[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 <asm/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;
}

/* 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) {
		pr_debug("%s: Free stat table\n", __func__);
		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)
		return;

	if (!cpufreq_frequency_get_table(cpu))
		goto put_ref;

	if (!policy_is_shared(policy)) {
		pr_debug("%s: Free sysfs stat\n", __func__);
		sysfs_remove_group(&policy->kobj, &stats_attr_group);
	}

put_ref:
	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 *current_policy;
	unsigned int alloc_size;
	unsigned int cpu = policy->cpu;
	if (per_cpu(cpufreq_stats_table, cpu))
		return -EBUSY;
	stat = kzalloc(sizeof(*stat), GFP_KERNEL);
	if ((stat) == NULL)
		return -ENOMEM;

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

	ret = sysfs_create_group(&current_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_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(current_policy);
	return 0;
error_out:
	cpufreq_cpu_put(current_policy);
error_get_fail:
	kfree(stat);
	per_cpu(cpufreq_stats_table, cpu) = NULL;
	return ret;
}

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;
	struct cpufreq_policy *policy = data;
	struct cpufreq_frequency_table *table;
	unsigned int cpu = policy->cpu;

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

	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);

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

	switch (action) {
	case CPU_DOWN_PREPARE:
		cpufreq_stats_free_sysfs(cpu);
		break;
	case CPU_DEAD:
		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;

	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);

