[linux-2.6-block.git] / drivers / cpufreq / cpufreq_stats.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  drivers/cpufreq/cpufreq_stats.c
 *
 *  Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
 *  (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
 */

#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/slab.h>


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;
	spinlock_t lock;
	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();

	stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
	stats->last_time = cur_time;
}

static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
{
	unsigned int count = stats->max_state;

	spin_lock(&stats->lock);
	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;
	spin_unlock(&stats->lock);
}

static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
	return sprintf(buf, "%d\n", policy->stats->total_trans);
}
cpufreq_freq_attr_ro(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;

	spin_lock(&stats->lock);
	cpufreq_stats_update(stats);
	spin_unlock(&stats->lock);

	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;
}
cpufreq_freq_attr_ro(time_in_state);

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;
}
cpufreq_freq_attr_wo(reset);

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);

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);
	spin_lock_init(&stats->lock);

	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;

	spin_lock(&stats->lock);
	cpufreq_stats_update(stats);

	stats->last_index = new_index;
	stats->trans_table[old_index * stats->max_state + new_index]++;
	stats->total_trans++;
	spin_unlock(&stats->lock);
}
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* drivers/cpufreq/cpufreq_stats.c
	4	*
	5	* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
0a829c5a	6	* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
1da177e4 LT	7	*/
1da177e4 LT	8
1da177e4	9	#include <linux/cpu.h>
1da177e4	10	#include <linux/cpufreq.h>
5c720d37	11	#include <linux/module.h>
5ff0a268	12	#include <linux/slab.h>
1da177e4	13
1da177e4	14
1da177e4	15	struct cpufreq_stats {
1da177e4	16	unsigned int total_trans;
bb176f7d	17	unsigned long long last_time;
1da177e4 LT	18	unsigned int max_state;
	19	unsigned int state_num;
	20	unsigned int last_index;
1e7586a1	21	u64 *time_in_state;
fcccc5c8	22	spinlock_t lock;
1da177e4	23	unsigned int *freq_table;
1da177e4	24	unsigned int *trans_table;
1da177e4 LT	25	};
1da177e4 LT	26
d476ec4f	27	static void cpufreq_stats_update(struct cpufreq_stats *stats)
1da177e4	28	{
9531347c	29	unsigned long long cur_time = get_jiffies_64();
58f1df25	30
c960f9b2	31	stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
50941607	32	stats->last_time = cur_time;
1da177e4 LT	33	}
1da177e4 LT	34
ee7930ee MM	35	static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
	36	{
	37	unsigned int count = stats->max_state;
	38
fcccc5c8	39	spin_lock(&stats->lock);
ee7930ee	40	memset(stats->time_in_state, 0, count * sizeof(u64));
ee7930ee	41	memset(stats->trans_table, 0, count * count * sizeof(int));
ee7930ee MM	42	stats->last_time = get_jiffies_64();
ee7930ee MM	43	stats->total_trans = 0;
fcccc5c8	44	spin_unlock(&stats->lock);
ee7930ee MM	45	}
ee7930ee MM	46
0a829c5a	47	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	48	{
a9aaf291	49	return sprintf(buf, "%d\n", policy->stats->total_trans);
1da177e4	50	}
10b81821	51	cpufreq_freq_attr_ro(total_trans);
1da177e4	52
0a829c5a	53	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4	54	{
50941607	55	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	56	ssize_t len = 0;
1da177e4 LT	57	int i;
a9aaf291	58
1aefc75b RW	59	if (policy->fast_switch_enabled)
	60	return 0;
	61
fcccc5c8	62	spin_lock(&stats->lock);
50941607	63	cpufreq_stats_update(stats);
fcccc5c8	64	spin_unlock(&stats->lock);
9795607d	65
50941607 VK	66	for (i = 0; i < stats->state_num; i++) {
50941607 VK	67	len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
0a829c5a	68	(unsigned long long)
50941607	69	jiffies_64_to_clock_t(stats->time_in_state[i]));
1da177e4 LT	70	}
	71	return len;
	72	}
10b81821	73	cpufreq_freq_attr_ro(time_in_state);
1da177e4	74
ee7930ee MM	75	static ssize_t store_reset(struct cpufreq_policy policy, const char buf,
	76	size_t count)
	77	{
	78	/* We don't care what is written to the attribute. */
	79	cpufreq_stats_clear_table(policy->stats);
	80	return count;
	81	}
10b81821	82	cpufreq_freq_attr_wo(reset);
ee7930ee	83
0a829c5a	84	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4	85	{
50941607	86	struct cpufreq_stats *stats = policy->stats;
1da177e4 LT	87	ssize_t len = 0;
	88	int i, j;
	89
1aefc75b RW	90	if (policy->fast_switch_enabled)
