Home Home > GIT Browse > stable-xen
summaryrefslogtreecommitdiff
blob: bd897e3e134de055e5120cc0fe63bc48a70b21c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158

/*
 *  linux/drivers/cpufreq/cpufreq_userspace.c
 *
 *  Copyright (C)  2001 Russell King
 *            (C)  2002 - 2004 Dominik Brodowski <linux@brodo.de>
 *
 * 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.
 *
 */

#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);