[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/kernel.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/kobject.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <asm/cputime.h>

static spinlock_t cpufreq_stats_lock;

#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
static struct freq_attr _attr_##_name = {\
	.attr = {.name = __stringify(_name), .mode = _mode, }, \
	.show = _show,\
};

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;
	cputime64_t *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] =
			cputime64_add(stat->time_in_state[stat->last_index],
				      cputime_sub(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)cputime64_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_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
#endif

CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);

static struct attribute *default_attrs[] = {
	&_attr_total_trans.attr,
	&_attr_time_in_state.attr,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	&_attr_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(unsigned int cpu)
{
	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
	if (policy && policy->cpu == cpu)
		sysfs_remove_group(&policy->kobj, &stats_attr_group);
	if (stat) {
		kfree(stat->time_in_state);
		kfree(stat);
	}
	per_cpu(cpufreq_stats_table, cpu) = NULL;
	if (policy)
		cpufreq_cpu_put(policy);
}

static int
cpufreq_stats_create_table (struct cpufreq_policy *policy,
		struct cpufreq_frequency_table *table)
{
	unsigned int i, j, count = 0, ret = 0;
	struct cpufreq_stats *stat;
	struct cpufreq_policy *data;
	unsigned int alloc_size;
	unsigned int cpu = policy->cpu;
	if (per_cpu(cpufreq_stats_table, cpu))
		return -EBUSY;
	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
		return -ENOMEM;

	data = cpufreq_cpu_get(cpu);
	if (data == NULL) {
		ret = -EINVAL;
		goto error_get_fail;
	}

	if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
		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(cputime64_t);

#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_out;
	}
	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);
	cpufreq_cpu_put(data);
	return 0;
error_out:
	cpufreq_cpu_put(data);
error_get_fail:
	kfree(stat);
	per_cpu(cpufreq_stats_table, cpu) = NULL;
	return ret;
}

static int
cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
		void *data)
{
	int ret;
	struct cpufreq_policy *policy = data;
	struct cpufreq_frequency_table *table;
	unsigned int cpu = policy->cpu;
	if (val != CPUFREQ_NOTIFY)
		return 0;
	table = cpufreq_frequency_get_table(cpu);
	if (!table)
		return 0;
	if ((ret = cpufreq_stats_create_table(policy, table)))
		return ret;
	return 0;
}

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);

	cpufreq_stats_update(freq->cpu);
	if (old_index == new_index)
		return 0;

	if (old_index == -1 || new_index == -1)
		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 int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
					       unsigned long action,
					       void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;

	switch (action) {
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
		cpufreq_update_policy(cpu);
		break;
	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
		cpufreq_stats_free_table(cpu);
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
{
	.notifier_call = cpufreq_stat_cpu_callback,
};

