[linux-2.6-block.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>

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++;
}
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>
1da177e4	16
1aefc75b	17	static DEFINE_SPINLOCK(cpufreq_stats_lock);
1da177e4	18
1da177e4	19	struct cpufreq_stats {
1da177e4	20	unsigned int total_trans;
bb176f7d	21	unsigned long long last_time;
1da177e4 LT	22	unsigned int max_state;
	23	unsigned int state_num;
	24	unsigned int last_index;
1e7586a1	25	u64 *time_in_state;
1da177e4	26	unsigned int *freq_table;
1da177e4	27	unsigned int *trans_table;
1da177e4 LT	28	};
1da177e4 LT	29
d476ec4f	30	static void cpufreq_stats_update(struct cpufreq_stats *stats)
1da177e4	31	{
9531347c	32	unsigned long long cur_time = get_jiffies_64();
58f1df25	33
1da177e4	34	spin_lock(&cpufreq_stats_lock);
c960f9b2	35	stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
50941607	36	stats->last_time = cur_time;
1da177e4	37	spin_unlock(&cpufreq_stats_lock);
1da177e4 LT	38	}
1da177e4 LT	39
ee7930ee MM	40	static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
	41	{
	42	unsigned int count = stats->max_state;
	43
	44	memset(stats->time_in_state, 0, count * sizeof(u64));
ee7930ee	45	memset(stats->trans_table, 0, count * count * sizeof(int));
ee7930ee MM	46	stats->last_time = get_jiffies_64();
	47	stats->total_trans = 0;
	48	}
	49
0a829c5a	50	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	51	{
a9aaf291	52	return sprintf(buf, "%d\n", policy->stats->total_trans);
1da177e4 LT	53	}
1da177e4 LT	54
0a829c5a	55	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4	56	{
50941607	57	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	58	ssize_t len = 0;
1da177e4 LT	59	int i;
a9aaf291	60
1aefc75b RW	61	if (policy->fast_switch_enabled)
	62	return 0;
	63
50941607 VK	64	cpufreq_stats_update(stats);
	65	for (i = 0; i < stats->state_num; i++) {
	66	len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
0a829c5a	67	(unsigned long long)
50941607	68	jiffies_64_to_clock_t(stats->time_in_state[i]));
1da177e4 LT	69	}
	70	return len;
	71	}
	72
ee7930ee MM	73	static ssize_t store_reset(struct cpufreq_policy policy, const char buf,
	74	size_t count)
	75	{
	76	/* We don't care what is written to the attribute. */
	77	cpufreq_stats_clear_table(policy->stats);
	78	return count;
	79	}
	80
0a829c5a	81	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4	82	{
50941607	83	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	84	ssize_t len = 0;
	85	int i, j;
	86
1aefc75b RW	87	if (policy->fast_switch_enabled)
	88	return 0;
	89
58f1df25 VP	90	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
58f1df25 VP	91	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
50941607	92	for (i = 0; i < stats->state_num; i++) {
58f1df25 VP	93	if (len >= PAGE_SIZE)
	94	break;
	95	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	96	stats->freq_table[i]);
58f1df25 VP	97	}
58f1df25 VP	98	if (len >= PAGE_SIZE)
25aca347	99	return PAGE_SIZE;
58f1df25 VP	100
	101	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	102
50941607	103	for (i = 0; i < stats->state_num; i++) {
1da177e4 LT	104	if (len >= PAGE_SIZE)
1da177e4 LT	105	break;
58f1df25 VP	106
58f1df25 VP	107	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
50941607	108	stats->freq_table[i]);
1da177e4	109
50941607	110	for (j = 0; j < stats->state_num; j++) {
1da177e4 LT	111	if (len >= PAGE_SIZE)
1da177e4 LT	112	break;
58f1df25	113	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	114	stats->trans_table[i*stats->max_state+j]);
1da177e4	115	}
25aca347 CEB	116	if (len >= PAGE_SIZE)
25aca347 CEB	117	break;
1da177e4 LT	118	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	119	}
f7bc9b20 GS	120
	121	if (len >= PAGE_SIZE) {
	122	pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
	123	return -EFBIG;
	124	}
1da177e4 LT	125	return len;
1da177e4 LT	126	}
df18e504	127	cpufreq_freq_attr_ro(trans_table);
1da177e4	128
df18e504 VK	129	cpufreq_freq_attr_ro(total_trans);
df18e504 VK	130	cpufreq_freq_attr_ro(time_in_state);
ee7930ee	131	cpufreq_freq_attr_wo(reset);
1da177e4 LT	132
