[linux-block.git] / drivers / cpufreq / cpufreq_userspace.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,
};

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;
}
#endif

cpufreq_governor_init(cpufreq_gov_userspace);
cpufreq_governor_exit(cpufreq_gov_userspace);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
c0672860	2
1da177e4 LT	3	/*
	4	* linux/drivers/cpufreq/cpufreq_userspace.c
	5	*
	6	* Copyright (C) 2001 Russell King
	7	* (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
1da177e4 LT	8	*/
1da177e4 LT	9
db701151 VK	10	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
db701151 VK	11
1da177e4	12	#include <linux/cpufreq.h>
d1922f02 VK	13	#include <linux/init.h>
d1922f02 VK	14	#include <linux/module.h>
3fc54d37	15	#include <linux/mutex.h>
e43e94c1	16	#include <linux/slab.h>
1da177e4	17
b38868aa	18	static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
1bceb8d1	19	static DEFINE_MUTEX(userspace_mutex);
1da177e4	20
32ee8c3e	21	/**
1da177e4	22	* cpufreq_set - set the CPU frequency
9e76988e	23	* @policy: pointer to policy struct where freq is being set
1da177e4	24	* @freq: target frequency in kHz
1da177e4 LT	25	*
	26	* Sets the CPU frequency to freq.
	27	*/
9e76988e	28	static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
1da177e4 LT	29	{
1da177e4 LT	30	int ret = -EINVAL;
e43e94c1	31	unsigned int *setspeed = policy->governor_data;
1da177e4	32
2d06d8c4	33	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
1da177e4	34
3fc54d37	35	mutex_lock(&userspace_mutex);
b38868aa	36	if (!per_cpu(cpu_is_managed, policy->cpu))
1da177e4 LT	37	goto err;
1da177e4 LT	38
e43e94c1 SG	39	*setspeed = freq;
e43e94c1 SG	40
c0672860	41	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
1da177e4	42	err:
3fc54d37	43	mutex_unlock(&userspace_mutex);
1da177e4 LT	44	return ret;
	45	}
	46
9e76988e	47	static ssize_t show_speed(struct cpufreq_policy policy, char buf)
1da177e4	48	{
d1922f02	49	return sprintf(buf, "%u\n", policy->cur);
1da177e4 LT	50	}
1da177e4 LT	51
e43e94c1 SG	52	static int cpufreq_userspace_policy_init(struct cpufreq_policy *policy)
	53	{
	54	unsigned int *setspeed;
	55
	56	setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
	57	if (!setspeed)
	58	return -ENOMEM;
	59
	60	policy->governor_data = setspeed;
	61	return 0;
	62	}
	63
e788892b RW	64	static void cpufreq_userspace_policy_exit(struct cpufreq_policy *policy)
	65	{
	66	mutex_lock(&userspace_mutex);
	67	kfree(policy->governor_data);
	68	policy->governor_data = NULL;
	69	mutex_unlock(&userspace_mutex);
	70	}
	71
	72	static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy)
1da177e4	73	{
e43e94c1	74	unsigned int *setspeed = policy->governor_data;
914f7c31	75
e788892b RW	76	BUG_ON(!policy->cur);
e788892b RW	77	pr_debug("started managing cpu %u\n", policy->cpu);
e43e94c1	78
e788892b RW	79	mutex_lock(&userspace_mutex);
	80	per_cpu(cpu_is_managed, policy->cpu) = 1;
	81	*setspeed = policy->cur;
	82	mutex_unlock(&userspace_mutex);
	83	return 0;
	84	}
	85
	86	static void cpufreq_userspace_policy_stop(struct cpufreq_policy *policy)
	87	{
	88	unsigned int *setspeed = policy->governor_data;
	89
	90	pr_debug("managing cpu %u stopped\n", policy->cpu);
	91
	92	mutex_lock(&userspace_mutex);
	93	per_cpu(cpu_is_managed, policy->cpu) = 0;
	94	*setspeed = 0;
	95	mutex_unlock(&userspace_mutex);
	96	}
	97
	98	static void cpufreq_userspace_policy_limits(struct cpufreq_policy *policy)
	99	{
	100	unsigned int *setspeed = policy->governor_data;
	101
	102	mutex_lock(&userspace_mutex);
	103
	104	pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
	105	policy->cpu, policy->min, policy->max, policy->cur, *setspeed);
	106
	107	if (policy->max < *setspeed)
	108	__cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H);
	109	else if (policy->min > *setspeed)
	110	__cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L);
	111	else
	112	__cpufreq_driver_target(policy, *setspeed, CPUFREQ_RELATION_L);
	113
	114	mutex_unlock(&userspace_mutex);
1da177e4 LT	115	}
1da177e4 LT	116
de1df26b	117	static struct cpufreq_governor cpufreq_gov_userspace = {
1da177e4	118	.name = "userspace",
e788892b RW	119	.init = cpufreq_userspace_policy_init,
	120	.exit = cpufreq_userspace_policy_exit,
	121	.start = cpufreq_userspace_policy_start,
	122	.stop = cpufreq_userspace_policy_stop,
	123	.limits = cpufreq_userspace_policy_limits,
9e76988e VP	124	.store_setspeed = cpufreq_set,
9e76988e VP	125	.show_setspeed = show_speed,
1da177e4 LT	126	.owner = THIS_MODULE,
1da177e4 LT	127	};
1da177e4	128
1bceb8d1 DJ	129	MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
	130	"Russell King <rmk@arm.linux.org.uk>");
	131	MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
	132	MODULE_LICENSE("GPL");
1da177e4	133
6915719b	134	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
de1df26b RW	135	struct cpufreq_governor *cpufreq_default_governor(void)
	136	{
	137	return &cpufreq_gov_userspace;
	138	}
6915719b	139	#endif
10dd8573 QP	140
	141	cpufreq_governor_init(cpufreq_gov_userspace);
	142	cpufreq_governor_exit(cpufreq_gov_userspace);