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 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
28 unsigned int *trans_table;
32 static int cpufreq_stats_update(struct cpufreq_stats *stats)
34 unsigned long long cur_time = get_jiffies_64();
36 spin_lock(&cpufreq_stats_lock);
37 stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
38 stats->last_time = cur_time;
39 spin_unlock(&cpufreq_stats_lock);
43 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
45 unsigned int count = stats->max_state;
47 memset(stats->time_in_state, 0, count * sizeof(u64));
48 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
49 memset(stats->trans_table, 0, count * count * sizeof(int));
51 stats->last_time = get_jiffies_64();
52 stats->total_trans = 0;
55 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
57 return sprintf(buf, "%d\n", policy->stats->total_trans);
60 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
62 struct cpufreq_stats *stats = policy->stats;
66 if (policy->fast_switch_enabled)
69 cpufreq_stats_update(stats);
70 for (i = 0; i < stats->state_num; i++) {
71 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
73 jiffies_64_to_clock_t(stats->time_in_state[i]));
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);
86 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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");
126 if (len >= PAGE_SIZE)
130 cpufreq_freq_attr_ro(trans_table);
133 cpufreq_freq_attr_ro(total_trans);
134 cpufreq_freq_attr_ro(time_in_state);
135 cpufreq_freq_attr_wo(reset);
137 static struct attribute *default_attrs[] = {
141 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
146 static struct attribute_group stats_attr_group = {
147 .attrs = default_attrs,
151 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
154 for (index = 0; index < stats->max_state; index++)
155 if (stats->freq_table[index] == freq)
160 void cpufreq_stats_free_table(struct cpufreq_policy *policy)
162 struct cpufreq_stats *stats = policy->stats;
168 pr_debug("%s: Free stats table\n", __func__);
170 sysfs_remove_group(&policy->kobj, &stats_attr_group);
171 kfree(stats->time_in_state);
173 policy->stats = NULL;
176 void cpufreq_stats_create_table(struct cpufreq_policy *policy)
178 unsigned int i = 0, count = 0, ret = -ENOMEM;
179 struct cpufreq_stats *stats;
180 unsigned int alloc_size;
181 struct cpufreq_frequency_table *pos, *table;
183 /* We need cpufreq table for creating stats table */
184 table = policy->freq_table;
185 if (unlikely(!table))
188 /* stats already initialized */
192 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
196 /* Find total allocation size */
197 cpufreq_for_each_valid_entry(pos, table)
200 alloc_size = count * sizeof(int) + count * sizeof(u64);
202 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
203 alloc_size += count * count * sizeof(int);
206 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
207 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
208 if (!stats->time_in_state)
211 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
213 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
214 stats->trans_table = stats->freq_table + count;
217 stats->max_state = count;
219 /* Find valid-unique entries */
220 cpufreq_for_each_valid_entry(pos, table)
221 if (freq_table_get_index(stats, pos->frequency) == -1)
222 stats->freq_table[i++] = pos->frequency;
224 stats->state_num = i;
225 stats->last_time = get_jiffies_64();
226 stats->last_index = freq_table_get_index(stats, policy->cur);
228 policy->stats = stats;
229 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
233 /* We failed, release resources */
234 policy->stats = NULL;
235 kfree(stats->time_in_state);
240 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
241 unsigned int new_freq)
243 struct cpufreq_stats *stats = policy->stats;
244 int old_index, new_index;
247 pr_debug("%s: No stats found\n", __func__);
251 old_index = stats->last_index;
252 new_index = freq_table_get_index(stats, new_freq);
254 /* We can't do stats->time_in_state[-1]= .. */
255 if (old_index == -1 || new_index == -1 || old_index == new_index)
258 cpufreq_stats_update(stats);
260 stats->last_index = new_index;
261 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
262 stats->trans_table[old_index * stats->max_state + new_index]++;
264 stats->total_trans++;