Line data Source code
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 : #include <linux/context_tracking.h>
18 :
19 : #define CPUIDLE_STATE_MAX 10
20 : #define CPUIDLE_NAME_LEN 16
21 : #define CPUIDLE_DESC_LEN 32
22 :
23 : struct module;
24 :
25 : struct cpuidle_device;
26 : struct cpuidle_driver;
27 :
28 :
29 : /****************************
30 : * CPUIDLE DEVICE INTERFACE *
31 : ****************************/
32 :
33 : #define CPUIDLE_STATE_DISABLED_BY_USER BIT(0)
34 : #define CPUIDLE_STATE_DISABLED_BY_DRIVER BIT(1)
35 :
36 : struct cpuidle_state_usage {
37 : unsigned long long disable;
38 : unsigned long long usage;
39 : u64 time_ns;
40 : unsigned long long above; /* Number of times it's been too deep */
41 : unsigned long long below; /* Number of times it's been too shallow */
42 : unsigned long long rejected; /* Number of times idle entry was rejected */
43 : #ifdef CONFIG_SUSPEND
44 : unsigned long long s2idle_usage;
45 : unsigned long long s2idle_time; /* in US */
46 : #endif
47 : };
48 :
49 : struct cpuidle_state {
50 : char name[CPUIDLE_NAME_LEN];
51 : char desc[CPUIDLE_DESC_LEN];
52 :
53 : s64 exit_latency_ns;
54 : s64 target_residency_ns;
55 : unsigned int flags;
56 : unsigned int exit_latency; /* in US */
57 : int power_usage; /* in mW */
58 : unsigned int target_residency; /* in US */
59 :
60 : int (*enter) (struct cpuidle_device *dev,
61 : struct cpuidle_driver *drv,
62 : int index);
63 :
64 : int (*enter_dead) (struct cpuidle_device *dev, int index);
65 :
66 : /*
67 : * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
68 : * suspended, so it must not re-enable interrupts at any point (even
69 : * temporarily) or attempt to change states of clock event devices.
70 : *
71 : * This callback may point to the same function as ->enter if all of
72 : * the above requirements are met by it.
73 : */
74 : int (*enter_s2idle)(struct cpuidle_device *dev,
75 : struct cpuidle_driver *drv,
76 : int index);
77 : };
78 :
79 : /* Idle State Flags */
80 : #define CPUIDLE_FLAG_NONE (0x00)
81 : #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
82 : #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
83 : #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
84 : #define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
85 : #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */
86 : #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */
87 : #define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */
88 :
89 : struct cpuidle_device_kobj;
90 : struct cpuidle_state_kobj;
91 : struct cpuidle_driver_kobj;
92 :
93 : struct cpuidle_device {
94 : unsigned int registered:1;
95 : unsigned int enabled:1;
96 : unsigned int poll_time_limit:1;
97 : unsigned int cpu;
98 : ktime_t next_hrtimer;
99 :
100 : int last_state_idx;
101 : u64 last_residency_ns;
102 : u64 poll_limit_ns;
103 : u64 forced_idle_latency_limit_ns;
104 : struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
105 : struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
106 : struct cpuidle_driver_kobj *kobj_driver;
107 : struct cpuidle_device_kobj *kobj_dev;
108 : struct list_head device_list;
109 :
110 : #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
111 : cpumask_t coupled_cpus;
112 : struct cpuidle_coupled *coupled;
113 : #endif
114 : };
115 :
116 : DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
117 : DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
118 :
119 : static __always_inline void ct_cpuidle_enter(void)
120 : {
121 : lockdep_assert_irqs_disabled();
122 : /*
123 : * Idle is allowed to (temporary) enable IRQs. It
124 : * will return with IRQs disabled.
125 : *
126 : * Trace IRQs enable here, then switch off RCU, and have
127 : * arch_cpu_idle() use raw_local_irq_enable(). Note that
128 : * ct_idle_enter() relies on lockdep IRQ state, so switch that
129 : * last -- this is very similar to the entry code.
