Loading...
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);
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#include <linux/slab.h>
21
22static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
23static DEFINE_MUTEX(userspace_mutex);
24
25/**
26 * cpufreq_set - set the CPU frequency
27 * @policy: pointer to policy struct where freq is being set
28 * @freq: target frequency in kHz
29 *
30 * Sets the CPU frequency to freq.
31 */
32static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
33{
34 int ret = -EINVAL;
35 unsigned int *setspeed = policy->governor_data;
36
37 pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
38
39 mutex_lock(&userspace_mutex);
40 if (!per_cpu(cpu_is_managed, policy->cpu))
41 goto err;
42
43 *setspeed = freq;
44
45 ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
46 err:
47 mutex_unlock(&userspace_mutex);
48 return ret;
49}
50
51static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
52{
53 return sprintf(buf, "%u\n", policy->cur);
54}
55
56static int cpufreq_userspace_policy_init(struct cpufreq_policy *policy)
57{
58 unsigned int *setspeed;
59
60 setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
61 if (!setspeed)
62 return -ENOMEM;
63
64 policy->governor_data = setspeed;
65 return 0;
66}
67
68static void cpufreq_userspace_policy_exit(struct cpufreq_policy *policy)
69{
70 mutex_lock(&userspace_mutex);
71 kfree(policy->governor_data);
72 policy->governor_data = NULL;
73 mutex_unlock(&userspace_mutex);
74}
75
76static int cpufreq_userspace_policy_start(struct cpufreq_policy *policy)
77{
78 unsigned int *setspeed = policy->governor_data;
79
80 BUG_ON(!policy->cur);
81 pr_debug("started managing cpu %u\n", policy->cpu);
82
83 mutex_lock(&userspace_mutex);
84 per_cpu(cpu_is_managed, policy->cpu) = 1;
85 *setspeed = policy->cur;
86 mutex_unlock(&userspace_mutex);
87 return 0;
88}
89
90static void cpufreq_userspace_policy_stop(struct cpufreq_policy *policy)
91{
92 unsigned int *setspeed = policy->governor_data;
93
94 pr_debug("managing cpu %u stopped\n", policy->cpu);
95
96 mutex_lock(&userspace_mutex);
97 per_cpu(cpu_is_managed, policy->cpu) = 0;
98 *setspeed = 0;
99 mutex_unlock(&userspace_mutex);
100}
101
102static void cpufreq_userspace_policy_limits(struct cpufreq_policy *policy)
103{
104 unsigned int *setspeed = policy->governor_data;
105
106 mutex_lock(&userspace_mutex);
107
108 pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
109 policy->cpu, policy->min, policy->max, policy->cur, *setspeed);
110
111 if (policy->max < *setspeed)
112 __cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H);
113 else if (policy->min > *setspeed)
114 __cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L);
115 else
116 __cpufreq_driver_target(policy, *setspeed, CPUFREQ_RELATION_L);
117
118 mutex_unlock(&userspace_mutex);
119}
120
121static struct cpufreq_governor cpufreq_gov_userspace = {
122 .name = "userspace",
123 .init = cpufreq_userspace_policy_init,
124 .exit = cpufreq_userspace_policy_exit,
125 .start = cpufreq_userspace_policy_start,
126 .stop = cpufreq_userspace_policy_stop,
127 .limits = cpufreq_userspace_policy_limits,
128 .store_setspeed = cpufreq_set,
129 .show_setspeed = show_speed,
130 .owner = THIS_MODULE,
131};
132
133static int __init cpufreq_gov_userspace_init(void)
134{
135 return cpufreq_register_governor(&cpufreq_gov_userspace);
136}
137
138static void __exit cpufreq_gov_userspace_exit(void)
139{
140 cpufreq_unregister_governor(&cpufreq_gov_userspace);
141}
142
143MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
144 "Russell King <rmk@arm.linux.org.uk>");
145MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
146MODULE_LICENSE("GPL");
147
148#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
149struct cpufreq_governor *cpufreq_default_governor(void)
150{
151 return &cpufreq_gov_userspace;
152}
153
154fs_initcall(cpufreq_gov_userspace_init);
155#else
156module_init(cpufreq_gov_userspace_init);
157#endif
158module_exit(cpufreq_gov_userspace_exit);