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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);
87DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
88
89/**
90 * cpuidle_get_last_residency - retrieves the last state's residency time
91 * @dev: the target CPU
92 *
93 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
94 */
95static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
96{
97 return dev->last_residency;
98}
99
100
101/****************************
102 * CPUIDLE DRIVER INTERFACE *
103 ****************************/
104
105struct cpuidle_driver {
106 const char *name;
107 struct module *owner;
108 int refcnt;
109
110 /* used by the cpuidle framework to setup the broadcast timer */
111 unsigned int bctimer:1;
112 /* states array must be ordered in decreasing power consumption */
113 struct cpuidle_state states[CPUIDLE_STATE_MAX];
114 int state_count;
115 int safe_state_index;
116
117 /* the driver handles the cpus in cpumask */
118 struct cpumask *cpumask;
119};
120
121#ifdef CONFIG_CPU_IDLE
122extern void disable_cpuidle(void);
123
124extern int cpuidle_select(struct cpuidle_driver *drv,
125 struct cpuidle_device *dev);
126extern int cpuidle_enter(struct cpuidle_driver *drv,
127 struct cpuidle_device *dev, int index);
128extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
129
130extern int cpuidle_register_driver(struct cpuidle_driver *drv);
131extern struct cpuidle_driver *cpuidle_get_driver(void);
132extern struct cpuidle_driver *cpuidle_driver_ref(void);
133extern void cpuidle_driver_unref(void);
134extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
135extern int cpuidle_register_device(struct cpuidle_device *dev);
136extern void cpuidle_unregister_device(struct cpuidle_device *dev);
137extern int cpuidle_register(struct cpuidle_driver *drv,
138 const struct cpumask *const coupled_cpus);
139extern void cpuidle_unregister(struct cpuidle_driver *drv);
140extern void cpuidle_pause_and_lock(void);
141extern void cpuidle_resume_and_unlock(void);
142extern void cpuidle_pause(void);
143extern void cpuidle_resume(void);
144extern int cpuidle_enable_device(struct cpuidle_device *dev);
145extern void cpuidle_disable_device(struct cpuidle_device *dev);
146extern int cpuidle_play_dead(void);
147extern void cpuidle_use_deepest_state(bool enable);
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_select(struct cpuidle_driver *drv,
153 struct cpuidle_device *dev)
154{return -ENODEV; }
155static inline int cpuidle_enter(struct cpuidle_driver *drv,
156 struct cpuidle_device *dev, int index)
157{return -ENODEV; }
158static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
159static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
160{return -ENODEV; }
161static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
162static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
163static inline void cpuidle_driver_unref(void) {}
164static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
165static inline int cpuidle_register_device(struct cpuidle_device *dev)
166{return -ENODEV; }
167static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
168static inline int cpuidle_register(struct cpuidle_driver *drv,
169 const struct cpumask *const coupled_cpus)
170{return -ENODEV; }
171static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
172static inline void cpuidle_pause_and_lock(void) { }
173static inline void cpuidle_resume_and_unlock(void) { }
174static inline void cpuidle_pause(void) { }
175static inline void cpuidle_resume(void) { }
176static inline int cpuidle_enable_device(struct cpuidle_device *dev)
177{return -ENODEV; }
178static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
179static inline int cpuidle_play_dead(void) {return -ENODEV; }
180static inline void cpuidle_use_deepest_state(bool enable) {}
181static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
182 struct cpuidle_device *dev) {return NULL; }
183#endif
184
185#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
186void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
187#else
188static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
189{
190}
191#endif
192
193/******************************
194 * CPUIDLE GOVERNOR INTERFACE *
195 ******************************/
196
197struct cpuidle_governor {
198 char name[CPUIDLE_NAME_LEN];
199 struct list_head governor_list;
200 unsigned int rating;
201
202 int (*enable) (struct cpuidle_driver *drv,
203 struct cpuidle_device *dev);
204 void (*disable) (struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206
207 int (*select) (struct cpuidle_driver *drv,
208 struct cpuidle_device *dev);
209 void (*reflect) (struct cpuidle_device *dev, int index);
210
211 struct module *owner;
212};
213
214#ifdef CONFIG_CPU_IDLE
215extern int cpuidle_register_governor(struct cpuidle_governor *gov);
216#else
217static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
218{return 0;}
219#endif
220
221#ifdef CONFIG_ARCH_HAS_CPU_RELAX
222#define CPUIDLE_DRIVER_STATE_START 1
223#else
224#define CPUIDLE_DRIVER_STATE_START 0
225#endif
226
227#endif /* _LINUX_CPUIDLE_H */