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
32struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
36};
37
38struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
41
42 unsigned int flags;
43 unsigned int exit_latency; /* in US */
44 int power_usage; /* in mW */
45 unsigned int target_residency; /* in US */
46 bool disabled; /* disabled on all CPUs */
47
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
50 int index);
51
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
53
54 /*
55 * CPUs execute ->enter_freeze with the local tick or entire timekeeping
56 * suspended, so it must not re-enable interrupts at any point (even
57 * temporarily) or attempt to change states of clock event devices.
58 */
59 void (*enter_freeze) (struct cpuidle_device *dev,
60 struct cpuidle_driver *drv,
61 int index);
62};
63
64/* Idle State Flags */
65#define CPUIDLE_FLAG_NONE (0x00)
66#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
67#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
68
69#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
70
71struct cpuidle_device_kobj;
72struct cpuidle_state_kobj;
73struct cpuidle_driver_kobj;
74
75struct cpuidle_device {
76 unsigned int registered:1;
77 unsigned int enabled:1;
78 unsigned int use_deepest_state:1;
79 unsigned int cpu;
80
81 int last_residency;
82 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
83 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
84 struct cpuidle_driver_kobj *kobj_driver;
85 struct cpuidle_device_kobj *kobj_dev;
86 struct list_head device_list;
87
88#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
89 cpumask_t coupled_cpus;
90 struct cpuidle_coupled *coupled;
91#endif
92};
93
94DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
95DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
96
97/**
98 * cpuidle_get_last_residency - retrieves the last state's residency time
99 * @dev: the target CPU
100 */
101static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
102{
103 return dev->last_residency;
104}
105
106
107/****************************
108 * CPUIDLE DRIVER INTERFACE *
109 ****************************/
110
111struct cpuidle_driver {
112 const char *name;
113 struct module *owner;
114 int refcnt;
115
116 /* used by the cpuidle framework to setup the broadcast timer */
117 unsigned int bctimer:1;
118 /* states array must be ordered in decreasing power consumption */
119 struct cpuidle_state states[CPUIDLE_STATE_MAX];
120 int state_count;
121 int safe_state_index;
122
123 /* the driver handles the cpus in cpumask */
124 struct cpumask *cpumask;
125};
126
127#ifdef CONFIG_CPU_IDLE
128extern void disable_cpuidle(void);
129extern bool cpuidle_not_available(struct cpuidle_driver *drv,
130 struct cpuidle_device *dev);
131
132extern int cpuidle_select(struct cpuidle_driver *drv,
133 struct cpuidle_device *dev);
134extern int cpuidle_enter(struct cpuidle_driver *drv,
135 struct cpuidle_device *dev, int index);
136extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
137
138extern int cpuidle_register_driver(struct cpuidle_driver *drv);
139extern struct cpuidle_driver *cpuidle_get_driver(void);
140extern struct cpuidle_driver *cpuidle_driver_ref(void);
141extern void cpuidle_driver_unref(void);
142extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
143extern int cpuidle_register_device(struct cpuidle_device *dev);
144extern void cpuidle_unregister_device(struct cpuidle_device *dev);
145extern int cpuidle_register(struct cpuidle_driver *drv,
146 const struct cpumask *const coupled_cpus);
147extern void cpuidle_unregister(struct cpuidle_driver *drv);
148extern void cpuidle_pause_and_lock(void);
149extern void cpuidle_resume_and_unlock(void);
150extern void cpuidle_pause(void);
151extern void cpuidle_resume(void);
152extern int cpuidle_enable_device(struct cpuidle_device *dev);
153extern void cpuidle_disable_device(struct cpuidle_device *dev);
154extern int cpuidle_play_dead(void);
155
156extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
157static inline struct cpuidle_device *cpuidle_get_device(void)
158{return __this_cpu_read(cpuidle_devices); }
159#else
160static inline void disable_cpuidle(void) { }
161static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
162 struct cpuidle_device *dev)
163{return true; }
164static inline int cpuidle_select(struct cpuidle_driver *drv,
165 struct cpuidle_device *dev)
166{return -ENODEV; }
167static inline int cpuidle_enter(struct cpuidle_driver *drv,
168 struct cpuidle_device *dev, int index)
169{return -ENODEV; }
170static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
171static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
172{return -ENODEV; }
173static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
174static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
175static inline void cpuidle_driver_unref(void) {}
176static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
177static inline int cpuidle_register_device(struct cpuidle_device *dev)
178{return -ENODEV; }
179static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
180static inline int cpuidle_register(struct cpuidle_driver *drv,
181 const struct cpumask *const coupled_cpus)
182{return -ENODEV; }
183static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
184static inline void cpuidle_pause_and_lock(void) { }
185static inline void cpuidle_resume_and_unlock(void) { }
186static inline void cpuidle_pause(void) { }
187static inline void cpuidle_resume(void) { }
188static inline int cpuidle_enable_device(struct cpuidle_device *dev)
189{return -ENODEV; }
190static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
191static inline int cpuidle_play_dead(void) {return -ENODEV; }
192static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
193 struct cpuidle_device *dev) {return NULL; }
194static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
195#endif
196
197#ifdef CONFIG_CPU_IDLE
198extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
199 struct cpuidle_device *dev);
200extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
201 struct cpuidle_device *dev);
202extern void cpuidle_use_deepest_state(bool enable);
203#else
204static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev)
206{return -ENODEV; }
207static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
208 struct cpuidle_device *dev)
209{return -ENODEV; }
210static inline void cpuidle_use_deepest_state(bool enable)
211{
212}
213#endif
214
215/* kernel/sched/idle.c */
216extern void sched_idle_set_state(struct cpuidle_state *idle_state);
217extern void default_idle_call(void);
218
219#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
220void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
221#else
222static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
223{
224}
225#endif
226
227/******************************
228 * CPUIDLE GOVERNOR INTERFACE *
229 ******************************/
230
231struct cpuidle_governor {
232 char name[CPUIDLE_NAME_LEN];
233 struct list_head governor_list;
234 unsigned int rating;
235
236 int (*enable) (struct cpuidle_driver *drv,
237 struct cpuidle_device *dev);
238 void (*disable) (struct cpuidle_driver *drv,
239 struct cpuidle_device *dev);
240
241 int (*select) (struct cpuidle_driver *drv,
242 struct cpuidle_device *dev);
243 void (*reflect) (struct cpuidle_device *dev, int index);
244};
245
246#ifdef CONFIG_CPU_IDLE
247extern int cpuidle_register_governor(struct cpuidle_governor *gov);
248#else
249static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
250{return 0;}
251#endif
252
253#ifdef CONFIG_ARCH_HAS_CPU_RELAX
254#define CPUIDLE_DRIVER_STATE_START 1
255#else
256#define CPUIDLE_DRIVER_STATE_START 0
257#endif
258
259#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
260({ \
261 int __ret; \
262 \
263 if (!idx) { \
264 cpu_do_idle(); \
265 return idx; \
266 } \
267 \
268 __ret = cpu_pm_enter(); \
269 if (!__ret) { \
270 __ret = low_level_idle_enter(idx); \
271 cpu_pm_exit(); \
272 } \
273 \
274 __ret ? -1 : idx; \
275})
276
277#endif /* _LINUX_CPUIDLE_H */