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 <asm/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 cputime64_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 /* should be called late in the CPU removal sequence so that the stats
155 * memory is still available in case someone tries to use it.
157 static void cpufreq_stats_free_table(unsigned int cpu)
159 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
162 pr_debug("%s: Free stat table\n", __func__);
163 kfree(stat->time_in_state);
165 per_cpu(cpufreq_stats_table, cpu) = NULL;
169 /* must be called early in the CPU removal sequence (before
170 * cpufreq_remove_dev) so that policy is still valid.
172 static void cpufreq_stats_free_sysfs(unsigned int cpu)
174 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
179 if (!cpufreq_frequency_get_table(cpu))
182 if (!policy_is_shared(policy)) {
183 pr_debug("%s: Free sysfs stat\n", __func__);
184 sysfs_remove_group(&policy->kobj, &stats_attr_group);
188 cpufreq_cpu_put(policy);
191 static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
192 struct cpufreq_frequency_table *table)
194 unsigned int i, j, count = 0, ret = 0;
195 struct cpufreq_stats *stat;
196 struct cpufreq_policy *current_policy;
197 unsigned int alloc_size;
198 unsigned int cpu = policy->cpu;
199 if (per_cpu(cpufreq_stats_table, cpu))
201 stat = kzalloc(sizeof(*stat), GFP_KERNEL);
205 current_policy = cpufreq_cpu_get(cpu);
206 if (current_policy == NULL) {
211 ret = sysfs_create_group(¤t_policy->kobj, &stats_attr_group);
216 per_cpu(cpufreq_stats_table, cpu) = stat;
218 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
219 unsigned int freq = table[i].frequency;
220 if (freq == CPUFREQ_ENTRY_INVALID)
225 alloc_size = count * sizeof(int) + count * sizeof(u64);
227 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
228 alloc_size += count * count * sizeof(int);
230 stat->max_state = count;
231 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
232 if (!stat->time_in_state) {
236 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
238 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
239 stat->trans_table = stat->freq_table + count;
242 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
243 unsigned int freq = table[i].frequency;
244 if (freq == CPUFREQ_ENTRY_INVALID)
246 if (freq_table_get_index(stat, freq) == -1)
247 stat->freq_table[j++] = freq;
250 spin_lock(&cpufreq_stats_lock);
251 stat->last_time = get_jiffies_64();
252 stat->last_index = freq_table_get_index(stat, policy->cur);
253 spin_unlock(&cpufreq_stats_lock);
254 cpufreq_cpu_put(current_policy);
257 cpufreq_cpu_put(current_policy);
260 per_cpu(cpufreq_stats_table, cpu) = NULL;
264 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
266 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
269 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
270 policy->cpu, policy->last_cpu);
271 per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
273 per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
274 stat->cpu = policy->cpu;
277 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
278 unsigned long val, void *data)
281 struct cpufreq_policy *policy = data;
282 struct cpufreq_frequency_table *table;
283 unsigned int cpu = policy->cpu;
285 if (val == CPUFREQ_UPDATE_POLICY_CPU) {
286 cpufreq_stats_update_policy_cpu(policy);
290 if (val != CPUFREQ_NOTIFY)
292 table = cpufreq_frequency_get_table(cpu);
295 ret = cpufreq_stats_create_table(policy, table);
301 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
302 unsigned long val, void *data)
304 struct cpufreq_freqs *freq = data;
305 struct cpufreq_stats *stat;
306 int old_index, new_index;
308 if (val != CPUFREQ_POSTCHANGE)
311 stat = per_cpu(cpufreq_stats_table, freq->cpu);
315 old_index = stat->last_index;
316 new_index = freq_table_get_index(stat, freq->new);
318 /* We can't do stat->time_in_state[-1]= .. */
319 if (old_index == -1 || new_index == -1)
322 cpufreq_stats_update(freq->cpu);
324 if (old_index == new_index)
327 spin_lock(&cpufreq_stats_lock);
328 stat->last_index = new_index;
329 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
330 stat->trans_table[old_index * stat->max_state + new_index]++;
333 spin_unlock(&cpufreq_stats_lock);
337 static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
338 unsigned long action,
341 unsigned int cpu = (unsigned long)hcpu;
344 case CPU_DOWN_PREPARE:
345 cpufreq_stats_free_sysfs(cpu);
348 cpufreq_stats_free_table(cpu);
354 /* priority=1 so this will get called before cpufreq_remove_dev */
355 static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
356 .notifier_call = cpufreq_stat_cpu_callback,
360 static struct notifier_block notifier_policy_block = {
361 .notifier_call = cpufreq_stat_notifier_policy
364 static struct notifier_block notifier_trans_block = {
365 .notifier_call = cpufreq_stat_notifier_trans
368 static int __init cpufreq_stats_init(void)
373 spin_lock_init(&cpufreq_stats_lock);
374 ret = cpufreq_register_notifier(¬ifier_policy_block,
375 CPUFREQ_POLICY_NOTIFIER);
379 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
381 ret = cpufreq_register_notifier(¬ifier_trans_block,
382 CPUFREQ_TRANSITION_NOTIFIER);
384 cpufreq_unregister_notifier(¬ifier_policy_block,
385 CPUFREQ_POLICY_NOTIFIER);
386 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
387 for_each_online_cpu(cpu)
388 cpufreq_stats_free_table(cpu);
394 static void __exit cpufreq_stats_exit(void)
398 cpufreq_unregister_notifier(¬ifier_policy_block,
399 CPUFREQ_POLICY_NOTIFIER);
400 cpufreq_unregister_notifier(¬ifier_trans_block,
401 CPUFREQ_TRANSITION_NOTIFIER);
402 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
403 for_each_online_cpu(cpu) {
404 cpufreq_stats_free_table(cpu);
405 cpufreq_stats_free_sysfs(cpu);
409 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
410 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
411 "through sysfs filesystem");
412 MODULE_LICENSE("GPL");
414 module_init(cpufreq_stats_init);
415 module_exit(cpufreq_stats_exit);