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/*
* 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
struct cpuidle_device;
/****************************
* CPUIDLE DEVICE INTERFACE *
****************************/
struct cpuidle_state {
char name[CPUIDLE_NAME_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 int usage;
unsigned int 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_SHALLOW (0x10) /* low latency, minimal savings */
#define CPUIDLE_FLAG_BALANCED (0x20) /* medium latency, moderate savings */
#define CPUIDLE_FLAG_DEEP (0x40) /* 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;
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);
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 0;}
static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
static inline int cpuidle_register_device(struct cpuidle_device *dev)
{return 0;}
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 0;}
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
#endif /* _LINUX_CPUIDLE_H */
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