[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/slab.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/module.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;

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)
			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_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 *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(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(data);
	return 0;
error_out:
	cpufreq_cpu_put(data);
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/kernel.h>
5a0e3ad6	13	#include <linux/slab.h>
1da177e4 LT	14	#include <linux/cpu.h>
	15	#include <linux/sysfs.h>
	16	#include <linux/cpufreq.h>
5c720d37	17	#include <linux/module.h>
1da177e4 LT	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
1da177e4 LT	27	struct cpufreq_stats {
	28	unsigned int cpu;
	29	unsigned int total_trans;
bb176f7d	30	unsigned long long last_time;
1da177e4 LT	31	unsigned int max_state;
	32	unsigned int state_num;
	33	unsigned int last_index;
1e7586a1	34	u64 *time_in_state;
1da177e4 LT	35	unsigned int *freq_table;
	36	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	37	unsigned int *trans_table;
	38	#endif
	39	};
	40
7a6aedfa	41	static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
1da177e4 LT	42
	43	struct cpufreq_stats_attribute {
	44	struct attribute attr;
	45	ssize_t(show) (struct cpufreq_stats , char *);
	46	};
	47
0a829c5a	48	static int cpufreq_stats_update(unsigned int cpu)
1da177e4 LT	49	{
1da177e4 LT	50	struct cpufreq_stats *stat;
58f1df25 VP	51	unsigned long long cur_time;
	52
	53	cur_time = get_jiffies_64();
1da177e4	54	spin_lock(&cpufreq_stats_lock);
7a6aedfa	55	stat = per_cpu(cpufreq_stats_table, cpu);
1da177e4	56	if (stat->time_in_state)
64861634 MS	57	stat->time_in_state[stat->last_index] +=
64861634 MS	58	cur_time - stat->last_time;
58f1df25	59	stat->last_time = cur_time;
1da177e4 LT	60	spin_unlock(&cpufreq_stats_lock);
	61	return 0;
	62	}
	63
0a829c5a	64	static ssize_t show_total_trans(struct cpufreq_policy policy, char buf)
1da177e4	65	{
7a6aedfa	66	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	67	if (!stat)
1da177e4 LT	68	return 0;
1da177e4 LT	69	return sprintf(buf, "%d\n",
7a6aedfa	70	per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
1da177e4 LT	71	}
1da177e4 LT	72
0a829c5a	73	static ssize_t show_time_in_state(struct cpufreq_policy policy, char buf)
1da177e4 LT	74	{
	75	ssize_t len = 0;
	76	int i;
7a6aedfa	77	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	78	if (!stat)
1da177e4 LT	79	return 0;
	80	cpufreq_stats_update(stat->cpu);
	81	for (i = 0; i < stat->state_num; i++) {
32ee8c3e	82	len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
0a829c5a DJ	83	(unsigned long long)
0a829c5a DJ	84	cputime64_to_clock_t(stat->time_in_state[i]));
1da177e4 LT	85	}
	86	return len;
	87	}
	88
	89	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
0a829c5a	90	static ssize_t show_trans_table(struct cpufreq_policy policy, char buf)
1da177e4 LT	91	{
	92	ssize_t len = 0;
	93	int i, j;
	94
7a6aedfa	95	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
511e9ee1	96	if (!stat)
1da177e4 LT	97	return 0;
1da177e4 LT	98	cpufreq_stats_update(stat->cpu);
58f1df25 VP	99	len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
	100	len += snprintf(buf + len, PAGE_SIZE - len, " : ");
	101	for (i = 0; i < stat->state_num; i++) {
	102	if (len >= PAGE_SIZE)
	103	break;
	104	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
