[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/config.h>
#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), .owner = THIS_MODULE, \
		.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 struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];

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 = 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 = cpufreq_stats_table[policy->cpu];
	if(!stat)
		return 0;
	return sprintf(buf, "%d\n",
			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 = 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 = 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 len;

	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]);
		}
		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	}
	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 = 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);
	}
	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 (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;
	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);
	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 = cpufreq_stats_table[freq->cpu];
	if (!stat)
		return 0;
	old_index = freq_table_get_index(stat, freq->old);
	new_index = freq_table_get_index(stat, freq->new);

	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 int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
					unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;

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

static struct notifier_block cpufreq_stat_cpu_notifier =
{
	.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_cpu_notifier(&cpufreq_stat_cpu_notifier);
	lock_cpu_hotplug();
	for_each_online_cpu(cpu) {
		cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
			(void *)(long)cpu);
	}
	unlock_cpu_hotplug();
	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_cpu_notifier(&cpufreq_stat_cpu_notifier);
	lock_cpu_hotplug();
	for_each_online_cpu(cpu) {
		cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
			(void *)(long)cpu);
	}
	unlock_cpu_hotplug();
}

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
	12	#include <linux/config.h>
	13	#include <linux/kernel.h>
	14	#include <linux/sysdev.h>
	15	#include <linux/cpu.h>
	16	#include <linux/sysfs.h>
	17	#include <linux/cpufreq.h>
	18	#include <linux/jiffies.h>
	19	#include <linux/percpu.h>
	20	#include <linux/kobject.h>
	21	#include <linux/spinlock.h>
c32b6b8e	22	#include <linux/notifier.h>
58f1df25	23	#include <asm/cputime.h>
1da177e4 LT	24
	25	static spinlock_t cpufreq_stats_lock;
	26
	27	#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
	28	static struct freq_attr _attr_##_name = {\
	29	.attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
	30	.mode = _mode, }, \
	31	.show = _show,\
	32	};
	33
1da177e4 LT	34	struct cpufreq_stats {
	35	unsigned int cpu;
	36	unsigned int total_trans;
58f1df25	37	unsigned long long last_time;
1da177e4 LT	38	unsigned int max_state;
	39	unsigned int state_num;
	40	unsigned int last_index;
58f1df25	41	cputime64_t *time_in_state;
1da177e4 LT	42	unsigned int *freq_table;
	43	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	44	unsigned int *trans_table;
	45	#endif
	46	};
	47
	48	static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
	49
	50	struct cpufreq_stats_attribute {
	51	struct attribute attr;
	52	ssize_t(show) (struct cpufreq_stats , char *);
	53	};
	54
	55	static int
	56	cpufreq_stats_update (unsigned int cpu)
	57	{
	58	struct cpufreq_stats *stat;
58f1df25 VP	59	unsigned long long cur_time;
	60
	61	cur_time = get_jiffies_64();
1da177e4 LT	62	spin_lock(&cpufreq_stats_lock);
	63	stat = cpufreq_stats_table[cpu];
	64	if (stat->time_in_state)
58f1df25 VP	65	stat->time_in_state[stat->last_index] =
	66	cputime64_add(stat->time_in_state[stat->last_index],
	67	cputime_sub(cur_time, stat->last_time));
	68	stat->last_time = cur_time;
1da177e4 LT	69	spin_unlock(&cpufreq_stats_lock);
	70	return 0;
	71	}
	72
	73	static ssize_t
	74	show_total_trans(struct cpufreq_policy policy, char buf)
	75	{
	76	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
	77	if(!stat)
	78	return 0;
	79	return sprintf(buf, "%d\n",
	80	cpufreq_stats_table[stat->cpu]->total_trans);
	81	}
	82
	83	static ssize_t
	84	show_time_in_state(struct cpufreq_policy policy, char buf)
	85	{
	86	ssize_t len = 0;
	87	int i;
	88	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
