[deliverable/linux.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 spinlock_t cpufreq_stats_lock;

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;
	u64 *time_in_state;
	unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	unsigned int *trans_table;
#endif
};

static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);

static int cpufreq_stats_update(unsigned int cpu)
{
	struct cpufreq_stats *stat;
	unsigned long long cur_time = get_jiffies_64();

	spin_lock(&cpufreq_stats_lock);
	stat = per_cpu(cpufreq_stats_table, cpu);
	if (stat->time_in_state)
		stat->time_in_state[stat->last_index] +=
			cur_time - stat->last_time;
	stat->last_time = cur_time;
	spin_unlock(&cpufreq_stats_lock);
	return 0;
}

static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
	if (!stat)
		return 0;
	return sprintf(buf, "%d\n",
			per_cpu(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 = per_cpu(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],
			(unsigned long long)
			jiffies_64_to_clock_t(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 = per_cpu(cpufreq_stats_table, policy->cpu);
	if (!stat)
		return 0;
	cpufreq_stats_update(stat->cpu);
	len += snprintf(buf + len, PAGE_SIZE - len, "   From  :    To\n");
	len += snprintf(buf + len, PAGE_SIZE - len, "         : ");
	for (i = 0; i < stat->state_num; i++) {
		if (len >= PAGE_SIZE)
			break;
		len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
				stat->freq_table[i]);
	}
	if (len >= PAGE_SIZE)
		return PAGE_SIZE;

	len += snprintf(buf + len, PAGE_SIZE - len, "\n");

	for (i = 0; i < stat->state_num; i++) {
		if (len >= PAGE_SIZE)
			break;

		len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
				stat->freq_table[i]);

		for (j = 0; j < stat->state_num; j++) {
			if (len >= PAGE_SIZE)
				break;
			len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
					stat->trans_table[i*stat->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);

static struct attribute *default_attrs[] = {
	&total_trans.attr,
	&time_in_state.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 *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(struct cpufreq_policy *policy)
{
	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);

	if (!stat)
		return;

	pr_debug("%s: Free stat table\n", __func__);

	sysfs_remove_group(&policy->kobj, &stats_attr_group);
	kfree(stat->time_in_state);
	kfree(stat);
	per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
}

static void cpufreq_stats_free_table(unsigned int cpu)
{
	struct cpufreq_policy *policy;

	policy = cpufreq_cpu_get(cpu);
	if (!policy)
		return;

	if (cpufreq_frequency_get_table(policy->cpu))
		__cpufreq_stats_free_table(policy);

	cpufreq_cpu_put(policy);
}

static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
{
	unsigned int i, count = 0, ret = 0;
	struct cpufreq_stats *stat;
	unsigned int alloc_size;
	unsigned int cpu = policy->cpu;
	struct cpufreq_frequency_table *pos, *table;

	table = cpufreq_frequency_get_table(cpu);
	if (unlikely(!table))
		return 0;

	/* stats already initialized */
	if (per_cpu(cpufreq_stats_table, cpu))
		return -EEXIST;

	stat = kzalloc(sizeof(*stat), GFP_KERNEL);
	if ((stat) == NULL)
		return -ENOMEM;

	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
	if (ret)
		goto error_out;

	stat->cpu = cpu;
	per_cpu(cpufreq_stats_table, cpu) = stat;

	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
	stat->max_state = count;
	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
	if (!stat->time_in_state) {
		ret = -ENOMEM;
		goto error_alloc;
	}
	stat->freq_table = (unsigned int *)(stat->time_in_state + count);

#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	stat->trans_table = stat->freq_table + count;
#endif
	i = 0;
	cpufreq_for_each_valid_entry(pos, table)
		if (freq_table_get_index(stat, pos->frequency) == -1)
			stat->freq_table[i++] = pos->frequency;
	stat->state_num = i;
	spin_lock(&cpufreq_stats_lock);
	stat->last_time = get_jiffies_64();
	stat->last_index = freq_table_get_index(stat, policy->cur);
	spin_unlock(&cpufreq_stats_lock);
	return 0;
error_alloc:
	sysfs_remove_group(&policy->kobj, &stats_attr_group);
error_out:
	kfree(stat);
	per_cpu(cpufreq_stats_table, cpu) = NULL;
	return ret;
}

static void cpufreq_stats_create_table(unsigned int cpu)
{
	struct cpufreq_policy *policy;

