linux-stable/include/linux/devfreq.h
Christophe JAILLET 4a3a2c32a5 PM / devfreq: Reorder fields in 'struct devfreq_dev_status'
Group some variables based on their sizes to reduce holes.
On x86_64, this shrinks the size of 'struct devfreq_dev_status' from 72 to
64 bytes.

This structure is used both to allocate static variables or is embedded in
some other structures. In both cases, reducing its size is nice to have.

Moreover, the whole structure now fits in a single cache line on x86_64.

Finally, it makes the order of code match the order of the above kernel
doc.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2023-05-29 23:23:04 +09:00

455 lines
14 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
* for Non-CPU Devices.
*
* Copyright (C) 2011 Samsung Electronics
* MyungJoo Ham <myungjoo.ham@samsung.com>
*/
#ifndef __LINUX_DEVFREQ_H__
#define __LINUX_DEVFREQ_H__
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pm_opp.h>
#include <linux/pm_qos.h>
/* DEVFREQ governor name */
#define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand"
#define DEVFREQ_GOV_PERFORMANCE "performance"
#define DEVFREQ_GOV_POWERSAVE "powersave"
#define DEVFREQ_GOV_USERSPACE "userspace"
#define DEVFREQ_GOV_PASSIVE "passive"
/* DEVFREQ notifier interface */
#define DEVFREQ_TRANSITION_NOTIFIER (0)
/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
#define DEVFREQ_PRECHANGE (0)
#define DEVFREQ_POSTCHANGE (1)
/* DEVFREQ work timers */
enum devfreq_timer {
DEVFREQ_TIMER_DEFERRABLE = 0,
DEVFREQ_TIMER_DELAYED,
DEVFREQ_TIMER_NUM,
};
struct devfreq;
struct devfreq_governor;
struct devfreq_cpu_data;
struct thermal_cooling_device;
/**
* struct devfreq_dev_status - Data given from devfreq user device to
* governors. Represents the performance
* statistics.
* @total_time: The total time represented by this instance of
* devfreq_dev_status
* @busy_time: The time that the device was working among the
* total_time.
* @current_frequency: The operating frequency.
* @private_data: An entry not specified by the devfreq framework.
* A device and a specific governor may have their
* own protocol with private_data. However, because
* this is governor-specific, a governor using this
* will be only compatible with devices aware of it.
*/
struct devfreq_dev_status {
/* both since the last measure */
unsigned long total_time;
unsigned long busy_time;
unsigned long current_frequency;
void *private_data;
};
/*
* The resulting frequency should be at most this. (this bound is the
* least upper bound; thus, the resulting freq should be lower or same)
* If the flag is not set, the resulting frequency should be at most the
* bound (greatest lower bound)
*/
#define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1
/**
* struct devfreq_dev_profile - Devfreq's user device profile
* @initial_freq: The operating frequency when devfreq_add_device() is
* called.
* @polling_ms: The polling interval in ms. 0 disables polling.
* @timer: Timer type is either deferrable or delayed timer.
* @target: The device should set its operating frequency at
* freq or lowest-upper-than-freq value. If freq is
* higher than any operable frequency, set maximum.
* Before returning, target function should set
* freq at the current frequency.
* The "flags" parameter's possible values are
* explained above with "DEVFREQ_FLAG_*" macros.
* @get_dev_status: The device should provide the current performance
* status to devfreq. Governors are recommended not to
* use this directly. Instead, governors are recommended
* to use devfreq_update_stats() along with
* devfreq.last_status.
* @get_cur_freq: The device should provide the current frequency
* at which it is operating.
* @exit: An optional callback that is called when devfreq
* is removing the devfreq object due to error or
* from devfreq_remove_device() call. If the user
* has registered devfreq->nb at a notifier-head,
* this is the time to unregister it.
* @freq_table: Optional list of frequencies to support statistics
* and freq_table must be generated in ascending order.
* @max_state: The size of freq_table.
*
* @is_cooling_device: A self-explanatory boolean giving the device a
* cooling effect property.
