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);
182 if (policy && !policy_is_shared(policy)) {
183 pr_debug("%s: Free sysfs stat\n", __func__);
184 sysfs_remove_group(&policy->kobj, &stats_attr_group);
187 cpufreq_cpu_put(policy);
190 static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
191 struct cpufreq_frequency_table *table)
193 unsigned int i, j, count = 0, ret = 0;
194 struct cpufreq_stats *stat;
195 struct cpufreq_policy *data;
196 unsigned int alloc_size;
197 unsigned int cpu = policy->cpu;
198 if (per_cpu(cpufreq_stats_table, cpu))
200 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
204 data = cpufreq_cpu_get(cpu);
210 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
215 per_cpu(cpufreq_stats_table, cpu) = stat;
217 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
218 unsigned int freq = table[i].frequency;
219 if (freq == CPUFREQ_ENTRY_INVALID)
224 alloc_size = count * sizeof(int) + count * sizeof(u64);
226 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
227 alloc_size += count * count * sizeof(int);
229 stat->max_state = count;
230 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
231 if (!stat->time_in_state) {
235 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
237 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
238 stat->trans_table = stat->freq_table + count;
241 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
242 unsigned int freq = table[i].frequency;
243 if (freq == CPUFREQ_ENTRY_INVALID)
245 if (freq_table_get_index(stat, freq) == -1)
246 stat->freq_table[j++] = freq;
249 spin_lock(&cpufreq_stats_lock);
250 stat->last_time = get_jiffies_64();
251 stat->last_index = freq_table_get_index(stat, policy->cur);
252 spin_unlock(&cpufreq_stats_lock);
253 cpufreq_cpu_put(data);
256 cpufreq_cpu_put(data);
259 per_cpu(cpufreq_stats_table, cpu) = NULL;
263 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
265 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
268 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
269 policy->cpu, policy->last_cpu);
270 per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
272 per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
273 stat->cpu = policy->cpu;
276 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
277 unsigned long val, void *data)
280 struct cpufreq_policy *policy = data;
281 struct cpufreq_frequency_table *table;
282 unsigned int cpu = policy->cpu;
284 if (val == CPUFREQ_UPDATE_POLICY_CPU) {
285 cpufreq_stats_update_policy_cpu(policy);
289 if (val != CPUFREQ_NOTIFY)
291 table = cpufreq_frequency_get_table(cpu);
294 ret = cpufreq_stats_create_table(policy, table);
300 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
301 unsigned long val, void *data)
303 struct cpufreq_freqs *freq = data;
304 struct cpufreq_stats *stat;
305 int old_index, new_index;
307 if (val != CPUFREQ_POSTCHANGE)
310 stat = per_cpu(cpufreq_stats_table, freq->cpu);
314 old_index = stat->last_index;
315 new_index = freq_table_get_index(stat, freq->new);
317 /* We can't do stat->time_in_state[-1]= .. */
318 if (old_index == -1 || new_index == -1)
321 cpufreq_stats_update(freq->cpu);
323 if (old_index == new_index)
326 spin_lock(&cpufreq_stats_lock);
327 stat->last_index = new_index;
328 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
329 stat->trans_table[old_index * stat->max_state + new_index]++;
332 spin_unlock(&cpufreq_stats_lock);
336 static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
337 unsigned long action,
340 unsigned int cpu = (unsigned long)hcpu;
344 case CPU_ONLINE_FROZEN:
345 cpufreq_update_policy(cpu);
347 case CPU_DOWN_PREPARE:
348 case CPU_DOWN_PREPARE_FROZEN:
349 cpufreq_stats_free_sysfs(cpu);
352 case CPU_DEAD_FROZEN:
353 cpufreq_stats_free_table(cpu);
359 /* priority=1 so this will get called before cpufreq_remove_dev */
360 static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
361 .notifier_call = cpufreq_stat_cpu_callback,
365 static struct notifier_block notifier_policy_block = {
366 .notifier_call = cpufreq_stat_notifier_policy
369 static struct notifier_block notifier_trans_block = {
370 .notifier_call = cpufreq_stat_notifier_trans
373 static int __init cpufreq_stats_init(void)
378 spin_lock_init(&cpufreq_stats_lock);
379 ret = cpufreq_register_notifier(¬ifier_policy_block,
380 CPUFREQ_POLICY_NOTIFIER);
384 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
385 for_each_online_cpu(cpu)
386 cpufreq_update_policy(cpu);
388 ret = cpufreq_register_notifier(¬ifier_trans_block,
389 CPUFREQ_TRANSITION_NOTIFIER);
391 cpufreq_unregister_notifier(¬ifier_policy_block,
392 CPUFREQ_POLICY_NOTIFIER);
393 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
394 for_each_online_cpu(cpu)
395 cpufreq_stats_free_table(cpu);
401 static void __exit cpufreq_stats_exit(void)
405 cpufreq_unregister_notifier(¬ifier_policy_block,
406 CPUFREQ_POLICY_NOTIFIER);
407 cpufreq_unregister_notifier(¬ifier_trans_block,
408 CPUFREQ_TRANSITION_NOTIFIER);
409 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
410 for_each_online_cpu(cpu) {
411 cpufreq_stats_free_table(cpu);
412 cpufreq_stats_free_sysfs(cpu);
416 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
417 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
418 "through sysfs filesystem");
419 MODULE_LICENSE("GPL");
421 module_init(cpufreq_stats_init);
422 module_exit(cpufreq_stats_exit);