	/*
	 * "likely(!policy)" because normally cpufreq_stats will be registered
	 * before cpufreq driver
	 */
	policy = cpufreq_cpu_get(cpu);
	if (likely(!policy))
		return;

	__cpufreq_stats_create_table(policy);

	cpufreq_cpu_put(policy);
}

static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
{
	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
			policy->last_cpu);

	pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
			policy->cpu, policy->last_cpu);
	per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
			policy->last_cpu);
	per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
	stat->cpu = policy->cpu;
}

static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
		unsigned long val, void *data)
{
	int ret = 0;
	struct cpufreq_policy *policy = data;

	if (val == CPUFREQ_UPDATE_POLICY_CPU) {
		cpufreq_stats_update_policy_cpu(policy);
		return 0;
	}

	if (val == CPUFREQ_CREATE_POLICY)
		ret = __cpufreq_stats_create_table(policy);
	else if (val == CPUFREQ_REMOVE_POLICY)
		__cpufreq_stats_free_table(policy);

	return ret;
}

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 = per_cpu(cpufreq_stats_table, freq->cpu);
	if (!stat)
		return 0;

	old_index = stat->last_index;
	new_index = freq_table_get_index(stat, freq->new);

	/* We can't do stat->time_in_state[-1]= .. */
	if (old_index == -1 || new_index == -1)
		return 0;

	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);
	ret = cpufreq_register_notifier(&notifier_policy_block,
				CPUFREQ_POLICY_NOTIFIER);
	if (ret)
		return ret;

	for_each_online_cpu(cpu)
		cpufreq_stats_create_table(cpu);

	ret = cpufreq_register_notifier(&notifier_trans_block,
				CPUFREQ_TRANSITION_NOTIFIER);
	if (ret) {
		cpufreq_unregister_notifier(&notifier_policy_block,
				CPUFREQ_POLICY_NOTIFIER);
		for_each_online_cpu(cpu)
			cpufreq_stats_free_table(cpu);
		return ret;
	}

	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_online_cpu(cpu)
		cpufreq_stats_free_table(cpu);
}

MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
MODULE_LICENSE("GPL");

