[net-next-2.6.git] / include / linux / cpuidle.h

/*
 * cpuidle.h - a generic framework for CPU idle power management
 *
 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *          Shaohua Li <shaohua.li@intel.com>
 *          Adam Belay <abelay@novell.com>
 *
 * This code is licenced under the GPL.
 */

#ifndef _LINUX_CPUIDLE_H
#define _LINUX_CPUIDLE_H

#include <linux/percpu.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/completion.h>

#define CPUIDLE_STATE_MAX	8
#define CPUIDLE_NAME_LEN	16
#define CPUIDLE_DESC_LEN	32

struct cpuidle_device;


/****************************
 * CPUIDLE DEVICE INTERFACE *
 ****************************/

struct cpuidle_state {
	char		name[CPUIDLE_NAME_LEN];
	char		desc[CPUIDLE_DESC_LEN];
	void		*driver_data;

	unsigned int	flags;
	unsigned int	exit_latency; /* in US */
	unsigned int	power_usage; /* in mW */
	unsigned int	target_residency; /* in US */

	unsigned long long	usage;
	unsigned long long	time; /* in US */

	int (*enter)	(struct cpuidle_device *dev,
			 struct cpuidle_state *state);
};

/* Idle State Flags */
#define CPUIDLE_FLAG_TIME_VALID	(0x01) /* is residency time measurable? */
#define CPUIDLE_FLAG_CHECK_BM	(0x02) /* BM activity will exit state */
#define CPUIDLE_FLAG_POLL	(0x10) /* no latency, no savings */
#define CPUIDLE_FLAG_SHALLOW	(0x20) /* low latency, minimal savings */
#define CPUIDLE_FLAG_BALANCED	(0x40) /* medium latency, moderate savings */
#define CPUIDLE_FLAG_DEEP	(0x80) /* high latency, large savings */

#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)

/**
 * cpuidle_get_statedata - retrieves private driver state data
 * @state: the state
 */
static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
{
	return state->driver_data;
}

/**
 * cpuidle_set_statedata - stores private driver state data
 * @state: the state
 * @data: the private data
 */
static inline void
cpuidle_set_statedata(struct cpuidle_state *state, void *data)
{
	state->driver_data = data;
}

struct cpuidle_state_kobj {
	struct cpuidle_state *state;
	struct completion kobj_unregister;
	struct kobject kobj;
};

struct cpuidle_device {
	unsigned int		registered:1;
	unsigned int		enabled:1;
	unsigned int		cpu;

	int			last_residency;
	int			state_count;
	struct cpuidle_state	states[CPUIDLE_STATE_MAX];
	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
	struct cpuidle_state	*last_state;

	struct list_head 	device_list;
	struct kobject		kobj;
	struct completion	kobj_unregister;
	void			*governor_data;
	struct cpuidle_state	*safe_state;
};

DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);

/**
 * cpuidle_get_last_residency - retrieves the last state's residency time
 * @dev: the target CPU
 *
 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 */
static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
{
	return dev->last_residency;
}


/****************************
 * CPUIDLE DRIVER INTERFACE *
 ****************************/

struct cpuidle_driver {
	char			name[CPUIDLE_NAME_LEN];
	struct module 		*owner;
};

#ifdef CONFIG_CPU_IDLE

extern int cpuidle_register_driver(struct cpuidle_driver *drv);
struct cpuidle_driver *cpuidle_get_driver(void);
extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
extern int cpuidle_register_device(struct cpuidle_device *dev);
extern void cpuidle_unregister_device(struct cpuidle_device *dev);

extern void cpuidle_pause_and_lock(void);
extern void cpuidle_resume_and_unlock(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);

#else

static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
{return -ENODEV; }
static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
static inline int cpuidle_register_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }

static inline void cpuidle_pause_and_lock(void) { }
static inline void cpuidle_resume_and_unlock(void) { }
static inline int cpuidle_enable_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }

#endif

/******************************
 * CPUIDLE GOVERNOR INTERFACE *
 ******************************/

struct cpuidle_governor {
	char			name[CPUIDLE_NAME_LEN];
	struct list_head 	governor_list;
	unsigned int		rating;

	int  (*enable)		(struct cpuidle_device *dev);
	void (*disable)		(struct cpuidle_device *dev);

	int  (*select)		(struct cpuidle_device *dev);
	void (*reflect)		(struct cpuidle_device *dev);

	struct module 		*owner;
};

#ifdef CONFIG_CPU_IDLE

extern int cpuidle_register_governor(struct cpuidle_governor *gov);
extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);

#else

static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
{return 0;}
static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }

#endif

#ifdef CONFIG_ARCH_HAS_CPU_RELAX
#define CPUIDLE_DRIVER_STATE_START	1
#else
#define CPUIDLE_DRIVER_STATE_START	0
#endif

