \
291 if (!__ret) { \
292 __ret = low_level_idle_enter(state); \
293 if (!is_retention) \
294 cpu_pm_exit(); \
295 } \
296 \
297 __ret ? -1 : idx; \
298 })
299
300 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
301 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
302
303 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
304 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
305
306 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
307 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
308
309 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
310 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
311
312 #endif /* _LINUX_CPUIDLE_H */
313