forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
291 lines
7.1 KiB
291 lines
7.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* drivers/cpufreq/cpufreq_stats.c |
|
* |
|
* Copyright (C) 2003-2004 Venkatesh Pallipadi <[email protected]>. |
|
* (C) 2004 Zou Nan hai <[email protected]>. |
|
*/ |
|
|
|
#include <linux/cpu.h> |
|
#include <linux/cpufreq.h> |
|
#include <linux/module.h> |
|
#include <linux/sched/clock.h> |
|
#include <linux/slab.h> |
|
|
|
struct cpufreq_stats { |
|
unsigned int total_trans; |
|
unsigned long long last_time; |
|
unsigned int max_state; |
|
unsigned int state_num; |
|
unsigned int last_index; |
|
u64 *time_in_state; |
|
unsigned int *freq_table; |
|
unsigned int *trans_table; |
|
|
|
/* Deferred reset */ |
|
unsigned int reset_pending; |
|
unsigned long long reset_time; |
|
}; |
|
|
|
static void cpufreq_stats_update(struct cpufreq_stats *stats, |
|
unsigned long long time) |
|
{ |
|
unsigned long long cur_time = local_clock(); |
|
|
|
stats->time_in_state[stats->last_index] += cur_time - time; |
|
stats->last_time = cur_time; |
|
} |
|
|
|
static void cpufreq_stats_reset_table(struct cpufreq_stats *stats) |
|
{ |
|
unsigned int count = stats->max_state; |
|
|
|
memset(stats->time_in_state, 0, count * sizeof(u64)); |
|
memset(stats->trans_table, 0, count * count * sizeof(int)); |
|
stats->last_time = local_clock(); |
|
stats->total_trans = 0; |
|
|
|
/* Adjust for the time elapsed since reset was requested */ |
|
WRITE_ONCE(stats->reset_pending, 0); |
|
/* |
|
* Prevent the reset_time read from being reordered before the |
|
* reset_pending accesses in cpufreq_stats_record_transition(). |
|
*/ |
|
smp_rmb(); |
|
cpufreq_stats_update(stats, READ_ONCE(stats->reset_time)); |
|
} |
|
|
|
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
|
|
if (READ_ONCE(stats->reset_pending)) |
|
return sprintf(buf, "%d\n", 0); |
|
else |
|
return sprintf(buf, "%u\n", stats->total_trans); |
|
} |
|
cpufreq_freq_attr_ro(total_trans); |
|
|
|
static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
bool pending = READ_ONCE(stats->reset_pending); |
|
unsigned long long time; |
|
ssize_t len = 0; |
|
int i; |
|
|
|
for (i = 0; i < stats->state_num; i++) { |
|
if (pending) { |
|
if (i == stats->last_index) { |
|
/* |
|
* Prevent the reset_time read from occurring |
|
* before the reset_pending read above. |
|
*/ |
|
smp_rmb(); |
|
time = local_clock() - READ_ONCE(stats->reset_time); |
|
} else { |
|
time = 0; |
|
} |
|
} else { |
|
time = stats->time_in_state[i]; |
|
if (i == stats->last_index) |
|
time += local_clock() - stats->last_time; |
|
} |
|
|
|
len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], |
|
nsec_to_clock_t(time)); |
|
} |
|
return len; |
|
} |
|
cpufreq_freq_attr_ro(time_in_state); |
|
|
|
/* We don't care what is written to the attribute */ |
|
static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, |
|
size_t count) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
|
|
/* |
|
* Defer resetting of stats to cpufreq_stats_record_transition() to |
|
* avoid races. |
|
*/ |
|
WRITE_ONCE(stats->reset_time, local_clock()); |
|
/* |
|
* The memory barrier below is to prevent the readers of reset_time from |
|
* seeing a stale or partially updated value. |
|
*/ |
|
smp_wmb(); |
|
WRITE_ONCE(stats->reset_pending, 1); |
|
|
|
return count; |
|
} |
|
cpufreq_freq_attr_wo(reset); |
|
|
|
static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
bool pending = READ_ONCE(stats->reset_pending); |
|
ssize_t len = 0; |
|
int i, j, count; |
|
|
|
len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n"); |
|
len += scnprintf(buf + len, PAGE_SIZE - len, " : "); |
|
for (i = 0; i < stats->state_num; i++) { |
|
if (len >= PAGE_SIZE) |
|
break; |
|
len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ", |
|
stats->freq_table[i]); |
|
} |
|
if (len >= PAGE_SIZE) |
|
return PAGE_SIZE; |
|
|
|
len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); |
