/* * 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); if (!stat->time_in_state) { ret = -ENOMEM; goto error_out; } 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); error_get_fail: kfree(stat); per_cpu(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; ret = cpufreq_stats_create_table(policy, table); if (ret) 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 = per_cpu(cpufreq_stats_table, freq->cpu); if (!stat) return 0; old_index = stat->last_index; new_index = freq_table_get_index(stat, freq->new); /* We can't do stat->time_in_state[-1]= .. */ if (old_index == -1 || new_index == -1) return 0; 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: case CPU_ONLINE_FROZEN: cpufreq_update_policy(cpu); break; case CPU_DOWN_PREPARE: cpufreq_stats_free_sysfs(cpu); break; case CPU_DEAD: case CPU_DEAD_FROZEN: cpufreq_stats_free_table(cpu); break; } return NOTIFY_OK; } /* priority=1 so this will get called before cpufreq_remove_dev */ static struct notifier_block cpufreq_stat_cpu_notifier __refdata = { .notifier_call = cpufreq_stat_cpu_callback, .priority = 1, }; 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); ret = cpufreq_register_notifier(¬ifier_policy_block, CPUFREQ_POLICY_NOTIFIER); if (ret) return ret; ret = cpufreq_register_notifier(¬ifier_trans_block, CPUFREQ_TRANSITION_NOTIFIER); if (ret) { cpufreq_unregister_notifier(¬ifier_policy_block, CPUFREQ_POLICY_NOTIFIER); return ret; } register_hotcpu_notifier(&cpufreq_stat_cpu_notifier); for_each_online_cpu(cpu) { cpufreq_update_policy(cpu); } return 0; } static void __exit cpufreq_stats_exit(void) { unsigned int cpu; cpufreq_unregister_notifier(¬ifier_policy_block, CPUFREQ_POLICY_NOTIFIER); cpufreq_unregister_notifier(¬ifier_trans_block, CPUFREQ_TRANSITION_NOTIFIER); unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier); for_each_online_cpu(cpu) { cpufreq_stats_free_table(cpu); cpufreq_stats_free_sysfs(cpu); } } 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);