module_init(cpufreq_stats_init);
module_exit(cpufreq_stats_exit);
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 LT	17
	18	static spinlock_t cpufreq_stats_lock;
	19
1da177e4 LT	20	struct cpufreq_stats {
	21	unsigned int cpu;
	22	unsigned int total_trans;
bb176f7d	23	unsigned long long last_time;
1da177e4 LT	24	unsigned int max_state;
	25	unsigned int state_num;
	26	unsigned int last_index;
1e7586a1	27	u64 *time_in_state;
1da177e4 LT	28	unsigned int *freq_table;
	29	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	30	unsigned int *trans_table;
	31	#endif
	32	};
	33
7a6aedfa	34	static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
1da177e4	35
0a829c5a	36	static int cpufreq_stats_update(unsigned int cpu)
1da177e4 LT	37	{
1da177e4 LT	38	struct cpufreq_stats *stat;
9531347c	39	unsigned long long cur_time = get_jiffies_64();
58f1df25	40
1da177e4	41	spin_lock(&cpufreq_stats_lock);
7a6aedfa	42	stat = per_cpu(cpufreq_stats_table, cpu);
1da177e4	43	if (stat->time_in_state)
64861634 MS	44	stat->time_in_state[stat->last_index] +=
64861634 MS	45	cur_time - stat->last_time;
58f1df25	46	stat->last_time = cur_time;
1da177e4 LT	47	spin_unlock(&cpufreq_stats_lock);
	48	return 0;
	49	}
	50
0a829c5a	51	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	52	{
7a6aedfa	53	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	54	if (!stat)
1da177e4 LT	55	return 0;
1da177e4 LT	56	return sprintf(buf, "%d\n",
7a6aedfa	57	per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
1da177e4 LT	58	}
1da177e4 LT	59
0a829c5a	60	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4 LT	61	{
	62	ssize_t len = 0;
	63	int i;
7a6aedfa	64	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	65	if (!stat)
1da177e4 LT	66	return 0;
	67	cpufreq_stats_update(stat->cpu);
	68	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	69	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
0a829c5a	70	(unsigned long long)
a857c0b9	71	jiffies_64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	72	}
	73	return len;
	74	}
	75
	76	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
0a829c5a	77	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4 LT	78	{
	79	ssize_t len = 0;
	80	int i, j;
	81
7a6aedfa	82	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	83	if (!stat)
1da177e4 LT	84	return 0;
1da177e4 LT	85	cpufreq_stats_update(stat->cpu);
58f1df25 VP	86	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	87	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	88	for (i = 0; i < stat->state_num; i++) {
	89	if (len >= PAGE_SIZE)
	90	break;
	91	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	92	stat->freq_table[i]);
	93	}
	94	if (len >= PAGE_SIZE)
25aca347	95	return PAGE_SIZE;
58f1df25 VP	96
	97	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	98
1da177e4 LT	99	for (i = 0; i < stat->state_num; i++) {
	100	if (len >= PAGE_SIZE)
	101	break;
58f1df25 VP	102
58f1df25 VP	103	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	104	stat->freq_table[i]);
1da177e4 LT	105
bb176f7d	106	for (j = 0; j < stat->state_num; j++) {
1da177e4 LT	107	if (len >= PAGE_SIZE)
1da177e4 LT	108	break;
58f1df25	109	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	110	stat->trans_table[i*stat->max_state+j]);
1da177e4 LT	111	}
25aca347 CEB	112	if (len >= PAGE_SIZE)
25aca347 CEB	113	break;
1da177e4 LT	114	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	115	}
25aca347 CEB	116	if (len >= PAGE_SIZE)
25aca347 CEB	117	return PAGE_SIZE;
1da177e4 LT	118	return len;
1da177e4 LT	119	}
df18e504	120	cpufreq_freq_attr_ro(trans_table);
1da177e4 LT	121	#endif
1da177e4 LT	122
df18e504 VK	123	cpufreq_freq_attr_ro(total_trans);
df18e504 VK	124	cpufreq_freq_attr_ro(time_in_state);
1da177e4 LT	125
1da177e4 LT	126	static struct attribute *default_attrs[] = {
df18e504 VK	127	&total_trans.attr,
df18e504 VK	128	&time_in_state.attr,
1da177e4	129	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
df18e504	130	&trans_table.attr,
1da177e4 LT	131	#endif
	132	NULL
	133	};
