[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);

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;
	unsigned long long cur_time;

	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, j, count = 0, ret = 0;
	struct cpufreq_stats *stat;
	unsigned int alloc_size;
	unsigned int cpu = policy->cpu;
	struct cpufreq_frequency_table *table;

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

	if (per_cpu(cpufreq_stats_table, cpu))
		return -EBUSY;
	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;

	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(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
	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 = 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("'cpufreq_stats' - A driver to export cpufreq stats "
				"through sysfs filesystem");
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 LT	35
	36	struct cpufreq_stats_attribute {
	37	struct attribute attr;
	38	ssize_t(show) (struct cpufreq_stats , char *);
	39	};
	40
0a829c5a	41	static int cpufreq_stats_update(unsigned int cpu)
1da177e4 LT	42	{
1da177e4 LT	43	struct cpufreq_stats *stat;
58f1df25 VP	44	unsigned long long cur_time;
	45
	46	cur_time = get_jiffies_64();
1da177e4	47	spin_lock(&cpufreq_stats_lock);
7a6aedfa	48	stat = per_cpu(cpufreq_stats_table, cpu);
1da177e4	49	if (stat->time_in_state)
64861634 MS	50	stat->time_in_state[stat->last_index] +=
64861634 MS	51	cur_time - stat->last_time;
58f1df25	52	stat->last_time = cur_time;
1da177e4 LT	53	spin_unlock(&cpufreq_stats_lock);
	54	return 0;
	55	}
	56
0a829c5a	57	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	58	{
7a6aedfa	59	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	60	if (!stat)
1da177e4 LT	61	return 0;
1da177e4 LT	62	return sprintf(buf, "%d\n",
7a6aedfa	63	per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
1da177e4 LT	64	}
1da177e4 LT	65
0a829c5a	66	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4 LT	67	{
	68	ssize_t len = 0;
	69	int i;
7a6aedfa	70	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	71	if (!stat)
1da177e4 LT	72	return 0;
	73	cpufreq_stats_update(stat->cpu);
	74	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	75	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
0a829c5a	76	(unsigned long long)
a857c0b9	77	jiffies_64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	78	}
	79	return len;
	80	}
	81
	82	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
0a829c5a	83	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4 LT	84	{
	85	ssize_t len = 0;
	86	int i, j;
	87
7a6aedfa	88	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	89	if (!stat)
1da177e4 LT	90	return 0;
1da177e4 LT	91	cpufreq_stats_update(stat->cpu);
58f1df25 VP	92	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	93	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	94	for (i = 0; i < stat->state_num; i++) {
	95	if (len >= PAGE_SIZE)
	96	break;
	97	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	98	stat->freq_table[i]);
	99	}
	100	if (len >= PAGE_SIZE)
25aca347	101	return PAGE_SIZE;
58f1df25 VP	102
	103	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	104
1da177e4 LT	105	for (i = 0; i < stat->state_num; i++) {
	106	if (len >= PAGE_SIZE)
	107	break;
58f1df25 VP	108
58f1df25 VP	109	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	110	stat->freq_table[i]);
1da177e4 LT	111
bb176f7d	112	for (j = 0; j < stat->state_num; j++) {
1da177e4 LT	113	if (len >= PAGE_SIZE)
1da177e4 LT	114	break;
58f1df25	115	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	116	stat->trans_table[i*stat->max_state+j]);
1da177e4 LT	117	}
25aca347 CEB	118	if (len >= PAGE_SIZE)
25aca347 CEB	119	break;
1da177e4 LT	120	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	121	}
25aca347 CEB	122	if (len >= PAGE_SIZE)
25aca347 CEB	123	return PAGE_SIZE;
1da177e4 LT	124	return len;
1da177e4 LT	125	}
df18e504	126	cpufreq_freq_attr_ro(trans_table);
1da177e4 LT	127	#endif
1da177e4 LT	128
df18e504 VK	129	cpufreq_freq_attr_ro(total_trans);
df18e504 VK	130	cpufreq_freq_attr_ro(time_in_state);
1da177e4 LT	131
1da177e4 LT	132	static struct attribute *default_attrs[] = {
df18e504 VK	133	&total_trans.attr,
