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path: root/drivers/cpufreq/cpufreq_stats.c
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-rw-r--r--drivers/cpufreq/cpufreq_stats.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
new file mode 100644
index 000000000000..2084593937c6
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -0,0 +1,334 @@
+/*
+ * 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/config.h>
+#include <linux/kernel.h>
+#include <linux/sysdev.h>
+#include <linux/cpu.h>
+#include <linux/sysfs.h>
+#include <linux/cpufreq.h>
+#include <linux/jiffies.h>
+#include <linux/percpu.h>
+#include <linux/kobject.h>
+#include <linux/spinlock.h>
+
+static spinlock_t cpufreq_stats_lock;
+
+#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
+static struct freq_attr _attr_##_name = {\
+ .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
+ .mode = _mode, }, \
+ .show = _show,\
+};
+
+static unsigned long
+delta_time(unsigned long old, unsigned long new)
+{
+ return (old > new) ? (old - new): (new + ~old + 1);
+}
+
+struct cpufreq_stats {
+ unsigned int cpu;
+ unsigned int total_trans;
+ unsigned long long last_time;
+ unsigned int max_state;
+ unsigned int state_num;
+ unsigned int last_index;
+ unsigned long long *time_in_state;
+ unsigned int *freq_table;
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ unsigned int *trans_table;
+#endif
+};
+
+static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
+
+struct cpufreq_stats_attribute {
+ struct attribute attr;
+ ssize_t(*show) (struct cpufreq_stats *, char *);
+};
+
+static int
+cpufreq_stats_update (unsigned int cpu)
+{
+ struct cpufreq_stats *stat;
+ spin_lock(&cpufreq_stats_lock);
+ stat = cpufreq_stats_table[cpu];
+ if (stat->time_in_state)
+ stat->time_in_state[stat->last_index] +=
+ delta_time(stat->last_time, jiffies);
+ stat->last_time = jiffies;
+ spin_unlock(&cpufreq_stats_lock);
+ return 0;
+}
+
+static ssize_t
+show_total_trans(struct cpufreq_policy *policy, char *buf)
+{
+ struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+ if(!stat)
+ return 0;
+ return sprintf(buf, "%d\n",
+ cpufreq_stats_table[stat->cpu]->total_trans);
+}
+
+static ssize_t
+show_time_in_state(struct cpufreq_policy *policy, char *buf)
+{
+ ssize_t len = 0;
+ int i;
+ struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+ if(!stat)
+ return 0;
+ cpufreq_stats_update(stat->cpu);
+ for (i = 0; i < stat->state_num; i++) {
+ len += sprintf(buf + len, "%u %llu\n",
+ stat->freq_table[i], stat->time_in_state[i]);
+ }
+ return len;
+}
+
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+static ssize_t
+show_trans_table(struct cpufreq_policy *policy, char *buf)
+{
+ ssize_t len = 0;
+ int i, j;
+
+ struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
+ if(!stat)
+ return 0;
+ cpufreq_stats_update(stat->cpu);
+ for (i = 0; i < stat->state_num; i++) {
+ if (len >= PAGE_SIZE)
+ break;
+ len += snprintf(buf + len, PAGE_SIZE - len, "%9u:\t",
+ stat->freq_table[i]);
+
+ for (j = 0; j < stat->state_num; j++) {
+ if (len >= PAGE_SIZE)
+ break;
+ len += snprintf(buf + len, PAGE_SIZE - len, "%u\t",
+ stat->trans_table[i*stat->max_state+j]);
+ }
+ len += snprintf(buf + len, PAGE_SIZE - len, "\n");
+ }
+ return len;
+}
+CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
+#endif
+
+CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
+CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
+
+static struct attribute *default_attrs[] = {
+ &_attr_total_trans.attr,
+ &_attr_time_in_state.attr,
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ &_attr_trans_table.attr,
+#endif
+ NULL
+};
+static struct attribute_group stats_attr_group = {
+ .attrs = default_attrs,
+ .name = "stats"
+};
+
+static int
+freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
+{
+ int index;
+ for (index = 0; index < stat->max_state; index++)
+ if (stat->freq_table[index] == freq)
+ return index;
+ return -1;
+}
+
+static void
+cpufreq_stats_free_table (unsigned int cpu)
+{
+ struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ if (policy && policy->cpu == cpu)
+ sysfs_remove_group(&policy->kobj, &stats_attr_group);
+ if (stat) {
+ kfree(stat->time_in_state);
+ kfree(stat);
+ }
+ cpufreq_stats_table[cpu] = NULL;
+ if (policy)
