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 {
22 unsigned int total_trans;
23 unsigned long long last_time;
24 unsigned int max_state;
25 unsigned int state_num;
26 unsigned int last_index;
28 unsigned int *freq_table;
29 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
30 unsigned int *trans_table;
34 static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
36 struct cpufreq_stats_attribute {
37 struct attribute attr;
38 ssize_t(*show) (struct cpufreq_stats *, char *);
41 static int cpufreq_stats_update(unsigned int cpu)
43 struct cpufreq_stats *stat;
44 unsigned long long cur_time;
46 cur_time = get_jiffies_64();
47 spin_lock(&cpufreq_stats_lock);
48 stat = per_cpu(cpufreq_stats_table, cpu);
49 if (stat->time_in_state)
50 stat->time_in_state[stat->last_index] +=
51 cur_time - stat->last_time;
52 stat->last_time = cur_time;
53 spin_unlock(&cpufreq_stats_lock);
57 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
59 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
62 return sprintf(buf, "%d\n",
63 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
66 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
70 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
73 cpufreq_stats_update(stat->cpu);
74 for (i = 0; i < stat->state_num; i++) {
75 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
77 jiffies_64_to_clock_t(stat->time_in_state[i]));
82 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
83 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
88 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
91 cpufreq_stats_update(stat->cpu);
92 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
93 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
94 for (i = 0; i < stat->state_num; i++) {
97 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
100 if (len >= PAGE_SIZE)
103 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
105 for (i = 0; i < stat->state_num; i++) {
106 if (len >= PAGE_SIZE)
109 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
110 stat->freq_table[i]);
112 for (j = 0; j < stat->state_num; j++) {
113 if (len >= PAGE_SIZE)
115 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
116 stat->trans_table[i*stat->max_state+j]);
118 if (len >= PAGE_SIZE)
120 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
122 if (len >= PAGE_SIZE)
126 cpufreq_freq_attr_ro(trans_table);
129 cpufreq_freq_attr_ro(total_trans);
130 cpufreq_freq_attr_ro(time_in_state);
132 static struct attribute *default_attrs[] = {
135 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
140 static struct attribute_group stats_attr_group = {
141 .attrs = default_attrs,
145 static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
148 for (index = 0; index < stat->max_state; index++)
149 if (stat->freq_table[index] == freq)
154 static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
156 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
161 pr_debug("%s: Free stat table\n", __func__);
163 sysfs_remove_group(&policy->kobj, &stats_attr_group);
164 kfree(stat->time_in_state);
166 per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
169 static void cpufreq_stats_free_table(unsigned int cpu)
171 struct cpufreq_policy *policy;
173 policy = cpufreq_cpu_get(cpu);
177 if (cpufreq_frequency_get_table(policy->cpu))
178 __cpufreq_stats_free_table(policy);
180 cpufreq_cpu_put(policy);
183 static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
185 unsigned int i, j, count = 0, ret = 0;
186 struct cpufreq_stats *stat;
187 unsigned int alloc_size;
188 unsigned int cpu = policy->cpu;
189 struct cpufreq_frequency_table *table;
191 table = cpufreq_frequency_get_table(cpu);
192 if (unlikely(!table))
195 if (per_cpu(cpufreq_stats_table, cpu))
197 stat = kzalloc(sizeof(*stat), GFP_KERNEL);
201 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
206 per_cpu(cpufreq_stats_table, cpu) = stat;
208 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
209 unsigned int freq = table[i].frequency;
210 if (freq == CPUFREQ_ENTRY_INVALID)
