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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 void (*enter_s2idle) (struct cpuidle_device *dev,
70 struct cpuidle_driver *drv,
71 int index);
72};
73
74/* Idle State Flags */
75#define CPUIDLE_FLAG_NONE (0x00)
76#define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
77#define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
78#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
79#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
80
81struct cpuidle_device_kobj;
82struct cpuidle_state_kobj;
83struct cpuidle_driver_kobj;
84
85struct cpuidle_device {
86 unsigned int registered:1;
87 unsigned int enabled:1;
88 unsigned int poll_time_limit:1;
89 unsigned int cpu;
90 ktime_t next_hrtimer;
91
92 int last_state_idx;
93 u64 last_residency_ns;
94 u64 poll_limit_ns;
95 u64 forced_idle_latency_limit_ns;
96 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
97 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
98 struct cpuidle_driver_kobj *kobj_driver;
99 struct cpuidle_device_kobj *kobj_dev;
100 struct list_head device_list;
101
102#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
103 cpumask_t coupled_cpus;
104 struct cpuidle_coupled *coupled;
105#endif
106};
107
108DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
109DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
110
111/****************************
112 * CPUIDLE DRIVER INTERFACE *
113 ****************************/
114
115struct cpuidle_driver {
116 const char *name;
117 struct module *owner;
118 int refcnt;
119
120 /* used by the cpuidle framework to setup the broadcast timer */
121 unsigned int bctimer:1;
122 /* states array must be ordered in decreasing power consumption */
123 struct cpuidle_state states[CPUIDLE_STATE_MAX];
124 int state_count;
125 int safe_state_index;
126
127 /* the driver handles the cpus in cpumask */
128 struct cpumask *cpumask;
129
130 /* preferred governor to switch at register time */
131 const char *governor;
132};
133
134#ifdef CONFIG_CPU_IDLE
135extern void disable_cpuidle(void);
136extern bool cpuidle_not_available(struct cpuidle_driver *drv,
137 struct cpuidle_device *dev);
138
139extern int cpuidle_select(struct cpuidle_driver *drv,
140 struct cpuidle_device *dev,
141 bool *stop_tick);
142extern int cpuidle_enter(struct cpuidle_driver *drv,
143 struct cpuidle_device *dev, int index);
144extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
145extern u64 cpuidle_poll_time(struct cpuidle_driver *drv,
146 struct cpuidle_device *dev);
147
148extern int cpuidle_register_driver(struct cpuidle_driver *drv);
149extern struct cpuidle_driver *cpuidle_get_driver(void);
150extern struct cpuidle_driver *cpuidle_driver_ref(void);
151extern void cpuidle_driver_unref(void);
152extern void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,
153 bool disable);
154extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
155extern int cpuidle_register_device(struct cpuidle_device *dev);
156extern void cpuidle_unregister_device(struct cpuidle_device *dev);
157extern int cpuidle_register(struct cpuidle_driver *drv,
158 const struct cpumask *const coupled_cpus);
159extern void cpuidle_unregister(struct cpuidle_driver *drv);
160extern void cpuidle_pause_and_lock(void);
161extern void cpuidle_resume_and_unlock(void);
162extern void cpuidle_pause(void);
163extern void cpuidle_resume(void);
164extern int cpuidle_enable_device(struct cpuidle_device *dev);
165extern void cpuidle_disable_device(struct cpuidle_device *dev);
166extern int cpuidle_play_dead(void);
167
168extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
169static inline struct cpuidle_device *cpuidle_get_device(void)
170{return __this_cpu_read(cpuidle_devices); }
171#else
172static inline void disable_cpuidle(void) { }
173static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
174 struct cpuidle_device *dev)
175{return true; }
176static inline int cpuidle_select(struct cpuidle_driver *drv,
177 struct cpuidle_device *dev, bool *stop_tick)
178{return -ENODEV; }
179static inline int cpuidle_enter(struct cpuidle_driver *drv,
180 struct cpuidle_device *dev, int index)
181{return -ENODEV; }
182static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
183static inline u64 cpuidle_poll_time(struct cpuidle_driver *drv,
184 struct cpuidle_device *dev)
185{return 0; }
186static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
187{return -ENODEV; }
188static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
189static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
190static inline void cpuidle_driver_unref(void) {}
191static inline void cpuidle_driver_state_disabled(struct cpuidle_driver *drv,
192 int idx, bool disable) { }
193static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
194static inline int cpuidle_register_device(struct cpuidle_device *dev)
195{return -ENODEV; }
196static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
197static inline int cpuidle_register(struct cpuidle_driver *drv,
198 const struct cpumask *const coupled_cpus)
199{return -ENODEV; }
200static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
201static inline void cpuidle_pause_and_lock(void) { }
202static inline void cpuidle_resume_and_unlock(void) { }
203static inline void cpuidle_pause(void) { }
204static inline void cpuidle_resume(void) { }
205static inline int cpuidle_enable_device(struct cpuidle_device *dev)
206{return -ENODEV; }
207static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
208static inline int cpuidle_play_dead(void) {return -ENODEV; }
209static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
210 struct cpuidle_device *dev) {return NULL; }
211static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
212#endif
213
214#ifdef CONFIG_CPU_IDLE
215extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
216 struct cpuidle_device *dev,
217 u64 latency_limit_ns);
218extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
219 struct cpuidle_device *dev);
220extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
221#else
222static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
223 struct cpuidle_device *dev,
224 u64 latency_limit_ns)
225{return -ENODEV; }
226static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
227 struct cpuidle_device *dev)
228{return -ENODEV; }
229static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
230{
231}
232#endif
233
234/* kernel/sched/idle.c */
235extern void sched_idle_set_state(struct cpuidle_state *idle_state);
236extern void default_idle_call(void);
237
238#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
239void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
240#else
241static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
242{
243}
244#endif
245
246#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX)
247void cpuidle_poll_state_init(struct cpuidle_driver *drv);
248#else
249static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {}
250#endif
251
252/******************************
253 * CPUIDLE GOVERNOR INTERFACE *
254 ******************************/
255
256struct cpuidle_governor {
257 char name[CPUIDLE_NAME_LEN];
258 struct list_head governor_list;
259 unsigned int rating;
260
261 int (*enable) (struct cpuidle_driver *drv,
262 struct cpuidle_device *dev);
263 void (*disable) (struct cpuidle_driver *drv,
264 struct cpuidle_device *dev);
265
266 int (*select) (struct cpuidle_driver *drv,
267 struct cpuidle_device *dev,
268 bool *stop_tick);
269 void (*reflect) (struct cpuidle_device *dev, int index);
270};
271
272#ifdef CONFIG_CPU_IDLE
273extern int cpuidle_register_governor(struct cpuidle_governor *gov);
274extern s64 cpuidle_governor_latency_req(unsigned int cpu);
275#else
276static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
277{return 0;}
278#endif
279
280#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
281 idx, \
282 state, \
283 is_retention) \
284({ \
285 int __ret = 0; \
286 \
287 if (!idx) { \
288 cpu_do_idle(); \
289 return idx; \
290 } \
291 \
292 if (!is_retention) \
293 __ret = cpu_pm_enter(); \
294 if (!__ret) { \
295 __ret = low_level_idle_enter(state); \
296 if (!is_retention) \
297 cpu_pm_exit(); \
298 } \
299 \
300 __ret ? -1 : idx; \
301})
302
303#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
304 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
305
306#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
307 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
308
309#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
310 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
311
312#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
313 __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
314
315#endif /* _LINUX_CPUIDLE_H */