+ cpufreq_cpu_put(policy);
+}
+
+static int
+cpufreq_stats_create_table (struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table)
+{
+ unsigned int i, j, count = 0, ret = 0;
+ struct cpufreq_stats *stat;
+ struct cpufreq_policy *data;
+ unsigned int alloc_size;
+ unsigned int cpu = policy->cpu;
+ if (cpufreq_stats_table[cpu])
+ return -EBUSY;
+ if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
+ return -ENOMEM;
+ memset(stat, 0, sizeof (struct cpufreq_stats));
+
+ data = cpufreq_cpu_get(cpu);
+ if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
+ goto error_out;
+
+ stat->cpu = cpu;
+ cpufreq_stats_table[cpu] = stat;
+
+ for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ unsigned int freq = table[i].frequency;
+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+ count++;
+ }
+
+ alloc_size = count * sizeof(int) + count * sizeof(long long);
+
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ alloc_size += count * count * sizeof(int);
+#endif
+ stat->max_state = count;
+ stat->time_in_state = kmalloc(alloc_size, GFP_KERNEL);
+ if (!stat->time_in_state) {
+ ret = -ENOMEM;
+ goto error_out;
+ }
+ memset(stat->time_in_state, 0, alloc_size);
+ stat->freq_table = (unsigned int *)(stat->time_in_state + count);
+
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ stat->trans_table = stat->freq_table + count;
+#endif
+ j = 0;
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ unsigned int freq = table[i].frequency;
+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+ if (freq_table_get_index(stat, freq) == -1)
+ stat->freq_table[j++] = freq;
+ }
+ stat->state_num = j;
+ spin_lock(&cpufreq_stats_lock);
+ stat->last_time = jiffies;
+ stat->last_index = freq_table_get_index(stat, policy->cur);
+ spin_unlock(&cpufreq_stats_lock);
+ cpufreq_cpu_put(data);
+ return 0;
+error_out:
+ cpufreq_cpu_put(data);
+ kfree(stat);
+ cpufreq_stats_table[cpu] = NULL;
+ return ret;
+}
+
+static int
+cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ int ret;
+ struct cpufreq_policy *policy = data;
+ struct cpufreq_frequency_table *table;
+ unsigned int cpu = policy->cpu;
+ if (val != CPUFREQ_NOTIFY)
+ return 0;
+ table = cpufreq_frequency_get_table(cpu);
+ if (!table)
+ return 0;
+ if ((ret = cpufreq_stats_create_table(policy, table)))
+ return ret;
+ return 0;
+}
+
+static int
+cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct cpufreq_freqs *freq = data;
+ struct cpufreq_stats *stat;
+ int old_index, new_index;
+
+ if (val != CPUFREQ_POSTCHANGE)
+ return 0;
+
+ stat = cpufreq_stats_table[freq->cpu];
+ if (!stat)
+ return 0;
+ old_index = freq_table_get_index(stat, freq->old);
+ new_index = freq_table_get_index(stat, freq->new);
+
+ cpufreq_stats_update(freq->cpu);
+ if (old_index == new_index)
+ return 0;
+
+ spin_lock(&cpufreq_stats_lock);
+ stat->last_index = new_index;
+#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
+ stat->trans_table[old_index * stat->max_state + new_index]++;
+#endif
+ stat->total_trans++;
+ spin_unlock(&cpufreq_stats_lock);
+ return 0;
+}
+
+static struct notifier_block notifier_policy_block = {
+ .notifier_call = cpufreq_stat_notifier_policy
+};
+
+static struct notifier_block notifier_trans_block = {
+ .notifier_call = cpufreq_stat_notifier_trans
+};
+
+static int
+__init cpufreq_stats_init(void)
+{
+ int ret;
+ unsigned int cpu;
+ spin_lock_init(&cpufreq_stats_lock);
+ if ((ret = cpufreq_register_notifier(&notifier_policy_block,
+ CPUFREQ_POLICY_NOTIFIER)))
+ return ret;
+
+ if ((ret = cpufreq_register_notifier(&notifier_trans_block,
+ CPUFREQ_TRANSITION_NOTIFIER))) {
+ cpufreq_unregister_notifier(&notifier_policy_block,
+ CPUFREQ_POLICY_NOTIFIER);
+ return ret;
+ }
+
+ for_each_cpu(cpu)
+ cpufreq_update_policy(cpu);
+ return 0;
+}
+static void
+__exit cpufreq_stats_exit(void)
+{
+ unsigned int cpu;
+ cpufreq_unregister_notifier(&notifier_policy_block,
+ CPUFREQ_POLICY_NOTIFIER);
+ cpufreq_unregister_notifier(&notifier_trans_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ for_each_cpu(cpu)
+ cpufreq_stats_free_table(cpu);
+}
+
+MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
+MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem");
+MODULE_LICENSE ("GPL");
+
+module_init(cpufreq_stats_init);
+module_exit(cpufreq_stats_exit);