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/sysdev.h>
15 #include <linux/cpu.h>
16 #include <linux/sysfs.h>
17 #include <linux/cpufreq.h>
18 #include <linux/module.h>
19 #include <linux/jiffies.h>
20 #include <linux/percpu.h>
21 #include <linux/kobject.h>
22 #include <linux/spinlock.h>
23 #include <linux/notifier.h>
24 #include <asm/cputime.h>
26 static spinlock_t cpufreq_stats_lock;
28 #define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
29 static struct freq_attr _attr_##_name = {\
30 .attr = {.name = __stringify(_name), .mode = _mode, }, \
34 struct cpufreq_stats {
36 unsigned int total_trans;
37 unsigned long long last_time;
38 unsigned int max_state;
39 unsigned int state_num;
40 unsigned int last_index;
41 cputime64_t *time_in_state;
42 unsigned int *freq_table;
43 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
44 unsigned int *trans_table;
48 static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
50 struct cpufreq_stats_attribute {
51 struct attribute attr;
52 ssize_t(*show) (struct cpufreq_stats *, char *);
55 static int cpufreq_stats_update(unsigned int cpu)
57 struct cpufreq_stats *stat;
58 unsigned long long cur_time;
60 cur_time = get_jiffies_64();
61 spin_lock(&cpufreq_stats_lock);
62 stat = per_cpu(cpufreq_stats_table, cpu);
63 if (stat->time_in_state)
64 stat->time_in_state[stat->last_index] =
65 cputime64_add(stat->time_in_state[stat->last_index],
66 cputime_sub(cur_time, stat->last_time));
67 stat->last_time = cur_time;
68 spin_unlock(&cpufreq_stats_lock);
72 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
74 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
77 return sprintf(buf, "%d\n",
78 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
81 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
85 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
88 cpufreq_stats_update(stat->cpu);
89 for (i = 0; i < stat->state_num; i++) {
90 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
92 cputime64_to_clock_t(stat->time_in_state[i]));
97 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
98 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
103 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
106 cpufreq_stats_update(stat->cpu);
107 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
108 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
109 for (i = 0; i < stat->state_num; i++) {
110 if (len >= PAGE_SIZE)
112 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
113 stat->freq_table[i]);
115 if (len >= PAGE_SIZE)
118 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
120 for (i = 0; i < stat->state_num; i++) {
121 if (len >= PAGE_SIZE)
124 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
125 stat->freq_table[i]);
127 for (j = 0; j < stat->state_num; j++) {
128 if (len >= PAGE_SIZE)
130 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
131 stat->trans_table[i*stat->max_state+j]);
133 if (len >= PAGE_SIZE)
135 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
137 if (len >= PAGE_SIZE)
141 CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
144 CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
145 CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
147 static struct attribute *default_attrs[] = {
148 &_attr_total_trans.attr,
149 &_attr_time_in_state.attr,
150 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
151 &_attr_trans_table.attr,
155 static struct attribute_group stats_attr_group = {
156 .attrs = default_attrs,
160 static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
163 for (index = 0; index < stat->max_state; index++)
164 if (stat->freq_table[index] == freq)
169 /* should be called late in the CPU removal sequence so that the stats
170 * memory is still available in case someone tries to use it.
172 static void cpufreq_stats_free_table(unsigned int cpu)
174 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
176 kfree(stat->time_in_state);
179 per_cpu(cpufreq_stats_table, cpu) = NULL;
182 /* must be called early in the CPU removal sequence (before
183 * cpufreq_remove_dev) so that policy is still valid.
