aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/cpufreq_userspace.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq/cpufreq_userspace.c')
-rw-r--r--drivers/cpufreq/cpufreq_userspace.c112
1 files changed, 12 insertions, 100 deletions
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index bbeb9c0720a6..03078090b5f7 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -13,55 +13,13 @@
13 13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/smp.h>
19#include <linux/init.h>
20#include <linux/spinlock.h>
21#include <linux/interrupt.h>
22#include <linux/cpufreq.h> 16#include <linux/cpufreq.h>
23#include <linux/cpu.h> 17#include <linux/init.h>
24#include <linux/types.h> 18#include <linux/module.h>
25#include <linux/fs.h>
26#include <linux/sysfs.h>
27#include <linux/mutex.h> 19#include <linux/mutex.h>
28 20
29/**
30 * A few values needed by the userspace governor
31 */
32static DEFINE_PER_CPU(unsigned int, cpu_max_freq);
33static DEFINE_PER_CPU(unsigned int, cpu_min_freq);
34static DEFINE_PER_CPU(unsigned int, cpu_cur_freq); /* current CPU freq */
35static DEFINE_PER_CPU(unsigned int, cpu_set_freq); /* CPU freq desired by
36 userspace */
37static DEFINE_PER_CPU(unsigned int, cpu_is_managed); 21static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
38
39static DEFINE_MUTEX(userspace_mutex); 22static DEFINE_MUTEX(userspace_mutex);
40static int cpus_using_userspace_governor;
41
42/* keep track of frequency transitions */
43static int
44userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
45 void *data)
46{
47 struct cpufreq_freqs *freq = data;
48
49 if (!per_cpu(cpu_is_managed, freq->cpu))
50 return 0;
51
52 if (val == CPUFREQ_POSTCHANGE) {
53 pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n",
54 freq->cpu, freq->new);
55 per_cpu(cpu_cur_freq, freq->cpu) = freq->new;
56 }
57
58 return 0;
59}
60
61static struct notifier_block userspace_cpufreq_notifier_block = {
62 .notifier_call = userspace_cpufreq_notifier
63};
64
65 23
66/** 24/**
67 * cpufreq_set - set the CPU frequency 25 * cpufreq_set - set the CPU frequency
@@ -80,13 +38,6 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
80 if (!per_cpu(cpu_is_managed, policy->cpu)) 38 if (!per_cpu(cpu_is_managed, policy->cpu))
81 goto err; 39 goto err;
82 40
83 per_cpu(cpu_set_freq, policy->cpu) = freq;
84
85 if (freq < per_cpu(cpu_min_freq, policy->cpu))
86 freq = per_cpu(cpu_min_freq, policy->cpu);
87 if (freq > per_cpu(cpu_max_freq, policy->cpu))
88 freq = per_cpu(cpu_max_freq, policy->cpu);
89
90 /* 41 /*
91 * We're safe from concurrent calls to ->target() here 42 * We're safe from concurrent calls to ->target() here
92 * as we hold the userspace_mutex lock. If we were calling 43 * as we hold the userspace_mutex lock. If we were calling
@@ -104,10 +55,9 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
104 return ret; 55 return ret;
105} 56}
106 57
107
108static ssize_t show_speed(struct cpufreq_policy *policy, char *buf) 58static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
109{ 59{
110 return sprintf(buf, "%u\n", per_cpu(cpu_cur_freq, policy->cpu)); 60 return sprintf(buf, "%u\n", policy->cur);
111} 61}
112 62
113static int cpufreq_governor_userspace(struct cpufreq_policy *policy, 63static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
@@ -119,73 +69,37 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
119 switch (event) { 69 switch (event) {
120 case CPUFREQ_GOV_START: 70 case CPUFREQ_GOV_START:
121 BUG_ON(!policy->cur); 71 BUG_ON(!policy->cur);
122 mutex_lock(&userspace_mutex); 72 pr_debug("started managing cpu %u\n", cpu);
123
124 if (cpus_using_userspace_governor == 0) {
125 cpufreq_register_notifier(