	89	if(!stat)
	90	return 0;
	91	cpufreq_stats_update(stat->cpu);
	92	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	93	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
58f1df25	94	(unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	95	}
	96	return len;
	97	}
	98
	99	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	100	static ssize_t
	101	show_trans_table(struct cpufreq_policy policy, char buf)
	102	{
	103	ssize_t len = 0;
	104	int i, j;
	105
	106	struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
	107	if(!stat)
	108	return 0;
	109	cpufreq_stats_update(stat->cpu);
58f1df25 VP	110	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	111	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	112	for (i = 0; i < stat->state_num; i++) {
	113	if (len >= PAGE_SIZE)
	114	break;
	115	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	116	stat->freq_table[i]);
	117	}
	118	if (len >= PAGE_SIZE)
	119	return len;
	120
	121	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	122
1da177e4 LT	123	for (i = 0; i < stat->state_num; i++) {
	124	if (len >= PAGE_SIZE)
	125	break;
58f1df25 VP	126
58f1df25 VP	127	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	128	stat->freq_table[i]);
	129
	130	for (j = 0; j < stat->state_num; j++) {
	131	if (len >= PAGE_SIZE)
	132	break;
58f1df25	133	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	134	stat->trans_table[i*stat->max_state+j]);
	135	}
	136	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	137	}
	138	return len;
	139	}
	140	CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
	141	#endif
	142
	143	CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
	144	CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
	145
	146	static struct attribute *default_attrs[] = {
	147	&_attr_total_trans.attr,
	148	&_attr_time_in_state.attr,
	149	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	150	&_attr_trans_table.attr,
	151	#endif
	152	NULL
	153	};
	154	static struct attribute_group stats_attr_group = {
	155	.attrs = default_attrs,
	156	.name = "stats"
	157	};
	158
	159	static int
	160	freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
	161	{
	162	int index;
	163	for (index = 0; index < stat->max_state; index++)
	164	if (stat->freq_table[index] == freq)
	165	return index;
	166	return -1;
	167	}
	168
	169	static void
	170	cpufreq_stats_free_table (unsigned int cpu)
	171	{
	172	struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
	173	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
32ee8c3e	174	if (policy && policy->cpu == cpu)
1da177e4 LT	175	sysfs_remove_group(&policy->kobj, &stats_attr_group);
	176	if (stat) {
	177	kfree(stat->time_in_state);
	178	kfree(stat);
	179	}
	180	cpufreq_stats_table[cpu] = NULL;
	181	if (policy)
	182	cpufreq_cpu_put(policy);
	183	}
	184
	185	static int
	186	cpufreq_stats_create_table (struct cpufreq_policy *policy,
	187	struct cpufreq_frequency_table *table)
	188	{
	189	unsigned int i, j, count = 0, ret = 0;
	190	struct cpufreq_stats *stat;
	191	struct cpufreq_policy *data;
	192	unsigned int alloc_size;
	193	unsigned int cpu = policy->cpu;
	194	if (cpufreq_stats_table[cpu])
	195	return -EBUSY;
e98df50c	196	if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
1da177e4	197	return -ENOMEM;
1da177e4 LT	198
1da177e4 LT	199	data = cpufreq_cpu_get(cpu);
bc7b26fd DJ	200	if (data == NULL) {
	201	ret = -EINVAL;
	202	goto error_get_fail;
	203	}
	204
1da177e4 LT	205	if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
	206	goto error_out;
	207
	208	stat->cpu = cpu;
	209	cpufreq_stats_table[cpu] = stat;
	210
	211	for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	212	unsigned int freq = table[i].frequency;
	213	if (freq == CPUFREQ_ENTRY_INVALID)
	214	continue;
	215	count++;
	216	}
	217
58f1df25	218	alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
1da177e4 LT	219
	220	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	221	alloc_size += count * count * sizeof(int);
	222	#endif
	223	stat->max_state = count;
e98df50c	224	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	225	if (!stat->time_in_state) {
	226	ret = -ENOMEM;
	227	goto error_out;
	228	}
1da177e4 LT	229	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	230
	231	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	232	stat->trans_table = stat->freq_table + count;
	233	#endif