1da177e4 LT	133	static struct attribute *default_attrs[] = {
df18e504 VK	134	&total_trans.attr,
df18e504 VK	135	&time_in_state.attr,
ee7930ee	136	&reset.attr,
df18e504	137	&trans_table.attr,
1da177e4 LT	138	NULL
1da177e4 LT	139	};
402202e8	140	static const struct attribute_group stats_attr_group = {
1da177e4 LT	141	.attrs = default_attrs,
	142	.name = "stats"
	143	};
	144
50941607	145	static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
1da177e4 LT	146	{
1da177e4 LT	147	int index;
50941607 VK	148	for (index = 0; index < stats->max_state; index++)
50941607 VK	149	if (stats->freq_table[index] == freq)
1da177e4 LT	150	return index;
	151	return -1;
	152	}
	153
1aefc75b	154	void cpufreq_stats_free_table(struct cpufreq_policy *policy)
1da177e4	155	{
50941607	156	struct cpufreq_stats *stats = policy->stats;
b8eed8af	157
a9aaf291	158	/* Already freed */
50941607	159	if (!stats)
2d13594d VK	160	return;
2d13594d VK	161
50941607	162	pr_debug("%s: Free stats table\n", __func__);
2d13594d VK	163
2d13594d VK	164	sysfs_remove_group(&policy->kobj, &stats_attr_group);
50941607 VK	165	kfree(stats->time_in_state);
50941607 VK	166	kfree(stats);
a9aaf291	167	policy->stats = NULL;
98586ed8	168	}
98586ed8	169
1aefc75b	170	void cpufreq_stats_create_table(struct cpufreq_policy *policy)
1da177e4	171	{
a685c6d0	172	unsigned int i = 0, count = 0, ret = -ENOMEM;
50941607	173	struct cpufreq_stats *stats;
1da177e4	174	unsigned int alloc_size;
55d85293	175	struct cpufreq_frequency_table *pos;
ad4c2302	176
55d85293 VK	177	count = cpufreq_table_count_valid_entries(policy);
55d85293 VK	178	if (!count)
1aefc75b	179	return;
ad4c2302	180
b8c67448	181	/* stats already initialized */
a9aaf291	182	if (policy->stats)
1aefc75b	183	return;
b8c67448	184
50941607	185	stats = kzalloc(sizeof(*stats), GFP_KERNEL);
a685c6d0	186	if (!stats)
1aefc75b	187	return;
1da177e4	188
1e7586a1	189	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4	190
1da177e4	191	alloc_size += count * count * sizeof(int);
a685c6d0 VK	192
a685c6d0 VK	193	/* Allocate memory for time_in_state/freq_table/trans_table in one go */
50941607	194	stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
a685c6d0 VK	195	if (!stats->time_in_state)
	196	goto free_stat;
	197
50941607	198	stats->freq_table = (unsigned int *)(stats->time_in_state + count);
1da177e4	199
50941607	200	stats->trans_table = stats->freq_table + count;
a685c6d0 VK	201
	202	stats->max_state = count;
	203
	204	/* Find valid-unique entries */
55d85293	205	cpufreq_for_each_valid_entry(pos, policy->freq_table)
50941607 VK	206	if (freq_table_get_index(stats, pos->frequency) == -1)
50941607 VK	207	stats->freq_table[i++] = pos->frequency;
a685c6d0	208
490285c6	209	stats->state_num = i;
50941607 VK	210	stats->last_time = get_jiffies_64();
50941607 VK	211	stats->last_index = freq_table_get_index(stats, policy->cur);
a685c6d0 VK	212
	213	policy->stats = stats;
	214	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
	215	if (!ret)
1aefc75b	216	return;
a685c6d0 VK	217
a685c6d0 VK	218	/* We failed, release resources */
a9aaf291	219	policy->stats = NULL;
a685c6d0 VK	220	kfree(stats->time_in_state);
	221	free_stat:
	222	kfree(stats);
b3f9ff88 VK	223	}
b3f9ff88 VK	224
1aefc75b RW	225	void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
1aefc75b RW	226	unsigned int new_freq)
1da177e4	227	{
1aefc75b	228	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	229	int old_index, new_index;
1da177e4 LT	230
1aefc75b	231	if (!stats) {
a9aaf291	232	pr_debug("%s: No stats found\n", __func__);
1aefc75b	233	return;
a9aaf291 VK	234	}
a9aaf291 VK	235
50941607	236	old_index = stats->last_index;
1aefc75b	237	new_index = freq_table_get_index(stats, new_freq);
1da177e4	238
50941607	239	/* We can't do stats->time_in_state[-1]= .. */
1aefc75b RW	240	if (old_index == -1 \|\| new_index == -1 \|\| old_index == new_index)
1aefc75b RW	241	return;
8edc59d9	242
e7347694 VK	243	cpufreq_stats_update(stats);
e7347694 VK	244
50941607	245	stats->last_index = new_index;
50941607	246	stats->trans_table[old_index * stats->max_state + new_index]++;
50941607	247	stats->total_trans++;
1da177e4	248	}