126 &userspace_cpufreq_notifier_block,
127 CPUFREQ_TRANSITION_NOTIFIER);
128 }
129 cpus_using_userspace_governor++;
130 73
74 mutex_lock(&userspace_mutex);
131 per_cpu(cpu_is_managed, cpu) = 1; 75 per_cpu(cpu_is_managed, cpu) = 1;
132 per_cpu(cpu_min_freq, cpu) = policy->min;
133 per_cpu(cpu_max_freq, cpu) = policy->max;
134 per_cpu(cpu_cur_freq, cpu) = policy->cur;
135 per_cpu(cpu_set_freq, cpu) = policy->cur;
136 pr_debug("managing cpu %u started "
137 "(%u - %u kHz, currently %u kHz)\n",
138 cpu,
139 per_cpu(cpu_min_freq, cpu),
140 per_cpu(cpu_max_freq, cpu),
141 per_cpu(cpu_cur_freq, cpu));
142
143 mutex_unlock(&userspace_mutex); 76 mutex_unlock(&userspace_mutex);
144 break; 77 break;
145 case CPUFREQ_GOV_STOP: 78 case CPUFREQ_GOV_STOP:
146 mutex_lock(&userspace_mutex); 79 pr_debug("managing cpu %u stopped\n", cpu);
147 cpus_using_userspace_governor--;
148 if (cpus_using_userspace_governor == 0) {
149 cpufreq_unregister_notifier(
150 &userspace_cpufreq_notifier_block,
151 CPUFREQ_TRANSITION_NOTIFIER);
152 }
153 80
81 mutex_lock(&userspace_mutex);
154 per_cpu(cpu_is_managed, cpu) = 0; 82 per_cpu(cpu_is_managed, cpu) = 0;
155 per_cpu(cpu_min_freq, cpu) = 0;
156 per_cpu(cpu_max_freq, cpu) = 0;
157 per_cpu(cpu_set_freq, cpu) = 0;
158 pr_debug("managing cpu %u stopped\n", cpu);
159 mutex_unlock(&userspace_mutex); 83 mutex_unlock(&userspace_mutex);
160 break; 84 break;
161 case CPUFREQ_GOV_LIMITS: 85 case CPUFREQ_GOV_LIMITS:
162 mutex_lock(&userspace_mutex); 86 mutex_lock(&userspace_mutex);
163 pr_debug("limit event for cpu %u: %u - %u kHz, " 87 pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
164 "currently %u kHz, last set to %u kHz\n",
165 cpu, policy->min, policy->max, 88 cpu, policy->min, policy->max,
166 per_cpu(cpu_cur_freq, cpu), 89 policy->cur);
167 per_cpu(cpu_set_freq, cpu)); 90
168 if (policy->max < per_cpu(cpu_set_freq, cpu)) { 91 if (policy->max < policy->cur)
169 __cpufreq_driver_target(policy, policy->max, 92 __cpufreq_driver_target(policy, policy->max,
170 CPUFREQ_RELATION_H); 93 CPUFREQ_RELATION_H);
171 } else if (policy->min > per_cpu(cpu_set_freq, cpu)) { 94 else if (policy->min > policy->cur)
172 __cpufreq_driver_target(policy, policy->min, 95 __cpufreq_driver_target(policy, policy->min,
173 CPUFREQ_RELATION_L); 96 CPUFREQ_RELATION_L);
174 } else {
175 __cpufreq_driver_target(policy,
176 per_cpu(cpu_set_freq, cpu),
177 CPUFREQ_RELATION_L);
178 }
179 per_cpu(cpu_min_freq, cpu) = policy->min;
180 per_cpu(cpu_max_freq, cpu) = policy->max;
181 per_cpu(cpu_cur_freq, cpu) = policy->cur;
182 mutex_unlock(&userspace_mutex); 97 mutex_unlock(&userspace_mutex);
183 break; 98 break;
184 } 99 }
185 return rc; 100 return rc;
186} 101}
187 102
188
189#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE 103#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
190static 104static
191#endif 105#endif
@@ -202,13 +116,11 @@ static int __init cpufreq_gov_userspace_init(void)
202 return cpufreq_register_governor(&cpufreq_gov_userspace); 116 return cpufreq_register_governor(&cpufreq_gov_userspace);
203} 117}
204 118
205
206static void __exit cpufreq_gov_userspace_exit(void) 119static void __exit cpufreq_gov_userspace_exit(void)
207{ 120{
208 cpufreq_unregister_governor(&cpufreq_gov_userspace); 121 cpufreq_unregister_governor(&cpufreq_gov_userspace);
209} 122}
210 123
211
212MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, " 124MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
213 "Russell King <rmk@arm.linux.org.uk>"); 125 "Russell King <rmk@arm.linux.org.uk>");
214MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'"); 126MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");