	ret = cpufreq_register_notifier(&notifier_trans_block,
				CPUFREQ_TRANSITION_NOTIFIER);
	if (ret) {
		cpufreq_unregister_notifier(&notifier_policy_block,
				CPUFREQ_POLICY_NOTIFIER);
		unregister_hotcpu_notifier(&cpufreq_stat_cpu_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);
	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
	for_each_online_cpu(cpu) {
		cpufreq_stats_free_table(cpu);
		cpufreq_stats_free_sysfs(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>
58f1df25	16	#include <asm/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
98586ed8	154	/* should be called late in the CPU removal sequence so that the stats
	155	* memory is still available in case someone tries to use it.
	156	*/
a3323473	157	static void cpufreq_stats_free_table(unsigned int cpu)
1da177e4	158	{
7a6aedfa	159	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
b8eed8af	160
1da177e4	161	if (stat) {
b8eed8af	162	pr_debug("%s: Free stat table\n", __func__);
1da177e4 LT	163	kfree(stat->time_in_state);
1da177e4 LT	164	kfree(stat);
b8eed8af	165	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4	166	}
98586ed8	167	}
	168
	169	/* must be called early in the CPU removal sequence (before
	170	* cpufreq_remove_dev) so that policy is still valid.
	171	*/
	172	static void cpufreq_stats_free_sysfs(unsigned int cpu)
	173	{
	174	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
633d47d6	175
187da1d9	176	if (!policy)
633d47d6 DB	177	return;
633d47d6 DB	178
187da1d9	179	if (!cpufreq_frequency_get_table(cpu))
	180	goto put_ref;
	181
	182	if (!policy_is_shared(policy)) {
b8eed8af	183	pr_debug("%s: Free sysfs stat\n", __func__);
98586ed8	184	sysfs_remove_group(&policy->kobj, &stats_attr_group);
b8eed8af	185	}
187da1d9	186
	187	put_ref:
	188	cpufreq_cpu_put(policy);
1da177e4 LT	189	}
1da177e4 LT	190
0a829c5a	191	static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
1da177e4 LT	192	struct cpufreq_frequency_table *table)
	193	{
	194	unsigned int i, j, count = 0, ret = 0;
	195	struct cpufreq_stats *stat;
3a3e9e06	196	struct cpufreq_policy *current_policy;
1da177e4 LT	197	unsigned int alloc_size;
1da177e4 LT	198	unsigned int cpu = policy->cpu;
7a6aedfa	199	if (per_cpu(cpufreq_stats_table, cpu))
1da177e4	200	return -EBUSY;
d5b73cd8	201	stat = kzalloc(sizeof(*stat), GFP_KERNEL);
0a829c5a	202	if ((stat) == NULL)
1da177e4	203	return -ENOMEM;
1da177e4	204
3a3e9e06 VK	205	current_policy = cpufreq_cpu_get(cpu);
3a3e9e06 VK	206	if (current_policy == NULL) {
bc7b26fd DJ	207	ret = -EINVAL;
	208	goto error_get_fail;
	209	}
	210
3a3e9e06	211	ret = sysfs_create_group(&current_policy->kobj, &stats_attr_group);
0a829c5a	212	if (ret)
1da177e4 LT	213	goto error_out;
	214
	215	stat->cpu = cpu;
7a6aedfa	216	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4	217
0a829c5a	218	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
1da177e4 LT	219	unsigned int freq = table[i].frequency;
	220	if (freq == CPUFREQ_ENTRY_INVALID)
	221	continue;
	222	count++;
	223	}
	224
1e7586a1	225	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4 LT	226
	227	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	228	alloc_size += count * count * sizeof(int);
	229	#endif
	230	stat->max_state = count;
e98df50c	231	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	232	if (!stat->time_in_state) {
	233	ret = -ENOMEM;
	234	goto error_out;
	235	}
1da177e4 LT	236	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	237
	238	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	239	stat->trans_table = stat->freq_table + count;
	240	#endif
	241	j = 0;
	242	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	243	unsigned int freq = table[i].frequency;
	244	if (freq == CPUFREQ_ENTRY_INVALID)
	245	continue;
	246	if (freq_table_get_index(stat, freq) == -1)
	247	stat->freq_table[j++] = freq;
	248	}
	249	stat->state_num = j;
	250	spin_lock(&cpufreq_stats_lock);
58f1df25	251	stat->last_time = get_jiffies_64();
1da177e4 LT	252	stat->last_index = freq_table_get_index(stat, policy->cur);
1da177e4 LT	253	spin_unlock(&cpufreq_stats_lock);
3a3e9e06	254	cpufreq_cpu_put(current_policy);
1da177e4 LT	255	return 0;
1da177e4 LT	256	error_out:
3a3e9e06	257	cpufreq_cpu_put(current_policy);
b7fb358c	258	error_get_fail:
1da177e4	259	kfree(stat);
7a6aedfa	260	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	261	return ret;
	262	}
	263
b8eed8af VK	264	static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
	265	{
	266	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
	267	policy->last_cpu);
	268
	269	pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
	270	policy->cpu, policy->last_cpu);
	271	per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
