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/sysdev.h>
14 #include <linux/cpu.h>
15 #include <linux/sysfs.h>
16 #include <linux/cpufreq.h>
17 #include <linux/jiffies.h>
18 #include <linux/percpu.h>
19 #include <linux/kobject.h>
20 #include <linux/spinlock.h>
21 #include <linux/notifier.h>
22 #include <asm/cputime.h>
24 static spinlock_t cpufreq_stats_lock;
26 #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
27 static struct freq_attr _attr_##_name = {\
28 .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
33 struct cpufreq_stats {
35 unsigned int total_trans;
36 unsigned long long last_time;
37 unsigned int max_state;
38 unsigned int state_num;
39 unsigned int last_index;
40 cputime64_t *time_in_state;
41 unsigned int *freq_table;
42 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
43 unsigned int *trans_table;
47 static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
49 struct cpufreq_stats_attribute {
50 struct attribute attr;
51 ssize_t(*show) (struct cpufreq_stats *, char *);
55 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 = 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);
73 show_total_trans(struct cpufreq_policy *policy, char *buf)
75 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
78 return sprintf(buf, "%d\n",
79 cpufreq_stats_table[stat->cpu]->total_trans);
83 show_time_in_state(struct cpufreq_policy *policy, char *buf)
87 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
90 cpufreq_stats_update(stat->cpu);
91 for (i = 0; i < stat->state_num; i++) {
92 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
93 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
98 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
100 show_trans_table(struct cpufreq_policy *policy, char *buf)
105 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
108 cpufreq_stats_update(stat->cpu);
109 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
110 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
111 for (i = 0; i < stat->state_num; i++) {
112 if (len >= PAGE_SIZE)
114 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
115 stat->freq_table[i]);
117 if (len >= PAGE_SIZE)
120 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
122 for (i = 0; i < stat->state_num; i++) {
123 if (len >= PAGE_SIZE)
126 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
127 stat->freq_table[i]);
129 for (j = 0; j < stat->state_num; j++) {
130 if (len >= PAGE_SIZE)
132 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
133 stat->trans_table[i*stat->max_state+j]);
135 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
139 CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
142 CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
143 CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
145 static struct attribute *default_attrs[] = {
146 &_attr_total_trans.attr,
147 &_attr_time_in_state.attr,
148 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
149 &_attr_trans_table.attr,
153 static struct attribute_group stats_attr_group = {
154 .attrs = default_attrs,
159 freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
162 for (index = 0; index < stat->max_state; index++)
163 if (stat->freq_table[index] == freq)
169 cpufreq_stats_free_table (unsigned int cpu)
171 struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
172 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
173 if (policy && policy->cpu == cpu)
174 sysfs_remove_group(&policy->kobj, &stats_attr_group);
176 kfree(stat->time_in_state);
179 cpufreq_stats_table[cpu] = NULL;
181 cpufreq_cpu_put(policy);
185 cpufreq_stats_create_table (struct cpufreq_policy *policy,
186 struct cpufreq_frequency_table *table)
188 unsigned int i, j, count = 0, ret = 0;
189 struct cpufreq_stats *stat;
190 struct cpufreq_policy *data;
191 unsigned int alloc_size;
192 unsigned int cpu = policy->cpu;
193 if (cpufreq_stats_table[cpu])
195 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
198 data = cpufreq_cpu_get(cpu);
204 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
208 cpufreq_stats_table[cpu] = stat;
210 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
211 unsigned int freq = table[i].frequency;
212 if (freq == CPUFREQ_ENTRY_INVALID)
217 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
219 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
220 alloc_size += count * count * sizeof(int);
222 stat->max_state = count;
223 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
224 if (!stat->time_in_state) {
228 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
230 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
231 stat->trans_table = stat->freq_table + count;
234 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
235 unsigned int freq = table[i].frequency;
236 if (freq == CPUFREQ_ENTRY_INVALID)
238 if (freq_table_get_index(stat, freq) == -1)
239 stat->freq_table[j++] = freq;
242 spin_lock(&cpufreq_stats_lock);
243 stat->last_time = get_jiffies_64();
244 stat->last_index = freq_table_get_index(stat, policy->cur);
245 spin_unlock(&cpufreq_stats_lock);
246 cpufreq_cpu_put(data);
249 cpufreq_cpu_put(data);
252 cpufreq_stats_table[cpu] = NULL;
257 cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
261 struct cpufreq_policy *policy = data;
262 struct cpufreq_frequency_table *table;
263 unsigned int cpu = policy->cpu;
264 if (val != CPUFREQ_NOTIFY)
266 table = cpufreq_frequency_get_table(cpu);
269 if ((ret = cpufreq_stats_create_table(policy, table)))
275 cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
278 struct cpufreq_freqs *freq = data;
279 struct cpufreq_stats *stat;
280 int old_index, new_index;
282 if (val != CPUFREQ_POSTCHANGE)
285 stat = cpufreq_stats_table[freq->cpu];
288 old_index = freq_table_get_index(stat, freq->old);
289 new_index = freq_table_get_index(stat, freq->new);
291 cpufreq_stats_update(freq->cpu);
292 if (old_index == new_index)
295 spin_lock(&cpufreq_stats_lock);
296 stat->last_index = new_index;
297 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
298 stat->trans_table[old_index * stat->max_state + new_index]++;
301 spin_unlock(&cpufreq_stats_lock);
305 static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
306 unsigned long action, void *hcpu)
308 unsigned int cpu = (unsigned long)hcpu;
312 cpufreq_update_policy(cpu);
315 cpufreq_stats_free_table(cpu);
321 static struct notifier_block cpufreq_stat_cpu_notifier =
323 .notifier_call = cpufreq_stat_cpu_callback,
326 static struct notifier_block notifier_policy_block = {
327 .notifier_call = cpufreq_stat_notifier_policy
330 static struct notifier_block notifier_trans_block = {
331 .notifier_call = cpufreq_stat_notifier_trans
335 __init cpufreq_stats_init(void)
340 spin_lock_init(&cpufreq_stats_lock);
341 if ((ret = cpufreq_register_notifier(¬ifier_policy_block,
342 CPUFREQ_POLICY_NOTIFIER)))
345 if ((ret = cpufreq_register_notifier(¬ifier_trans_block,
346 CPUFREQ_TRANSITION_NOTIFIER))) {
347 cpufreq_unregister_notifier(¬ifier_policy_block,
348 CPUFREQ_POLICY_NOTIFIER);
352 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
354 for_each_online_cpu(cpu) {
355 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
358 unlock_cpu_hotplug();
362 __exit cpufreq_stats_exit(void)
366 cpufreq_unregister_notifier(¬ifier_policy_block,
367 CPUFREQ_POLICY_NOTIFIER);
368 cpufreq_unregister_notifier(¬ifier_trans_block,
369 CPUFREQ_TRANSITION_NOTIFIER);
370 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
372 for_each_online_cpu(cpu) {
373 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
376 unlock_cpu_hotplug();
379 MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
380 MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem");
381 MODULE_LICENSE ("GPL");
383 module_init(cpufreq_stats_init);
384 module_exit(cpufreq_stats_exit);