*/
struct devfreq_dev_profile {
unsigned long initial_freq;
unsigned int polling_ms;
enum devfreq_timer timer;
int (*target)(struct device *dev, unsigned long *freq, u32 flags);
int (*get_dev_status)(struct device *dev,
struct devfreq_dev_status *stat);
int (*get_cur_freq)(struct device *dev, unsigned long *freq);
void (*exit)(struct device *dev);
unsigned long *freq_table;
unsigned int max_state;
bool is_cooling_device;
};
/**
* struct devfreq_stats - Statistics of devfreq device behavior
* @total_trans: Number of devfreq transitions.
* @trans_table: Statistics of devfreq transitions.
* @time_in_state: Statistics of devfreq states.
* @last_update: The last time stats were updated.
*/
struct devfreq_stats {
unsigned int total_trans;
unsigned int *trans_table;
u64 *time_in_state;
u64 last_update;
};
/**
* struct devfreq - Device devfreq structure
* @node: list node - contains the devices with devfreq that have been
* registered.
* @lock: a mutex to protect accessing devfreq.
* @dev: device registered by devfreq class. dev.parent is the device
* using devfreq.
* @profile: device-specific devfreq profile
* @governor: method how to choose frequency based on the usage.
* @opp_table: Reference to OPP table of dev.parent, if one exists.
* @nb: notifier block used to notify devfreq object that it should
* reevaluate operable frequencies. Devfreq users may use
* devfreq.nb to the corresponding register notifier call chain.
* @work: delayed work for load monitoring.
* @freq_table: current frequency table used by the devfreq driver.
* @max_state: count of entry present in the frequency table.
* @previous_freq: previously configured frequency value.
* @last_status: devfreq user device info, performance statistics
* @data: devfreq driver pass to governors, governor should not change it.
* @governor_data: private data for governors, devfreq core doesn't touch it.
* @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs)
* @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs)
* @scaling_min_freq: Limit minimum frequency requested by OPP interface
* @scaling_max_freq: Limit maximum frequency requested by OPP interface
* @stop_polling: devfreq polling status of a device.
* @suspend_freq: frequency of a device set during suspend phase.
* @resume_freq: frequency of a device set in resume phase.
* @suspend_count: suspend requests counter for a device.
* @stats: Statistics of devfreq device behavior
* @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
* @cdev: Cooling device pointer if the devfreq has cooling property
* @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY
* @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY
*
* This structure stores the devfreq information for a given device.
*
* Note that when a governor accesses entries in struct devfreq in its
* functions except for the context of callbacks defined in struct
* devfreq_governor, the governor should protect its access with the
* struct mutex lock in struct devfreq. A governor may use this mutex
* to protect its own private data in ``void *data`` as well.
*/
struct devfreq {
struct list_head node;
struct mutex lock;
struct device dev;
struct devfreq_dev_profile *profile;
const struct devfreq_governor *governor;
struct opp_table *opp_table;
struct notifier_block nb;
struct delayed_work work;
unsigned long *freq_table;
unsigned int max_state;
unsigned long previous_freq;
struct devfreq_dev_status last_status;
void *data;
void *governor_data;
struct dev_pm_qos_request user_min_freq_req;
struct dev_pm_qos_request user_max_freq_req;
unsigned long scaling_min_freq;
unsigned long scaling_max_freq;
bool stop_polling;
unsigned long suspend_freq;
unsigned long resume_freq;
atomic_t suspend_count;
/* information for device frequency transitions */
struct devfreq_stats stats;
struct srcu_notifier_head transition_notifier_list;
/* Pointer to the cooling device if used for thermal mitigation */
struct thermal_cooling_device *cdev;
struct notifier_block nb_min;
struct notifier_block nb_max;
};
struct devfreq_freqs {
unsigned long old;
unsigned long new;
};
#if defined(CONFIG_PM_DEVFREQ)
struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
const char *governor_name,
void *data);
int devfreq_remove_device(struct devfreq *devfreq);
struct devfreq *devm_devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
const char *governor_name,
void *data);
void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq);
/* Supposed to be called by PM callbacks */
int devfreq_suspend_device(struct devfreq *devfreq);
int devfreq_resume_device(struct devfreq *devfreq);
void devfreq_suspend(void);
void devfreq_resume(void);
/* update_devfreq() - Reevaluate the device and configure frequency */
int update_devfreq(struct devfreq *devfreq);
/* Helper functions for devfreq user device driver with OPP. */
struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
unsigned long *freq, u32 flags);
int devfreq_register_opp_notifier(struct device *dev,
struct devfreq *devfreq);
int devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq);
int devm_devfreq_register_opp_notifier(struct device *dev,
struct devfreq *devfreq);
void devm_devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq);
int devfreq_register_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list);
int devfreq_unregister_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list);
int devm_devfreq_register_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list);
void devm_devfreq_unregister_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list);
struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
const char *phandle_name, int index);
#endif /* CONFIG_PM_DEVFREQ */
/**
* struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
* and devfreq_add_device
* @upthreshold: If the load is over this value, the frequency jumps.
