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
23struct module;
24
25struct cpuidle_device;
26struct 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
36struct 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
49struct 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 void (*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
89struct cpuidle_device_kobj;
90struct cpuidle_state_kobj;
91struct cpuidle_driver_kobj;
92
93struct 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
116DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
117DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
118
119static __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 lockdep_hardirqs_on(_RET_IP_);
136}
137
138static __always_inline void ct_cpuidle_exit(void)
139{
140 /*
141 * Carefully undo the above.
142 */
143 lockdep_hardirqs_off(_RET_IP_);
144 ct_idle_exit();
145 instrumentation_begin();
146}
147
148/****************************
149 * CPUIDLE DRIVER INTERFACE *
150 ****************************/
151
152struct 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
171extern void disable_cpuidle(void);
172extern bool cpuidle_not_available(struct cpuidle_driver *drv,
173 struct cpuidle_device *dev);
174
175extern int cpuidle_select(struct cpuidle_driver *drv,
176 struct cpuidle_device *dev,
177 bool *stop_tick);
178extern int cpuidle_enter(struct cpuidle_driver *drv,
179 struct cpuidle_device *dev, int index);
180extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
181extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
182 struct cpuidle_device *dev);
183
184extern int cpuidle_register_driver(struct cpuidle_driver *drv);
185extern struct cpuidle_driver *cpuidle_get_driver(void);
186extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
187 bool disable);
188extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
189extern int cpuidle_register_device(struct cpuidle_device *dev);
190extern void cpuidle_unregister_device(struct cpuidle_device *dev);
191extern int cpuidle_register(struct cpuidle_driver *drv,
192 const struct cpumask *const coupled_cpus);
193extern void cpuidle_unregister(struct cpuidle_driver *drv);
194extern void cpuidle_pause_and_lock(void);
195extern void cpuidle_resume_and_unlock(void);
196extern void cpuidle_pause(void);
197extern void cpuidle_resume(void);
198extern int cpuidle_enable_device(struct cpuidle_device *dev);
199extern void cpuidle_disable_device(struct cpuidle_device *dev);
200extern int cpuidle_play_dead(void);
201
202extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
203static inline struct cpuidle_device *cpuidle_get_device(void)
204{return __this_cpu_read(cpuidle_devices); }
205#else
206static inline void disable_cpuidle(void) { }
207static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
208 struct cpuidle_device *dev)
209{return true; }
210static inline int cpuidle_select(struct cpuidle_driver *drv,
211 struct cpuidle_device *dev, bool *stop_tick)
212{return -ENODEV; }
213static inline int cpuidle_enter(struct cpuidle_driver *drv,
214 struct cpuidle_device *dev, int index)
215{return -ENODEV; }
216static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
217static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
218 struct cpuidle_device *dev)
219{return 0; }
220static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
221{return -ENODEV; }
222static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
223static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
224 int idx, bool disable) { }
225static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
226static inline int cpuidle_register_device(struct cpuidle_device *dev)
227{return -ENODEV; }
228static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
229static inline int cpuidle_register(struct cpuidle_driver *drv,
230 const struct cpumask *const coupled_cpus)
231{return -ENODEV; }
232static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
233static inline void cpuidle_pause_and_lock(void) { }
234static inline void cpuidle_resume_and_unlock(void) { }
235static inline void cpuidle_pause(void) { }
236static inline void cpuidle_resume(void) { }
237static inline int cpuidle_enable_device(struct cpuidle_device *dev)
238{return -ENODEV; }
239static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
240static inline int cpuidle_play_dead(void) {return -ENODEV; }
241static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
242 struct cpuidle_device *dev) {return NULL; }
243static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
244#endif
245
246#ifdef CONFIG_CPU_IDLE
247extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
248 struct cpuidle_device *dev,
249 u64 latency_limit_ns);
250extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
251 struct cpuidle_device *dev);
252extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
253#else
254static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
255 struct cpuidle_device *dev,
256 u64 latency_limit_ns)
257{return -ENODEV; }
258static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
259 struct cpuidle_device *dev)
260{return -ENODEV; }
261static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
262{
263}
264#endif
265
266/* kernel/sched/idle.c */
267extern void sched_idle_set_state(struct cpuidle_state *idle_state);
268extern void default_idle_call(void);
269
270#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
271void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
272#else
273static 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)
279void cpuidle_poll_state_init(struct cpuidle_driver *drv);
280#else
281static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
282#endif
283
284/******************************
285 * CPUIDLE GOVERNOR INTERFACE *
286 ******************************/
287
288struct 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
304extern int cpuidle_register_governor(struct cpuidle_governor *gov);
305extern 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 */
353