2 * drivers/cpufreq/cpufreq_stats.c
4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/cpu.h>
15 #include <linux/sysfs.h>
16 #include <linux/cpufreq.h>
17 #include <linux/module.h>
18 #include <linux/jiffies.h>
19 #include <linux/percpu.h>
20 #include <linux/kobject.h>
21 #include <linux/spinlock.h>
22 #include <linux/notifier.h>
23 #include <asm/cputime.h>
25 static spinlock_t cpufreq_stats_lock;
27 struct cpufreq_stats {
29 unsigned int total_trans;
30 unsigned long long last_time;
31 unsigned int max_state;
32 unsigned int state_num;
33 unsigned int last_index;
35 unsigned int *freq_table;
36 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
37 unsigned int *trans_table;
41 static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
43 struct cpufreq_stats_attribute {
44 struct attribute attr;
45 ssize_t(*show) (struct cpufreq_stats *, char *);
48 static int cpufreq_stats_update(unsigned int cpu)
50 struct cpufreq_stats *stat;
51 unsigned long long cur_time;
53 cur_time = get_jiffies_64();
54 spin_lock(&cpufreq_stats_lock);
55 stat = per_cpu(cpufreq_stats_table, cpu);
56 if (stat->time_in_state)
57 stat->time_in_state[stat->last_index] +=
58 cur_time - stat->last_time;
59 stat->last_time = cur_time;
60 spin_unlock(&cpufreq_stats_lock);
64 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
66 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
69 return sprintf(buf, "%d\n",
70 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
73 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
77 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
80 cpufreq_stats_update(stat->cpu);
81 for (i = 0; i < stat->state_num; i++) {
82 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
84 cputime64_to_clock_t(stat->time_in_state[i]));
89 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
90 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
95 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
98 cpufreq_stats_update(stat->cpu);
99 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
100 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
101 for (i = 0; i < stat->state_num; i++) {
102 if (len >= PAGE_SIZE)
104 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
105 stat->freq_table[i]);
107 if (len >= PAGE_SIZE)
110 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
112 for (i = 0; i < stat->state_num; i++) {
113 if (len >= PAGE_SIZE)
116 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
117 stat->freq_table[i]);
119 for (j = 0; j < stat->state_num; j++) {
120 if (len >= PAGE_SIZE)
122 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
123 stat->trans_table[i*stat->max_state+j]);
125 if (len >= PAGE_SIZE)
127 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
129 if (len >= PAGE_SIZE)
133 cpufreq_freq_attr_ro(trans_table);
136 cpufreq_freq_attr_ro(total_trans);
137 cpufreq_freq_attr_ro(time_in_state);
139 static struct attribute *default_attrs[] = {
142 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
147 static struct attribute_group stats_attr_group = {
148 .attrs = default_attrs,
152 static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
155 for (index = 0; index < stat->max_state; index++)
156 if (stat->freq_table[index] == freq)
161 /* should be called late in the CPU removal sequence so that the stats
162 * memory is still available in case someone tries to use it.
164 static void cpufreq_stats_free_table(unsigned int cpu)
166 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
169 pr_debug("%s: Free stat table\n", __func__);
170 kfree(stat->time_in_state);
172 per_cpu(cpufreq_stats_table, cpu) = NULL;
176 /* must be called early in the CPU removal sequence (before
177 * cpufreq_remove_dev) so that policy is still valid.