130 : */
131 : trace_hardirqs_on_prepare();
132 : lockdep_hardirqs_on_prepare();
133 : instrumentation_end();
134 : ct_idle_enter();
135 0 : lockdep_hardirqs_on(_RET_IP_);
136 : }
137 :
138 : static __always_inline void ct_cpuidle_exit(void)
139 : {
140 : /*
141 : * Carefully undo the above.
142 : */
143 0 : lockdep_hardirqs_off(_RET_IP_);
144 : ct_idle_exit();
145 : instrumentation_begin();
146 : }
147 :
148 : /****************************
149 : * CPUIDLE DRIVER INTERFACE *
150 : ****************************/
151 :
152 : struct cpuidle_driver {
153 : const char *name;
154 : struct module *owner;
155 :
156 : /* used by the cpuidle framework to setup the broadcast timer */
157 : unsigned int bctimer:1;
158 : /* states array must be ordered in decreasing power consumption */
159 : struct cpuidle_state states[CPUIDLE_STATE_MAX];
160 : int state_count;
161 : int safe_state_index;
162 :
163 : /* the driver handles the cpus in cpumask */
164 : struct cpumask *cpumask;
165 :
166 : /* preferred governor to switch at register time */
167 : const char *governor;
168 : };
169 :
170 : #ifdef CONFIG_CPU_IDLE
171 : extern void disable_cpuidle(void);
172 : extern bool cpuidle_not_available(struct cpuidle_driver *drv,
173 : struct cpuidle_device *dev);
174 :
175 : extern int cpuidle_select(struct cpuidle_driver *drv,
176 : struct cpuidle_device *dev,
177 : bool *stop_tick);
178 : extern int cpuidle_enter(struct cpuidle_driver *drv,
179 : struct cpuidle_device *dev, int index);
180 : extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
181 : extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
182 : struct cpuidle_device *dev);
183 :
184 : extern int cpuidle_register_driver(struct cpuidle_driver *drv);
185 : extern struct cpuidle_driver *cpuidle_get_driver(void);
186 : extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
187 : bool disable);
188 : extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
189 : extern int cpuidle_register_device(struct cpuidle_device *dev);
190 : extern void cpuidle_unregister_device(struct cpuidle_device *dev);
191 : extern int cpuidle_register(struct cpuidle_driver *drv,
192 : const struct cpumask *const coupled_cpus);
193 : extern void cpuidle_unregister(struct cpuidle_driver *drv);
194 : extern void cpuidle_pause_and_lock(void);
195 : extern void cpuidle_resume_and_unlock(void);
196 : extern void cpuidle_pause(void);
197 : extern void cpuidle_resume(void);
198 : extern int cpuidle_enable_device(struct cpuidle_device *dev);
199 : extern void cpuidle_disable_device(struct cpuidle_device *dev);
200 : extern int cpuidle_play_dead(void);
201 :
202 : extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
203 : static inline struct cpuidle_device *cpuidle_get_device(void)
204 : {return __this_cpu_read(cpuidle_devices); }
205 : #else
206 : static inline void disable_cpuidle(void) { }
207 : static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
208 : struct cpuidle_device *dev)
209 : {return true; }
210 : static inline int cpuidle_select(struct cpuidle_driver *drv,
211 : struct cpuidle_device *dev, bool *stop_tick)
212 : {return -ENODEV; }
213 : static inline int cpuidle_enter(struct cpuidle_driver *drv,
214 : struct cpuidle_device *dev, int index)
215 : {return -ENODEV; }
216 : static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
217 : static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
218 : struct cpuidle_device *dev)
219 : {return 0; }
220 : static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
221 : {return -ENODEV; }
222 : static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
223 : static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
224 : int idx, bool disable) { }
225 : static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
226 : static inline int cpuidle_register_device(struct cpuidle_device *dev)
227 : {return -ENODEV; }
228 : static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
229 : static inline int cpuidle_register(struct cpuidle_driver *drv,
230 : const struct cpumask *const coupled_cpus)
231 : {return -ENODEV; }
232 : static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
233 : static inline void cpuidle_pause_and_lock(void) { }
