linux/drivers/cpufreq/cpufreq_userspace.c
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

155 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/drivers/cpufreq/cpufreq_userspace.c
*
* Copyright (C) 2001 Russell King
* (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
static DEFINE_MUTEX(userspace_mutex);
/**
* cpufreq_set - set the CPU frequency
* @policy: pointer to policy struct where freq is being set
* @freq: target frequency in kHz
*
* Sets the CPU frequency to freq.
*/
static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
{
int ret = -EINVAL;
unsigned int *setspeed = policy->governor_data;
pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
mutex_lock(&userspace_mutex);
if (!per_cpu(cpu_is_managed, policy->cpu))
goto err;
*setspeed = freq;
ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
err:
mutex_unlock(&userspace_mutex);
return ret;
}
static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
{
return sprintf(buf, "%u\n", policy->cur);
}
static int cpufreq_userspace_policy_init(struct cpufreq_policy *policy)
{
unsigned int *setspeed;
setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
if (!setspeed)
return -ENOMEM;
policy->governor_data = setspeed;
return 0;
}
static void cpufreq_userspace_policy_exit(struct cpufreq_policy *policy)
{
mutex_lock(&userspace_mutex);
kfree(policy->governor_data);
policy->governor_data = NULL;
mutex_unlock(&userspace_mutex);
}
static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy)
{
unsigned int *setspeed = policy->governor_data;
BUG_ON(!policy->cur);
pr_debug("started managing cpu %u\n", policy->cpu);
mutex_lock(&userspace_mutex);
per_cpu(cpu_is_managed, policy->cpu) = 1;
*setspeed = policy->cur;
mutex_unlock(&userspace_mutex);
return 0;
}
static void cpufreq_userspace_policy_stop(struct cpufreq_policy *policy)
{
unsigned int *setspeed = policy->governor_data;
pr_debug("managing cpu %u stopped\n", policy->cpu);
mutex_lock(&userspace_mutex);
per_cpu(cpu_is_managed, policy->cpu) = 0;
*setspeed = 0;
mutex_unlock(&userspace_mutex);
}
static void cpufreq_userspace_policy_limits(struct cpufreq_policy *policy)
{
unsigned int *setspeed = policy->governor_data;
mutex_lock(&userspace_mutex);
pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
policy->cpu, policy->min, policy->max, policy->cur, *setspeed);
if (policy->max < *setspeed)
__cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H);
else if (policy->min > *setspeed)
__cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L);
else
__cpufreq_driver_target(policy, *setspeed, CPUFREQ_RELATION_L);
mutex_unlock(&userspace_mutex);
}
static struct cpufreq_governor cpufreq_gov_userspace = {
.name = "userspace",
.init = cpufreq_userspace_policy_init,
.exit = cpufreq_userspace_policy_exit,
.start = cpufreq_userspace_policy_start,
.stop = cpufreq_userspace_policy_stop,
.limits = cpufreq_userspace_policy_limits,
.store_setspeed = cpufreq_set,
.show_setspeed = show_speed,
.owner = THIS_MODULE,
};
static int __init cpufreq_gov_userspace_init(void)
{
return cpufreq_register_governor(&cpufreq_gov_userspace);
}
static void __exit cpufreq_gov_userspace_exit(void)
{
cpufreq_unregister_governor(&cpufreq_gov_userspace);
}
MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
"Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
MODULE_LICENSE("GPL");
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
struct cpufreq_governor *cpufreq_default_governor(void)
{
return &cpufreq_gov_userspace;
}
fs_initcall(cpufreq_gov_userspace_init);
#else
module_init(cpufreq_gov_userspace_init);
#endif
module_exit(cpufreq_gov_userspace_exit);