diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq_stats.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_stats.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c new file mode 100644 index 000000000..157212984 --- /dev/null +++ b/drivers/cpufreq/cpufreq_stats.c @@ -0,0 +1,248 @@ +/* + * 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(); + + spin_lock(&cpufreq_stats_lock); + stats->time_in_state[stats->last_index] += cur_time - stats->last_time; + stats->last_time = cur_time; + spin_unlock(&cpufreq_stats_lock); +} + +static void cpufreq_stats_clear_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 = get_jiffies_64(); + stats->total_trans = 0; +} + +static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) +{ + return sprintf(buf, "%d\n", policy->stats->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; + + cpufreq_stats_update(stats); + 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; +} + +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; +} + +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); + +cpufreq_freq_attr_ro(total_trans); +cpufreq_freq_attr_ro(time_in_state); +cpufreq_freq_attr_wo(reset); + +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; + + cpufreq_stats_update(stats); + + stats->last_index = new_index; + stats->trans_table[old_index * stats->max_state + new_index]++; + stats->total_trans++; +} |