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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/* Idle State Flags */
56#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
57#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
58#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
59
60#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
61
62struct cpuidle_device_kobj;
63struct cpuidle_state_kobj;
64struct cpuidle_driver_kobj;
65
66struct cpuidle_device {
67 unsigned int registered:1;
68 unsigned int enabled:1;
69 unsigned int cpu;
70
71 int last_residency;
72 int state_count;
73 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
74 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
75 struct cpuidle_driver_kobj *kobj_driver;
76 struct cpuidle_device_kobj *kobj_dev;
77 struct list_head device_list;
78
79#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
80 int safe_state_index;
81 cpumask_t coupled_cpus;
82 struct cpuidle_coupled *coupled;
83#endif
84};
85
86DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
87
88/**
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
91 *
92 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
93 */
94static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
95{
96 return dev->last_residency;
97}
98
99
100/****************************
101 * CPUIDLE DRIVER INTERFACE *
102 ****************************/
103
104struct cpuidle_driver {
105 const char *name;
106 struct module *owner;
107 int refcnt;
108
109 /* used by the cpuidle framework to setup the broadcast timer */
110 unsigned int bctimer:1;
111 /* states array must be ordered in decreasing power consumption */
112 struct cpuidle_state states[CPUIDLE_STATE_MAX];
113 int state_count;
114 int safe_state_index;
115
116 /* the driver handles the cpus in cpumask */
117 struct cpumask *cpumask;
118};
119
120#ifdef CONFIG_CPU_IDLE
121extern void disable_cpuidle(void);
122
123extern int cpuidle_enabled(struct cpuidle_driver *drv,
124 struct cpuidle_device *dev);
125extern int cpuidle_select(struct cpuidle_driver *drv,
126 struct cpuidle_device *dev);
127extern int cpuidle_enter(struct cpuidle_driver *drv,
128 struct cpuidle_device *dev, int index);
129extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
130
131extern int cpuidle_register_driver(struct cpuidle_driver *drv);
132extern struct cpuidle_driver *cpuidle_get_driver(void);
133extern struct cpuidle_driver *cpuidle_driver_ref(void);
134extern void cpuidle_driver_unref(void);
135extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
136extern int cpuidle_register_device(struct cpuidle_device *dev);
137extern void cpuidle_unregister_device(struct cpuidle_device *dev);
138extern int cpuidle_register(struct cpuidle_driver *drv,
139 const struct cpumask *const coupled_cpus);
140extern void cpuidle_unregister(struct cpuidle_driver *drv);
141extern void cpuidle_pause_and_lock(void);
142extern void cpuidle_resume_and_unlock(void);
143extern void cpuidle_pause(void);
144extern void cpuidle_resume(void);
145extern int cpuidle_enable_device(struct cpuidle_device *dev);
146extern void cpuidle_disable_device(struct cpuidle_device *dev);
147extern int cpuidle_play_dead(void);
148
149extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
150#else
151static inline void disable_cpuidle(void) { }
152static inline int cpuidle_enabled(struct cpuidle_driver *drv,
153 struct cpuidle_device *dev)
154{return -ENODEV; }
155static inline int cpuidle_select(struct cpuidle_driver *drv,
156 struct cpuidle_device *dev)
157{return -ENODEV; }
158static inline int cpuidle_enter(struct cpuidle_driver *drv,
159 struct cpuidle_device *dev, int index)
160{return -ENODEV; }
161static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
162static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
163{return -ENODEV; }
164static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
165static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
166static inline void cpuidle_driver_unref(void) {}
167static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
168static inline int cpuidle_register_device(struct cpuidle_device *dev)
169{return -ENODEV; }
170static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
171static inline int cpuidle_register(struct cpuidle_driver *drv,
172 const struct cpumask *const coupled_cpus)
173{return -ENODEV; }
174static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
175static inline void cpuidle_pause_and_lock(void) { }
176static inline void cpuidle_resume_and_unlock(void) { }
177static inline void cpuidle_pause(void) { }
178static inline void cpuidle_resume(void) { }
179static inline int cpuidle_enable_device(struct cpuidle_device *dev)
180{return -ENODEV; }
181static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
182static inline int cpuidle_play_dead(void) {return -ENODEV; }
183static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
184 struct cpuidle_device *dev) {return NULL; }
185#endif
186
187#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
188void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
189#else
190static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
191{
192}
193#endif
194
195/******************************
196 * CPUIDLE GOVERNOR INTERFACE *
197 ******************************/
198
199struct cpuidle_governor {
200 char name[CPUIDLE_NAME_LEN];
201 struct list_head governor_list;
202 unsigned int rating;
203
204 int (*enable) (struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206 void (*disable) (struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208
209 int (*select) (struct cpuidle_driver *drv,
210 struct cpuidle_device *dev);
211 void (*reflect) (struct cpuidle_device *dev, int index);
212
213 struct module *owner;
214};
215
216#ifdef CONFIG_CPU_IDLE
217extern int cpuidle_register_governor(struct cpuidle_governor *gov);
218#else
219static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
220{return 0;}
221#endif
222
223#ifdef CONFIG_ARCH_HAS_CPU_RELAX
224#define CPUIDLE_DRIVER_STATE_START 1
225#else
226#define CPUIDLE_DRIVER_STATE_START 0
227#endif
228
229#endif /* _LINUX_CPUIDLE_H */