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

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

	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
	for_each_online_cpu(cpu) {
		cpufreq_update_policy(cpu);
	}
	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);
	unregister_hotcpu_notifier(&cpufreq_stat_cpu_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>.
32ee8c3e	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 LT	12	#include <linux/kernel.h>
	13	#include <linux/sysdev.h>
	14	#include <linux/cpu.h>
	15	#include <linux/sysfs.h>
	16	#include <linux/cpufreq.h>
	17	#include <linux/jiffies.h>
	18	#include <linux/percpu.h>
	19	#include <linux/kobject.h>
	20	#include <linux/spinlock.h>
c32b6b8e	21	#include <linux/notifier.h>
58f1df25	22	#include <asm/cputime.h>
1da177e4 LT	23
	24	static spinlock_t cpufreq_stats_lock;
	25
	26	#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
	27	static struct freq_attr _attr_##_name = {\
7b595756	28	.attr = {.name = __stringify(_name), .mode = _mode, }, \
1da177e4 LT	29	.show = _show,\
	30	};
	31
1da177e4 LT	32	struct cpufreq_stats {
	33	unsigned int cpu;
	34	unsigned int total_trans;
58f1df25	35	unsigned long long last_time;
1da177e4 LT	36	unsigned int max_state;
	37	unsigned int state_num;
	38	unsigned int last_index;
58f1df25	39	cputime64_t *time_in_state;
1da177e4 LT	40	unsigned int *freq_table;
	41	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	42	unsigned int *trans_table;
	43	#endif
	44	};
	45
7a6aedfa	46	static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
1da177e4 LT	47
	48	struct cpufreq_stats_attribute {
	49	struct attribute attr;
	50	ssize_t(show) (struct cpufreq_stats , char *);
	51	};
	52
	53	static int
	54	cpufreq_stats_update (unsigned int cpu)
	55	{
	56	struct cpufreq_stats *stat;
58f1df25 VP	57	unsigned long long cur_time;
	58
	59	cur_time = get_jiffies_64();
1da177e4	60	spin_lock(&cpufreq_stats_lock);
7a6aedfa	61	stat = per_cpu(cpufreq_stats_table, cpu);
1da177e4	62	if (stat->time_in_state)
58f1df25 VP	63	stat->time_in_state[stat->last_index] =
	64	cputime64_add(stat->time_in_state[stat->last_index],
	65	cputime_sub(cur_time, stat->last_time));
	66	stat->last_time = cur_time;
1da177e4 LT	67	spin_unlock(&cpufreq_stats_lock);
	68	return 0;
	69	}
	70
	71	static ssize_t
	72	show_total_trans(struct cpufreq_policy policy, char buf)
	73	{
7a6aedfa	74	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	75	if (!stat)
1da177e4 LT	76	return 0;
1da177e4 LT	77	return sprintf(buf, "%d\n",
7a6aedfa	78	per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
1da177e4 LT	79	}
	80
	81	static ssize_t
	82	show_time_in_state(struct cpufreq_policy policy, char buf)
	83	{
	84	ssize_t len = 0;
	85	int i;
7a6aedfa	86	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	87	if (!stat)
1da177e4 LT	88	return 0;
	89	cpufreq_stats_update(stat->cpu);
	90	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	91	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
58f1df25	92	(unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	93	}
	94	return len;
	95	}
	96
	97	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	98	static ssize_t
	99	show_trans_table(struct cpufreq_policy policy, char buf)
	100	{
	101	ssize_t len = 0;
	102	int i, j;
	103
7a6aedfa	104	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	105	if (!stat)
1da177e4 LT	106	return 0;
1da177e4 LT	107	cpufreq_stats_update(stat->cpu);
58f1df25 VP	108	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	109	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	110	for (i = 0; i < stat->state_num; i++) {
	111	if (len >= PAGE_SIZE)
	112	break;
	113	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	114	stat->freq_table[i]);
	115	}
	116	if (len >= PAGE_SIZE)
25aca347	117	return PAGE_SIZE;
58f1df25 VP	118
	119	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	120
1da177e4 LT	121	for (i = 0; i < stat->state_num; i++) {
	122	if (len >= PAGE_SIZE)
	123	break;
58f1df25 VP	124
