1 // SPDX-License-Identifier: GPL-2.0-only
3 * drivers/cpufreq/cpufreq_stats.c
5 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
6 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
10 #include <linux/cpufreq.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
15 struct cpufreq_stats {
16 unsigned int total_trans;
17 unsigned long long last_time;
18 unsigned int max_state;
19 unsigned int state_num;
20 unsigned int last_index;
22 unsigned int *freq_table;
23 unsigned int *trans_table;
26 unsigned int reset_pending;
27 unsigned long long reset_time;
30 static void cpufreq_stats_update(struct cpufreq_stats *stats,
31 unsigned long long time)
33 unsigned long long cur_time = get_jiffies_64();
35 stats->time_in_state[stats->last_index] += cur_time - time;
36 stats->last_time = cur_time;
39 static void cpufreq_stats_reset_table(struct cpufreq_stats *stats)
41 unsigned int count = stats->max_state;
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;
48 /* Adjust for the time elapsed since reset was requested */
49 WRITE_ONCE(stats->reset_pending, 0);
50 cpufreq_stats_update(stats, READ_ONCE(stats->reset_time));
53 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
55 struct cpufreq_stats *stats = policy->stats;
57 if (READ_ONCE(stats->reset_pending))
58 return sprintf(buf, "%d\n", 0);
60 return sprintf(buf, "%d\n", stats->total_trans);
62 cpufreq_freq_attr_ro(total_trans);
64 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
66 struct cpufreq_stats *stats = policy->stats;
67 bool pending = READ_ONCE(stats->reset_pending);
68 unsigned long long time;
72 if (policy->fast_switch_enabled)
75 for (i = 0; i < stats->state_num; i++) {
77 if (i == stats->last_index)
78 time = get_jiffies_64() - READ_ONCE(stats->reset_time);
82 time = stats->time_in_state[i];
83 if (i == stats->last_index)
84 time += get_jiffies_64() - stats->last_time;
87 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
88 jiffies_64_to_clock_t(time));
92 cpufreq_freq_attr_ro(time_in_state);
94 /* We don't care what is written to the attribute */
95 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
98 struct cpufreq_stats *stats = policy->stats;
101 * Defer resetting of stats to cpufreq_stats_record_transition() to
104 WRITE_ONCE(stats->reset_time, get_jiffies_64());
105 WRITE_ONCE(stats->reset_pending, 1);
109 cpufreq_freq_attr_wo(reset);
111 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
113 struct cpufreq_stats *stats = policy->stats;
114 bool pending = READ_ONCE(stats->reset_pending);
118 if (policy->fast_switch_enabled)
121 len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n");
122 len += scnprintf(buf + len, PAGE_SIZE - len, " : ");
123 for (i = 0; i < stats->state_num; i++) {
124 if (len >= PAGE_SIZE)
126 len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ",
127 stats->freq_table[i]);
129 if (len >= PAGE_SIZE)
132 len += scnprintf(buf + len, PAGE_SIZE - len, "\n");
134 for (i = 0; i < stats->state_num; i++) {
135 if (len >= PAGE_SIZE)
138 len += scnprintf(buf + len, PAGE_SIZE - len, "%9u: ",
139 stats->freq_table[i]);
141 for (j = 0; j < stats->state_num; j++) {
142 if (len >= PAGE_SIZE)
148 count = stats->trans_table[i * stats->max_state + j];
150 len += scnprintf(buf + len, PAGE_SIZE - len, "%9u ", count);
152 if (len >= PAGE_SIZE)
154 len += scnprintf(buf + len, PAGE_SIZE - len, "\n");
157 if (len >= PAGE_SIZE) {
158 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
163 cpufreq_freq_attr_ro(trans_table);
165 static struct attribute *default_attrs[] = {
172 static const struct attribute_group stats_attr_group = {
173 .attrs = default_attrs,
177 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
180 for (index = 0; index < stats->max_state; index++)
181 if (stats->freq_table[index] == freq)
186 void cpufreq_stats_free_table(struct cpufreq_policy *policy)
188 struct cpufreq_stats *stats = policy->stats;
194 pr_debug("%s: Free stats table\n", __func__);
196 sysfs_remove_group(&policy->kobj, &stats_attr_group);
197 kfree(stats->time_in_state);
199 policy->stats = NULL;
202 void cpufreq_stats_create_table(struct cpufreq_policy *policy)
204 unsigned int i = 0, count = 0, ret = -ENOMEM;
205 struct cpufreq_stats *stats;
206 unsigned int alloc_size;
207 struct cpufreq_frequency_table *pos;
209 count = cpufreq_table_count_valid_entries(policy);
213 /* stats already initialized */
217 stats = kzalloc(sizeof(*stats), GFP_KERNEL);
221 alloc_size = count * sizeof(int) + count * sizeof(u64);
223 alloc_size += count * count * sizeof(int);
225 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
226 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
227 if (!stats->time_in_state)
230 stats->freq_table = (unsigned int *)(stats->time_in_state + count);
232 stats->trans_table = stats->freq_table + count;
234 stats->max_state = count;
236 /* Find valid-unique entries */
237 cpufreq_for_each_valid_entry(pos, policy->freq_table)
238 if (freq_table_get_index(stats, pos->frequency) == -1)
239 stats->freq_table[i++] = pos->frequency;
241 stats->state_num = i;
242 stats->last_time = get_jiffies_64();
243 stats->last_index = freq_table_get_index(stats, policy->cur);
245 policy->stats = stats;
246 ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
250 /* We failed, release resources */
251 policy->stats = NULL;
252 kfree(stats->time_in_state);
257 void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
258 unsigned int new_freq)
260 struct cpufreq_stats *stats = policy->stats;
261 int old_index, new_index;
263 if (unlikely(!stats))
266 if (unlikely(READ_ONCE(stats->reset_pending)))
267 cpufreq_stats_reset_table(stats);
269 old_index = stats->last_index;
270 new_index = freq_table_get_index(stats, new_freq);
272 /* We can't do stats->time_in_state[-1]= .. */
273 if (unlikely(old_index == -1 || new_index == -1 || old_index == new_index))
276 cpufreq_stats_update(stats, stats->last_time);
278 stats->last_index = new_index;
279 stats->trans_table[old_index * stats->max_state + new_index]++;
280 stats->total_trans++;