+
/*
* linux/drivers/cpufreq/cpufreq_userspace.c
*
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
+#include <linux/mutex.h>
#include <asm/uaccess.h>
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 struct cpufreq_policy current_policy[NR_CPUS];
-static DECLARE_MUTEX (userspace_sem);
+static DEFINE_MUTEX (userspace_mutex);
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg)
/* keep track of frequency transitions */
-static int
+static int
userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
};
-/**
+/**
* cpufreq_set - set the CPU frequency
* @freq: target frequency in kHz
* @cpu: CPU for which the frequency is to be set
*
* Sets the CPU frequency to freq.
*/
-static int cpufreq_set(unsigned int freq, unsigned int cpu)
+static int cpufreq_set(unsigned int freq, struct cpufreq_policy *policy)
{
int ret = -EINVAL;
- dprintk("cpufreq_set for cpu %u, freq %u kHz\n", cpu, freq);
+ dprintk("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
- down(&userspace_sem);
- if (!cpu_is_managed[cpu])
+ mutex_lock(&userspace_mutex);
+ if (!cpu_is_managed[policy->cpu])
goto err;
- cpu_set_freq[cpu] = freq;
+ cpu_set_freq[policy->cpu] = freq;
- if (freq < cpu_min_freq[cpu])
- freq = cpu_min_freq[cpu];
- if (freq > cpu_max_freq[cpu])
- freq = cpu_max_freq[cpu];
+ 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_sem lock. If we were calling
+ * as we hold the userspace_mutex lock. If we were calling
* cpufreq_driver_target, a deadlock situation might occur:
- * A: cpufreq_set (lock userspace_sem) -> cpufreq_driver_target(lock policy->lock)
- * B: cpufreq_set_policy(lock policy->lock) -> __cpufreq_governor -> cpufreq_governor_userspace (lock userspace_sem)
+ * 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(¤t_policy[cpu], freq,
- CPUFREQ_RELATION_L);
+ ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
err:
- up(&userspace_sem);
+ mutex_unlock(&userspace_mutex);
return ret;
}
return sprintf (buf, "%u\n", cpu_cur_freq[policy->cpu]);
}
-static ssize_t
-store_speed (struct cpufreq_policy *policy, const char *buf, size_t count)
+static ssize_t
+store_speed (struct cpufreq_policy *policy, const char *buf, size_t count)
{
unsigned int freq = 0;
unsigned int ret;
if (ret != 1)
return -EINVAL;
- cpufreq_set(freq, policy->cpu);
+ cpufreq_set(freq, policy);
return count;
}
-static struct freq_attr freq_attr_scaling_setspeed =
+static struct freq_attr freq_attr_scaling_setspeed =
{
.attr = { .name = "scaling_setspeed", .mode = 0644, .owner = THIS_MODULE },
.show = show_speed,
if (!cpu_online(cpu))
return -EINVAL;
BUG_ON(!policy->cur);
- down(&userspace_sem);
- cpu_is_managed[cpu] = 1;
+ mutex_lock(&userspace_mutex);
+ 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;
sysfs_create_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
- memcpy (¤t_policy[cpu], policy, sizeof(struct cpufreq_policy));
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]);
- up(&userspace_sem);
+ mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_STOP:
- down(&userspace_sem);
+ mutex_lock(&userspace_mutex);
cpu_is_managed[cpu] = 0;
cpu_min_freq[cpu] = 0;
cpu_max_freq[cpu] = 0;
cpu_set_freq[cpu] = 0;
sysfs_remove_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
dprintk("managing cpu %u stopped\n", cpu);
- up(&userspace_sem);
+ mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_LIMITS:
- down(&userspace_sem);
- cpu_min_freq[cpu] = policy->min;
- cpu_max_freq[cpu] = policy->max;
- dprintk("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu], cpu_set_freq[cpu]);
+ mutex_lock(&userspace_mutex);
+ dprintk("limit event for cpu %u: %u - %u kHz,"
+ "currently %u kHz, last set to %u kHz\n",
+ cpu, policy->min, policy->max,
+ cpu_cur_freq[cpu], cpu_set_freq[cpu]);
if (policy->max < cpu_set_freq[cpu]) {
- __cpufreq_driver_target(¤t_policy[cpu], policy->max,
- CPUFREQ_RELATION_H);
- } else if (policy->min > cpu_set_freq[cpu]) {
- __cpufreq_driver_target(¤t_policy[cpu], policy->min,
- CPUFREQ_RELATION_L);
- } else {
- __cpufreq_driver_target(¤t_policy[cpu], cpu_set_freq[cpu],
- CPUFREQ_RELATION_L);
+ __cpufreq_driver_target(policy, policy->max,
+ CPUFREQ_RELATION_H);
+ }
+ else if (policy->min > cpu_set_freq[cpu]) {
+ __cpufreq_driver_target(policy, policy->min,
+ CPUFREQ_RELATION_L);
}
- memcpy (¤t_policy[cpu], policy, sizeof(struct cpufreq_policy));
- up(&userspace_sem);
+ 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 0;
git://git.onelab.eu / linux-2.6.git / blobdiff