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