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/cpu.h>
13 #include <linux/cpufreq.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/cputime.h>
18 static spinlock_t cpufreq_stats_lock;
20 struct cpufreq_stats {
21 unsigned int total_trans;
22 unsigned long long last_time;
23 unsigned int max_state;
24 unsigned int state_num;
25 unsigned int last_index;
27 unsigned int *freq_table;
28 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
29 unsigned int *trans_table;
33 static int cpufreq_stats_update(struct cpufreq_stats *stats)
35 unsigned long long cur_time = get_jiffies_64();
37 spin_lock(&cpufreq_stats_lock);
38 stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
39 stats->last_time = cur_time;
40 spin_unlock(&cpufreq_stats_lock);
44 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
46 return sprintf(buf, "%d\n", policy->stats->total_trans);
49 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
51 struct cpufreq_stats *stats = policy->stats;
55 cpufreq_stats_update(stats);
56 for (i = 0; i < stats->state_num; i++) {
57 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
59 jiffies_64_to_clock_t(stats->time_in_state[i]));
64 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
65 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
67 struct cpufreq_stats *stats = policy->stats;
71 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
72 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
73 for (i = 0; i < stats->state_num; i++) {
76 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
77 stats->freq_table[i]);
82 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
84 for (i = 0; i < stats->state_num; i++) {
88 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
89 stats->freq_table[i]);
91 for (j = 0; j < stats->state_num; j++) {
94 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
95 stats->trans_table[i*stats->max_state+j]);
99 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
101 if (len >= PAGE_SIZE)
105 cpufreq_freq_attr_ro(trans_table);
108 cpufreq_freq_attr_ro(total_trans);
109 cpufreq_freq_attr_ro(time_in_state);
111 static struct attribute *default_attrs[] = {
114 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
119 static struct attribute_group stats_attr_group = {
120 .attrs = default_attrs,
124 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
127 for (index = 0; index < stats->max_state; index++)
128 if (stats->freq_table[index] == freq)
133 static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
135 struct cpufreq_stats *stats = policy->stats;
141 pr_debug("%s: Free stats table\n", __func__);
143 sysfs_remove_group(&policy->kobj, &stats_attr_group);
144 kfree(stats->time_in_state);
146 policy->stats = NULL;
149 static void cpufreq_stats_free_table(unsigned int cpu)
151 struct cpufreq_policy *policy;
153 policy = cpufreq_cpu_get(cpu);
157 __cpufreq_stats_free_table(policy);
159 cpufreq_cpu_put(policy);
162 static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
164 unsigned int i = 0, count = 0, ret = -ENOMEM;
165 struct cpufreq_stats *stats;
166 unsigned int alloc_size;
167 unsigned int cpu = policy->cpu;
168 struct cpufreq_frequency_table *pos, *table;
170 /* We need cpufreq table for creating stats table */
171 table = cpufreq_frequency_get_table(cpu);
172 if (unlikely(!table))
175 /* stats already initialized */
179 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
183 /* Find total allocation size */
184 cpufreq_for_each_valid_entry(pos, table)
187 alloc_size = count * sizeof(int) + count * sizeof(u64);
189 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
190 alloc_size += count * count * sizeof(int);
193 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
194 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
195 if (!stats->time_in_state)
198 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
200 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
201 stats->trans_table = stats->freq_table + count;
204 stats->max_state = count;
206 /* Find valid-unique entries */
207 cpufreq_for_each_valid_entry(pos, table)
208 if (freq_table_get_index(stats, pos->frequency) == -1)
209 stats->freq_table[i++] = pos->frequency;
211 stats->state_num = i;
212 stats->last_time = get_jiffies_64();
213 stats->last_index = freq_table_get_index(stats, policy->cur);
215 policy->stats = stats;
216 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
220 /* We failed, release resources */
221 policy->stats = NULL;
222 kfree(stats->time_in_state);
229 static void cpufreq_stats_create_table(unsigned int cpu)
231 struct cpufreq_policy *policy;
234 * "likely(!policy)" because normally cpufreq_stats will be registered
235 * before cpufreq driver
237 policy = cpufreq_cpu_get(cpu);
241 __cpufreq_stats_create_table(policy);
243 cpufreq_cpu_put(policy);
246 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
247 unsigned long val, void *data)
250 struct cpufreq_policy *policy = data;
252 if (val == CPUFREQ_CREATE_POLICY)
253 ret = __cpufreq_stats_create_table(policy);
254 else if (val == CPUFREQ_REMOVE_POLICY)
255 __cpufreq_stats_free_table(policy);
260 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
261 unsigned long val, void *data)
263 struct cpufreq_freqs *freq = data;
264 struct cpufreq_policy *policy = cpufreq_cpu_get(freq->cpu);
265 struct cpufreq_stats *stats;
266 int old_index, new_index;
269 pr_err("%s: No policy found\n", __func__);
273 if (val != CPUFREQ_POSTCHANGE)
276 if (!policy->stats) {
277 pr_debug("%s: No stats found\n", __func__);
281 stats = policy->stats;
283 old_index = stats->last_index;
284 new_index = freq_table_get_index(stats, freq->new);
286 /* We can't do stats->time_in_state[-1]= .. */
287 if (old_index == -1 || new_index == -1)
290 if (old_index == new_index)
293 cpufreq_stats_update(stats);
295 stats->last_index = new_index;
296 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
297 stats->trans_table[old_index * stats->max_state + new_index]++;
299 stats->total_trans++;
302 cpufreq_cpu_put(policy);
306 static struct notifier_block notifier_policy_block = {
307 .notifier_call = cpufreq_stat_notifier_policy
310 static struct notifier_block notifier_trans_block = {
311 .notifier_call = cpufreq_stat_notifier_trans
314 static int __init cpufreq_stats_init(void)
319 spin_lock_init(&cpufreq_stats_lock);
320 ret = cpufreq_register_notifier(¬ifier_policy_block,
321 CPUFREQ_POLICY_NOTIFIER);
325 for_each_online_cpu(cpu)
326 cpufreq_stats_create_table(cpu);
328 ret = cpufreq_register_notifier(¬ifier_trans_block,
329 CPUFREQ_TRANSITION_NOTIFIER);
331 cpufreq_unregister_notifier(¬ifier_policy_block,
332 CPUFREQ_POLICY_NOTIFIER);
333 for_each_online_cpu(cpu)
334 cpufreq_stats_free_table(cpu);
340 static void __exit cpufreq_stats_exit(void)
344 cpufreq_unregister_notifier(¬ifier_policy_block,
345 CPUFREQ_POLICY_NOTIFIER);
346 cpufreq_unregister_notifier(¬ifier_trans_block,
347 CPUFREQ_TRANSITION_NOTIFIER);
348 for_each_online_cpu(cpu)
349 cpufreq_stats_free_table(cpu);
352 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
353 MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
354 MODULE_LICENSE("GPL");
356 module_init(cpufreq_stats_init);
357 module_exit(cpufreq_stats_exit);