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path: root/drivers/cpufreq/cpufreq_userspace.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq_userspace.c')
-rw-r--r--drivers/cpufreq/cpufreq_userspace.c144
1 files changed, 27 insertions, 117 deletions
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index cb2ac01a41a..4dbf1db16ac 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -11,57 +11,15 @@
*
*/
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/smp.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/cpufreq.h>
-#include <linux/cpu.h>
-#include <linux/types.h>
-#include <linux/fs.h>
-#include <linux/sysfs.h>
+#include <linux/init.h>
+#include <linux/module.h>
#include <linux/mutex.h>
-#include <asm/uaccess.h>
-
-
-/**
- * A few values needed by the userspace governor
- */
-static unsigned int cpu_max_freq[NR_CPUS];
-static unsigned int cpu_min_freq[NR_CPUS];
-static unsigned int cpu_cur_freq[NR_CPUS]; /* current CPU freq */
-static unsigned int cpu_set_freq[NR_CPUS]; /* CPU freq desired by userspace */
-static unsigned int cpu_is_managed[NR_CPUS];
-
-static DEFINE_MUTEX (userspace_mutex);
-static int cpus_using_userspace_governor;
-
-#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg)
-
-/* keep track of frequency transitions */
-static int
-userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
- void *data)
-{
- struct cpufreq_freqs *freq = data;
-
- if (!cpu_is_managed[freq->cpu])
- return 0;
-
- dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n",
- freq->cpu, freq->new);
- cpu_cur_freq[freq->cpu] = freq->new;
-
- return 0;
-}
-
-static struct notifier_block userspace_cpufreq_notifier_block = {
- .notifier_call = userspace_cpufreq_notifier
-};
-
+static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
+static DEFINE_MUTEX(userspace_mutex);
/**
* cpufreq_set - set the CPU frequency
@@ -74,37 +32,21 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
{
int ret = -EINVAL;
- dprintk("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
+ pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
mutex_lock(&userspace_mutex);
- if (!cpu_is_managed[policy->cpu])
+ if (!per_cpu(cpu_is_managed, policy->cpu))
goto err;
- cpu_set_freq[policy->cpu] = freq;
-
- if (freq < cpu_min_freq[policy->cpu])
- freq = cpu_min_freq[policy->cpu];
- if (freq > cpu_max_freq[policy->cpu])
- freq = cpu_max_freq[policy->cpu];
-
- /*
- * We're safe from concurrent calls to ->target() here
- * as we hold the userspace_mutex lock. If we were calling
- * cpufreq_driver_target, a deadlock situation might occur:
- * A: cpufreq_set (lock userspace_mutex) -> cpufreq_driver_target(lock policy->lock)
- * B: cpufreq_set_policy(lock policy->lock) -> __cpufreq_governor -> cpufreq_governor_userspace (lock userspace_mutex)
- */
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", cpu_cur_freq[policy->cpu]);
+ return sprintf(buf, "%u\n", policy->cur);
}
static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
@@ -115,71 +57,41 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
switch (event) {
case CPUFREQ_GOV_START:
- if (!cpu_online(cpu))
- return -EINVAL;
BUG_ON(!policy->cur);
- mutex_lock(&userspace_mutex);
-
- if (cpus_using_userspace_governor == 0) {
- cpufreq_register_notifier(
- &userspace_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- }
- cpus_using_userspace_governor++;
-
- cpu_is_managed[cpu] = 1;
- cpu_min_freq[cpu] = policy->min;
- cpu_max_freq[cpu] = policy->max;
- cpu_cur_freq[cpu] = policy->cur;
- cpu_set_freq[cpu] = policy->cur;
- dprintk("managing cpu %u started (%u - %u kHz, currently %u kHz)\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu]);
+ pr_debug("started managing cpu %u\n", cpu);
+ mutex_lock(&userspace_mutex);
+ per_cpu(cpu_is_managed, cpu) = 1;
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_STOP:
+ pr_debug("managing cpu %u stopped\n", cpu);
+
mutex_lock(&userspace_mutex);
- cpus_using_userspace_governor--;
- if (cpus_using_userspace_governor == 0) {
- cpufreq_unregister_notifier(
- &userspace_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- }
-
- cpu_is_managed[cpu] = 0;
- cpu_min_freq[cpu] = 0;
- cpu_max_freq[cpu] = 0;
- cpu_set_freq[cpu] = 0;
- dprintk("managing cpu %u stopped\n", cpu);
+ per_cpu(cpu_is_managed, cpu) = 0;
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&userspace_mutex);
- dprintk("limit event for cpu %u: %u - %u kHz,"
- "currently %u kHz, last set to %u kHz\n",
+ pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
cpu, policy->min, policy->max,
- cpu_cur_freq[cpu], cpu_set_freq[cpu]);
- if (policy->max < cpu_set_freq[cpu]) {
+ policy->cur);
+
+ if (policy->max < policy->cur)
__cpufreq_driver_target(policy, policy->max,
CPUFREQ_RELATION_H);
- }
- else if (policy->min > cpu_set_freq[cpu]) {
+ else if (policy->min > policy->cur)
__cpufreq_driver_target(policy, policy->min,
CPUFREQ_RELATION_L);
- }
- else {
- __cpufreq_driver_target(policy, cpu_set_freq[cpu],
- CPUFREQ_RELATION_L);
- }
- cpu_min_freq[cpu] = policy->min;
- cpu_max_freq[cpu] = policy->max;
- cpu_cur_freq[cpu] = policy->cur;
mutex_unlock(&userspace_mutex);
break;
}
return rc;
}
-
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
+static
+#endif
struct cpufreq_governor cpufreq_gov_userspace = {
.name = "userspace",
.governor = cpufreq_governor_userspace,
@@ -187,23 +99,21 @@ struct cpufreq_governor cpufreq_gov_userspace = {
.show_setspeed = show_speed,
.owner = THIS_MODULE,
};
-EXPORT_SYMBOL(cpufreq_gov_userspace);
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");
+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
fs_initcall(cpufreq_gov_userspace_init);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 07:21:10 +0000