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/*
* drivers/cpufreq/cpufreq_stats.c
*
* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/kobject.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <asm/cputime.h>
static spinlock_t cpufreq_stats_lock;
#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
static struct freq_attr _attr_##_name = {\
.attr = {.name = __stringify(_name), .mode = _mode, }, \
.show = _show,\
};
struct cpufreq_stats {
unsigned int cpu;
unsigned int total_trans;
unsigned long long last_time;
unsigned int max_state;
unsigned int state_num;
unsigned int last_index;
cputime64_t *time_in_state;
unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
unsigned int *trans_table;
#endif
};
static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
struct cpufreq_stats_attribute {
struct attribute attr;
ssize_t(*show) (struct cpufreq_stats *, char *);
};
static int cpufreq_stats_update(unsigned int cpu)
{
struct cpufreq_stats *stat;
unsigned long long cur_time;
cur_time = get_jiffies_64();
spin_lock(&cpufreq_stats_lock);
stat = per_cpu(cpufreq_stats_table, cpu);
if (stat->time_in_state)
stat->time_in_state[stat->last_index] +=
cur_time - stat->last_time;
stat->last_time = cur_time;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
return sprintf(buf, "%d\n",
per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
}
static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i;
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
for (i = 0; i < stat->state_num; i++) {
len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
(unsigned long long)
cputime64_to_clock_t(stat->time_in_state[i]));
}
return len;
}
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i, j;
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
len += snprintf(buf + len, PAGE_SIZE - len, " : ");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->freq_table[i]);
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
stat->freq_table[i]);
for (j = 0; j < stat->state_num; j++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->trans_table[i*stat->max_state+j]);
}
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
return len;
}
CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
#endif
CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
static struct attribute *default_attrs[] = {
&_attr_total_trans.attr,
&_attr_time_in_state.attr,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
&_attr_trans_table.attr,
#endif
NULL
};
static struct attribute_group stats_attr_group = {
.attrs = default_attrs,
.name = "stats"
};
static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
{
int index;
for (index = 0; index < stat->max_state; index++)
if (stat->freq_table[index] == freq)
return index;
return -1;
}
/* should be called late in the CPU removal sequence so that the stats
* memory is still available in case someone tries to use it.
*/
static void cpufreq_stats_free_table(unsigned int cpu)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
if (stat) {
kfree(stat->time_in_state);
kfree(stat);
}
per_cpu(cpufreq_stats_table, cpu) = NULL;
}
/* must be called early in the CPU removal sequence (before
* cpufreq_remove_dev) so that policy is still valid.
*/
static void cpufreq_stats_free_sysfs(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (policy && policy->cpu == cpu)
sysfs_remove_group(&policy->kobj, &stats_attr_group);
if (policy)
cpufreq_cpu_put(policy);
}
static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
unsigned int i, j, count = 0, ret = 0;
struct cpufreq_stats *stat;
struct cpufreq_policy *data;
unsigned int alloc_size;
unsigned int cpu = policy->cpu;
if (per_cpu(cpufreq_stats_table, cpu))
return -EBUSY;
stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
if ((stat) == NULL)
return -ENOMEM;
data = cpufreq_cpu_get(cpu);
if (data == NULL) {
ret = -EINVAL;
goto error_get_fail;
}
ret = sysfs_create_group(&data->kobj, &stats_attr_group);
if (ret)
goto error_out;
stat->cpu = cpu;
per_cpu(cpufreq_stats_table, cpu) = stat;
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
count++;
}
alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
alloc_size += count * count * sizeof(int);
#endif
stat->max_state = count;
stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL
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