215 alloc_size = count * sizeof(int) + count * sizeof(u64);
217 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
218 alloc_size += count * count * sizeof(int);
220 stat->max_state = count;
221 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
222 if (!stat->time_in_state) {
226 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
228 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
229 stat->trans_table = stat->freq_table + count;
232 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
233 unsigned int freq = table[i].frequency;
234 if (freq == CPUFREQ_ENTRY_INVALID)
236 if (freq_table_get_index(stat, freq) == -1)
237 stat->freq_table[j++] = freq;
240 spin_lock(&cpufreq_stats_lock);
241 stat->last_time = get_jiffies_64();
242 stat->last_index = freq_table_get_index(stat, policy->cur);
243 spin_unlock(&cpufreq_stats_lock);
246 sysfs_remove_group(&policy->kobj, &stats_attr_group);
249 per_cpu(cpufreq_stats_table, cpu) = NULL;
253 static void cpufreq_stats_create_table(unsigned int cpu)
255 struct cpufreq_policy *policy;
258 * "likely(!policy)" because normally cpufreq_stats will be registered
259 * before cpufreq driver
261 policy = cpufreq_cpu_get(cpu);
265 __cpufreq_stats_create_table(policy);
267 cpufreq_cpu_put(policy);
270 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
272 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
275 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
276 policy->cpu, policy->last_cpu);
277 per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
279 per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
280 stat->cpu = policy->cpu;
283 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
284 unsigned long val, void *data)
287 struct cpufreq_policy *policy = data;
289 if (val == CPUFREQ_UPDATE_POLICY_CPU) {
290 cpufreq_stats_update_policy_cpu(policy);
294 if (val == CPUFREQ_CREATE_POLICY)
295 ret = __cpufreq_stats_create_table(policy);
296 else if (val == CPUFREQ_REMOVE_POLICY)
297 __cpufreq_stats_free_table(policy);
302 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
303 unsigned long val, void *data)
305 struct cpufreq_freqs *freq = data;
306 struct cpufreq_stats *stat;
307 int old_index, new_index;
309 if (val != CPUFREQ_POSTCHANGE)
312 stat = per_cpu(cpufreq_stats_table, freq->cpu);
316 old_index = stat->last_index;
317 new_index = freq_table_get_index(stat, freq->new);
319 /* We can't do stat->time_in_state[-1]= .. */
320 if (old_index == -1 || new_index == -1)
323 cpufreq_stats_update(freq->cpu);
325 if (old_index == new_index)
328 spin_lock(&cpufreq_stats_lock);
329 stat->last_index = new_index;
330 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
331 stat->trans_table[old_index * stat->max_state + new_index]++;
334 spin_unlock(&cpufreq_stats_lock);
338 static struct notifier_block notifier_policy_block = {
339 .notifier_call = cpufreq_stat_notifier_policy
342 static struct notifier_block notifier_trans_block = {
343 .notifier_call = cpufreq_stat_notifier_trans
346 static int __init cpufreq_stats_init(void)
351 spin_lock_init(&cpufreq_stats_lock);
352 ret = cpufreq_register_notifier(¬ifier_policy_block,
353 CPUFREQ_POLICY_NOTIFIER);
357 for_each_online_cpu(cpu)
358 cpufreq_stats_create_table(cpu);
360 ret = cpufreq_register_notifier(¬ifier_trans_block,
361 CPUFREQ_TRANSITION_NOTIFIER);
363 cpufreq_unregister_notifier(¬ifier_policy_block,
364 CPUFREQ_POLICY_NOTIFIER);
365 for_each_online_cpu(cpu)
366 cpufreq_stats_free_table(cpu);
372 static void __exit cpufreq_stats_exit(void)
376 cpufreq_unregister_notifier(¬ifier_policy_block,
377 CPUFREQ_POLICY_NOTIFIER);
378 cpufreq_unregister_notifier(¬ifier_trans_block,
379 CPUFREQ_TRANSITION_NOTIFIER);
380 for_each_online_cpu(cpu)
381 cpufreq_stats_free_table(cpu);
384 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
385 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
386 "through sysfs filesystem");
387 MODULE_LICENSE("GPL");
389 module_init(cpufreq_stats_init);
390 module_exit(cpufreq_stats_exit);