	272	policy->last_cpu);
	273	per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
	274	stat->cpu = policy->cpu;
	275	}
	276
0a829c5a DJ	277	static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
0a829c5a DJ	278	unsigned long val, void *data)
1da177e4 LT	279	{
	280	int ret;
	281	struct cpufreq_policy *policy = data;
	282	struct cpufreq_frequency_table *table;
	283	unsigned int cpu = policy->cpu;
b8eed8af VK	284
	285	if (val == CPUFREQ_UPDATE_POLICY_CPU) {
	286	cpufreq_stats_update_policy_cpu(policy);
	287	return 0;
	288	}
	289
1da177e4 LT	290	if (val != CPUFREQ_NOTIFY)
	291	return 0;
	292	table = cpufreq_frequency_get_table(cpu);
	293	if (!table)
	294	return 0;
0a829c5a DJ	295	ret = cpufreq_stats_create_table(policy, table);
0a829c5a DJ	296	if (ret)
1da177e4 LT	297	return ret;
	298	return 0;
	299	}
	300
0a829c5a DJ	301	static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
0a829c5a DJ	302	unsigned long val, void *data)
1da177e4 LT	303	{
	304	struct cpufreq_freqs *freq = data;
	305	struct cpufreq_stats *stat;
	306	int old_index, new_index;
	307
	308	if (val != CPUFREQ_POSTCHANGE)
	309	return 0;
	310
7a6aedfa	311	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	312	if (!stat)
1da177e4 LT	313	return 0;
8edc59d9	314
6501faf8	315	old_index = stat->last_index;
1da177e4 LT	316	new_index = freq_table_get_index(stat, freq->new);
1da177e4 LT	317
46a310b8 KRW	318	/* We can't do stat->time_in_state[-1]= .. */
46a310b8 KRW	319	if (old_index == -1 \|\| new_index == -1)
1da177e4 LT	320	return 0;
1da177e4 LT	321
46a310b8 KRW	322	cpufreq_stats_update(freq->cpu);
	323
	324	if (old_index == new_index)
8edc59d9 VP	325	return 0;
8edc59d9 VP	326
1da177e4 LT	327	spin_lock(&cpufreq_stats_lock);
	328	stat->last_index = new_index;
	329	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	330	stat->trans_table[old_index * stat->max_state + new_index]++;
	331	#endif
	332	stat->total_trans++;
	333	spin_unlock(&cpufreq_stats_lock);
	334	return 0;
	335	}
	336
2760984f	337	static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
55395ae7 SS	338	unsigned long action,
55395ae7 SS	339	void *hcpu)
c32b6b8e AR	340	{
	341	unsigned int cpu = (unsigned long)hcpu;
	342
	343	switch (action) {
98586ed8	344	case CPU_DOWN_PREPARE:
	345	cpufreq_stats_free_sysfs(cpu);
	346	break;
c32b6b8e AR	347	case CPU_DEAD:
	348	cpufreq_stats_free_table(cpu);
	349	break;
	350	}
	351	return NOTIFY_OK;
	352	}
	353
98586ed8	354	/* priority=1 so this will get called before cpufreq_remove_dev */
469057d5	355	static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
c32b6b8e	356	.notifier_call = cpufreq_stat_cpu_callback,
98586ed8	357	.priority = 1,
c32b6b8e AR	358	};
c32b6b8e AR	359
1da177e4 LT	360	static struct notifier_block notifier_policy_block = {
	361	.notifier_call = cpufreq_stat_notifier_policy
	362	};
	363
	364	static struct notifier_block notifier_trans_block = {
	365	.notifier_call = cpufreq_stat_notifier_trans
	366	};
	367
0a829c5a	368	static int __init cpufreq_stats_init(void)
1da177e4 LT	369	{
	370	int ret;
	371	unsigned int cpu;
c32b6b8e	372
1da177e4	373	spin_lock_init(&cpufreq_stats_lock);
0a829c5a DJ	374	ret = cpufreq_register_notifier(&notifier_policy_block,
	375	CPUFREQ_POLICY_NOTIFIER);
	376	if (ret)
1da177e4 LT	377	return ret;
1da177e4 LT	378
56836fb4	379	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
56836fb4	380
0a829c5a DJ	381	ret = cpufreq_register_notifier(&notifier_trans_block,
	382	CPUFREQ_TRANSITION_NOTIFIER);
	383	if (ret) {
1da177e4 LT	384	cpufreq_unregister_notifier(&notifier_policy_block,
1da177e4 LT	385	CPUFREQ_POLICY_NOTIFIER);
56836fb4 KK	386	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
	387	for_each_online_cpu(cpu)
	388	cpufreq_stats_free_table(cpu);
1da177e4 LT	389	return ret;
	390	}
	391
1da177e4 LT	392	return 0;
1da177e4 LT	393	}
0a829c5a	394	static void __exit cpufreq_stats_exit(void)
1da177e4 LT	395	{
1da177e4 LT	396	unsigned int cpu;
c32b6b8e	397
1da177e4 LT	398	cpufreq_unregister_notifier(&notifier_policy_block,
	399	CPUFREQ_POLICY_NOTIFIER);
	400	cpufreq_unregister_notifier(&notifier_trans_block,
	401	CPUFREQ_TRANSITION_NOTIFIER);
65edc68c	402	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	403	for_each_online_cpu(cpu) {
55395ae7	404	cpufreq_stats_free_table(cpu);
13f06753	405	cpufreq_stats_free_sysfs(cpu);
c32b6b8e	406	}
1da177e4 LT	407	}
1da177e4 LT	408
0a829c5a DJ	409	MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
0a829c5a DJ	410	MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
e08f5f5b	411	"through sysfs filesystem");
0a829c5a	412	MODULE_LICENSE("GPL");
1da177e4 LT	413
	414	module_init(cpufreq_stats_init);
	415	module_exit(cpufreq_stats_exit);