	91	return 0;
	92
58f1df25 VP	93	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
58f1df25 VP	94	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
50941607	95	for (i = 0; i < stats->state_num; i++) {
58f1df25 VP	96	if (len >= PAGE_SIZE)
	97	break;
	98	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	99	stats->freq_table[i]);
58f1df25 VP	100	}
58f1df25 VP	101	if (len >= PAGE_SIZE)
25aca347	102	return PAGE_SIZE;
58f1df25 VP	103
	104	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	105
50941607	106	for (i = 0; i < stats->state_num; i++) {
1da177e4 LT	107	if (len >= PAGE_SIZE)
1da177e4 LT	108	break;
58f1df25 VP	109
58f1df25 VP	110	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
50941607	111	stats->freq_table[i]);
1da177e4	112
50941607	113	for (j = 0; j < stats->state_num; j++) {
1da177e4 LT	114	if (len >= PAGE_SIZE)
1da177e4 LT	115	break;
58f1df25	116	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
50941607	117	stats->trans_table[i*stats->max_state+j]);
1da177e4	118	}
25aca347 CEB	119	if (len >= PAGE_SIZE)
25aca347 CEB	120	break;
1da177e4 LT	121	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	122	}
f7bc9b20 GS	123
	124	if (len >= PAGE_SIZE) {
	125	pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
	126	return -EFBIG;
	127	}
1da177e4 LT	128	return len;
1da177e4 LT	129	}
df18e504	130	cpufreq_freq_attr_ro(trans_table);
1da177e4	131
1da177e4	132	static struct attribute *default_attrs[] = {
df18e504 VK	133	&total_trans.attr,
df18e504 VK	134	&time_in_state.attr,
ee7930ee	135	&reset.attr,
df18e504	136	&trans_table.attr,
1da177e4 LT	137	NULL
1da177e4 LT	138	};
402202e8	139	static const struct attribute_group stats_attr_group = {
1da177e4 LT	140	.attrs = default_attrs,
	141	.name = "stats"
	142	};
	143
50941607	144	static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
1da177e4 LT	145	{
1da177e4 LT	146	int index;
50941607 VK	147	for (index = 0; index < stats->max_state; index++)
50941607 VK	148	if (stats->freq_table[index] == freq)
1da177e4 LT	149	return index;
	150	return -1;
	151	}
	152
1aefc75b	153	void cpufreq_stats_free_table(struct cpufreq_policy *policy)
1da177e4	154	{
50941607	155	struct cpufreq_stats *stats = policy->stats;
b8eed8af	156
a9aaf291	157	/* Already freed */
50941607	158	if (!stats)
2d13594d VK	159	return;
2d13594d VK	160
50941607	161	pr_debug("%s: Free stats table\n", __func__);
2d13594d VK	162
2d13594d VK	163	sysfs_remove_group(&policy->kobj, &stats_attr_group);
50941607 VK	164	kfree(stats->time_in_state);
50941607 VK	165	kfree(stats);
a9aaf291	166	policy->stats = NULL;
98586ed8	167	}
98586ed8	168
1aefc75b	169	void cpufreq_stats_create_table(struct cpufreq_policy *policy)
1da177e4	170	{
a685c6d0	171	unsigned int i = 0, count = 0, ret = -ENOMEM;
50941607	172	struct cpufreq_stats *stats;
1da177e4	173	unsigned int alloc_size;
55d85293	174	struct cpufreq_frequency_table *pos;
ad4c2302	175
55d85293 VK	176	count = cpufreq_table_count_valid_entries(policy);
55d85293 VK	177	if (!count)
1aefc75b	178	return;
ad4c2302	179
b8c67448	180	/* stats already initialized */
a9aaf291	181	if (policy->stats)
1aefc75b	182	return;
b8c67448	183
50941607	184	stats = kzalloc(sizeof(*stats), GFP_KERNEL);
a685c6d0	185	if (!stats)
1aefc75b	186	return;
1da177e4	187
1e7586a1	188	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4	189
1da177e4	190	alloc_size += count * count * sizeof(int);
a685c6d0 VK	191
a685c6d0 VK	192	/* Allocate memory for time_in_state/freq_table/trans_table in one go */
50941607	193	stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
a685c6d0 VK	194	if (!stats->time_in_state)
	195	goto free_stat;
	196
50941607	197	stats->freq_table = (unsigned int *)(stats->time_in_state + count);
1da177e4	198
50941607	199	stats->trans_table = stats->freq_table + count;
a685c6d0 VK	200
	201	stats->max_state = count;
	202
	203	/* Find valid-unique entries */
55d85293	204	cpufreq_for_each_valid_entry(pos, policy->freq_table)
50941607 VK	205	if (freq_table_get_index(stats, pos->frequency) == -1)
50941607 VK	206	stats->freq_table[i++] = pos->frequency;
a685c6d0	207
490285c6	208	stats->state_num = i;
50941607 VK	209	stats->last_time = get_jiffies_64();
50941607 VK	210	stats->last_index = freq_table_get_index(stats, policy->cur);
fcccc5c8	211	spin_lock_init(&stats->lock);
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
fcccc5c8	243	spin_lock(&stats->lock);
e7347694 VK	244	cpufreq_stats_update(stats);
e7347694 VK	245
50941607	246	stats->last_index = new_index;
50941607	247	stats->trans_table[old_index * stats->max_state + new_index]++;
50941607	248	stats->total_trans++;
fcccc5c8	249	spin_unlock(&stats->lock);
1da177e4	250	}