#endif /* _LINUX_CPUIDLE_H */
Commit	Line	Data
4f86d3a8 LB	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/module.h>
	17	#include <linux/kobject.h>
	18	#include <linux/completion.h>
	19
	20	#define CPUIDLE_STATE_MAX 8
	21	#define CPUIDLE_NAME_LEN 16
4fcb2fcd	22	#define CPUIDLE_DESC_LEN 32
4f86d3a8 LB	23
	24	struct cpuidle_device;
	25
	26
	27	/****************************
	28	* CPUIDLE DEVICE INTERFACE *
	29	****************************/
	30
	31	struct cpuidle_state {
	32	char name[CPUIDLE_NAME_LEN];
4fcb2fcd	33	char desc[CPUIDLE_DESC_LEN];
4f86d3a8 LB	34	void *driver_data;
	35
	36	unsigned int flags;
	37	unsigned int exit_latency; /* in US */
	38	unsigned int power_usage; /* in mW */
	39	unsigned int target_residency; /* in US */
	40
8b78cf60 YY	41	unsigned long long usage;
8b78cf60 YY	42	unsigned long long time; /* in US */
4f86d3a8 LB	43
	44	int (enter) (struct cpuidle_device dev,
	45	struct cpuidle_state *state);
	46	};
	47
	48	/* Idle State Flags */
	49	#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
	50	#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
9a0b8415	51	#define CPUIDLE_FLAG_POLL (0x10) /* no latency, no savings */
	52	#define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */
	53	#define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */
	54	#define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */
4f86d3a8 LB	55
	56	#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
	57
	58	/**
	59	* cpuidle_get_statedata - retrieves private driver state data
	60	* @state: the state
	61	*/
	62	static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
	63	{
	64	return state->driver_data;
	65	}
	66
	67	/**
	68	* cpuidle_set_statedata - stores private driver state data
	69	* @state: the state
	70	* @data: the private data
	71	*/
	72	static inline void
	73	cpuidle_set_statedata(struct cpuidle_state state, void data)
	74	{
	75	state->driver_data = data;
	76	}
	77
	78	struct cpuidle_state_kobj {
	79	struct cpuidle_state *state;
	80	struct completion kobj_unregister;
	81	struct kobject kobj;
	82	};
	83
	84	struct cpuidle_device {
dcb84f33	85	unsigned int registered:1;
b5556a67	86	unsigned int enabled:1;
4f86d3a8 LB	87	unsigned int cpu;
	88
	89	int last_residency;
	90	int state_count;
	91	struct cpuidle_state states[CPUIDLE_STATE_MAX];
	92	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
	93	struct cpuidle_state *last_state;
	94
	95	struct list_head device_list;
	96	struct kobject kobj;
	97	struct completion kobj_unregister;
	98	void *governor_data;
ddc081a1	99	struct cpuidle_state *safe_state;
4f86d3a8 LB	100	};
	101
	102	DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
	103
	104	/**
	105	* cpuidle_get_last_residency - retrieves the last state's residency time
	106	* @dev: the target CPU
	107	*
	108	* NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
	109	*/
	110	static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
	111	{
	112	return dev->last_residency;
	113	}
	114
	115
	116	/****************************
	117	* CPUIDLE DRIVER INTERFACE *
	118	****************************/
	119
	120	struct cpuidle_driver {
	121	char name[CPUIDLE_NAME_LEN];
	122	struct module *owner;
	123	};
	124
	125	#ifdef CONFIG_CPU_IDLE
	126
	127	extern int cpuidle_register_driver(struct cpuidle_driver *drv);
752138df	128	struct cpuidle_driver *cpuidle_get_driver(void);
4f86d3a8 LB	129	extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
	130	extern int cpuidle_register_device(struct cpuidle_device *dev);
	131	extern void cpuidle_unregister_device(struct cpuidle_device *dev);
	132
	133	extern void cpuidle_pause_and_lock(void);
	134	extern void cpuidle_resume_and_unlock(void);
	135	extern int cpuidle_enable_device(struct cpuidle_device *dev);
	136	extern void cpuidle_disable_device(struct cpuidle_device *dev);
	137
	138	#else
	139
	140	static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
6b2c676b	141	{return -ENODEV; }
752138df	142	static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
4f86d3a8 LB	143	static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
4f86d3a8 LB	144	static inline int cpuidle_register_device(struct cpuidle_device *dev)
6b2c676b	145	{return -ENODEV; }
4f86d3a8 LB	146	static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
	147
	148	static inline void cpuidle_pause_and_lock(void) { }
	149	static inline void cpuidle_resume_and_unlock(void) { }
	150	static inline int cpuidle_enable_device(struct cpuidle_device *dev)
6b2c676b	151	{return -ENODEV; }
4f86d3a8 LB	152	static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
	153
	154	#endif
	155
	156	/******************************
	157	* CPUIDLE GOVERNOR INTERFACE *
	158	******************************/
	159
	160	struct cpuidle_governor {
	161	char name[CPUIDLE_NAME_LEN];
	162	struct list_head governor_list;
	163	unsigned int rating;
	164
	165	int (enable) (struct cpuidle_device dev);
	166	void (disable) (struct cpuidle_device dev);
	167
	168	int (select) (struct cpuidle_device dev);
	169	void (reflect) (struct cpuidle_device dev);
	170
	171	struct module *owner;
	172	};
	173
	174	#ifdef CONFIG_CPU_IDLE
	175
	176	extern int cpuidle_register_governor(struct cpuidle_governor *gov);
	177	extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
	178
	179	#else
	180
	181	static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
	182	{return 0;}
	183	static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
	184
	185	#endif
	186
9a0b8415	187	#ifdef CONFIG_ARCH_HAS_CPU_RELAX
	188	#define CPUIDLE_DRIVER_STATE_START 1
	189	#else
	190	#define CPUIDLE_DRIVER_STATE_START 0
	191	#endif
	192
4f86d3a8	193	#endif /* _LINUX_CPUIDLE_H */