	105	stat->freq_table[i]);
	106	}
	107	if (len >= PAGE_SIZE)
25aca347	108	return PAGE_SIZE;
58f1df25 VP	109
	110	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
	111
1da177e4 LT	112	for (i = 0; i < stat->state_num; i++) {
	113	if (len >= PAGE_SIZE)
	114	break;
58f1df25 VP	115
58f1df25 VP	116	len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
1da177e4 LT	117	stat->freq_table[i]);
1da177e4 LT	118
bb176f7d	119	for (j = 0; j < stat->state_num; j++) {
1da177e4 LT	120	if (len >= PAGE_SIZE)
1da177e4 LT	121	break;
58f1df25	122	len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
1da177e4 LT	123	stat->trans_table[i*stat->max_state+j]);
1da177e4 LT	124	}
25aca347 CEB	125	if (len >= PAGE_SIZE)
25aca347 CEB	126	break;
1da177e4 LT	127	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1da177e4 LT	128	}
25aca347 CEB	129	if (len >= PAGE_SIZE)
25aca347 CEB	130	return PAGE_SIZE;
1da177e4 LT	131	return len;
1da177e4 LT	132	}
df18e504	133	cpufreq_freq_attr_ro(trans_table);
1da177e4 LT	134	#endif
1da177e4 LT	135
df18e504 VK	136	cpufreq_freq_attr_ro(total_trans);
df18e504 VK	137	cpufreq_freq_attr_ro(time_in_state);
1da177e4 LT	138
1da177e4 LT	139	static struct attribute *default_attrs[] = {
df18e504 VK	140	&total_trans.attr,
df18e504 VK	141	&time_in_state.attr,
1da177e4	142	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
df18e504	143	&trans_table.attr,
1da177e4 LT	144	#endif
	145	NULL
	146	};
	147	static struct attribute_group stats_attr_group = {
	148	.attrs = default_attrs,
	149	.name = "stats"
	150	};
	151
0a829c5a	152	static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
1da177e4 LT	153	{
	154	int index;
	155	for (index = 0; index < stat->max_state; index++)
	156	if (stat->freq_table[index] == freq)
	157	return index;
	158	return -1;
	159	}
	160
98586ed8	161	/* should be called late in the CPU removal sequence so that the stats
	162	* memory is still available in case someone tries to use it.
	163	*/
a3323473	164	static void cpufreq_stats_free_table(unsigned int cpu)
1da177e4	165	{
7a6aedfa	166	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
b8eed8af	167
1da177e4	168	if (stat) {
b8eed8af	169	pr_debug("%s: Free stat table\n", __func__);
1da177e4 LT	170	kfree(stat->time_in_state);
1da177e4 LT	171	kfree(stat);
b8eed8af	172	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4	173	}
98586ed8	174	}
	175
	176	/* must be called early in the CPU removal sequence (before
	177	* cpufreq_remove_dev) so that policy is still valid.
	178	*/
	179	static void cpufreq_stats_free_sysfs(unsigned int cpu)
	180	{
	181	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
633d47d6	182
187da1d9	183	if (!policy)
633d47d6 DB	184	return;
633d47d6 DB	185
187da1d9	186	if (!cpufreq_frequency_get_table(cpu))
	187	goto put_ref;
	188
	189	if (!policy_is_shared(policy)) {
b8eed8af	190	pr_debug("%s: Free sysfs stat\n", __func__);
98586ed8	191	sysfs_remove_group(&policy->kobj, &stats_attr_group);
b8eed8af	192	}
187da1d9	193
	194	put_ref:
	195	cpufreq_cpu_put(policy);
1da177e4 LT	196	}
1da177e4 LT	197
0a829c5a	198	static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
1da177e4 LT	199	struct cpufreq_frequency_table *table)
	200	{
	201	unsigned int i, j, count = 0, ret = 0;
	202	struct cpufreq_stats *stat;
	203	struct cpufreq_policy *data;
	204	unsigned int alloc_size;
	205	unsigned int cpu = policy->cpu;
7a6aedfa	206	if (per_cpu(cpufreq_stats_table, cpu))
1da177e4	207	return -EBUSY;
0a829c5a DJ	208	stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