|
|
|
for (i = 0; i < stats->state_num; i++) { |
|
if (len >= PAGE_SIZE) |
|
break; |
|
|
|
len += scnprintf(buf + len, PAGE_SIZE - len, "%9u: ", |
|
stats->freq_table[i]); |
|
|
|
for (j = 0; j < stats->state_num; j++) { |
|
if (len >= PAGE_SIZE) |
|
break; |
|
|
|
if (pending) |
|
count = 0; |
|
else |
|
count = stats->trans_table[i * stats->max_state + j]; |
|
|
|
len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ", count); |
|
} |
|
if (len >= PAGE_SIZE) |
|
break; |
|
len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); |
|
} |
|
|
|
if (len >= PAGE_SIZE) { |
|
pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n"); |
|
return -EFBIG; |
|
} |
|
return len; |
|
} |
|
cpufreq_freq_attr_ro(trans_table); |
|
|
|
static struct attribute *default_attrs[] = { |
|
&total_trans.attr, |
|
&time_in_state.attr, |
|
&reset.attr, |
|
&trans_table.attr, |
|
NULL |
|
}; |
|
static const struct attribute_group stats_attr_group = { |
|
.attrs = default_attrs, |
|
.name = "stats" |
|
}; |
|
|
|
static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq) |
|
{ |
|
int index; |
|
for (index = 0; index < stats->max_state; index++) |
|
if (stats->freq_table[index] == freq) |
|
return index; |
|
return -1; |
|
} |
|
|
|
void cpufreq_stats_free_table(struct cpufreq_policy *policy) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
|
|
/* Already freed */ |
|
if (!stats) |
|
return; |
|
|
|
pr_debug("%s: Free stats table\n", __func__); |
|
|
|
sysfs_remove_group(&policy->kobj, &stats_attr_group); |
|
kfree(stats->time_in_state); |
|
kfree(stats); |
|
policy->stats = NULL; |
|
} |
|
|
|
void cpufreq_stats_create_table(struct cpufreq_policy *policy) |
|
{ |
|
unsigned int i = 0, count = 0, ret = -ENOMEM; |
|
struct cpufreq_stats *stats; |
|
unsigned int alloc_size; |
|
struct cpufreq_frequency_table *pos; |
|
|
|
count = cpufreq_table_count_valid_entries(policy); |
|
if (!count) |
|
return; |
|
|
|
/* stats already initialized */ |
|
if (policy->stats) |
|
return; |
|
|
|
stats = kzalloc(sizeof(*stats), GFP_KERNEL); |
|
if (!stats) |
|
return; |
|
|
|
alloc_size = count * sizeof(int) + count * sizeof(u64); |
|
|
|
alloc_size += count * count * sizeof(int); |
|
|
|
/* Allocate memory for time_in_state/freq_table/trans_table in one go */ |
|
stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL); |
|
if (!stats->time_in_state) |
|
goto free_stat; |
|
|
|
stats->freq_table = (unsigned int *)(stats->time_in_state + count); |
|
|
|
stats->trans_table = stats->freq_table + count; |
|
|
|
stats->max_state = count; |
|
|
|
/* Find valid-unique entries */ |
|
cpufreq_for_each_valid_entry(pos, policy->freq_table) |
|
if (freq_table_get_index(stats, pos->frequency) == -1) |
|
stats->freq_table[i++] = pos->frequency; |
|
|
|
stats->state_num = i; |
|
stats->last_time = local_clock(); |
|
stats->last_index = freq_table_get_index(stats, policy->cur); |
|
|
|
policy->stats = stats; |
|
ret = sysfs_create_group(&policy->kobj, &stats_attr_group); |
|
if (!ret) |
|
return; |
|
|
|
/* We failed, release resources */ |
|
policy->stats = NULL; |
|
kfree(stats->time_in_state); |
|
free_stat: |
|
kfree(stats); |
|
} |
|
|
|
void cpufreq_stats_record_transition(struct cpufreq_policy *policy, |
|
unsigned int new_freq) |
|
{ |
|
struct cpufreq_stats *stats = policy->stats; |
|
int old_index, new_index; |
|
|
|
if (unlikely(!stats)) |
|
return; |
|
|
|
if (unlikely(READ_ONCE(stats->reset_pending))) |
|
cpufreq_stats_reset_table(stats); |
|
|
|
old_index = stats->last_index; |
|
new_index = freq_table_get_index(stats, new_freq); |
|
|
|
/* We can't do stats->time_in_state[-1]= .. */ |
|
if (unlikely(old_index == -1 || new_index == -1 || old_index == new_index)) |
|
return; |
|
|
|
cpufreq_stats_update(stats, stats->last_time); |
|
|
|
stats->last_index = new_index; |
|
stats->trans_table[old_index * stats->max_state + new_index]++; |
|
stats->total_trans++; |
|
}
|
|
|