[mirror_ubuntu-zesty-kernel.git] / drivers / cpufreq / cpufreq_stats.c

/*
 *  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>
#include <linux/cputime.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;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	unsigned int *trans_table;
#endif
};

static int 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);
	return 0;
}

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));
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	memset(stats->trans_table, 0, count * count * sizeof(int));
#endif
	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;
}

#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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)
		return PAGE_SIZE;
	return len;
}
cpufreq_freq_attr_ro(trans_table);
#endif

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,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	&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 *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, *table;

	/* We need cpufreq table for creating stats table */
	table = policy->freq_table;
	if (unlikely(!table))
		return;

	/* stats already initialized */
	if (policy->stats)
		return;

	stats = kzalloc(sizeof(*stats), GFP_KERNEL);
	if (!stats)
		return;

	/* Find total allocation size */
	cpufreq_for_each_valid_entry(pos, table)
		count++;

	alloc_size = count * sizeof(int) + count * sizeof(u64);

#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	alloc_size += count * count * sizeof(int);
#endif

	/* 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);

#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	stats->trans_table = stats->freq_table + count;
#endif

	stats->max_state = count;

	/* Find valid-unique entries */
	cpufreq_for_each_valid_entry(pos, 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;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	stats->trans_table[old_index * stats->max_state + new_index]++;
#endif
	stats->total_trans++;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/cpufreq/cpufreq_stats.c
	3	*
	4	* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
0a829c5a	5	* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
1da177e4 LT	6	*
	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.
	10	*/
	11
1da177e4	12	#include <linux/cpu.h>
1da177e4	13	#include <linux/cpufreq.h>
5c720d37	14	#include <linux/module.h>
5ff0a268	15	#include <linux/slab.h>
bfc3f028	16	#include <linux/cputime.h>
1da177e4	17
1aefc75b	18	static DEFINE_SPINLOCK(cpufreq_stats_lock);
1da177e4	19
1da177e4	20	struct cpufreq_stats {
1da177e4	21	unsigned int total_trans;
bb176f7d	22	unsigned long long last_time;
1da177e4 LT	23	unsigned int max_state;
	24	unsigned int state_num;
	25	unsigned int last_index;
1e7586a1	26	u64 *time_in_state;
1da177e4 LT	27	unsigned int *freq_table;
	28	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	29	unsigned int *trans_table;
	30	#endif
	31	};
	32
50941607	33	static int cpufreq_stats_update(struct cpufreq_stats *stats)
1da177e4	34	{
9531347c	35	unsigned long long cur_time = get_jiffies_64();
58f1df25	36
1da177e4	37	spin_lock(&cpufreq_stats_lock);
c960f9b2	38	stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
50941607	39	stats->last_time = cur_time;
1da177e4 LT	40	spin_unlock(&cpufreq_stats_lock);
	41	return 0;
	42	}
	43
ee7930ee MM	44	static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
	45	{
	46	unsigned int count = stats->max_state;
	47
	48	memset(stats->time_in_state, 0, count * sizeof(u64));
	49	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	50	memset(stats->trans_table, 0, count * count * sizeof(int));
	51	#endif
	52	stats->last_time = get_jiffies_64();