58f1df25 VP	125	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	126	stat->freq_table[i]);
	127
	128	for (j = 0; j < stat->state_num; j++) {
	129	if (len >= PAGE_SIZE)
	130	break;
58f1df25	131	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	132	stat->trans_table[i*stat->max_state+j]);
1da177e4 LT	133	}
25aca347 CEB	134	if (len >= PAGE_SIZE)
25aca347 CEB	135	break;
1da177e4 LT	136	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	137	}
25aca347 CEB	138	if (len >= PAGE_SIZE)
25aca347 CEB	139	return PAGE_SIZE;
1da177e4 LT	140	return len;
	141	}
	142	CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
	143	#endif
	144
	145	CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
	146	CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
	147
	148	static struct attribute *default_attrs[] = {
	149	&_attr_total_trans.attr,
	150	&_attr_time_in_state.attr,
	151	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	152	&_attr_trans_table.attr,
	153	#endif
	154	NULL
	155	};
	156	static struct attribute_group stats_attr_group = {
	157	.attrs = default_attrs,
	158	.name = "stats"
	159	};
	160
	161	static int
	162	freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
	163	{
	164	int index;
	165	for (index = 0; index < stat->max_state; index++)
	166	if (stat->freq_table[index] == freq)
	167	return index;
	168	return -1;
	169	}
	170
a3323473	171	static void cpufreq_stats_free_table(unsigned int cpu)
1da177e4	172	{
7a6aedfa	173	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
1da177e4	174	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
32ee8c3e	175	if (policy && policy->cpu == cpu)
1da177e4 LT	176	sysfs_remove_group(&policy->kobj, &stats_attr_group);
	177	if (stat) {
	178	kfree(stat->time_in_state);
	179	kfree(stat);
	180	}
7a6aedfa	181	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	182	if (policy)
	183	cpufreq_cpu_put(policy);
	184	}
	185
	186	static int
	187	cpufreq_stats_create_table (struct cpufreq_policy *policy,
	188	struct cpufreq_frequency_table *table)
	189	{
	190	unsigned int i, j, count = 0, ret = 0;
	191	struct cpufreq_stats *stat;
	192	struct cpufreq_policy *data;
	193	unsigned int alloc_size;
	194	unsigned int cpu = policy->cpu;
7a6aedfa	195	if (per_cpu(cpufreq_stats_table, cpu))
1da177e4	196	return -EBUSY;
e98df50c	197	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
1da177e4	198	return -ENOMEM;
1da177e4 LT	199
1da177e4 LT	200	data = cpufreq_cpu_get(cpu);
bc7b26fd DJ	201	if (data == NULL) {
	202	ret = -EINVAL;
	203	goto error_get_fail;
	204	}
	205
1da177e4 LT	206	if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
	207	goto error_out;
	208
	209	stat->cpu = cpu;
7a6aedfa	210	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4 LT	211
	212	for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	213	unsigned int freq = table[i].frequency;
	214	if (freq == CPUFREQ_ENTRY_INVALID)
	215	continue;
	216	count++;
	217	}
	218
58f1df25	219	alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
1da177e4 LT	220
	221	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	222	alloc_size += count * count * sizeof(int);
	223	#endif
	224	stat->max_state = count;
e98df50c	225	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	226	if (!stat->time_in_state) {
	227	ret = -ENOMEM;
	228	goto error_out;
	229	}
1da177e4 LT	230	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	231
	232	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	233	stat->trans_table = stat->freq_table + count;
	234	#endif
	235	j = 0;
	236	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	237	unsigned int freq = table[i].frequency;
	238	if (freq == CPUFREQ_ENTRY_INVALID)
	239	continue;
	240	if (freq_table_get_index(stat, freq) == -1)
	241	stat->freq_table[j++] = freq;
	242	}
	243	stat->state_num = j;
	244	spin_lock(&cpufreq_stats_lock);
58f1df25	245	stat->last_time = get_jiffies_64();
1da177e4 LT	246	stat->last_index = freq_table_get_index(stat, policy->cur);
	247	spin_unlock(&cpufreq_stats_lock);
	248	cpufreq_cpu_put(data);
