blob: 3597f25d5efa8957a0ee1ed8389131a71675f91d [file] [log] [blame]
/*
* 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/config.h>
#include <linux/kernel.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.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), .owner = THIS_MODULE, \
.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 struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
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 = cpufreq_stats_table[cpu];
if (stat->time_in_state)
stat->time_in_state[stat->last_index] =
cputime64_add(stat->time_in_state[stat->last_index],
cputime_sub(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 = cpufreq_stats_table[policy->cpu];
if(!stat)
return 0;
return sprintf(buf, "%d\n",
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 = 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 = 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 len;
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]);
}
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
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;
}
static void
cpufreq_stats_free_table (unsigned int cpu)
{
struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (policy && policy->cpu == cpu)
sysfs_remove_group(&policy->kobj, &stats_attr_group);
if (stat) {
kfree(stat->time_in_state);
kfree(stat);
}
cpufreq_stats_table[cpu] = NULL;
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 (cpufreq_stats_table[cpu])
return -EBUSY;
if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
return -ENOMEM;
memset(stat, 0, sizeof (struct cpufreq_stats));
data = cpufreq_cpu_get(cpu);
if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
goto error_out;
stat->cpu = 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 = kmalloc(alloc_size, GFP_KERNEL);
if (!stat->time_in_state) {
ret = -ENOMEM;
goto error_out;
}
memset(stat->time_in_state, 0, alloc_size);
stat->freq_table = (unsigned int *)(stat->time_in_state + count);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table = stat->freq_table + count;
#endif
j = 0;
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if (freq_table_get_index(stat, freq) == -1)
stat->freq_table[j++] = freq;
}
stat->state_num = j;
spin_lock(&cpufreq_stats_lock);
stat->last_time = get_jiffies_64();
stat->last_index = freq_table_get_index(stat, policy->cur);
spin_unlock(&cpufreq_stats_lock);
cpufreq_cpu_put(data);
return 0;
error_out:
cpufreq_cpu_put(data);
kfree(stat);
cpufreq_stats_table[cpu] = NULL;
return ret;
}
static int
cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
void *data)
{
int ret;
struct cpufreq_policy *policy = data;
struct cpufreq_frequency_table *table;
unsigned int cpu = policy->cpu;
if (val != CPUFREQ_NOTIFY)
return 0;
table = cpufreq_frequency_get_table(cpu);
if (!table)
return 0;
if ((ret = cpufreq_stats_create_table(policy, table)))
return ret;
return 0;
}
static int
cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
struct cpufreq_stats *stat;
int old_index, new_index;
if (val != CPUFREQ_POSTCHANGE)
return 0;
stat = cpufreq_stats_table[freq->cpu];
if (!stat)
return 0;
old_index = freq_table_get_index(stat, freq->old);
new_index = freq_table_get_index(stat, freq->new);
cpufreq_stats_update(freq->cpu);
if (old_index == new_index)
return 0;
spin_lock(&cpufreq_stats_lock);
stat->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table[old_index * stat->max_state + new_index]++;
#endif
stat->total_trans++;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
switch (action) {
case CPU_ONLINE:
cpufreq_update_policy(cpu);
break;
case CPU_DEAD:
cpufreq_stats_free_table(cpu);
break;
}
return NOTIFY_OK;
}
static struct notifier_block cpufreq_stat_cpu_notifier =
{
.notifier_call = cpufreq_stat_cpu_callback,
};
static struct notifier_block notifier_policy_block = {
.notifier_call = cpufreq_stat_notifier_policy
};
static struct notifier_block notifier_trans_block = {
.notifier_call = cpufreq_stat_notifier_trans
};
static int
__init cpufreq_stats_init(void)
{
int ret;
unsigned int cpu;
spin_lock_init(&cpufreq_stats_lock);
if ((ret = cpufreq_register_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER)))
return ret;
if ((ret = cpufreq_register_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER))) {
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
return ret;
}
register_cpu_notifier(&cpufreq_stat_cpu_notifier);
lock_cpu_hotplug();
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
(void *)(long)cpu);
}
unlock_cpu_hotplug();
return 0;
}
static void
__exit cpufreq_stats_exit(void)
{
unsigned int cpu;
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
cpufreq_unregister_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
unregister_cpu_notifier(&cpufreq_stat_cpu_notifier);
lock_cpu_hotplug();
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
(void *)(long)cpu);
}
unlock_cpu_hotplug();
}
MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem");
MODULE_LICENSE ("GPL");
module_init(cpufreq_stats_init);
module_exit(cpufreq_stats_exit);