* Specify 0 to use the default. Valid value = 0 to 100.
* @downdifferential: If the load is under upthreshold - downdifferential,
* the governor may consider slowing the frequency down.
* Specify 0 to use the default. Valid value = 0 to 100.
* downdifferential < upthreshold must hold.
*
* If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
* the governor uses the default values.
*/
struct devfreq_simple_ondemand_data {
unsigned int upthreshold;
unsigned int downdifferential;
};
enum devfreq_parent_dev_type {
DEVFREQ_PARENT_DEV,
CPUFREQ_PARENT_DEV,
};
/**
* struct devfreq_passive_data - ``void *data`` fed to struct devfreq
* and devfreq_add_device
* @parent: the devfreq instance of parent device.
* @get_target_freq: Optional callback, Returns desired operating frequency
* for the device using passive governor. That is called
* when passive governor should decide the next frequency
* by using the new frequency of parent devfreq device
* using governors except for passive governor.
* If the devfreq device has the specific method to decide
* the next frequency, should use this callback.
* @parent_type: the parent type of the device.
* @this: the devfreq instance of own device.
* @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
* CPUFREQ_TRANSITION_NOTIFIER list.
* @cpu_data_list: the list of cpu frequency data for all cpufreq_policy.
*
* The devfreq_passive_data have to set the devfreq instance of parent
* device with governors except for the passive governor. But, don't need to
* initialize the 'this' and 'nb' field because the devfreq core will handle
* them.
*/
struct devfreq_passive_data {
/* Should set the devfreq instance of parent device */
struct devfreq *parent;
/* Optional callback to decide the next frequency of passvice device */
int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
/* Should set the type of parent device */
enum devfreq_parent_dev_type parent_type;
/* For passive governor's internal use. Don't need to set them */
struct devfreq *this;
struct notifier_block nb;
struct list_head cpu_data_list;
};
#if !defined(CONFIG_PM_DEVFREQ)
static inline struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
const char *governor_name,
void *data)
{
return ERR_PTR(-ENOSYS);
}
static inline int devfreq_remove_device(struct devfreq *devfreq)
{
return 0;
}
static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
const char *governor_name,
void *data)
{
return ERR_PTR(-ENOSYS);
}
static inline void devm_devfreq_remove_device(struct device *dev,
struct devfreq *devfreq)
{
}
static inline int devfreq_suspend_device(struct devfreq *devfreq)
{
return 0;
}
static inline int devfreq_resume_device(struct devfreq *devfreq)
{
return 0;
}
static inline void devfreq_suspend(void) {}
static inline void devfreq_resume(void) {}
static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
unsigned long *freq, u32 flags)
{
return ERR_PTR(-EINVAL);
}
static inline int devfreq_register_opp_notifier(struct device *dev,
struct devfreq *devfreq)
{
return -EINVAL;
}
static inline int devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq)
{
return -EINVAL;
}
static inline int devm_devfreq_register_opp_notifier(struct device *dev,
struct devfreq *devfreq)
{
return -EINVAL;
}
static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
struct devfreq *devfreq)
{
}
static inline int devfreq_register_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
return 0;
}
static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
return 0;
}
static inline int devm_devfreq_register_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
return 0;
}
static inline void devm_devfreq_unregister_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
}
static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
{
return ERR_PTR(-ENODEV);
}
static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
const char *phandle_name, int index)
{
return ERR_PTR(-ENODEV);
}
static inline int devfreq_update_stats(struct devfreq *df)
{
return -EINVAL;
}
#endif /* CONFIG_PM_DEVFREQ */
#endif /* __LINUX_DEVFREQ_H__ */