179 static void cpufreq_stats_free_sysfs(unsigned int cpu)
181 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
186 if (!cpufreq_frequency_get_table(cpu))
189 if (!policy_is_shared(policy)) {
190 pr_debug("%s: Free sysfs stat\n", __func__);
191 sysfs_remove_group(&policy->kobj, &stats_attr_group);
195 cpufreq_cpu_put(policy);
198 static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
199 struct cpufreq_frequency_table *table)
201 unsigned int i, j, count = 0, ret = 0;
202 struct cpufreq_stats *stat;
203 struct cpufreq_policy *data;
204 unsigned int alloc_size;
205 unsigned int cpu = policy->cpu;
206 if (per_cpu(cpufreq_stats_table, cpu))
208 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
212 data = cpufreq_cpu_get(cpu);
218 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
223 per_cpu(cpufreq_stats_table, cpu) = stat;
225 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
226 unsigned int freq = table[i].frequency;
227 if (freq == CPUFREQ_ENTRY_INVALID)
232 alloc_size = count * sizeof(int) + count * sizeof(u64);
234 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
235 alloc_size += count * count * sizeof(int);
237 stat->max_state = count;
238 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
239 if (!stat->time_in_state) {
243 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
245 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
246 stat->trans_table = stat->freq_table + count;
249 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
250 unsigned int freq = table[i].frequency;
251 if (freq == CPUFREQ_ENTRY_INVALID)
253 if (freq_table_get_index(stat, freq) == -1)
254 stat->freq_table[j++] = freq;
257 spin_lock(&cpufreq_stats_lock);
258 stat->last_time = get_jiffies_64();
259 stat->last_index = freq_table_get_index(stat, policy->cur);
260 spin_unlock(&cpufreq_stats_lock);
261 cpufreq_cpu_put(data);
264 cpufreq_cpu_put(data);
267 per_cpu(cpufreq_stats_table, cpu) = NULL;
271 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
273 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
276 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
277 policy->cpu, policy->last_cpu);
278 per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
280 per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
281 stat->cpu = policy->cpu;
284 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
285 unsigned long val, void *data)
288 struct cpufreq_policy *policy = data;
289 struct cpufreq_frequency_table *table;
290 unsigned int cpu = policy->cpu;
292 if (val == CPUFREQ_UPDATE_POLICY_CPU) {
293 cpufreq_stats_update_policy_cpu(policy);
297 if (val != CPUFREQ_NOTIFY)
299 table = cpufreq_frequency_get_table(cpu);
302 ret = cpufreq_stats_create_table(policy, table);
308 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
309 unsigned long val, void *data)
311 struct cpufreq_freqs *freq = data;
312 struct cpufreq_stats *stat;
313 int old_index, new_index;
315 if (val != CPUFREQ_POSTCHANGE)
318 stat = per_cpu(cpufreq_stats_table, freq->cpu);
322 old_index = stat->last_index;
323 new_index = freq_table_get_index(stat, freq->new);
325 /* We can't do stat->time_in_state[-1]= .. */
326 if (old_index == -1 || new_index == -1)
329 cpufreq_stats_update(freq->cpu);
331 if (old_index == new_index)
334 spin_lock(&cpufreq_stats_lock);
335 stat->last_index = new_index;
336 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
337 stat->trans_table[old_index * stat->max_state + new_index]++;
340 spin_unlock(&cpufreq_stats_lock);
344 static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
345 unsigned long action,
348 unsigned int cpu = (unsigned long)hcpu;
352 cpufreq_update_policy(cpu);
354 case CPU_DOWN_PREPARE:
355 cpufreq_stats_free_sysfs(cpu);
358 cpufreq_stats_free_table(cpu);
360 case CPU_UP_CANCELED_FROZEN:
361 cpufreq_stats_free_sysfs(cpu);
362 cpufreq_stats_free_table(cpu);
368 /* priority=1 so this will get called before cpufreq_remove_dev */
369 static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
370 .notifier_call = cpufreq_stat_cpu_callback,
374 static struct notifier_block notifier_policy_block = {
375 .notifier_call = cpufreq_stat_notifier_policy
378 static struct notifier_block notifier_trans_block = {
379 .notifier_call = cpufreq_stat_notifier_trans
382 static int __init cpufreq_stats_init(void)
387 spin_lock_init(&cpufreq_stats_lock);
388 ret = cpufreq_register_notifier(¬ifier_policy_block,
389 CPUFREQ_POLICY_NOTIFIER);
393 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
394 for_each_online_cpu(cpu)
395 cpufreq_update_policy(cpu);
397 ret = cpufreq_register_notifier(¬ifier_trans_block,
398 CPUFREQ_TRANSITION_NOTIFIER);
400 cpufreq_unregister_notifier(¬ifier_policy_block,
401 CPUFREQ_POLICY_NOTIFIER);
402 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
403 for_each_online_cpu(cpu)
404 cpufreq_stats_free_table(cpu);
410 static void __exit cpufreq_stats_exit(void)
414 cpufreq_unregister_notifier(¬ifier_policy_block,
415 CPUFREQ_POLICY_NOTIFIER);
416 cpufreq_unregister_notifier(¬ifier_trans_block,
417 CPUFREQ_TRANSITION_NOTIFIER);
418 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
419 for_each_online_cpu(cpu) {
420 cpufreq_stats_free_table(cpu);
421 cpufreq_stats_free_sysfs(cpu);
425 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
426 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
427 "through sysfs filesystem");
428 MODULE_LICENSE("GPL");
430 module_init(cpufreq_stats_init);
431 module_exit(cpufreq_stats_exit);