	53	stats->total_trans = 0;
	54	}
	55
0a829c5a	56	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	57	{
a9aaf291	58	return sprintf(buf, "%d\n", policy->stats->total_trans);
1da177e4 LT	59	}
1da177e4 LT	60
0a829c5a	61	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4	62	{
50941607	63	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	64	ssize_t len = 0;
1da177e4 LT	65	int i;
a9aaf291	66
1aefc75b RW	67	if (policy->fast_switch_enabled)
	68	return 0;
	69
50941607 VK	70	cpufreq_stats_update(stats);
	71	for (i = 0; i < stats->state_num; i++) {
	72	len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
0a829c5a	73	(unsigned long long)
50941607	74	jiffies_64_to_clock_t(stats->time_in_state[i]));
1da177e4 LT	75	}
	76	return len;
	77	}
	78
ee7930ee MM	79	static ssize_t store_reset(struct cpufreq_policy policy, const char buf,
	80	size_t count)
	81	{
	82	/* We don't care what is written to the attribute. */
	83	cpufreq_stats_clear_table(policy->stats);
	84	return count;
	85	}
	86
1da177e4	87	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
0a829c5a	88	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4	89	{
50941607	90	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	91	ssize_t len = 0;
	92	int i, j;
	93
1aefc75b RW	94	if (policy->fast_switch_enabled)
	95	return 0;
	96
58f1df25 VP	97	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
58f1df25 VP	98	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
50941607	99	for (i = 0; i < stats->state_num; i++) {
58f1df25 VP	100	if (len >= PAGE_SIZE)
	101	break;
	102	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	103	stats->freq_table[i]);
58f1df25 VP	104	}
58f1df25 VP	105	if (len >= PAGE_SIZE)
25aca347	106	return PAGE_SIZE;
58f1df25 VP	107
	108	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	109
50941607	110	for (i = 0; i < stats->state_num; i++) {
1da177e4 LT	111	if (len >= PAGE_SIZE)
1da177e4 LT	112	break;
58f1df25 VP	113
58f1df25 VP	114	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
50941607	115	stats->freq_table[i]);
1da177e4	116
50941607	117	for (j = 0; j < stats->state_num; j++) {
1da177e4 LT	118	if (len >= PAGE_SIZE)
1da177e4 LT	119	break;
58f1df25	120	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	121	stats->trans_table[i*stats->max_state+j]);
1da177e4	122	}
25aca347 CEB	123	if (len >= PAGE_SIZE)
25aca347 CEB	124	break;
1da177e4 LT	125	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	126	}
25aca347 CEB	127	if (len >= PAGE_SIZE)
25aca347 CEB	128	return PAGE_SIZE;
1da177e4 LT	129	return len;
1da177e4 LT	130	}
df18e504	131	cpufreq_freq_attr_ro(trans_table);
1da177e4 LT	132	#endif
1da177e4 LT	133
df18e504 VK	134	cpufreq_freq_attr_ro(total_trans);
df18e504 VK	135	cpufreq_freq_attr_ro(time_in_state);
ee7930ee	136	cpufreq_freq_attr_wo(reset);
1da177e4 LT	137
1da177e4 LT	138	static struct attribute *default_attrs[] = {
df18e504 VK	139	&total_trans.attr,
df18e504 VK	140	&time_in_state.attr,
ee7930ee	141	&reset.attr,
1da177e4	142	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
df18e504	143	&trans_table.attr,
1da177e4 LT	144	#endif
	145	NULL
	146	};
	147	static struct attribute_group stats_attr_group = {
	148	.attrs = default_attrs,
	149	.name = "stats"
	150	};
	151
50941607	152	static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
1da177e4 LT	153	{
1da177e4 LT	154	int index;
50941607 VK	155	for (index = 0; index < stats->max_state; index++)
50941607 VK	156	if (stats->freq_table[index] == freq)
1da177e4 LT	157	return index;
	158	return -1;
	159	}
	160
1aefc75b	161	void cpufreq_stats_free_table(struct cpufreq_policy *policy)
1da177e4	162	{
50941607	163	struct cpufreq_stats *stats = policy->stats;
b8eed8af	164