185 static void cpufreq_stats_free_sysfs(unsigned int cpu)
187 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
188 if (policy && policy->cpu == cpu)
189 sysfs_remove_group(&policy->kobj, &stats_attr_group);
191 cpufreq_cpu_put(policy);
194 static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
195 struct cpufreq_frequency_table *table)
197 unsigned int i, j, count = 0, ret = 0;
198 struct cpufreq_stats *stat;
199 struct cpufreq_policy *data;
200 unsigned int alloc_size;
201 unsigned int cpu = policy->cpu;
202 if (per_cpu(cpufreq_stats_table, cpu))
204 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
208 data = cpufreq_cpu_get(cpu);
214 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
219 per_cpu(cpufreq_stats_table, cpu) = stat;
221 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
222 unsigned int freq = table[i].frequency;
223 if (freq == CPUFREQ_ENTRY_INVALID)
228 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
230 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
231 alloc_size += count * count * sizeof(int);
233 stat->max_state = count;
234 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
235 if (!stat->time_in_state) {
239 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
241 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
242 stat->trans_table = stat->freq_table + count;
245 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
246 unsigned int freq = table[i].frequency;
247 if (freq == CPUFREQ_ENTRY_INVALID)
249 if (freq_table_get_index(stat, freq) == -1)
250 stat->freq_table[j++] = freq;
253 spin_lock(&cpufreq_stats_lock);
254 stat->last_time = get_jiffies_64();
255 stat->last_index = freq_table_get_index(stat, policy->cur);
256 spin_unlock(&cpufreq_stats_lock);
257 cpufreq_cpu_put(data);
260 cpufreq_cpu_put(data);
263 per_cpu(cpufreq_stats_table, cpu) = NULL;
267 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
268 unsigned long val, void *data)
271 struct cpufreq_policy *policy = data;
272 struct cpufreq_frequency_table *table;
273 unsigned int cpu = policy->cpu;
274 if (val != CPUFREQ_NOTIFY)
276 table = cpufreq_frequency_get_table(cpu);
279 ret = cpufreq_stats_create_table(policy, table);
285 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
286 unsigned long val, void *data)
288 struct cpufreq_freqs *freq = data;
289 struct cpufreq_stats *stat;
290 int old_index, new_index;
292 if (val != CPUFREQ_POSTCHANGE)
295 stat = per_cpu(cpufreq_stats_table, freq->cpu);
299 old_index = stat->last_index;
300 new_index = freq_table_get_index(stat, freq->new);
302 /* We can't do stat->time_in_state[-1]= .. */
303 if (old_index == -1 || new_index == -1)
306 cpufreq_stats_update(freq->cpu);
308 if (old_index == new_index)
311 spin_lock(&cpufreq_stats_lock);
312 stat->last_index = new_index;
313 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
314 stat->trans_table[old_index * stat->max_state + new_index]++;
317 spin_unlock(&cpufreq_stats_lock);
321 static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
322 unsigned long action,
325 unsigned int cpu = (unsigned long)hcpu;
329 case CPU_ONLINE_FROZEN:
330 cpufreq_update_policy(cpu);
332 case CPU_DOWN_PREPARE:
333 cpufreq_stats_free_sysfs(cpu);
336 case CPU_DEAD_FROZEN:
337 cpufreq_stats_free_table(cpu);
343 /* priority=1 so this will get called before cpufreq_remove_dev */
344 static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
345 .notifier_call = cpufreq_stat_cpu_callback,
349 static struct notifier_block notifier_policy_block = {
350 .notifier_call = cpufreq_stat_notifier_policy
353 static struct notifier_block notifier_trans_block = {
354 .notifier_call = cpufreq_stat_notifier_trans
357 static int __init cpufreq_stats_init(void)
362 spin_lock_init(&cpufreq_stats_lock);
363 ret = cpufreq_register_notifier(¬ifier_policy_block,
364 CPUFREQ_POLICY_NOTIFIER);
368 ret = cpufreq_register_notifier(¬ifier_trans_block,
369 CPUFREQ_TRANSITION_NOTIFIER);
371 cpufreq_unregister_notifier(¬ifier_policy_block,
372 CPUFREQ_POLICY_NOTIFIER);
376 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
377 for_each_online_cpu(cpu) {
378 cpufreq_update_policy(cpu);
382 static void __exit cpufreq_stats_exit(void)
386 cpufreq_unregister_notifier(¬ifier_policy_block,
387 CPUFREQ_POLICY_NOTIFIER);
388 cpufreq_unregister_notifier(¬ifier_trans_block,
389 CPUFREQ_TRANSITION_NOTIFIER);
390 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
391 for_each_online_cpu(cpu) {
392 cpufreq_stats_free_table(cpu);
393 cpufreq_stats_free_sysfs(cpu);
397 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
398 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
399 "through sysfs filesystem");
400 MODULE_LICENSE("GPL");
402 module_init(cpufreq_stats_init);
403 module_exit(cpufreq_stats_exit);