2 * cpuidle.h - a generic framework for CPU idle power management
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
8 * This code is licenced under the GPL.
11 #ifndef _LINUX_CPUIDLE_H
12 #define _LINUX_CPUIDLE_H
14 #include <linux/percpu.h>
15 #include <linux/list.h>
16 #include <linux/hrtimer.h>
18 #define CPUIDLE_STATE_MAX 10
19 #define CPUIDLE_NAME_LEN 16
20 #define CPUIDLE_DESC_LEN 32
24 struct cpuidle_device;
25 struct cpuidle_driver;
28 /****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
32 struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
38 struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
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 */
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
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 */
60 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
62 struct cpuidle_device_kobj;
63 struct cpuidle_state_kobj;
64 struct cpuidle_driver_kobj;
66 struct cpuidle_device {
67 unsigned int registered:1;
68 unsigned int enabled:1;
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;
79 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
81 cpumask_t coupled_cpus;
82 struct cpuidle_coupled *coupled;
86 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
92 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
94 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
96 return dev->last_residency;
100 /****************************
101 * CPUIDLE DRIVER INTERFACE *
102 ****************************/
104 struct cpuidle_driver {
106 struct module *owner;
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];
114 int safe_state_index;
116 /* the driver handles the cpus in cpumask */
117 struct cpumask *cpumask;
120 #ifdef CONFIG_CPU_IDLE
121 extern void disable_cpuidle(void);
123 extern int cpuidle_select(struct cpuidle_driver *drv,
124 struct cpuidle_device *dev);
125 extern int cpuidle_enter(struct cpuidle_driver *drv,
126 struct cpuidle_device *dev, int index);
127 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
129 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
130 extern struct cpuidle_driver *cpuidle_get_driver(void);
131 extern struct cpuidle_driver *cpuidle_driver_ref(void);
132 extern void cpuidle_driver_unref(void);
133 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
134 extern int cpuidle_register_device(struct cpuidle_device *dev);
135 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
136 extern int cpuidle_register(struct cpuidle_driver *drv,
137 const struct cpumask *const coupled_cpus);
138 extern void cpuidle_unregister(struct cpuidle_driver *drv);
139 extern void cpuidle_pause_and_lock(void);
140 extern void cpuidle_resume_and_unlock(void);
141 extern void cpuidle_pause(void);
142 extern void cpuidle_resume(void);
143 extern int cpuidle_enable_device(struct cpuidle_device *dev);
144 extern void cpuidle_disable_device(struct cpuidle_device *dev);
145 extern int cpuidle_play_dead(void);
146 extern void cpuidle_use_deepest_state(bool enable);
148 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
150 static inline void disable_cpuidle(void) { }
151 static inline int cpuidle_select(struct cpuidle_driver *drv,
152 struct cpuidle_device *dev)
154 static inline int cpuidle_enter(struct cpuidle_driver *drv,
155 struct cpuidle_device *dev, int index)
157 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
158 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
160 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
161 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
162 static inline void cpuidle_driver_unref(void) {}
163 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
164 static inline int cpuidle_register_device(struct cpuidle_device *dev)
166 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
167 static inline int cpuidle_register(struct cpuidle_driver *drv,
168 const struct cpumask *const coupled_cpus)
170 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
171 static inline void cpuidle_pause_and_lock(void) { }
172 static inline void cpuidle_resume_and_unlock(void) { }
173 static inline void cpuidle_pause(void) { }
174 static inline void cpuidle_resume(void) { }
175 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
177 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
178 static inline int cpuidle_play_dead(void) {return -ENODEV; }
179 static inline void cpuidle_use_deepest_state(bool enable) {}
180 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
181 struct cpuidle_device *dev) {return NULL; }
184 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
185 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
187 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
192 /******************************
193 * CPUIDLE GOVERNOR INTERFACE *
194 ******************************/
196 struct cpuidle_governor {
197 char name[CPUIDLE_NAME_LEN];
198 struct list_head governor_list;
201 int (*enable) (struct cpuidle_driver *drv,
202 struct cpuidle_device *dev);
203 void (*disable) (struct cpuidle_driver *drv,
204 struct cpuidle_device *dev);
206 int (*select) (struct cpuidle_driver *drv,
207 struct cpuidle_device *dev);
208 void (*reflect) (struct cpuidle_device *dev, int index);
210 struct module *owner;
213 #ifdef CONFIG_CPU_IDLE
214 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
216 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
220 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
221 #define CPUIDLE_DRIVER_STATE_START 1
223 #define CPUIDLE_DRIVER_STATE_START 0
226 #endif /* _LINUX_CPUIDLE_H */