	234	j = 0;
	235	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	236	unsigned int freq = table[i].frequency;
	237	if (freq == CPUFREQ_ENTRY_INVALID)
	238	continue;
	239	if (freq_table_get_index(stat, freq) == -1)
	240	stat->freq_table[j++] = freq;
	241	}
	242	stat->state_num = j;
	243	spin_lock(&cpufreq_stats_lock);
58f1df25	244	stat->last_time = get_jiffies_64();
1da177e4 LT	245	stat->last_index = freq_table_get_index(stat, policy->cur);
	246	spin_unlock(&cpufreq_stats_lock);
	247	cpufreq_cpu_put(data);
	248	return 0;
	249	error_out:
	250	cpufreq_cpu_put(data);
b7fb358c	251	error_get_fail:
1da177e4 LT	252	kfree(stat);
	253	cpufreq_stats_table[cpu] = NULL;
	254	return ret;
	255	}
	256
	257	static int
	258	cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
	259	void *data)
	260	{
	261	int ret;
	262	struct cpufreq_policy *policy = data;
	263	struct cpufreq_frequency_table *table;
	264	unsigned int cpu = policy->cpu;
	265	if (val != CPUFREQ_NOTIFY)
	266	return 0;
	267	table = cpufreq_frequency_get_table(cpu);
	268	if (!table)
	269	return 0;
	270	if ((ret = cpufreq_stats_create_table(policy, table)))
	271	return ret;
	272	return 0;
	273	}
	274
	275	static int
	276	cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
	277	void *data)
	278	{
	279	struct cpufreq_freqs *freq = data;
	280	struct cpufreq_stats *stat;
	281	int old_index, new_index;
	282
	283	if (val != CPUFREQ_POSTCHANGE)
	284	return 0;
	285
	286	stat = cpufreq_stats_table[freq->cpu];
	287	if (!stat)
	288	return 0;
	289	old_index = freq_table_get_index(stat, freq->old);
	290	new_index = freq_table_get_index(stat, freq->new);
	291
	292	cpufreq_stats_update(freq->cpu);
	293	if (old_index == new_index)
	294	return 0;
	295
	296	spin_lock(&cpufreq_stats_lock);
	297	stat->last_index = new_index;
	298	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	299	stat->trans_table[old_index * stat->max_state + new_index]++;
	300	#endif
	301	stat->total_trans++;
	302	spin_unlock(&cpufreq_stats_lock);
	303	return 0;
	304	}
	305
bb1a813d	306	static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
c32b6b8e AR	307	unsigned long action, void *hcpu)
	308	{
	309	unsigned int cpu = (unsigned long)hcpu;
	310
	311	switch (action) {
	312	case CPU_ONLINE:
	313	cpufreq_update_policy(cpu);
	314	break;
	315	case CPU_DEAD:
	316	cpufreq_stats_free_table(cpu);
	317	break;
	318	}
	319	return NOTIFY_OK;
	320	}
	321
	322	static struct notifier_block cpufreq_stat_cpu_notifier =
	323	{
	324	.notifier_call = cpufreq_stat_cpu_callback,
	325	};
	326
1da177e4 LT	327	static struct notifier_block notifier_policy_block = {
	328	.notifier_call = cpufreq_stat_notifier_policy
	329	};
	330
	331	static struct notifier_block notifier_trans_block = {
	332	.notifier_call = cpufreq_stat_notifier_trans
	333	};
	334
	335	static int
	336	__init cpufreq_stats_init(void)
	337	{
	338	int ret;
	339	unsigned int cpu;
c32b6b8e	340
1da177e4 LT	341	spin_lock_init(&cpufreq_stats_lock);
	342	if ((ret = cpufreq_register_notifier(&notifier_policy_block,
	343	CPUFREQ_POLICY_NOTIFIER)))
	344	return ret;
	345
	346	if ((ret = cpufreq_register_notifier(&notifier_trans_block,
	347	CPUFREQ_TRANSITION_NOTIFIER))) {
	348	cpufreq_unregister_notifier(&notifier_policy_block,
	349	CPUFREQ_POLICY_NOTIFIER);
	350	return ret;
	351	}
	352
c32b6b8e AR	353	register_cpu_notifier(&cpufreq_stat_cpu_notifier);
	354	lock_cpu_hotplug();
	355	for_each_online_cpu(cpu) {
	356	cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
	357	(void *)(long)cpu);
	358	}
	359	unlock_cpu_hotplug();
1da177e4 LT	360	return 0;
	361	}
	362	static void
	363	__exit cpufreq_stats_exit(void)
	364	{
	365	unsigned int cpu;
c32b6b8e	366
1da177e4 LT	367	cpufreq_unregister_notifier(&notifier_policy_block,
	368	CPUFREQ_POLICY_NOTIFIER);
	369	cpufreq_unregister_notifier(&notifier_trans_block,
	370	CPUFREQ_TRANSITION_NOTIFIER);
c32b6b8e AR	371	unregister_cpu_notifier(&cpufreq_stat_cpu_notifier);
	372	lock_cpu_hotplug();
	373	for_each_online_cpu(cpu) {
	374	cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD,
	375	(void *)(long)cpu);
	376	}
	377	unlock_cpu_hotplug();
1da177e4 LT	378	}
	379
	380	MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
	381	MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem");
	382	MODULE_LICENSE ("GPL");
	383
	384	module_init(cpufreq_stats_init);
	385	module_exit(cpufreq_stats_exit);