234 : static inline void cpuidle_resume_and_unlock(void) { }
235 : static inline void cpuidle_pause(void) { }
236 : static inline void cpuidle_resume(void) { }
237 : static inline int cpuidle_enable_device(struct cpuidle_device *dev)
238 : {return -ENODEV; }
239 : static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
240 : static inline int cpuidle_play_dead(void) {return -ENODEV; }
241 : static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
242 : struct cpuidle_device *dev) {return NULL; }
243 : static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
244 : #endif
245 :
246 : #ifdef CONFIG_CPU_IDLE
247 : extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
248 : struct cpuidle_device *dev,
249 : u64 latency_limit_ns);
250 : extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
251 : struct cpuidle_device *dev);
252 : extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
253 : #else
254 : static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
255 : struct cpuidle_device *dev,
256 : u64 latency_limit_ns)
257 : {return -ENODEV; }
258 : static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
259 : struct cpuidle_device *dev)
260 : {return -ENODEV; }
261 : static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
262 : {
263 : }
264 : #endif
265 :
266 : /* kernel/sched/idle.c */
267 : extern void sched_idle_set_state(struct cpuidle_state *idle_state);
268 : extern void default_idle_call(void);
269 :
270 : #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
271 : void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
272 : #else
273 : static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
274 : {
275 : }
276 : #endif
277 :
278 : #if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
279 : void cpuidle_poll_state_init(struct cpuidle_driver *drv);
280 : #else
281 : static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
282 : #endif
283 :
284 : /******************************
285 : * CPUIDLE GOVERNOR INTERFACE *
286 : ******************************/
287 :
288 : struct cpuidle_governor {
289 : char name[CPUIDLE_NAME_LEN];
290 : struct list_head governor_list;
291 : unsigned int rating;
292 :
293 : int (*enable) (struct cpuidle_driver *drv,
294 : struct cpuidle_device *dev);
295 : void (*disable) (struct cpuidle_driver *drv,
296 : struct cpuidle_device *dev);
297 :
298 : int (*select) (struct cpuidle_driver *drv,
299 : struct cpuidle_device *dev,
300 : bool *stop_tick);
301 : void (*reflect) (struct cpuidle_device *dev, int index);
302 : };
303 :
304 : extern int cpuidle_register_governor(struct cpuidle_governor *gov);
305 : extern s64 cpuidle_governor_latency_req(unsigned int cpu);
306 :
307 : #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
308 : idx, \
309 : state, \
310 : is_retention, is_rcu) \
311 : ({ \
312 : int __ret = 0; \
313 : \
314 : if (!idx) { \
315 : cpu_do_idle(); \
316 : return idx; \
317 : } \
318 : \
319 : if (!is_retention) \
320 : __ret = cpu_pm_enter(); \
321 : if (!__ret) { \
322 : if (!is_rcu) \
323 : ct_cpuidle_enter(); \
324 : __ret = low_level_idle_enter(state); \
325 : if (!is_rcu) \
326 : ct_cpuidle_exit(); \
327 : if (!is_retention) \
328 : cpu_pm_exit(); \
329 : } \
330 : \
331 : __ret ? -1 : idx; \
332 : })
333 :
334 : #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
335 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0, 0)
336 :
337 : #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
338 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1, 0)
339 :
340 : #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
341 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 0)
342 :
343 : #define CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(low_level_idle_enter, idx, state) \
344 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 1)
345 :
346 : #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
347 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 0)
348 :
349 : #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(low_level_idle_enter, idx, state) \
350 : __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 1)
351 :
352 : #endif /* _LINUX_CPUIDLE_H */
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