0a829c5a DJ	209	if ((stat) == NULL)
1da177e4	210	return -ENOMEM;
1da177e4 LT	211
1da177e4 LT	212	data = cpufreq_cpu_get(cpu);
bc7b26fd DJ	213	if (data == NULL) {
	214	ret = -EINVAL;
	215	goto error_get_fail;
	216	}
	217
0a829c5a DJ	218	ret = sysfs_create_group(&data->kobj, &stats_attr_group);
0a829c5a DJ	219	if (ret)
1da177e4 LT	220	goto error_out;
	221
	222	stat->cpu = cpu;
7a6aedfa	223	per_cpu(cpufreq_stats_table, cpu) = stat;
1da177e4	224
0a829c5a	225	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
1da177e4 LT	226	unsigned int freq = table[i].frequency;
	227	if (freq == CPUFREQ_ENTRY_INVALID)
	228	continue;
	229	count++;
	230	}
	231
1e7586a1	232	alloc_size = count * sizeof(int) + count * sizeof(u64);
1da177e4 LT	233
	234	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	235	alloc_size += count * count * sizeof(int);
	236	#endif
	237	stat->max_state = count;
e98df50c	238	stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	239	if (!stat->time_in_state) {
	240	ret = -ENOMEM;
	241	goto error_out;
	242	}
1da177e4 LT	243	stat->freq_table = (unsigned int *)(stat->time_in_state + count);
	244
	245	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	246	stat->trans_table = stat->freq_table + count;
	247	#endif
	248	j = 0;
	249	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	250	unsigned int freq = table[i].frequency;
	251	if (freq == CPUFREQ_ENTRY_INVALID)
	252	continue;
	253	if (freq_table_get_index(stat, freq) == -1)
	254	stat->freq_table[j++] = freq;
	255	}
	256	stat->state_num = j;
	257	spin_lock(&cpufreq_stats_lock);
58f1df25	258	stat->last_time = get_jiffies_64();
1da177e4 LT	259	stat->last_index = freq_table_get_index(stat, policy->cur);
	260	spin_unlock(&cpufreq_stats_lock);
	261	cpufreq_cpu_put(data);
	262	return 0;
	263	error_out:
	264	cpufreq_cpu_put(data);
b7fb358c	265	error_get_fail:
1da177e4	266	kfree(stat);
7a6aedfa	267	per_cpu(cpufreq_stats_table, cpu) = NULL;
1da177e4 LT	268	return ret;
	269	}
	270
b8eed8af VK	271	static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
	272	{
	273	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
	274	policy->last_cpu);
	275
	276	pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
	277	policy->cpu, policy->last_cpu);
	278	per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
	279	policy->last_cpu);
	280	per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
	281	stat->cpu = policy->cpu;
	282	}
	283
0a829c5a DJ	284	static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
0a829c5a DJ	285	unsigned long val, void *data)
1da177e4 LT	286	{
	287	int ret;
	288	struct cpufreq_policy *policy = data;
	289	struct cpufreq_frequency_table *table;
	290	unsigned int cpu = policy->cpu;
b8eed8af VK	291
	292	if (val == CPUFREQ_UPDATE_POLICY_CPU) {
	293	cpufreq_stats_update_policy_cpu(policy);
	294	return 0;
	295	}
	296
1da177e4 LT	297	if (val != CPUFREQ_NOTIFY)
	298	return 0;
	299	table = cpufreq_frequency_get_table(cpu);
	300	if (!table)
	301	return 0;
0a829c5a DJ	302	ret = cpufreq_stats_create_table(policy, table);
0a829c5a DJ	303	if (ret)
1da177e4 LT	304	return ret;
	305	return 0;
	306	}
	307
0a829c5a DJ	308	static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
0a829c5a DJ	309	unsigned long val, void *data)
1da177e4 LT	310	{
	311	struct cpufreq_freqs *freq = data;
	312	struct cpufreq_stats *stat;
	313	int old_index, new_index;
	314
	315	if (val != CPUFREQ_POSTCHANGE)
	316	return 0;
	317
7a6aedfa	318	stat = per_cpu(cpufreq_stats_table, freq->cpu);
