Loading...
1
2/*
3 * linux/drivers/cpufreq/cpufreq_userspace.c
4 *
5 * Copyright (C) 2001 Russell King
6 * (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/cpufreq.h>
17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/mutex.h>
20
21static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
22static DEFINE_MUTEX(userspace_mutex);
23
24/**
25 * cpufreq_set - set the CPU frequency
26 * @policy: pointer to policy struct where freq is being set
27 * @freq: target frequency in kHz
28 *
29 * Sets the CPU frequency to freq.
30 */
31static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
32{
33 int ret = -EINVAL;
34
35 pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
36
37 mutex_lock(&userspace_mutex);
38 if (!per_cpu(cpu_is_managed, policy->cpu))
39 goto err;
40
41 ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
42 err:
43 mutex_unlock(&userspace_mutex);
44 return ret;
45}
46
47static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
48{
49 return sprintf(buf, "%u\n", policy->cur);
50}
51
52static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
53 unsigned int event)
54{
55 unsigned int cpu = policy->cpu;
56 int rc = 0;
57
58 switch (event) {
59 case CPUFREQ_GOV_START:
60 BUG_ON(!policy->cur);
61 pr_debug("started managing cpu %u\n", cpu);
62
63 mutex_lock(&userspace_mutex);
64 per_cpu(cpu_is_managed, cpu) = 1;
65 mutex_unlock(&userspace_mutex);
66 break;
67 case CPUFREQ_GOV_STOP:
68 pr_debug("managing cpu %u stopped\n", cpu);
69
70 mutex_lock(&userspace_mutex);
71 per_cpu(cpu_is_managed, cpu) = 0;
72 mutex_unlock(&userspace_mutex);
73 break;
74 case CPUFREQ_GOV_LIMITS:
75 mutex_lock(&userspace_mutex);
76 pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
77 cpu, policy->min, policy->max,
78 policy->cur);
79
80 if (policy->max < policy->cur)
81 __cpufreq_driver_target(policy, policy->max,
82 CPUFREQ_RELATION_H);
83 else if (policy->min > policy->cur)
84 __cpufreq_driver_target(policy, policy->min,
85 CPUFREQ_RELATION_L);
86 mutex_unlock(&userspace_mutex);
87 break;
88 }
89 return rc;
90}
91
92#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
93static
94#endif
95struct cpufreq_governor cpufreq_gov_userspace = {
96 .name = "userspace",
97 .governor = cpufreq_governor_userspace,
98 .store_setspeed = cpufreq_set,
99 .show_setspeed = show_speed,
100 .owner = THIS_MODULE,
101};
102
103static int __init cpufreq_gov_userspace_init(void)
104{
105 return cpufreq_register_governor(&cpufreq_gov_userspace);
106}
107
108static void __exit cpufreq_gov_userspace_exit(void)
109{
110 cpufreq_unregister_governor(&cpufreq_gov_userspace);
111}
112
113MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
114 "Russell King <rmk@arm.linux.org.uk>");
115MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
116MODULE_LICENSE("GPL");
117
118#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
119fs_initcall(cpufreq_gov_userspace_init);
120#else
121module_init(cpufreq_gov_userspace_init);
122#endif
123module_exit(cpufreq_gov_userspace_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2
3/*
4 * linux/drivers/cpufreq/cpufreq_userspace.c
5 *
6 * Copyright (C) 2001 Russell King
7 * (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/cpufreq.h>
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/slab.h>
17
18static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
19static DEFINE_MUTEX(userspace_mutex);
20
21/**
22 * cpufreq_set - set the CPU frequency
23 * @policy: pointer to policy struct where freq is being set
24 * @freq: target frequency in kHz
25 *
26 * Sets the CPU frequency to freq.
27 */
28static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
29{
30 int ret = -EINVAL;
31 unsigned int *setspeed = policy->governor_data;
32
33 pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
34
35 mutex_lock(&userspace_mutex);
36 if (!per_cpu(cpu_is_managed, policy->cpu))
37 goto err;
38
39 *setspeed = freq;
40
41 ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
42 err:
43 mutex_unlock(&userspace_mutex);
44 return ret;
45}
46
47static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
48{
49 return sprintf(buf, "%u\n", policy->cur);
50}
51
52static 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
64static 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
72static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy)
73{
74 unsigned int *setspeed = policy->governor_data;
75
76 BUG_ON(!policy->cur);
77 pr_debug("started managing cpu %u\n", policy->cpu);
78
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
86static 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
98static 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);
115}
116
117static struct cpufreq_governor cpufreq_gov_userspace = {
118 .name = "userspace",
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,
124 .store_setspeed = cpufreq_set,
125 .show_setspeed = show_speed,
126 .owner = THIS_MODULE,
127};
128
129MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
130 "Russell King <rmk@arm.linux.org.uk>");
131MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
132MODULE_LICENSE("GPL");
133
134#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
135struct cpufreq_governor *cpufreq_default_governor(void)
136{
137 return &cpufreq_gov_userspace;
138}
139#endif
140
141cpufreq_governor_init(cpufreq_gov_userspace);
142cpufreq_governor_exit(cpufreq_gov_userspace);