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	 * CPUs execute ->enter_freeze with the local tick or entire timekeeping
56	 * suspended, so it must not re-enable interrupts at any point (even
57	 * temporarily) or attempt to change states of clock event devices.
58	 */
59	void (*enter_freeze) (struct cpuidle_device *dev,
60			      struct cpuidle_driver *drv,
61			      int index);
62};
63
64/* Idle State Flags */
65#define CPUIDLE_FLAG_COUPLED	(0x02) /* state applies to multiple cpus */
66#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
67
68#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
69
70struct cpuidle_device_kobj;
71struct cpuidle_state_kobj;
72struct cpuidle_driver_kobj;
73
74struct cpuidle_device {
75	unsigned int		registered:1;
76	unsigned int		enabled:1;
77	unsigned int		cpu;
78
79	int			last_residency;
80	struct cpuidle_state_usage	states_usage[CPUIDLE_STATE_MAX];
81	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
82	struct cpuidle_driver_kobj *kobj_driver;
83	struct cpuidle_device_kobj *kobj_dev;
84	struct list_head 	device_list;
85
86#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
87	int			safe_state_index;
88	cpumask_t		coupled_cpus;
89	struct cpuidle_coupled	*coupled;
90#endif
91};
92
93DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
94DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
95
96/**
97 * cpuidle_get_last_residency - retrieves the last state's residency time
98 * @dev: the target CPU
99 */
100static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
101{
102	return dev->last_residency;
103}
104
105
106/****************************
107 * CPUIDLE DRIVER INTERFACE *
108 ****************************/
109
110struct cpuidle_driver {
111	const char		*name;
112	struct module 		*owner;
113	int                     refcnt;
114
115        /* used by the cpuidle framework to setup the broadcast timer */
116	unsigned int            bctimer:1;
117	/* states array must be ordered in decreasing power consumption */
118	struct cpuidle_state	states[CPUIDLE_STATE_MAX];
119	int			state_count;
120	int			safe_state_index;
121
122	/* the driver handles the cpus in cpumask */
123	struct cpumask		*cpumask;
124};
125
126#ifdef CONFIG_CPU_IDLE
127extern void disable_cpuidle(void);
128extern bool cpuidle_not_available(struct cpuidle_driver *drv,
129				  struct cpuidle_device *dev);
130
131extern int cpuidle_select(struct cpuidle_driver *drv,
132			  struct cpuidle_device *dev);
133extern int cpuidle_enter(struct cpuidle_driver *drv,
134			 struct cpuidle_device *dev, int index);
135extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
136
137extern int cpuidle_register_driver(struct cpuidle_driver *drv);
138extern struct cpuidle_driver *cpuidle_get_driver(void);
139extern struct cpuidle_driver *cpuidle_driver_ref(void);
140extern void cpuidle_driver_unref(void);
141extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
142extern int cpuidle_register_device(struct cpuidle_device *dev);
143extern void cpuidle_unregister_device(struct cpuidle_device *dev);
144extern int cpuidle_register(struct cpuidle_driver *drv,
145			    const struct cpumask *const coupled_cpus);
146extern void cpuidle_unregister(struct cpuidle_driver *drv);
147extern void cpuidle_pause_and_lock(void);
148extern void cpuidle_resume_and_unlock(void);
149extern void cpuidle_pause(void);
150extern void cpuidle_resume(void);
151extern int cpuidle_enable_device(struct cpuidle_device *dev);
152extern void cpuidle_disable_device(struct cpuidle_device *dev);
153extern int cpuidle_play_dead(void);
154extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
155				      struct cpuidle_device *dev);
156extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
157				struct cpuidle_device *dev);
158
159extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
160#else
161static inline void disable_cpuidle(void) { }
162static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
163					 struct cpuidle_device *dev)
164{return true; }
165static inline int cpuidle_select(struct cpuidle_driver *drv,
166				 struct cpuidle_device *dev)
167{return -ENODEV; }
168static inline int cpuidle_enter(struct cpuidle_driver *drv,
169				struct cpuidle_device *dev, int index)
170{return -ENODEV; }
171static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
172static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
173{return -ENODEV; }
174static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
175static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
176static inline void cpuidle_driver_unref(void) {}
177static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
178static inline int cpuidle_register_device(struct cpuidle_device *dev)
179{return -ENODEV; }
180static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
181static inline int cpuidle_register(struct cpuidle_driver *drv,
182				   const struct cpumask *const coupled_cpus)
183{return -ENODEV; }
184static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
185static inline void cpuidle_pause_and_lock(void) { }
186static inline void cpuidle_resume_and_unlock(void) { }
187static inline void cpuidle_pause(void) { }
188static inline void cpuidle_resume(void) { }
189static inline int cpuidle_enable_device(struct cpuidle_device *dev)
190{return -ENODEV; }
191static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
192static inline int cpuidle_play_dead(void) {return -ENODEV; }
193static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
194					     struct cpuidle_device *dev)
195{return -ENODEV; }
196static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
197				       struct cpuidle_device *dev)
198{return -ENODEV; }
199static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
200	struct cpuidle_device *dev) {return NULL; }
201#endif
202
203#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
204void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
205#else
206static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
207{
208}
209#endif
210
211/******************************
212 * CPUIDLE GOVERNOR INTERFACE *
213 ******************************/
214
215struct cpuidle_governor {
216	char			name[CPUIDLE_NAME_LEN];
217	struct list_head 	governor_list;
218	unsigned int		rating;
219
220	int  (*enable)		(struct cpuidle_driver *drv,
221					struct cpuidle_device *dev);
222	void (*disable)		(struct cpuidle_driver *drv,
223					struct cpuidle_device *dev);
224
225	int  (*select)		(struct cpuidle_driver *drv,
226					struct cpuidle_device *dev);
227	void (*reflect)		(struct cpuidle_device *dev, int index);
228
229	struct module 		*owner;
230};
231
232#ifdef CONFIG_CPU_IDLE
233extern int cpuidle_register_governor(struct cpuidle_governor *gov);
234#else
235static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
236{return 0;}
237#endif
238
239#ifdef CONFIG_ARCH_HAS_CPU_RELAX
240#define CPUIDLE_DRIVER_STATE_START	1
241#else
242#define CPUIDLE_DRIVER_STATE_START	0
243#endif
244
245#endif /* _LINUX_CPUIDLE_H */
246