	249	return 0;
	250	error_out:
	251	cpufreq_cpu_put(data);
b7fb358c	252	error_get_fail:
1da177e4	253	kfree(stat);
7a6aedfa	254	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	255	return ret;
	256	}
	257
	258	static int
	259	cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
	260	void *data)
	261	{
	262	int ret;
	263	struct cpufreq_policy *policy = data;
	264	struct cpufreq_frequency_table *table;
	265	unsigned int cpu = policy->cpu;
	266	if (val != CPUFREQ_NOTIFY)
	267	return 0;
	268	table = cpufreq_frequency_get_table(cpu);
	269	if (!table)
	270	return 0;
	271	if ((ret = cpufreq_stats_create_table(policy, table)))
	272	return ret;
	273	return 0;
	274	}
	275
	276	static int
	277	cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
	278	void *data)
	279	{
	280	struct cpufreq_freqs *freq = data;
	281	struct cpufreq_stats *stat;
	282	int old_index, new_index;
	283
	284	if (val != CPUFREQ_POSTCHANGE)
	285	return 0;
	286
7a6aedfa	287	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	288	if (!stat)
1da177e4 LT	289	return 0;
8edc59d9	290
6501faf8	291	old_index = stat->last_index;
1da177e4 LT	292	new_index = freq_table_get_index(stat, freq->new);
	293
	294	cpufreq_stats_update(freq->cpu);
	295	if (old_index == new_index)
	296	return 0;
	297
8edc59d9 VP	298	if (old_index == -1 \|\| new_index == -1)
	299	return 0;
	300
1da177e4 LT	301	spin_lock(&cpufreq_stats_lock);
	302	stat->last_index = new_index;
	303	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	304	stat->trans_table[old_index * stat->max_state + new_index]++;
	305	#endif
	306	stat->total_trans++;
	307	spin_unlock(&cpufreq_stats_lock);
	308	return 0;
	309	}
	310
55395ae7 SS	311	static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
	312	unsigned long action,
	313	void *hcpu)
c32b6b8e AR	314	{
	315	unsigned int cpu = (unsigned long)hcpu;
	316
	317	switch (action) {
	318	case CPU_ONLINE:
8bb78442	319	case CPU_ONLINE_FROZEN:
c32b6b8e AR	320	cpufreq_update_policy(cpu);
	321	break;
	322	case CPU_DEAD:
8bb78442	323	case CPU_DEAD_FROZEN:
c32b6b8e AR	324	cpufreq_stats_free_table(cpu);
	325	break;
	326	}
	327	return NOTIFY_OK;
	328	}
	329
f6ebef30	330	static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
c32b6b8e AR	331	{
	332	.notifier_call = cpufreq_stat_cpu_callback,
	333	};
	334
1da177e4 LT	335	static struct notifier_block notifier_policy_block = {
	336	.notifier_call = cpufreq_stat_notifier_policy
	337	};
	338
	339	static struct notifier_block notifier_trans_block = {
	340	.notifier_call = cpufreq_stat_notifier_trans
	341	};
	342
	343	static int
	344	__init cpufreq_stats_init(void)
	345	{
	346	int ret;
	347	unsigned int cpu;
c32b6b8e	348
1da177e4 LT	349	spin_lock_init(&cpufreq_stats_lock);
	350	if ((ret = cpufreq_register_notifier(&notifier_policy_block,
	351	CPUFREQ_POLICY_NOTIFIER)))
	352	return ret;
	353
	354	if ((ret = cpufreq_register_notifier(&notifier_trans_block,
	355	CPUFREQ_TRANSITION_NOTIFIER))) {
	356	cpufreq_unregister_notifier(&notifier_policy_block,
	357	CPUFREQ_POLICY_NOTIFIER);
	358	return ret;
	359	}
	360
65edc68c	361	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	362	for_each_online_cpu(cpu) {
55395ae7	363	cpufreq_update_policy(cpu);
c32b6b8e	364	}
1da177e4 LT	365	return 0;
	366	}
	367	static void
	368	__exit cpufreq_stats_exit(void)
	369	{
	370	unsigned int cpu;
c32b6b8e	371
1da177e4 LT	372	cpufreq_unregister_notifier(&notifier_policy_block,
	373	CPUFREQ_POLICY_NOTIFIER);
	374	cpufreq_unregister_notifier(&notifier_trans_block,
	375	CPUFREQ_TRANSITION_NOTIFIER);
65edc68c	376	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	377	for_each_online_cpu(cpu) {
55395ae7	378	cpufreq_stats_free_table(cpu);
c32b6b8e	379	}
1da177e4 LT	380	}
	381
	382	MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
55395ae7	383	MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats "
e08f5f5b	384	"through sysfs filesystem");
1da177e4 LT	385	MODULE_LICENSE ("GPL");
	386
	387	module_init(cpufreq_stats_init);
	388	module_exit(cpufreq_stats_exit);