a9aaf291	165	/* Already freed */
50941607	166	if (!stats)
2d13594d VK	167	return;
2d13594d VK	168
50941607	169	pr_debug("%s: Free stats table\n", __func__);
2d13594d VK	170
2d13594d VK	171	sysfs_remove_group(&policy->kobj, &stats_attr_group);
50941607 VK	172	kfree(stats->time_in_state);
50941607 VK	173	kfree(stats);
a9aaf291	174	policy->stats = NULL;
98586ed8	175	}
98586ed8	176
1aefc75b	177	void cpufreq_stats_create_table(struct cpufreq_policy *policy)
1da177e4	178	{
a685c6d0	179	unsigned int i = 0, count = 0, ret = -ENOMEM;
50941607	180	struct cpufreq_stats *stats;
1da177e4	181	unsigned int alloc_size;
041526f9	182	struct cpufreq_frequency_table pos, table;
ad4c2302	183
a685c6d0	184	/* We need cpufreq table for creating stats table */
f8bfc116	185	table = policy->freq_table;
ad4c2302	186	if (unlikely(!table))
1aefc75b	187	return;
ad4c2302	188
b8c67448	189	/* stats already initialized */
a9aaf291	190	if (policy->stats)
1aefc75b	191	return;
b8c67448	192
50941607	193	stats = kzalloc(sizeof(*stats), GFP_KERNEL);
a685c6d0	194	if (!stats)
1aefc75b	195	return;
1da177e4	196
a685c6d0	197	/* Find total allocation size */
041526f9	198	cpufreq_for_each_valid_entry(pos, table)
1da177e4	199	count++;
1da177e4	200
1e7586a1	201	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4 LT	202
	203	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	204	alloc_size += count * count * sizeof(int);
	205	#endif
a685c6d0 VK	206
a685c6d0 VK	207	/* Allocate memory for time_in_state/freq_table/trans_table in one go */
50941607	208	stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
a685c6d0 VK	209	if (!stats->time_in_state)
	210	goto free_stat;
	211
50941607	212	stats->freq_table = (unsigned int *)(stats->time_in_state + count);
1da177e4 LT	213
1da177e4 LT	214	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
50941607	215	stats->trans_table = stats->freq_table + count;
1da177e4	216	#endif
a685c6d0 VK	217
	218	stats->max_state = count;
	219
	220	/* Find valid-unique entries */
041526f9	221	cpufreq_for_each_valid_entry(pos, table)
50941607 VK	222	if (freq_table_get_index(stats, pos->frequency) == -1)
50941607 VK	223	stats->freq_table[i++] = pos->frequency;
a685c6d0	224
490285c6	225	stats->state_num = i;
50941607 VK	226	stats->last_time = get_jiffies_64();
50941607 VK	227	stats->last_index = freq_table_get_index(stats, policy->cur);
a685c6d0 VK	228
	229	policy->stats = stats;
	230	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
	231	if (!ret)
1aefc75b	232	return;
a685c6d0 VK	233
a685c6d0 VK	234	/* We failed, release resources */
a9aaf291	235	policy->stats = NULL;
a685c6d0 VK	236	kfree(stats->time_in_state);
	237	free_stat:
	238	kfree(stats);
b3f9ff88 VK	239	}
b3f9ff88 VK	240
1aefc75b RW	241	void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
1aefc75b RW	242	unsigned int new_freq)
1da177e4	243	{
1aefc75b	244	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	245	int old_index, new_index;
1da177e4 LT	246
1aefc75b	247	if (!stats) {
a9aaf291	248	pr_debug("%s: No stats found\n", __func__);
1aefc75b	249	return;
a9aaf291 VK	250	}
a9aaf291 VK	251
50941607	252	old_index = stats->last_index;
1aefc75b	253	new_index = freq_table_get_index(stats, new_freq);
1da177e4	254
50941607	255	/* We can't do stats->time_in_state[-1]= .. */
1aefc75b RW	256	if (old_index == -1 \|\| new_index == -1 \|\| old_index == new_index)
1aefc75b RW	257	return;
8edc59d9	258
e7347694 VK	259	cpufreq_stats_update(stats);
e7347694 VK	260
50941607	261	stats->last_index = new_index;
1da177e4	262	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
50941607	263	stats->trans_table[old_index * stats->max_state + new_index]++;
1da177e4	264	#endif
50941607	265	stats->total_trans++;
1da177e4	266	}