v4.19.13 snapshot.
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
new file mode 100644
index 0000000..1572129
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -0,0 +1,248 @@
+/*
+ * drivers/cpufreq/cpufreq_stats.c
+ *
+ * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+static DEFINE_SPINLOCK(cpufreq_stats_lock);
+
+struct cpufreq_stats {
+ unsigned int total_trans;
+ unsigned long long last_time;
+ unsigned int max_state;
+ unsigned int state_num;
+ unsigned int last_index;
+ u64 *time_in_state;
+ unsigned int *freq_table;
+ unsigned int *trans_table;
+};
+
+static void cpufreq_stats_update(struct cpufreq_stats *stats)
+{
+ unsigned long long cur_time = get_jiffies_64();
+
+ spin_lock(&cpufreq_stats_lock);
+ stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
+ stats->last_time = cur_time;
+ spin_unlock(&cpufreq_stats_lock);
+}
+
+static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
+{
+ unsigned int count = stats->max_state;
+
+ memset(stats->time_in_state, 0, count * sizeof(u64));
+ memset(stats->trans_table, 0, count * count * sizeof(int));
+ stats->last_time = get_jiffies_64();
+ stats->total_trans = 0;
+}
+
+static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
+{
+ return sprintf(buf, "%d\n", policy->stats->total_trans);
+}
+
+static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
+{
+ struct cpufreq_stats *stats = policy->stats;
+ ssize_t len = 0;
+ int i;
+
+ if (policy->fast_switch_enabled)
+ return 0;
+
+ cpufreq_stats_update(stats);
+ for (i = 0; i < stats->state_num; i++) {
+ len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
+ (unsigned long long)
+ jiffies_64_to_clock_t(stats->time_in_state[i]));
+ }
+ return len;
+}
+
+static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
+ size_t count)
+{
+ /* We don't care what is written to the attribute. */
+ cpufreq_stats_clear_table(policy->stats);
+ return count;
+}
+
+static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
+{
+ struct cpufreq_stats *stats = policy->stats;
+ ssize_t len = 0;
+ int i, j;
+
+ if (policy->fast_switch_enabled)
+ return 0;
+
+ len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
+ len += snprintf(buf + len, PAGE_SIZE - len, " : ");
+ for (i = 0; i < stats->state_num; i++) {
+ if (len >= PAGE_SIZE)
+ break;
+ len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
+ stats->freq_table[i]);
+ }
+ if (len >= PAGE_SIZE)
+ return PAGE_SIZE;
+
+ len += snprintf(buf + len, PAGE_SIZE - len, "\n");
+
+ for (i = 0; i < stats->state_num; i++) {
+ if (len >= PAGE_SIZE)
+ break;
+
+ len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
+ stats->freq_table[i]);
+
+ for (j = 0; j < stats->state_num; j++) {
+ if (len >= PAGE_SIZE)
+ break;
+ len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
+ stats->trans_table[i*stats->max_state+j]);
+ }
+ if (len >= PAGE_SIZE)
+ break;
+ len += snprintf(buf + len, PAGE_SIZE - len, "\n");
+ }
+
+ if (len >= PAGE_SIZE) {
+ pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
+ return -EFBIG;
+ }
+ return len;
+}
+cpufreq_freq_attr_ro(trans_table);
+
+cpufreq_freq_attr_ro(total_trans);
+cpufreq_freq_attr_ro(time_in_state);
+cpufreq_freq_attr_wo(reset);
+
+static struct attribute *default_attrs[] = {
+ &total_trans.attr,
+ &time_in_state.attr,
+ &reset.attr,
+ &trans_table.attr,
+ NULL
+};
+static const struct attribute_group stats_attr_group = {
+ .attrs = default_attrs,
+ .name = "stats"
+};
+
+static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
+{
+ int index;
+ for (index = 0; index < stats->max_state; index++)
+ if (stats->freq_table[index] == freq)
+ return index;
+ return -1;
+}
+
+void cpufreq_stats_free_table(struct cpufreq_policy *policy)
+{
+ struct cpufreq_stats *stats = policy->stats;
+
+ /* Already freed */
+ if (!stats)
+ return;
+
+ pr_debug("%s: Free stats table\n", __func__);
+
+ sysfs_remove_group(&policy->kobj, &stats_attr_group);
+ kfree(stats->time_in_state);
+ kfree(stats);
+ policy->stats = NULL;
+}
+
+void cpufreq_stats_create_table(struct cpufreq_policy *policy)
+{
+ unsigned int i = 0, count = 0, ret = -ENOMEM;
+ struct cpufreq_stats *stats;
+ unsigned int alloc_size;
+ struct cpufreq_frequency_table *pos;
+
+ count = cpufreq_table_count_valid_entries(policy);
+ if (!count)
+ return;
+
+ /* stats already initialized */
+ if (policy->stats)
+ return;
+
+ stats = kzalloc(sizeof(*stats), GFP_KERNEL);
+ if (!stats)
+ return;
+
+ alloc_size = count * sizeof(int) + count * sizeof(u64);
+
+ alloc_size += count * count * sizeof(int);
+
+ /* Allocate memory for time_in_state/freq_table/trans_table in one go */
+ stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
+ if (!stats->time_in_state)
+ goto free_stat;
+
+ stats->freq_table = (unsigned int *)(stats->time_in_state + count);
+
+ stats->trans_table = stats->freq_table + count;
+
+ stats->max_state = count;
+
+ /* Find valid-unique entries */
+ cpufreq_for_each_valid_entry(pos, policy->freq_table)
+ if (freq_table_get_index(stats, pos->frequency) == -1)
+ stats->freq_table[i++] = pos->frequency;
+
+ stats->state_num = i;
+ stats->last_time = get_jiffies_64();
+ stats->last_index = freq_table_get_index(stats, policy->cur);
+
+ policy->stats = stats;
+ ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
+ if (!ret)
+ return;
+
+ /* We failed, release resources */
+ policy->stats = NULL;
+ kfree(stats->time_in_state);
+free_stat:
+ kfree(stats);
+}
+
+void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
+ unsigned int new_freq)
+{
+ struct cpufreq_stats *stats = policy->stats;
+ int old_index, new_index;
+
+ if (!stats) {
+ pr_debug("%s: No stats found\n", __func__);
+ return;
+ }
+
+ old_index = stats->last_index;
+ new_index = freq_table_get_index(stats, new_freq);
+
+ /* We can't do stats->time_in_state[-1]= .. */
+ if (old_index == -1 || new_index == -1 || old_index == new_index)
+ return;
+
+ cpufreq_stats_update(stats);
+
+ stats->last_index = new_index;
+ stats->trans_table[old_index * stats->max_state + new_index]++;
+ stats->total_trans++;
+}