| /* |
| * 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/cpu.h> |
| #include <linux/cpufreq.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| |
| static DEFINE_SPINLOCK(cpufreq_stats_lock); |
| |
| 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; |
| }; |
| |
| static void cpufreq_stats_update(struct cpufreq_stats *stats) |
| { |
| unsigned long long cur_time = get_jiffies_64(); |
| |
| stats->time_in_state[stats->last_index] += cur_time - stats->last_time; |
| stats->last_time = cur_time; |
| } |
| |
| static void cpufreq_stats_clear_table(struct cpufreq_stats *stats) |
| { |
| unsigned int count = stats->max_state; |
| |
| spin_lock(&cpufreq_stats_lock); |
| memset(stats->time_in_state, 0, count * sizeof(u64)); |
| memset(stats->trans_table, 0, count * count * sizeof(int)); |
| stats->last_time = get_jiffies_64(); |
| stats->total_trans = 0; |
| spin_unlock(&cpufreq_stats_lock); |
| } |
| |
| static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) |
| { |
| return sprintf(buf, "%d\n", policy->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; |
| ssize_t len = 0; |
| int i; |
| |
| if (policy->fast_switch_enabled) |
| return 0; |
| |
| spin_lock(&cpufreq_stats_lock); |
| cpufreq_stats_update(stats); |
| spin_unlock(&cpufreq_stats_lock); |
| |
| for (i = 0; i < stats->state_num; i++) { |
| len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], |
| (unsigned long long) |
| jiffies_64_to_clock_t(stats->time_in_state[i])); |
| } |
| return len; |
| } |
| cpufreq_freq_attr_ro(time_in_state); |
| |
| static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, |
| size_t count) |
| { |
| /* We don't care what is written to the attribute. */ |
| cpufreq_stats_clear_table(policy->stats); |
| 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; |
| ssize_t len = 0; |
| int i, j; |
| |
| if (policy->fast_switch_enabled) |
| return 0; |
| |
| len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); |
| len += snprintf(buf + len, PAGE_SIZE - len, " : "); |
| for (i = 0; i < stats->state_num; i++) { |
| if (len >= PAGE_SIZE) |
| break; |
| len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", |
| stats->freq_table[i]); |
| } |
| if (len >= PAGE_SIZE) |
| return PAGE_SIZE; |
| |
| len += snprintf(buf + len, PAGE_SIZE - len, "\n"); |
| |
| for (i = 0; i < stats->state_num; i++) { |
| if (len >= PAGE_SIZE) |
| break; |
| |
| len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", |
| stats->freq_table[i]); |
| |
| for (j = 0; j < stats->state_num; j++) { |
| if (len >= PAGE_SIZE) |
| break; |
| len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", |
| stats->trans_table[i*stats->max_state+j]); |
| } |
| if (len >= PAGE_SIZE) |
| break; |
| len += snprintf(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 = get_jiffies_64(); |
| 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 (!stats) { |
| pr_debug("%s: No stats found\n", __func__); |
| return; |
| } |
| |
| old_index = stats->last_index; |
| new_index = freq_table_get_index(stats, new_freq); |
| |
| /* We can't do stats->time_in_state[-1]= .. */ |
| if (old_index == -1 || new_index == -1 || old_index == new_index) |
| return; |
| |
| spin_lock(&cpufreq_stats_lock); |
| cpufreq_stats_update(stats); |
| |
| stats->last_index = new_index; |
| stats->trans_table[old_index * stats->max_state + new_index]++; |
| stats->total_trans++; |
| spin_unlock(&cpufreq_stats_lock); |
| } |