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cpufreq: Simplify userspace governor

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Userspace governor has got more code than what it needs for its
functioning, so simplify it.

Portions of code removed are:
 - Extra header files which aren't required anymore (rearrange them
   as well).
 - cpu_{max|min|cur|set}_freq, as they are always the same as
   policy->{max|min|cur}.
 - userspace_cpufreq_notifier_block as we don't need to set
   cpu_cur_freq anymore.
 - cpus_using_userspace_governor as it was for the notifier code.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2013-06-05 11:47:38 +05:30 committed by Rafael J. Wysocki
parent 7fb6a53db5
commit d1922f0256
1 changed files with 13 additions and 97 deletions
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110
drivers/cpufreq/cpufreq_userspace.c
View file

@ -13,55 +13,13 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#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>
/**
* A few values needed by the userspace governor
*/
static DEFINE_PER_CPU(unsigned int, cpu_max_freq);
static DEFINE_PER_CPU(unsigned int, cpu_min_freq);
static DEFINE_PER_CPU(unsigned int, cpu_cur_freq); /* current CPU freq */
static DEFINE_PER_CPU(unsigned int, cpu_set_freq); /* CPU freq desired by
userspace */
static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
static DEFINE_MUTEX(userspace_mutex);
static int cpus_using_userspace_governor;
/* 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 (!per_cpu(cpu_is_managed, freq->cpu))
return 0;
if (val == CPUFREQ_POSTCHANGE) {
pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n",
freq->cpu, freq->new);
per_cpu(cpu_cur_freq, freq->cpu) = freq->new;
}
return 0;
}
static struct notifier_block userspace_cpufreq_notifier_block = {
.notifier_call = userspace_cpufreq_notifier
};
/**
* cpufreq_set - set the CPU frequency
@ -80,13 +38,6 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
if (!per_cpu(cpu_is_managed, policy->cpu))
goto err;
per_cpu(cpu_set_freq, policy->cpu) = freq;
if (freq < per_cpu(cpu_min_freq, policy->cpu))
freq = per_cpu(cpu_min_freq, policy->cpu);
if (freq > per_cpu(cpu_max_freq, policy->cpu))
freq = per_cpu(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
@ -107,7 +58,7 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
{
return sprintf(buf, "%u\n", per_cpu(cpu_cur_freq, policy->cpu));
return sprintf(buf, "%u\n", policy->cur);
}
static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
@ -119,66 +70,31 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
switch (event) {
case CPUFREQ_GOV_START:
BUG_ON(!policy->cur);
pr_debug("started managing cpu %u\n", cpu);
mutex_lock(&userspace_mutex);
if (cpus_using_userspace_governor == 0) {
cpufreq_register_notifier(
&userspace_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
cpus_using_userspace_governor++;
per_cpu(cpu_is_managed, cpu) = 1;
per_cpu(cpu_min_freq, cpu) = policy->min;
per_cpu(cpu_max_freq, cpu) = policy->max;
per_cpu(cpu_cur_freq, cpu) = policy->cur;
per_cpu(cpu_set_freq, cpu) = policy->cur;
pr_debug("managing cpu %u started "
"(%u - %u kHz, currently %u kHz)\n",
cpu,
per_cpu(cpu_min_freq, cpu),
per_cpu(cpu_max_freq, cpu),
per_cpu(cpu_cur_freq, cpu));
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_STOP:
mutex_lock(&userspace_mutex);
cpus_using_userspace_governor--;
if (cpus_using_userspace_governor == 0) {
cpufreq_unregister_notifier(
&userspace_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
per_cpu(cpu_is_managed, cpu) = 0;
per_cpu(cpu_min_freq, cpu) = 0;
per_cpu(cpu_max_freq, cpu) = 0;
per_cpu(cpu_set_freq, cpu) = 0;
pr_debug("managing cpu %u stopped\n", cpu);
mutex_lock(&userspace_mutex);
per_cpu(cpu_is_managed, cpu) = 0;
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&userspace_mutex);
pr_debug("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,
per_cpu(cpu_cur_freq, cpu),
per_cpu(cpu_set_freq, cpu));
if (policy->max < per_cpu(cpu_set_freq, cpu)) {
policy->cur);
if (policy->max < policy->cur)
__cpufreq_driver_target(policy, policy->max,
CPUFREQ_RELATION_H);
} else if (policy->min > per_cpu(cpu_set_freq, cpu)) {
else if (policy->min > policy->cur)
__cpufreq_driver_target(policy, policy->min,
CPUFREQ_RELATION_L);
} else {
__cpufreq_driver_target(policy,
per_cpu(cpu_set_freq, cpu),
CPUFREQ_RELATION_L);
}
per_cpu(cpu_min_freq, cpu) = policy->min;
per_cpu(cpu_max_freq, cpu) = policy->max;
per_cpu(cpu_cur_freq, cpu) = policy->cur;
mutex_unlock(&userspace_mutex);
break;
}