	134	static struct attribute_group stats_attr_group = {
	135	.attrs = default_attrs,
	136	.name = "stats"
	137	};
	138
0a829c5a	139	static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
1da177e4 LT	140	{
	141	int index;
	142	for (index = 0; index < stat->max_state; index++)
	143	if (stat->freq_table[index] == freq)
	144	return index;
	145	return -1;
	146	}
	147
2d13594d	148	static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
1da177e4	149	{
2d13594d	150	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
b8eed8af	151
2d13594d VK	152	if (!stat)
	153	return;
	154
	155	pr_debug("%s: Free stat table\n", __func__);
	156
	157	sysfs_remove_group(&policy->kobj, &stats_attr_group);
	158	kfree(stat->time_in_state);
	159	kfree(stat);
	160	per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
98586ed8	161	}
98586ed8	162
2d13594d	163	static void cpufreq_stats_free_table(unsigned int cpu)
98586ed8	164	{
2d13594d	165	struct cpufreq_policy *policy;
633d47d6	166
2d13594d	167	policy = cpufreq_cpu_get(cpu);
187da1d9	168	if (!policy)
633d47d6 DB	169	return;
633d47d6 DB	170
2d13594d VK	171	if (cpufreq_frequency_get_table(policy->cpu))
2d13594d VK	172	__cpufreq_stats_free_table(policy);
187da1d9	173
187da1d9	174	cpufreq_cpu_put(policy);
1da177e4 LT	175	}
1da177e4 LT	176
ad4c2302	177	static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
1da177e4	178	{
041526f9	179	unsigned int i, count = 0, ret = 0;
1da177e4	180	struct cpufreq_stats *stat;
1da177e4 LT	181	unsigned int alloc_size;
1da177e4 LT	182	unsigned int cpu = policy->cpu;
041526f9	183	struct cpufreq_frequency_table pos, table;
ad4c2302 SK	184
	185	table = cpufreq_frequency_get_table(cpu);
	186	if (unlikely(!table))
	187	return 0;
	188
b8c67448	189	/* stats already initialized */
7a6aedfa	190	if (per_cpu(cpufreq_stats_table, cpu))
b8c67448 VK	191	return -EEXIST;
b8c67448 VK	192
d5b73cd8	193	stat = kzalloc(sizeof(*stat), GFP_KERNEL);
0a829c5a	194	if ((stat) == NULL)
1da177e4	195	return -ENOMEM;
1da177e4	196
b24a5b65	197	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
0a829c5a	198	if (ret)
1da177e4 LT	199	goto error_out;
	200
	201	stat->cpu = cpu;
7a6aedfa	202	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4	203
041526f9	204	cpufreq_for_each_valid_entry(pos, table)
1da177e4	205	count++;
1da177e4	206
1e7586a1	207	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4 LT	208
	209	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	210	alloc_size += count * count * sizeof(int);
	211	#endif
	212	stat->max_state = count;
e98df50c	213	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	214	if (!stat->time_in_state) {
1da177e4 LT	215	ret = -ENOMEM;
0b7528d9	216	goto error_alloc;
1da177e4	217	}
1da177e4 LT	218	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	219
	220	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	221	stat->trans_table = stat->freq_table + count;
	222	#endif
041526f9 SK	223	i = 0;
	224	cpufreq_for_each_valid_entry(pos, table)
	225	if (freq_table_get_index(stat, pos->frequency) == -1)
	226	stat->freq_table[i++] = pos->frequency;
	227	stat->state_num = i;
1da177e4	228	spin_lock(&cpufreq_stats_lock);
58f1df25	229	stat->last_time = get_jiffies_64();
1da177e4 LT	230	stat->last_index = freq_table_get_index(stat, policy->cur);
1da177e4 LT	231	spin_unlock(&cpufreq_stats_lock);
1da177e4	232	return 0;
0b7528d9 SK	233	error_alloc:
0b7528d9 SK	234	sysfs_remove_group(&policy->kobj, &stats_attr_group);
1da177e4	235	error_out:
1da177e4	236	kfree(stat);
7a6aedfa	237	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	238	return ret;
	239	}
	240
b3f9ff88 VK	241	static void cpufreq_stats_create_table(unsigned int cpu)
	242	{
	243	struct cpufreq_policy *policy;
b3f9ff88 VK	244
	245	/*
	246	* "likely(!policy)" because normally cpufreq_stats will be registered
	247	* before cpufreq driver
	248	*/
	249	policy = cpufreq_cpu_get(cpu);
	250	if (likely(!policy))
	251	return;
	252
ad4c2302	253	__cpufreq_stats_create_table(policy);
b3f9ff88 VK	254
	255	cpufreq_cpu_put(policy);
	256	}
	257
