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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/kobject.h>
17#include <linux/completion.h>
18#include <linux/hrtimer.h>
19
20#define CPUIDLE_STATE_MAX 8
21#define CPUIDLE_NAME_LEN 16
22#define CPUIDLE_DESC_LEN 32
23
24struct module;
25
26struct cpuidle_device;
27struct cpuidle_driver;
28
29
30/****************************
31 * CPUIDLE DEVICE INTERFACE *
32 ****************************/
33
34struct cpuidle_state_usage {
35 void *driver_data;
36
37 unsigned long long disable;
38 unsigned long long usage;
39 unsigned long long time; /* in US */
40};
41
42struct cpuidle_state {
43 char name[CPUIDLE_NAME_LEN];
44 char desc[CPUIDLE_DESC_LEN];
45
46 unsigned int flags;
47 unsigned int exit_latency; /* in US */
48 int power_usage; /* in mW */
49 unsigned int target_residency; /* in US */
50 bool disabled; /* disabled on all CPUs */
51
52 int (*enter) (struct cpuidle_device *dev,
53 struct cpuidle_driver *drv,
54 int index);
55
56 int (*enter_dead) (struct cpuidle_device *dev, int index);
57};
58
59/* Idle State Flags */
60#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
61#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
62
63#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
64
65/**
66 * cpuidle_get_statedata - retrieves private driver state data
67 * @st_usage: the state usage statistics
68 */
69static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)
70{
71 return st_usage->driver_data;
72}
73
74/**
75 * cpuidle_set_statedata - stores private driver state data
76 * @st_usage: the state usage statistics
77 * @data: the private data
78 */
79static inline void
80cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)
81{
82 st_usage->driver_data = data;
83}
84
85struct cpuidle_device {
86 unsigned int registered:1;
87 unsigned int enabled:1;
88 unsigned int cpu;
89
90 int last_residency;
91 int state_count;
92 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
93 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
94 struct cpuidle_driver_kobj *kobj_driver;
95 struct list_head device_list;
96 struct kobject kobj;
97 struct completion kobj_unregister;
98
99#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
100 int safe_state_index;
101 cpumask_t coupled_cpus;
102 struct cpuidle_coupled *coupled;
103#endif
104};
105
106DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
107
108/**
109 * cpuidle_get_last_residency - retrieves the last state's residency time
110 * @dev: the target CPU
111 *
112 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
113 */
114static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
115{
116 return dev->last_residency;
117}
118
119
120/****************************
121 * CPUIDLE DRIVER INTERFACE *
122 ****************************/
123
124struct cpuidle_driver {
125 const char *name;
126 struct module *owner;
127 int refcnt;
128
129 /* set to 1 to use the core cpuidle time keeping (for all states). */
130 unsigned int en_core_tk_irqen:1;
131 /* states array must be ordered in decreasing power consumption */
132 struct cpuidle_state states[CPUIDLE_STATE_MAX];
133 int state_count;
134 int safe_state_index;
135};
136
137#ifdef CONFIG_CPU_IDLE
138extern void disable_cpuidle(void);
139extern int cpuidle_idle_call(void);
140extern int cpuidle_register_driver(struct cpuidle_driver *drv);
141extern struct cpuidle_driver *cpuidle_get_driver(void);
142extern struct cpuidle_driver *cpuidle_driver_ref(void);
143extern void cpuidle_driver_unref(void);
144extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
145extern int cpuidle_register_device(struct cpuidle_device *dev);
146extern void cpuidle_unregister_device(struct cpuidle_device *dev);
147
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_wrap_enter(struct cpuidle_device *dev,
155 struct cpuidle_driver *drv, int index,
156 int (*enter)(struct cpuidle_device *dev,
157 struct cpuidle_driver *drv, int index));
158extern int cpuidle_play_dead(void);
159
160extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
161extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
162extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
163
164#else
165static inline void disable_cpuidle(void) { }
166static inline int cpuidle_idle_call(void) { return -ENODEV; }
167static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
168{return -ENODEV; }
169static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
170static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
171static inline void cpuidle_driver_unref(void) {}
172static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
173static inline int cpuidle_register_device(struct cpuidle_device *dev)
174{return -ENODEV; }
175static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
176
177static inline void cpuidle_pause_and_lock(void) { }
178static inline void cpuidle_resume_and_unlock(void) { }
179static inline void cpuidle_pause(void) { }
180static inline void cpuidle_resume(void) { }
181static inline int cpuidle_enable_device(struct cpuidle_device *dev)
182{return -ENODEV; }
183static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
184static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
185 struct cpuidle_driver *drv, int index,
186 int (*enter)(struct cpuidle_device *dev,
187 struct cpuidle_driver *drv, int index))
188{ return -ENODEV; }
189static inline int cpuidle_play_dead(void) {return -ENODEV; }
190#endif
191
192#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
193void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
194#else
195static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
196{
197}
198#endif
199
200/******************************
201 * CPUIDLE GOVERNOR INTERFACE *
202 ******************************/
203
204struct cpuidle_governor {
205 char name[CPUIDLE_NAME_LEN];
206 struct list_head governor_list;
207 unsigned int rating;
208
209 int (*enable) (struct cpuidle_driver *drv,
210 struct cpuidle_device *dev);
211 void (*disable) (struct cpuidle_driver *drv,
212 struct cpuidle_device *dev);
213
214 int (*select) (struct cpuidle_driver *drv,
215 struct cpuidle_device *dev);
216 void (*reflect) (struct cpuidle_device *dev, int index);
217
218 struct module *owner;
219};
220
221#ifdef CONFIG_CPU_IDLE
222
223extern int cpuidle_register_governor(struct cpuidle_governor *gov);
224extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
225
226#else
227
228static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
229{return 0;}
230static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
231
232#endif
233
234#ifdef CONFIG_ARCH_HAS_CPU_RELAX
235#define CPUIDLE_DRIVER_STATE_START 1
236#else
237#define CPUIDLE_DRIVER_STATE_START 0
238#endif
239
240#endif /* _LINUX_CPUIDLE_H */