[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/kernel.h>
#include <linux/slab.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;
}

/* should be called late in the CPU removal sequence so that the stats
 * memory is still available in case someone tries to use it.
 */
static void cpufreq_stats_free_table(unsigned int cpu)
{
	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
	if (stat) {
		kfree(stat->time_in_state);
		kfree(stat);
	}
	per_cpu(cpufreq_stats_table, cpu) = NULL;
}

/* must be called early in the CPU removal sequence (before
 * cpufreq_remove_dev) so that policy is still valid.
 */
static void cpufreq_stats_free_sysfs(unsigned int cpu)
{
	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
	if (policy && policy->cpu == cpu)
		sysfs_remove_group(&policy->kobj, &stats_attr_group);
	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;
	stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
	if ((stat) == NULL)
		return -ENOMEM;

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

	ret = sysfs_create_group(&data->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(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;
	ret = cpufreq_stats_create_table(policy, table);
	if (ret)
		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_DOWN_PREPARE:
		cpufreq_stats_free_sysfs(cpu);
		break;
	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
		cpufreq_stats_free_table(cpu);
		break;
	}
	return NOTIFY_OK;
}

/* priority=1 so this will get called before cpufreq_remove_dev */
static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
	.notifier_call = cpufreq_stat_cpu_callback,
	.priority = 1,
};

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;

