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>
17 static DEFINE_SPINLOCK(cpufreq_stats_lock);
19 struct cpufreq_stats {
20 unsigned int total_trans;
21 unsigned long long last_time;
22 unsigned int max_state;
23 unsigned int state_num;
24 unsigned int last_index;
26 unsigned int *freq_table;
27 unsigned int *trans_table;
30 static int cpufreq_stats_update(struct cpufreq_stats *stats)
32 unsigned long long cur_time = get_jiffies_64();
34 spin_lock(&cpufreq_stats_lock);
35 stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
36 stats->last_time = cur_time;
37 spin_unlock(&cpufreq_stats_lock);
41 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
43 unsigned int count = stats->max_state;
45 memset(stats->time_in_state, 0, count * sizeof(u64));
46 memset(stats->trans_table, 0, count * count * sizeof(int));
47 stats->last_time = get_jiffies_64();
48 stats->total_trans = 0;
51 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
53 return sprintf(buf, "%d\n", policy->stats->total_trans);
56 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
58 struct cpufreq_stats *stats = policy->stats;
62 if (policy->fast_switch_enabled)
65 cpufreq_stats_update(stats);
66 for (i = 0; i < stats->state_num; i++) {
67 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
69 jiffies_64_to_clock_t(stats->time_in_state[i]));
74 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
77 /* We don't care what is written to the attribute. */
78 cpufreq_stats_clear_table(policy->stats);
82 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
84 struct cpufreq_stats *stats = policy->stats;
88 if (policy->fast_switch_enabled)
91 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
92 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
93 for (i = 0; i < stats->state_num; i++) {
96 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
97 stats->freq_table[i]);
102 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
104 for (i = 0; i < stats->state_num; i++) {
105 if (len >= PAGE_SIZE)
108 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
109 stats->freq_table[i]);
111 for (j = 0; j < stats->state_num; j++) {
112 if (len >= PAGE_SIZE)
114 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
115 stats->trans_table[i*stats->max_state+j]);
117 if (len >= PAGE_SIZE)
119 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
122 if (len >= PAGE_SIZE) {
123 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
128 cpufreq_freq_attr_ro(trans_table);
130 cpufreq_freq_attr_ro(total_trans);
131 cpufreq_freq_attr_ro(time_in_state);
132 cpufreq_freq_attr_wo(reset);
134 static struct attribute *default_attrs[] = {
141 static const struct attribute_group stats_attr_group = {
142 .attrs = default_attrs,
146 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
149 for (index = 0; index < stats->max_state; index++)
150 if (stats->freq_table[index] == freq)
155 void cpufreq_stats_free_table(struct cpufreq_policy *policy)
157 struct cpufreq_stats *stats = policy->stats;
163 pr_debug("%s: Free stats table\n", __func__);
165 sysfs_remove_group(&policy->kobj, &stats_attr_group);
166 kfree(stats->time_in_state);
168 policy->stats = NULL;
171 void cpufreq_stats_create_table(struct cpufreq_policy *policy)
173 unsigned int i = 0, count = 0, ret = -ENOMEM;
174 struct cpufreq_stats *stats;
175 unsigned int alloc_size;
176 struct cpufreq_frequency_table *pos;
178 count = cpufreq_table_count_valid_entries(policy);
182 /* stats already initialized */
186 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
190 alloc_size = count * sizeof(int) + count * sizeof(u64);
192 alloc_size += count * count * sizeof(int);
194 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
195 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
196 if (!stats->time_in_state)
199 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
201 stats->trans_table = stats->freq_table + count;
203 stats->max_state = count;
205 /* Find valid-unique entries */
206 cpufreq_for_each_valid_entry(pos, policy->freq_table)
207 if (freq_table_get_index(stats, pos->frequency) == -1)
208 stats->freq_table[i++] = pos->frequency;
210 stats->state_num = i;
211 stats->last_time = get_jiffies_64();
212 stats->last_index = freq_table_get_index(stats, policy->cur);
214 policy->stats = stats;
215 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
219 /* We failed, release resources */
220 policy->stats = NULL;
221 kfree(stats->time_in_state);
226 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
227 unsigned int new_freq)
229 struct cpufreq_stats *stats = policy->stats;
230 int old_index, new_index;
233 pr_debug("%s: No stats found\n", __func__);
237 old_index = stats->last_index;
238 new_index = freq_table_get_index(stats, new_freq);
240 /* We can't do stats->time_in_state[-1]= .. */
241 if (old_index == -1 || new_index == -1 || old_index == new_index)
244 cpufreq_stats_update(stats);
246 stats->last_index = new_index;
247 stats->trans_table[old_index * stats->max_state + new_index]++;
248 stats->total_trans++;