df18e504 VK	134	&time_in_state.attr,
1da177e4	135	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
df18e504	136	&trans_table.attr,
1da177e4 LT	137	#endif
	138	NULL
	139	};
	140	static struct attribute_group stats_attr_group = {
	141	.attrs = default_attrs,
	142	.name = "stats"
	143	};
	144
0a829c5a	145	static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
1da177e4 LT	146	{
	147	int index;
	148	for (index = 0; index < stat->max_state; index++)
	149	if (stat->freq_table[index] == freq)
	150	return index;
	151	return -1;
	152	}
	153
2d13594d	154	static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
1da177e4	155	{
2d13594d	156	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
b8eed8af	157
2d13594d VK	158	if (!stat)
	159	return;
	160
	161	pr_debug("%s: Free stat table\n", __func__);
	162
	163	sysfs_remove_group(&policy->kobj, &stats_attr_group);
	164	kfree(stat->time_in_state);
	165	kfree(stat);
	166	per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
98586ed8	167	}
98586ed8	168
2d13594d	169	static void cpufreq_stats_free_table(unsigned int cpu)
98586ed8	170	{
2d13594d	171	struct cpufreq_policy *policy;
633d47d6	172
2d13594d	173	policy = cpufreq_cpu_get(cpu);
187da1d9	174	if (!policy)
633d47d6 DB	175	return;
633d47d6 DB	176
2d13594d VK	177	if (cpufreq_frequency_get_table(policy->cpu))
2d13594d VK	178	__cpufreq_stats_free_table(policy);
187da1d9	179
187da1d9	180	cpufreq_cpu_put(policy);
1da177e4 LT	181	}
1da177e4 LT	182
ad4c2302	183	static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
1da177e4 LT	184	{
	185	unsigned int i, j, count = 0, ret = 0;
	186	struct cpufreq_stats *stat;
1da177e4 LT	187	unsigned int alloc_size;
1da177e4 LT	188	unsigned int cpu = policy->cpu;
ad4c2302 SK	189	struct cpufreq_frequency_table *table;
	190
	191	table = cpufreq_frequency_get_table(cpu);
	192	if (unlikely(!table))
	193	return 0;
	194
7a6aedfa	195	if (per_cpu(cpufreq_stats_table, cpu))
1da177e4	196	return -EBUSY;
d5b73cd8	197	stat = kzalloc(sizeof(*stat), GFP_KERNEL);
0a829c5a	198	if ((stat) == NULL)
1da177e4	199	return -ENOMEM;
1da177e4	200
b24a5b65	201	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
0a829c5a	202	if (ret)
1da177e4 LT	203	goto error_out;
	204
	205	stat->cpu = cpu;
7a6aedfa	206	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4	207
0a829c5a	208	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
1da177e4 LT	209	unsigned int freq = table[i].frequency;
	210	if (freq == CPUFREQ_ENTRY_INVALID)
	211	continue;
	212	count++;
	213	}
	214
1e7586a1	215	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4 LT	216
	217	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	218	alloc_size += count * count * sizeof(int);
	219	#endif
	220	stat->max_state = count;
e98df50c	221	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	222	if (!stat->time_in_state) {
1da177e4 LT	223	ret = -ENOMEM;
0b7528d9	224	goto error_alloc;
1da177e4	225	}
1da177e4 LT	226	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	227
	228	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	229	stat->trans_table = stat->freq_table + count;
	230	#endif
	231	j = 0;
	232	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	233	unsigned int freq = table[i].frequency;
	234	if (freq == CPUFREQ_ENTRY_INVALID)
	235	continue;
	236	if (freq_table_get_index(stat, freq) == -1)
	237	stat->freq_table[j++] = freq;
	238	}
	239	stat->state_num = j;
	240	spin_lock(&cpufreq_stats_lock);
58f1df25	241	stat->last_time = get_jiffies_64();
1da177e4 LT	242	stat->last_index = freq_table_get_index(stat, policy->cur);
1da177e4 LT	243	spin_unlock(&cpufreq_stats_lock);
1da177e4	244	return 0;
0b7528d9 SK	245	error_alloc:
0b7528d9 SK	246	sysfs_remove_group(&policy->kobj, &stats_attr_group);
1da177e4	247	error_out:
1da177e4	248	kfree(stat);
7a6aedfa	249	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	250	return ret;
	251	}
	252
b3f9ff88 VK	253	static void cpufreq_stats_create_table(unsigned int cpu)
	254	{
	255	struct cpufreq_policy *policy;
b3f9ff88 VK	256
	257	/*
	258	* "likely(!policy)" because normally cpufreq_stats will be registered
	259	* before cpufreq driver
	260	*/
	261	policy = cpufreq_cpu_get(cpu);
	262	if (likely(!policy))
	263	return;