	ret = cpufreq_register_notifier(&notifier_trans_block,
				CPUFREQ_TRANSITION_NOTIFIER);
	if (ret) {
		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>.
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/kernel.h>
5a0e3ad6	13	#include <linux/slab.h>
1da177e4 LT	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
0a829c5a	27	#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
1da177e4	28	static struct freq_attr _attr_##_name = {\
7b595756	29	.attr = {.name = __stringify(_name), .mode = _mode, }, \
1da177e4 LT	30	.show = _show,\
	31	};
	32
1da177e4 LT	33	struct cpufreq_stats {
	34	unsigned int cpu;
	35	unsigned int total_trans;
58f1df25	36	unsigned long long last_time;
1da177e4 LT	37	unsigned int max_state;
	38	unsigned int state_num;
	39	unsigned int last_index;
58f1df25	40	cputime64_t *time_in_state;
1da177e4 LT	41	unsigned int *freq_table;
	42	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	43	unsigned int *trans_table;
	44	#endif
	45	};
	46
7a6aedfa	47	static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
1da177e4 LT	48
	49	struct cpufreq_stats_attribute {
	50	struct attribute attr;
	51	ssize_t(show) (struct cpufreq_stats , char *);
	52	};
	53
0a829c5a	54	static int cpufreq_stats_update(unsigned int cpu)
1da177e4 LT	55	{
1da177e4 LT	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
0a829c5a	71	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	72	{
7a6aedfa	73	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	74	if (!stat)
1da177e4 LT	75	return 0;
1da177e4 LT	76	return sprintf(buf, "%d\n",
7a6aedfa	77	per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
1da177e4 LT	78	}
1da177e4 LT	79
0a829c5a	80	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4 LT	81	{
	82	ssize_t len = 0;
	83	int i;
7a6aedfa	84	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	85	if (!stat)
1da177e4 LT	86	return 0;
	87	cpufreq_stats_update(stat->cpu);
	88	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	89	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
0a829c5a DJ	90	(unsigned long long)
0a829c5a DJ	91	cputime64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	92	}
	93	return len;
	94	}
	95
	96	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
0a829c5a	97	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4 LT	98	{
	99	ssize_t len = 0;
	100	int i, j;
	101
7a6aedfa	102	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	103	if (!stat)
1da177e4 LT	104	return 0;
1da177e4 LT	105	cpufreq_stats_update(stat->cpu);
58f1df25 VP	106	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	107	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	108	for (i = 0; i < stat->state_num; i++) {
	109	if (len >= PAGE_SIZE)
	110	break;
	111	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	112	stat->freq_table[i]);
	113	}
	114	if (len >= PAGE_SIZE)
25aca347	115	return PAGE_SIZE;
58f1df25 VP	116
	117	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	118
1da177e4 LT	119	for (i = 0; i < stat->state_num; i++) {
	120	if (len >= PAGE_SIZE)
	121	break;
58f1df25 VP	122
58f1df25 VP	123	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	124	stat->freq_table[i]);
	125
	126	for (j = 0; j < stat->state_num; j++) {
	127	if (len >= PAGE_SIZE)
	128	break;
58f1df25	129	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	130	stat->trans_table[i*stat->max_state+j]);
1da177e4 LT	131	}
25aca347 CEB	132	if (len >= PAGE_SIZE)
25aca347 CEB	133	break;
1da177e4 LT	134	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	135	}
25aca347 CEB	136	if (len >= PAGE_SIZE)
25aca347 CEB	137	return PAGE_SIZE;
1da177e4 LT	138	return len;
1da177e4 LT	139	}
0a829c5a	140	CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
1da177e4 LT	141	#endif
1da177e4 LT	142
0a829c5a DJ	143	CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
0a829c5a DJ	144	CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
1da177e4 LT	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
0a829c5a	159	static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
1da177e4 LT	160	{
	161	int index;
	162	for (index = 0; index < stat->max_state; index++)
	163	if (stat->freq_table[index] == freq)
	164	return index;
	165	return -1;
	166	}
	167
98586ed8	168	/* should be called late in the CPU removal sequence so that the stats
	169	* memory is still available in case someone tries to use it.
	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 LT	174	if (stat) {
	175	kfree(stat->time_in_state);
	176	kfree(stat);
	177	}
7a6aedfa	178	per_cpu(cpufreq_stats_table, cpu) = NULL;
98586ed8	179	}
	180
	181	/* must be called early in the CPU removal sequence (before
	182	* cpufreq_remove_dev) so that policy is still valid.
	183	*/
	184	static void cpufreq_stats_free_sysfs(unsigned int cpu)
	185	{
	186	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
	187	if (policy && policy->cpu == cpu)
	188	sysfs_remove_group(&policy->kobj, &stats_attr_group);
1da177e4 LT	189	if (policy)
	190	cpufreq_cpu_put(policy);
	191	}
	192
0a829c5a	193	static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
1da177e4 LT	194	struct cpufreq_frequency_table *table)
	195	{
	196	unsigned int i, j, count = 0, ret = 0;
	197	struct cpufreq_stats *stat;
	198	struct cpufreq_policy *data;
	199	unsigned int alloc_size;
	200	unsigned int cpu = policy->cpu;
7a6aedfa	201	if (per_cpu(cpufreq_stats_table, cpu))
1da177e4	202	return -EBUSY;
0a829c5a DJ	203	stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
0a829c5a DJ	204	if ((stat) == NULL)
1da177e4	205	return -ENOMEM;
1da177e4 LT	206
1da177e4 LT	207	data = cpufreq_cpu_get(cpu);
bc7b26fd DJ	208	if (data == NULL) {
	209	ret = -EINVAL;
	210	goto error_get_fail;
	211	}
	212
0a829c5a DJ	213	ret = sysfs_create_group(&data->kobj, &stats_attr_group);
0a829c5a DJ	214	if (ret)
1da177e4 LT	215	goto error_out;
	216
	217	stat->cpu = cpu;