b8eed8af VK	258	static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
	259	{
	260	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
	261	policy->last_cpu);
	262
	263	pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
	264	policy->cpu, policy->last_cpu);
	265	per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
	266	policy->last_cpu);
	267	per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
	268	stat->cpu = policy->cpu;
	269	}
	270
0a829c5a DJ	271	static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
0a829c5a DJ	272	unsigned long val, void *data)
1da177e4	273	{
fcd7af91	274	int ret = 0;
1da177e4	275	struct cpufreq_policy *policy = data;
b8eed8af VK	276
	277	if (val == CPUFREQ_UPDATE_POLICY_CPU) {
	278	cpufreq_stats_update_policy_cpu(policy);
	279	return 0;
	280	}
	281
fcd7af91	282	if (val == CPUFREQ_CREATE_POLICY)
ad4c2302	283	ret = __cpufreq_stats_create_table(policy);
2d13594d VK	284	else if (val == CPUFREQ_REMOVE_POLICY)
2d13594d VK	285	__cpufreq_stats_free_table(policy);
fcd7af91 VK	286
fcd7af91 VK	287	return ret;
1da177e4 LT	288	}
1da177e4 LT	289
0a829c5a DJ	290	static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
0a829c5a DJ	291	unsigned long val, void *data)
1da177e4 LT	292	{
	293	struct cpufreq_freqs *freq = data;
	294	struct cpufreq_stats *stat;
	295	int old_index, new_index;
	296
	297	if (val != CPUFREQ_POSTCHANGE)
	298	return 0;
	299
7a6aedfa	300	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	301	if (!stat)
1da177e4 LT	302	return 0;
8edc59d9	303
6501faf8	304	old_index = stat->last_index;
1da177e4 LT	305	new_index = freq_table_get_index(stat, freq->new);
1da177e4 LT	306
46a310b8 KRW	307	/* We can't do stat->time_in_state[-1]= .. */
46a310b8 KRW	308	if (old_index == -1 \|\| new_index == -1)
1da177e4 LT	309	return 0;
1da177e4 LT	310
46a310b8 KRW	311	cpufreq_stats_update(freq->cpu);
	312
	313	if (old_index == new_index)
8edc59d9 VP	314	return 0;
8edc59d9 VP	315
1da177e4 LT	316	spin_lock(&cpufreq_stats_lock);
	317	stat->last_index = new_index;
	318	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	319	stat->trans_table[old_index * stat->max_state + new_index]++;
	320	#endif
	321	stat->total_trans++;
	322	spin_unlock(&cpufreq_stats_lock);
	323	return 0;
	324	}
	325
	326	static struct notifier_block notifier_policy_block = {
	327	.notifier_call = cpufreq_stat_notifier_policy
	328	};
	329
	330	static struct notifier_block notifier_trans_block = {
	331	.notifier_call = cpufreq_stat_notifier_trans
	332	};
	333
0a829c5a	334	static int __init cpufreq_stats_init(void)
1da177e4 LT	335	{
	336	int ret;
	337	unsigned int cpu;
c32b6b8e	338
1da177e4	339	spin_lock_init(&cpufreq_stats_lock);
0a829c5a DJ	340	ret = cpufreq_register_notifier(&notifier_policy_block,
	341	CPUFREQ_POLICY_NOTIFIER);
	342	if (ret)
1da177e4 LT	343	return ret;
1da177e4 LT	344
b3f9ff88 VK	345	for_each_online_cpu(cpu)
	346	cpufreq_stats_create_table(cpu);
	347
0a829c5a DJ	348	ret = cpufreq_register_notifier(&notifier_trans_block,
	349	CPUFREQ_TRANSITION_NOTIFIER);
	350	if (ret) {
1da177e4 LT	351	cpufreq_unregister_notifier(&notifier_policy_block,
1da177e4 LT	352	CPUFREQ_POLICY_NOTIFIER);
56836fb4 KK	353	for_each_online_cpu(cpu)
56836fb4 KK	354	cpufreq_stats_free_table(cpu);
1da177e4 LT	355	return ret;
	356	}
	357
1da177e4 LT	358	return 0;
1da177e4 LT	359	}
0a829c5a	360	static void __exit cpufreq_stats_exit(void)
1da177e4 LT	361	{
1da177e4 LT	362	unsigned int cpu;
c32b6b8e	363
1da177e4 LT	364	cpufreq_unregister_notifier(&notifier_policy_block,
	365	CPUFREQ_POLICY_NOTIFIER);
	366	cpufreq_unregister_notifier(&notifier_trans_block,
	367	CPUFREQ_TRANSITION_NOTIFIER);
2d13594d	368	for_each_online_cpu(cpu)
55395ae7	369	cpufreq_stats_free_table(cpu);
1da177e4 LT	370	}
1da177e4 LT	371
0a829c5a	372	MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
00d0b294	373	MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
0a829c5a	374	MODULE_LICENSE("GPL");
1da177e4 LT	375
	376	module_init(cpufreq_stats_init);
	377	module_exit(cpufreq_stats_exit);