1da177e4 LT	319	if (!stat)
1da177e4 LT	320	return 0;
8edc59d9	321
6501faf8	322	old_index = stat->last_index;
1da177e4 LT	323	new_index = freq_table_get_index(stat, freq->new);
1da177e4 LT	324
46a310b8 KRW	325	/* We can't do stat->time_in_state[-1]= .. */
46a310b8 KRW	326	if (old_index == -1 \|\| new_index == -1)
1da177e4 LT	327	return 0;
1da177e4 LT	328
46a310b8 KRW	329	cpufreq_stats_update(freq->cpu);
	330
	331	if (old_index == new_index)
8edc59d9 VP	332	return 0;
8edc59d9 VP	333
1da177e4 LT	334	spin_lock(&cpufreq_stats_lock);
	335	stat->last_index = new_index;
	336	#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
	337	stat->trans_table[old_index * stat->max_state + new_index]++;
	338	#endif
	339	stat->total_trans++;
	340	spin_unlock(&cpufreq_stats_lock);
	341	return 0;
	342	}
	343
2760984f	344	static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
55395ae7 SS	345	unsigned long action,
55395ae7 SS	346	void *hcpu)
c32b6b8e AR	347	{
	348	unsigned int cpu = (unsigned long)hcpu;
	349
	350	switch (action) {
98586ed8	351	case CPU_DOWN_PREPARE:
	352	cpufreq_stats_free_sysfs(cpu);
	353	break;
c32b6b8e AR	354	case CPU_DEAD:
	355	cpufreq_stats_free_table(cpu);
	356	break;
	357	}
	358	return NOTIFY_OK;
	359	}
	360
98586ed8	361	/* priority=1 so this will get called before cpufreq_remove_dev */
469057d5	362	static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
c32b6b8e	363	.notifier_call = cpufreq_stat_cpu_callback,
98586ed8	364	.priority = 1,
c32b6b8e AR	365	};
c32b6b8e AR	366
1da177e4 LT	367	static struct notifier_block notifier_policy_block = {
	368	.notifier_call = cpufreq_stat_notifier_policy
	369	};
	370
	371	static struct notifier_block notifier_trans_block = {
	372	.notifier_call = cpufreq_stat_notifier_trans
	373	};
	374
0a829c5a	375	static int __init cpufreq_stats_init(void)
1da177e4 LT	376	{
	377	int ret;
	378	unsigned int cpu;
c32b6b8e	379
1da177e4	380	spin_lock_init(&cpufreq_stats_lock);
0a829c5a DJ	381	ret = cpufreq_register_notifier(&notifier_policy_block,
	382	CPUFREQ_POLICY_NOTIFIER);
	383	if (ret)
1da177e4 LT	384	return ret;
1da177e4 LT	385
56836fb4	386	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
56836fb4	387
0a829c5a DJ	388	ret = cpufreq_register_notifier(&notifier_trans_block,
	389	CPUFREQ_TRANSITION_NOTIFIER);
	390	if (ret) {
1da177e4 LT	391	cpufreq_unregister_notifier(&notifier_policy_block,
1da177e4 LT	392	CPUFREQ_POLICY_NOTIFIER);
56836fb4 KK	393	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
	394	for_each_online_cpu(cpu)
	395	cpufreq_stats_free_table(cpu);
1da177e4 LT	396	return ret;
	397	}
	398
1da177e4 LT	399	return 0;
1da177e4 LT	400	}
0a829c5a	401	static void __exit cpufreq_stats_exit(void)
1da177e4 LT	402	{
1da177e4 LT	403	unsigned int cpu;
c32b6b8e	404
1da177e4 LT	405	cpufreq_unregister_notifier(&notifier_policy_block,
	406	CPUFREQ_POLICY_NOTIFIER);
	407	cpufreq_unregister_notifier(&notifier_trans_block,
	408	CPUFREQ_TRANSITION_NOTIFIER);
65edc68c	409	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
c32b6b8e	410	for_each_online_cpu(cpu) {
55395ae7	411	cpufreq_stats_free_table(cpu);
13f06753	412	cpufreq_stats_free_sysfs(cpu);
c32b6b8e	413	}
1da177e4 LT	414	}
1da177e4 LT	415
0a829c5a DJ	416	MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
0a829c5a DJ	417	MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
e08f5f5b	418	"through sysfs filesystem");
0a829c5a	419	MODULE_LICENSE("GPL");
1da177e4 LT	420
	421	module_init(cpufreq_stats_init);
	422	module_exit(cpufreq_stats_exit);