7a6aedfa	218	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4	219
0a829c5a	220	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
1da177e4 LT	221	unsigned int freq = table[i].frequency;
	222	if (freq == CPUFREQ_ENTRY_INVALID)
	223	continue;
	224	count++;
	225	}
	226
58f1df25	227	alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
1da177e4 LT	228
	229	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	230	alloc_size += count * count * sizeof(int);
	231	#endif
	232	stat->max_state = count;
e98df50c	233	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	234	if (!stat->time_in_state) {
	235	ret = -ENOMEM;
	236	goto error_out;
	237	}
1da177e4 LT	238	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	239
	240	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	241	stat->trans_table = stat->freq_table + count;
	242	#endif
	243	j = 0;
	244	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	245	unsigned int freq = table[i].frequency;
	246	if (freq == CPUFREQ_ENTRY_INVALID)
	247	continue;
	248	if (freq_table_get_index(stat, freq) == -1)
	249	stat->freq_table[j++] = freq;
	250	}
	251	stat->state_num = j;
	252	spin_lock(&cpufreq_stats_lock);
58f1df25	253	stat->last_time = get_jiffies_64();
1da177e4 LT	254	stat->last_index = freq_table_get_index(stat, policy->cur);
	255	spin_unlock(&cpufreq_stats_lock);
	256	cpufreq_cpu_put(data);
	257	return 0;
	258	error_out:
	259	cpufreq_cpu_put(data);
b7fb358c	260	error_get_fail:
1da177e4	261	kfree(stat);
7a6aedfa	262	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	263	return ret;
	264	}
	265
0a829c5a DJ	266	static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
0a829c5a DJ	267	unsigned long val, void *data)
1da177e4 LT	268	{
	269	int ret;
	270	struct cpufreq_policy *policy = data;
	271	struct cpufreq_frequency_table *table;
	272	unsigned int cpu = policy->cpu;
	273	if (val != CPUFREQ_NOTIFY)
	274	return 0;
	275	table = cpufreq_frequency_get_table(cpu);
	276	if (!table)
	277	return 0;
0a829c5a DJ	278	ret = cpufreq_stats_create_table(policy, table);
0a829c5a DJ	279	if (ret)
1da177e4 LT	280	return ret;
	281	return 0;
	282	}
	283
0a829c5a DJ	284	static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
0a829c5a DJ	285	unsigned long val, void *data)
1da177e4 LT	286	{
	287	struct cpufreq_freqs *freq = data;
	288	struct cpufreq_stats *stat;
	289	int old_index, new_index;
	290
	291	if (val != CPUFREQ_POSTCHANGE)
	292	return 0;
	293
7a6aedfa	294	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	295	if (!stat)
1da177e4 LT	296	return 0;
8edc59d9	297
6501faf8	298	old_index = stat->last_index;
1da177e4 LT	299	new_index = freq_table_get_index(stat, freq->new);
	300
	301	cpufreq_stats_update(freq->cpu);
	302	if (old_index == new_index)
	303	return 0;
	304
8edc59d9 VP	305	if (old_index == -1 \|\| new_index == -1)
	306	return 0;
	307
1da177e4 LT	308	spin_lock(&cpufreq_stats_lock);
	309	stat->last_index = new_index;
	310	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	311	stat->trans_table[old_index * stat->max_state + new_index]++;
	312	#endif
	313	stat->total_trans++;
	314	spin_unlock(&cpufreq_stats_lock);
	315	return 0;
	316	}
	317
55395ae7 SS	318	static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
	319	unsigned long action,
	320	void *hcpu)
c32b6b8e AR	321	{
	322	unsigned int cpu = (unsigned long)hcpu;
	323
	324	switch (action) {
	325	case CPU_ONLINE:
8bb78442	326	case CPU_ONLINE_FROZEN:
c32b6b8e AR	327	cpufreq_update_policy(cpu);
c32b6b8e AR	328	break;
98586ed8	329	case CPU_DOWN_PREPARE:
	330	cpufreq_stats_free_sysfs(cpu);
	331	break;
c32b6b8e	332	case CPU_DEAD:
8bb78442	333	case CPU_DEAD_FROZEN:
c32b6b8e AR	334	cpufreq_stats_free_table(cpu);
	335	break;
	336	}
	337	return NOTIFY_OK;
	338	}
	339
98586ed8	340	/* priority=1 so this will get called before cpufreq_remove_dev */
469057d5	341	static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
c32b6b8e	342	.notifier_call = cpufreq_stat_cpu_callback,
98586ed8	343	.priority = 1,
c32b6b8e AR	344	};
c32b6b8e AR	345
1da177e4 LT	346	static struct notifier_block notifier_policy_block = {
	347	.notifier_call = cpufreq_stat_notifier_policy
	348	};
	349
	350	static struct notifier_block notifier_trans_block = {
	351	.notifier_call = cpufreq_stat_notifier_trans
	352	};
	353
0a829c5a	354	static int __init cpufreq_stats_init(void)
1da177e4 LT	355	{
	356	int ret;
	357	unsigned int cpu;
c32b6b8e	358
1da177e4	359	spin_lock_init(&cpufreq_stats_lock);
0a829c5a DJ	360	ret = cpufreq_register_notifier(&notifier_policy_block,
	361	CPUFREQ_POLICY_NOTIFIER);
	362	if (ret)
1da177e4 LT	363	return ret;
1da177e4 LT	364
0a829c5a DJ	365	ret = cpufreq_register_notifier(&notifier_trans_block,
	366	CPUFREQ_TRANSITION_NOTIFIER);
	367	if (ret) {
1da177e4 LT	368	cpufreq_unregister_notifier(&notifier_policy_block,
	369	CPUFREQ_POLICY_NOTIFIER);
	370	return ret;
	371	}
	372
65edc68c	373	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	374	for_each_online_cpu(cpu) {
55395ae7	375	cpufreq_update_policy(cpu);
c32b6b8e	376	}
1da177e4 LT	377	return 0;
1da177e4 LT	378	}
0a829c5a	379	static void __exit cpufreq_stats_exit(void)
1da177e4 LT	380	{
1da177e4 LT	381	unsigned int cpu;
c32b6b8e	382
1da177e4 LT	383	cpufreq_unregister_notifier(&notifier_policy_block,
	384	CPUFREQ_POLICY_NOTIFIER);
	385	cpufreq_unregister_notifier(&notifier_trans_block,
	386	CPUFREQ_TRANSITION_NOTIFIER);
65edc68c	387	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	388	for_each_online_cpu(cpu) {
55395ae7	389	cpufreq_stats_free_table(cpu);
c32b6b8e	390	}
1da177e4 LT	391	}
1da177e4 LT	392
0a829c5a DJ	393	MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
0a829c5a DJ	394	MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
e08f5f5b	395	"through sysfs filesystem");
0a829c5a	396	MODULE_LICENSE("GPL");
1da177e4 LT	397
	398	module_init(cpufreq_stats_init);
	399	module_exit(cpufreq_stats_exit);