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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
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_COUPLED (0x02) /* state applies to multiple cpus */
66#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
67
68#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
69
70struct cpuidle_device_kobj;
71struct cpuidle_state_kobj;
72struct cpuidle_driver_kobj;
73
74struct cpuidle_device {
75 unsigned int registered:1;
76 unsigned int enabled:1;
77 unsigned int cpu;
78
79 int last_residency;
80 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
81 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
82 struct cpuidle_driver_kobj *kobj_driver;
83 struct cpuidle_device_kobj *kobj_dev;
84 struct list_head device_list;
85
86#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
87 cpumask_t coupled_cpus;
88 struct cpuidle_coupled *coupled;
89#endif
90};
91
92DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
93DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
94
95/**
96 * cpuidle_get_last_residency - retrieves the last state's residency time
97 * @dev: the target CPU
98 */
99static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
100{
101 return dev->last_residency;
102}
103
104
105/****************************
106 * CPUIDLE DRIVER INTERFACE *
107 ****************************/
108
109struct cpuidle_driver {
110 const char *name;
111 struct module *owner;
112 int refcnt;
113
114 /* used by the cpuidle framework to setup the broadcast timer */
115 unsigned int bctimer:1;
116 /* states array must be ordered in decreasing power consumption */
117 struct cpuidle_state states[CPUIDLE_STATE_MAX];
118 int state_count;
119 int safe_state_index;
120
121 /* the driver handles the cpus in cpumask */
122 struct cpumask *cpumask;
123};
124
125#ifdef CONFIG_CPU_IDLE
126extern void disable_cpuidle(void);
127extern bool cpuidle_not_available(struct cpuidle_driver *drv,
128 struct cpuidle_device *dev);
129
130extern int cpuidle_select(struct cpuidle_driver *drv,
131 struct cpuidle_device *dev);
132extern int cpuidle_enter(struct cpuidle_driver *drv,
133 struct cpuidle_device *dev, int index);
134extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
135
136extern int cpuidle_register_driver(struct cpuidle_driver *drv);
137extern struct cpuidle_driver *cpuidle_get_driver(void);
138extern struct cpuidle_driver *cpuidle_driver_ref(void);
139extern void cpuidle_driver_unref(void);
140extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
141extern int cpuidle_register_device(struct cpuidle_device *dev);
142extern void cpuidle_unregister_device(struct cpuidle_device *dev);
143extern int cpuidle_register(struct cpuidle_driver *drv,
144 const struct cpumask *const coupled_cpus);
145extern void cpuidle_unregister(struct cpuidle_driver *drv);
146extern void cpuidle_pause_and_lock(void);
147extern void cpuidle_resume_and_unlock(void);
148extern void cpuidle_pause(void);
149extern void cpuidle_resume(void);
150extern int cpuidle_enable_device(struct cpuidle_device *dev);
151extern void cpuidle_disable_device(struct cpuidle_device *dev);
152extern int cpuidle_play_dead(void);
153
154extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
155static inline struct cpuidle_device *cpuidle_get_device(void)
156{return __this_cpu_read(cpuidle_devices); }
157#else
158static inline void disable_cpuidle(void) { }
159static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
160 struct cpuidle_device *dev)
161{return true; }
162static inline int cpuidle_select(struct cpuidle_driver *drv,
163 struct cpuidle_device *dev)
164{return -ENODEV; }
165static inline int cpuidle_enter(struct cpuidle_driver *drv,
166 struct cpuidle_device *dev, int index)
167{return -ENODEV; }
168static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
169static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
170{return -ENODEV; }
171static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
172static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
173static inline void cpuidle_driver_unref(void) {}
174static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
175static inline int cpuidle_register_device(struct cpuidle_device *dev)
176{return -ENODEV; }
177static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
178static inline int cpuidle_register(struct cpuidle_driver *drv,
179 const struct cpumask *const coupled_cpus)
180{return -ENODEV; }
181static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
182static inline void cpuidle_pause_and_lock(void) { }
183static inline void cpuidle_resume_and_unlock(void) { }
184static inline void cpuidle_pause(void) { }
185static inline void cpuidle_resume(void) { }
186static inline int cpuidle_enable_device(struct cpuidle_device *dev)
187{return -ENODEV; }
188static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
189static inline int cpuidle_play_dead(void) {return -ENODEV; }
190static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
191 struct cpuidle_device *dev) {return NULL; }
192static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
193#endif
194
195#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
196extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
197 struct cpuidle_device *dev);
198extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
199 struct cpuidle_device *dev);
200#else
201static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
202 struct cpuidle_device *dev)
203{return -ENODEV; }
204static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
205 struct cpuidle_device *dev)
206{return -ENODEV; }
207#endif
208
209/* kernel/sched/idle.c */
210extern void sched_idle_set_state(struct cpuidle_state *idle_state);
211extern void default_idle_call(void);
212
213#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
214void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
215#else
216static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
217{
218}
219#endif
220
221/******************************
222 * CPUIDLE GOVERNOR INTERFACE *
223 ******************************/
224
225struct cpuidle_governor {
226 char name[CPUIDLE_NAME_LEN];
227 struct list_head governor_list;
228 unsigned int rating;
229
230 int (*enable) (struct cpuidle_driver *drv,
231 struct cpuidle_device *dev);
232 void (*disable) (struct cpuidle_driver *drv,
233 struct cpuidle_device *dev);
234
235 int (*select) (struct cpuidle_driver *drv,
236 struct cpuidle_device *dev);
237 void (*reflect) (struct cpuidle_device *dev, int index);
238
239 struct module *owner;
240};
241
242#ifdef CONFIG_CPU_IDLE
243extern int cpuidle_register_governor(struct cpuidle_governor *gov);
244#else
245static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
246{return 0;}
247#endif
248
249#ifdef CONFIG_ARCH_HAS_CPU_RELAX
250#define CPUIDLE_DRIVER_STATE_START 1
251#else
252#define CPUIDLE_DRIVER_STATE_START 0
253#endif
254
255#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
256({ \
257 int __ret; \
258 \
259 if (!idx) { \
260 cpu_do_idle(); \
261 return idx; \
262 } \
263 \
264 __ret = cpu_pm_enter(); \
265 if (!__ret) { \
266 __ret = low_level_idle_enter(idx); \
267 cpu_pm_exit(); \
268 } \
269 \
270 __ret ? -1 : idx; \
271})
272
273#endif /* _LINUX_CPUIDLE_H */