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_COUPLED (0x02) /* state applies to multiple cpus */
57 #define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
59 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
61 struct cpuidle_device_kobj;
62 struct cpuidle_state_kobj;
63 struct cpuidle_driver_kobj;
65 struct cpuidle_device {
66 unsigned int registered:1;
67 unsigned int enabled:1;
72 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
73 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
74 struct cpuidle_driver_kobj *kobj_driver;
75 struct cpuidle_device_kobj *kobj_dev;
76 struct list_head device_list;
78 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
80 cpumask_t coupled_cpus;
81 struct cpuidle_coupled *coupled;
85 DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
86 DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
92 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
94 return dev->last_residency;
98 /****************************
99 * CPUIDLE DRIVER INTERFACE *
100 ****************************/
102 struct cpuidle_driver {
104 struct module *owner;
107 /* used by the cpuidle framework to setup the broadcast timer */
108 unsigned int bctimer:1;
109 /* states array must be ordered in decreasing power consumption */
110 struct cpuidle_state states[CPUIDLE_STATE_MAX];
112 int safe_state_index;
114 /* the driver handles the cpus in cpumask */
115 struct cpumask *cpumask;
118 #ifdef CONFIG_CPU_IDLE
119 extern void disable_cpuidle(void);
121 extern int cpuidle_select(struct cpuidle_driver *drv,
122 struct cpuidle_device *dev);
123 extern int cpuidle_enter(struct cpuidle_driver *drv,
124 struct cpuidle_device *dev, int index);
125 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
127 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
128 extern struct cpuidle_driver *cpuidle_get_driver(void);
129 extern struct cpuidle_driver *cpuidle_driver_ref(void);
130 extern void cpuidle_driver_unref(void);
131 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
132 extern int cpuidle_register_device(struct cpuidle_device *dev);
133 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
134 extern int cpuidle_register(struct cpuidle_driver *drv,
135 const struct cpumask *const coupled_cpus);
136 extern void cpuidle_unregister(struct cpuidle_driver *drv);
137 extern void cpuidle_pause_and_lock(void);
138 extern void cpuidle_resume_and_unlock(void);
139 extern void cpuidle_pause(void);
140 extern void cpuidle_resume(void);
141 extern int cpuidle_enable_device(struct cpuidle_device *dev);
142 extern void cpuidle_disable_device(struct cpuidle_device *dev);
143 extern int cpuidle_play_dead(void);
144 extern void cpuidle_use_deepest_state(bool enable);
146 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
148 static inline void disable_cpuidle(void) { }
149 static inline int cpuidle_select(struct cpuidle_driver *drv,
150 struct cpuidle_device *dev)
152 static inline int cpuidle_enter(struct cpuidle_driver *drv,
153 struct cpuidle_device *dev, int index)
155 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
156 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
158 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
159 static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
160 static inline void cpuidle_driver_unref(void) {}
161 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
162 static inline int cpuidle_register_device(struct cpuidle_device *dev)
164 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
165 static inline int cpuidle_register(struct cpuidle_driver *drv,
166 const struct cpumask *const coupled_cpus)
168 static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
169 static inline void cpuidle_pause_and_lock(void) { }
170 static inline void cpuidle_resume_and_unlock(void) { }
171 static inline void cpuidle_pause(void) { }
172 static inline void cpuidle_resume(void) { }
173 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
175 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
176 static inline int cpuidle_play_dead(void) {return -ENODEV; }
177 static inline void cpuidle_use_deepest_state(bool enable) {}
178 static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
179 struct cpuidle_device *dev) {return NULL; }
182 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
183 void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
185 static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
190 /******************************
191 * CPUIDLE GOVERNOR INTERFACE *
192 ******************************/
194 struct cpuidle_governor {
195 char name[CPUIDLE_NAME_LEN];
196 struct list_head governor_list;
199 int (*enable) (struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201 void (*disable) (struct cpuidle_driver *drv,
202 struct cpuidle_device *dev);
204 int (*select) (struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206 void (*reflect) (struct cpuidle_device *dev, int index);
208 struct module *owner;
211 #ifdef CONFIG_CPU_IDLE
212 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
214 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
218 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
219 #define CPUIDLE_DRIVER_STATE_START 1
221 #define CPUIDLE_DRIVER_STATE_START 0
224 #endif /* _LINUX_CPUIDLE_H */