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>
18 struct cpufreq_stats {
19 unsigned int total_trans;
20 unsigned long long last_time;
21 unsigned int max_state;
22 unsigned int state_num;
23 unsigned int last_index;
26 unsigned int *freq_table;
27 unsigned int *trans_table;
30 static void cpufreq_stats_update(struct cpufreq_stats *stats)
32 unsigned long long cur_time = get_jiffies_64();
34 stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
35 stats->last_time = cur_time;
38 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
40 unsigned int count = stats->max_state;
42 spin_lock(&stats->lock);
43 memset(stats->time_in_state, 0, count * sizeof(u64));
44 memset(stats->trans_table, 0, count * count * sizeof(int));
45 stats->last_time = get_jiffies_64();
46 stats->total_trans = 0;
47 spin_unlock(&stats->lock);
50 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
52 return sprintf(buf, "%d\n", policy->stats->total_trans);
54 cpufreq_freq_attr_ro(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 spin_lock(&stats->lock);
66 cpufreq_stats_update(stats);
67 spin_unlock(&stats->lock);
69 for (i = 0; i < stats->state_num; i++) {
70 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
72 jiffies_64_to_clock_t(stats->time_in_state[i]));
76 cpufreq_freq_attr_ro(time_in_state);
78 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
81 /* We don't care what is written to the attribute. */
82 cpufreq_stats_clear_table(policy->stats);
85 cpufreq_freq_attr_wo(reset);
87 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
89 struct cpufreq_stats *stats = policy->stats;
93 if (policy->fast_switch_enabled)
96 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
97 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
98 for (i = 0; i < stats->state_num; i++) {
101 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
102 stats->freq_table[i]);
104 if (len >= PAGE_SIZE)
107 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
109 for (i = 0; i < stats->state_num; i++) {
110 if (len >= PAGE_SIZE)
113 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
114 stats->freq_table[i]);
116 for (j = 0; j < stats->state_num; j++) {
117 if (len >= PAGE_SIZE)
119 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
120 stats->trans_table[i*stats->max_state+j]);
122 if (len >= PAGE_SIZE)
124 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
127 if (len >= PAGE_SIZE) {
128 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
133 cpufreq_freq_attr_ro(trans_table);
135 static struct attribute *default_attrs[] = {
142 static const struct attribute_group stats_attr_group = {
143 .attrs = default_attrs,
147 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
150 for (index = 0; index < stats->max_state; index++)
151 if (stats->freq_table[index] == freq)
156 void cpufreq_stats_free_table(struct cpufreq_policy *policy)
158 struct cpufreq_stats *stats = policy->stats;
164 pr_debug("%s: Free stats table\n", __func__);
166 sysfs_remove_group(&policy->kobj, &stats_attr_group);
167 kfree(stats->time_in_state);
169 policy->stats = NULL;
172 void cpufreq_stats_create_table(struct cpufreq_policy *policy)
174 unsigned int i = 0, count = 0, ret = -ENOMEM;
175 struct cpufreq_stats *stats;
176 unsigned int alloc_size;
177 struct cpufreq_frequency_table *pos;
179 count = cpufreq_table_count_valid_entries(policy);
183 /* stats already initialized */
187 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
191 alloc_size = count * sizeof(int) + count * sizeof(u64);
193 alloc_size += count * count * sizeof(int);
195 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
196 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
197 if (!stats->time_in_state)
200 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
202 stats->trans_table = stats->freq_table + count;
204 stats->max_state = count;
206 /* Find valid-unique entries */
207 cpufreq_for_each_valid_entry(pos, policy->freq_table)
208 if (freq_table_get_index(stats, pos->frequency) == -1)
209 stats->freq_table[i++] = pos->frequency;
211 stats->state_num = i;
212 stats->last_time = get_jiffies_64();
213 stats->last_index = freq_table_get_index(stats, policy->cur);
214 spin_lock_init(&stats->lock);
216 policy->stats = stats;
217 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
221 /* We failed, release resources */
222 policy->stats = NULL;
223 kfree(stats->time_in_state);
228 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
229 unsigned int new_freq)
231 struct cpufreq_stats *stats = policy->stats;
232 int old_index, new_index;
235 pr_debug("%s: No stats found\n", __func__);
239 old_index = stats->last_index;
240 new_index = freq_table_get_index(stats, new_freq);
242 /* We can't do stats->time_in_state[-1]= .. */
243 if (old_index == -1 || new_index == -1 || old_index == new_index)
246 spin_lock(&stats->lock);
247 cpufreq_stats_update(stats);
249 stats->last_index = new_index;
250 stats->trans_table[old_index * stats->max_state + new_index]++;
251 stats->total_trans++;
252 spin_unlock(&stats->lock);