Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
85struct cpuidle_device_kobj;
86struct cpuidle_state_kobj;
87struct cpuidle_driver_kobj;
88
89struct cpuidle_device {
90 unsigned int registered:1;
91 unsigned int enabled:1;
92 unsigned int poll_time_limit:1;
93 unsigned int cpu;
94 ktime_t next_hrtimer;
95
96 int last_state_idx;
97 u64 last_residency_ns;
98 u64 poll_limit_ns;
99 u64 forced_idle_latency_limit_ns;
100 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
101 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
102 struct cpuidle_driver_kobj *kobj_driver;
103 struct cpuidle_device_kobj *kobj_dev;
104 struct list_head device_list;
105
106#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
107 cpumask_t coupled_cpus;
108 struct cpuidle_coupled *coupled;
109#endif
110};
111
112DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
113DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
114
115/****************************
116 * CPUIDLE DRIVER INTERFACE *
117 ****************************/
118
119struct cpuidle_driver {
120 const char *name;
121 struct module *owner;
122
123 /* used by the cpuidle framework to setup the broadcast timer */
124 unsigned int bctimer:1;
125 /* states array must be ordered in decreasing power consumption */
126 struct cpuidle_state states[CPUIDLE_STATE_MAX];
127 int state_count;
128 int safe_state_index;
129
130 /* the driver handles the cpus in cpumask */
131 struct cpumask *cpumask;
132
133 /* preferred governor to switch at register time */
134 const char *governor;
135};
136
137#ifdef CONFIG_CPU_IDLE
138extern void disable_cpuidle(void);
139extern bool cpuidle_not_available(struct cpuidle_driver *drv,
140 struct cpuidle_device *dev);
141
142extern int cpuidle_select(struct cpuidle_driver *drv,
143 struct cpuidle_device *dev,
144 bool *stop_tick);
145extern int cpuidle_enter(struct cpuidle_driver *drv,
146 struct cpuidle_device *dev, int index);
147extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
148extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
149 struct cpuidle_device *dev);
150
151extern int cpuidle_register_driver(struct cpuidle_driver *drv);
152extern struct cpuidle_driver *cpuidle_get_driver(void);
153extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
154 bool disable);
155extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
156extern int cpuidle_register_device(struct cpuidle_device *dev);
157extern void cpuidle_unregister_device(struct cpuidle_device *dev);
158extern int cpuidle_register(struct cpuidle_driver *drv,
159 const struct cpumask *const coupled_cpus);
160extern void cpuidle_unregister(struct cpuidle_driver *drv);
161extern void cpuidle_pause_and_lock(void);
162extern void cpuidle_resume_and_unlock(void);
163extern void cpuidle_pause(void);
164extern void cpuidle_resume(void);
165extern int cpuidle_enable_device(struct cpuidle_device *dev);
166extern void cpuidle_disable_device(struct cpuidle_device *dev);
167extern int cpuidle_play_dead(void);
168
169extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
170static inline struct cpuidle_device *cpuidle_get_device(void)
171{return __this_cpu_read(cpuidle_devices); }
172#else
173static inline void disable_cpuidle(void) { }
174static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
175 struct cpuidle_device *dev)
176{return true; }
177static inline int cpuidle_select(struct cpuidle_driver *drv,
178 struct cpuidle_device *dev, bool *stop_tick)
179{return -ENODEV; }
180static inline int cpuidle_enter(struct cpuidle_driver *drv,
181 struct cpuidle_device *dev, int index)
182{return -ENODEV; }
183static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
184static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
185 struct cpuidle_device *dev)
186{return 0; }
187static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
188{return -ENODEV; }
189static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
190static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
191 int idx, bool disable) { }
192static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
193static inline int cpuidle_register_device(struct cpuidle_device *dev)
194{return -ENODEV; }
195static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
196static inline int cpuidle_register(struct cpuidle_driver *drv,
197 const struct cpumask *const coupled_cpus)
198{return -ENODEV; }
199static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
200static inline void cpuidle_pause_and_lock(void) { }
201static inline void cpuidle_resume_and_unlock(void) { }
202static inline void cpuidle_pause(void) { }
203static inline void cpuidle_resume(void) { }
204static inline int cpuidle_enable_device(struct cpuidle_device *dev)
205{return -ENODEV; }
206static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
207static inline int cpuidle_play_dead(void) {return -ENODEV; }
208static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
209 struct cpuidle_device *dev) {return NULL; }
210static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
211#endif
212
213#ifdef CONFIG_CPU_IDLE
214extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
215 struct cpuidle_device *dev,
216 u64 latency_limit_ns);
217extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
218 struct cpuidle_device *dev);
219extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
220#else
221static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
222 struct cpuidle_device *dev,
223 u64 latency_limit_ns)
224{return -ENODEV; }
225static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
226 struct cpuidle_device *dev)
227{return -ENODEV; }
228static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
229{
230}
231#endif
232
233/* kernel/sched/idle.c */
234extern void sched_idle_set_state(struct cpuidle_state *idle_state);
235extern void default_idle_call(void);
236
237#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
238void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
239#else
240static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
241{
242}
243#endif
244
245#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
246void cpuidle_poll_state_init(struct cpuidle_driver *drv);
247#else
248static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
249#endif
250
251/******************************
252 * CPUIDLE GOVERNOR INTERFACE *
253 ******************************/
254
255struct cpuidle_governor {
256 char name[CPUIDLE_NAME_LEN];
257 struct list_head governor_list;
258 unsigned int rating;
259
260 int (*enable) (struct cpuidle_driver *drv,
261 struct cpuidle_device *dev);
262 void (*disable) (struct cpuidle_driver *drv,
263 struct cpuidle_device *dev);
264
265 int (*select) (struct cpuidle_driver *drv,
266 struct cpuidle_device *dev,
267 bool *stop_tick);
268 void (*reflect) (struct cpuidle_device *dev, int index);
269};
270
271#ifdef CONFIG_CPU_IDLE
272extern int cpuidle_register_governor(struct cpuidle_governor *gov);
273extern s64 cpuidle_governor_latency_req(unsigned int cpu);
274#else
275static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
276{return 0;}
277#endif
278
279#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
280 idx, \
281 state, \
282 is_retention) \
283({ \
284 int __ret = 0; \
285 \
286 if (!idx) { \
287 cpu_do_idle(); \
288 return idx; \
289 } \
290 \
291 if (!is_retention) \
292 __ret = cpu_pm_enter(); \
293 if (!__ret) { \
294 __ret = low_level_idle_enter(state); \
295 if (!is_retention) \
296 cpu_pm_exit(); \
297 } \
298 \
299 __ret ? -1 : idx; \
300})
301
302#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
303 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
304
305#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
306 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
307
308#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
309 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
310
311#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
312 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
313
314#endif /* _LINUX_CPUIDLE_H */