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 <linux/cputime.h>
18 static DEFINE_SPINLOCK(cpufreq_stats_lock);
20 struct cpufreq_stats {
21 unsigned int total_trans;
22 unsigned long long last_time;
23 unsigned int max_state;
24 unsigned int state_num;
25 unsigned int last_index;
27 unsigned int *freq_table;
28 unsigned int *trans_table;
31 static int cpufreq_stats_update(struct cpufreq_stats *stats)
33 unsigned long long cur_time = get_jiffies_64();
35 spin_lock(&cpufreq_stats_lock);
36 stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
37 stats->last_time = cur_time;
38 spin_unlock(&cpufreq_stats_lock);
42 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
44 unsigned int count = stats->max_state;
46 memset(stats->time_in_state, 0, count * sizeof(u64));
47 memset(stats->trans_table, 0, count * count * sizeof(int));
48 stats->last_time = get_jiffies_64();
49 stats->total_trans = 0;
52 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
54 return sprintf(buf, "%d\n", policy->stats->total_trans);
57 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
59 struct cpufreq_stats *stats = policy->stats;
63 if (policy->fast_switch_enabled)
66 cpufreq_stats_update(stats);
67 for (i = 0; i < stats->state_num; i++) {
68 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
70 jiffies_64_to_clock_t(stats->time_in_state[i]));
75 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
78 /* We don't care what is written to the attribute. */
79 cpufreq_stats_clear_table(policy->stats);
83 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
85 struct cpufreq_stats *stats = policy->stats;
89 if (policy->fast_switch_enabled)
92 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
93 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
94 for (i = 0; i < stats->state_num; i++) {
97 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
98 stats->freq_table[i]);
100 if (len >= PAGE_SIZE)
103 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
105 for (i = 0; i < stats->state_num; i++) {
106 if (len >= PAGE_SIZE)
109 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
110 stats->freq_table[i]);
112 for (j = 0; j < stats->state_num; j++) {
113 if (len >= PAGE_SIZE)
115 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
116 stats->trans_table[i*stats->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);
128 cpufreq_freq_attr_ro(total_trans);
129 cpufreq_freq_attr_ro(time_in_state);
130 cpufreq_freq_attr_wo(reset);
132 static struct attribute *default_attrs[] = {
139 static struct attribute_group stats_attr_group = {
140 .attrs = default_attrs,
144 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
147 for (index = 0; index < stats->max_state; index++)
148 if (stats->freq_table[index] == freq)
153 void cpufreq_stats_free_table(struct cpufreq_policy *policy)
155 struct cpufreq_stats *stats = policy->stats;
161 pr_debug("%s: Free stats table\n", __func__);
163 sysfs_remove_group(&policy->kobj, &stats_attr_group);
164 kfree(stats->time_in_state);
166 policy->stats = NULL;
169 void cpufreq_stats_create_table(struct cpufreq_policy *policy)
171 unsigned int i = 0, count = 0, ret = -ENOMEM;
172 struct cpufreq_stats *stats;
173 unsigned int alloc_size;
174 struct cpufreq_frequency_table *pos, *table;
176 /* We need cpufreq table for creating stats table */
177 table = policy->freq_table;
178 if (unlikely(!table))
181 /* stats already initialized */
185 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
189 /* Find total allocation size */
190 cpufreq_for_each_valid_entry(pos, table)
193 alloc_size = count * sizeof(int) + count * sizeof(u64);
195 alloc_size += count * count * sizeof(int);
197 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
198 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
199 if (!stats->time_in_state)
202 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
204 stats->trans_table = stats->freq_table + count;
206 stats->max_state = count;
208 /* Find valid-unique entries */
209 cpufreq_for_each_valid_entry(pos, table)
210 if (freq_table_get_index(stats, pos->frequency) == -1)
211 stats->freq_table[i++] = pos->frequency;
213 stats->state_num = i;
214 stats->last_time = get_jiffies_64();
215 stats->last_index = freq_table_get_index(stats, policy->cur);
217 policy->stats = stats;
218 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
222 /* We failed, release resources */
223 policy->stats = NULL;
224 kfree(stats->time_in_state);
229 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
230 unsigned int new_freq)
232 struct cpufreq_stats *stats = policy->stats;
233 int old_index, new_index;
236 pr_debug("%s: No stats found\n", __func__);
240 old_index = stats->last_index;
241 new_index = freq_table_get_index(stats, new_freq);
243 /* We can't do stats->time_in_state[-1]= .. */
244 if (old_index == -1 || new_index == -1 || old_index == new_index)
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++;