	264
ad4c2302	265	__cpufreq_stats_create_table(policy);
b3f9ff88 VK	266
	267	cpufreq_cpu_put(policy);
	268	}
	269
b8eed8af VK	270	static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
	271	{
	272	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
	273	policy->last_cpu);
	274
	275	pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
	276	policy->cpu, policy->last_cpu);
	277	per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
	278	policy->last_cpu);
	279	per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
	280	stat->cpu = policy->cpu;
	281	}
	282
0a829c5a DJ	283	static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
0a829c5a DJ	284	unsigned long val, void *data)
1da177e4	285	{
fcd7af91	286	int ret = 0;
1da177e4	287	struct cpufreq_policy *policy = data;
b8eed8af VK	288
	289	if (val == CPUFREQ_UPDATE_POLICY_CPU) {
	290	cpufreq_stats_update_policy_cpu(policy);
	291	return 0;
	292	}
	293
fcd7af91	294	if (val == CPUFREQ_CREATE_POLICY)
ad4c2302	295	ret = __cpufreq_stats_create_table(policy);
2d13594d VK	296	else if (val == CPUFREQ_REMOVE_POLICY)
2d13594d VK	297	__cpufreq_stats_free_table(policy);
fcd7af91 VK	298
fcd7af91 VK	299	return ret;
1da177e4 LT	300	}
1da177e4 LT	301
0a829c5a DJ	302	static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
0a829c5a DJ	303	unsigned long val, void *data)
1da177e4 LT	304	{
	305	struct cpufreq_freqs *freq = data;
	306	struct cpufreq_stats *stat;
	307	int old_index, new_index;
	308
	309	if (val != CPUFREQ_POSTCHANGE)
	310	return 0;
	311
7a6aedfa	312	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	313	if (!stat)
1da177e4 LT	314	return 0;
8edc59d9	315
6501faf8	316	old_index = stat->last_index;
1da177e4 LT	317	new_index = freq_table_get_index(stat, freq->new);
1da177e4 LT	318
46a310b8 KRW	319	/* We can't do stat->time_in_state[-1]= .. */
46a310b8 KRW	320	if (old_index == -1 \|\| new_index == -1)
1da177e4 LT	321	return 0;
1da177e4 LT	322
46a310b8 KRW	323	cpufreq_stats_update(freq->cpu);
	324
	325	if (old_index == new_index)
8edc59d9 VP	326	return 0;
8edc59d9 VP	327
1da177e4 LT	328	spin_lock(&cpufreq_stats_lock);
	329	stat->last_index = new_index;
	330	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	331	stat->trans_table[old_index * stat->max_state + new_index]++;
	332	#endif
	333	stat->total_trans++;
	334	spin_unlock(&cpufreq_stats_lock);
	335	return 0;
	336	}
	337
	338	static struct notifier_block notifier_policy_block = {
	339	.notifier_call = cpufreq_stat_notifier_policy
	340	};
	341
	342	static struct notifier_block notifier_trans_block = {
	343	.notifier_call = cpufreq_stat_notifier_trans
	344	};
	345
0a829c5a	346	static int __init cpufreq_stats_init(void)
1da177e4 LT	347	{
	348	int ret;
	349	unsigned int cpu;
c32b6b8e	350
1da177e4	351	spin_lock_init(&cpufreq_stats_lock);
0a829c5a DJ	352	ret = cpufreq_register_notifier(&notifier_policy_block,
	353	CPUFREQ_POLICY_NOTIFIER);
	354	if (ret)
1da177e4 LT	355	return ret;
1da177e4 LT	356
b3f9ff88 VK	357	for_each_online_cpu(cpu)
	358	cpufreq_stats_create_table(cpu);
	359
0a829c5a DJ	360	ret = cpufreq_register_notifier(&notifier_trans_block,
	361	CPUFREQ_TRANSITION_NOTIFIER);
	362	if (ret) {
1da177e4 LT	363	cpufreq_unregister_notifier(&notifier_policy_block,
1da177e4 LT	364	CPUFREQ_POLICY_NOTIFIER);
56836fb4 KK	365	for_each_online_cpu(cpu)
56836fb4 KK	366	cpufreq_stats_free_table(cpu);
1da177e4 LT	367	return ret;
	368	}
	369
1da177e4 LT	370	return 0;
1da177e4 LT	371	}
0a829c5a	372	static void __exit cpufreq_stats_exit(void)
1da177e4 LT	373	{
1da177e4 LT	374	unsigned int cpu;
c32b6b8e	375
1da177e4 LT	376	cpufreq_unregister_notifier(&notifier_policy_block,
	377	CPUFREQ_POLICY_NOTIFIER);
	378	cpufreq_unregister_notifier(&notifier_trans_block,
	379	CPUFREQ_TRANSITION_NOTIFIER);
2d13594d	380	for_each_online_cpu(cpu)
55395ae7	381	cpufreq_stats_free_table(cpu);
1da177e4 LT	382	}
1da177e4 LT	383
0a829c5a DJ	384	MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
0a829c5a DJ	385	MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
e08f5f5b	386	"through sysfs filesystem");
0a829c5a	387	MODULE_LICENSE("GPL");
1da177e4 LT	388
	389	module_init(cpufreq_stats_init);
	390	module_exit(cpufreq_stats_exit);