1 files changed, 97 insertions, 122 deletions

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 0cd9b4dcef99..5e370a30a964 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -18,7 +18,6 @@
 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;
@@ -31,50 +30,33 @@ struct cpufreq_stats {
 #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)
+static int cpufreq_stats_update(struct cpufreq_stats *stats)
 {
-        struct cpufreq_stats *stat;
-        unsigned long long cur_time;
+        unsigned long long cur_time = get_jiffies_64();
 
-        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;
+        stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
+        stats->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);
+        return sprintf(buf, "%d\n", policy->stats->total_trans);
 }
 
 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
 {
+        struct cpufreq_stats *stats = policy->stats;
         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],
+
+        cpufreq_stats_update(stats);
+        for (i = 0; i < stats->state_num; i++) {
+                len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
                         (unsigned long long)
-                        jiffies_64_to_clock_t(stat->time_in_state[i]));
+                        jiffies_64_to_clock_t(stats->time_in_state[i]));
         }
         return len;
 }
@@ -82,38 +64,35 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
 {
+        struct cpufreq_stats *stats = policy->stats;
         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++) {
+        for (i = 0; i < stats->state_num; i++) {
                 if (len >= PAGE_SIZE)
                         break;
                 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
-                                stat->freq_table[i]);
+                                stats->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++) {
+        for (i = 0; i < stats->state_num; i++) {
                 if (len >= PAGE_SIZE)
                         break;
 
                 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
-                                stat->freq_table[i]);
+                                stats->freq_table[i]);
 
-                for (j = 0; j < stat->state_num; j++) {
+                for (j = 0; j < stats->state_num; j++) {
                         if (len >= PAGE_SIZE)
                                 break;
                         len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
-                                        stat->trans_table[i*stat->max_state+j]);
+                                        stats->trans_table[i*stats->max_state+j]);
                 }
                 if (len >= PAGE_SIZE)
                         break;
@@ -142,28 +121,29 @@ static struct attribute_group stats_attr_group = {
         .name = "stats"
 };
 
-static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
+static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
 {
         int index;
-        for (index = 0; index < stat->max_state; index++)
-                if (stat->freq_table[index] == freq)
+        for (index = 0; index < stats->max_state; index++)
+                if (stats->freq_table[index] == freq)
                         return index;
         return -1;
 }
 
 static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
 {
-        struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
+        struct cpufreq_stats *stats = policy->stats;
 
-        if (!stat)
+        /* Already freed */
+        if (!stats)
                 return;
 
-        pr_debug("%s: Free stat table\n", __func__);
+        pr_debug("%s: Free stats table\n", __func__);
 
         sysfs_remove_group(&policy->kobj, &stats_attr_group);
-        kfree(stat->time_in_state);
-        kfree(stat);
-        per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
+        kfree(stats->time_in_state);
+        kfree(stats);
+        policy->stats = NULL;
 }
 
 static void cpufreq_stats_free_table(unsigned int cpu)
@@ -174,37 +154,33 @@ static void cpufreq_stats_free_table(unsigned int cpu)
         if (!policy)
                 return;
 
-        if (cpufreq_frequency_get_table(policy->cpu))
-                __cpufreq_stats_free_table(policy);
+        __cpufreq_stats_free_table(policy);
 
         cpufreq_cpu_put(policy);
 }
 
 static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
 {
-        unsigned int i, count = 0, ret = 0;
-        struct cpufreq_stats *stat;
+        unsigned int i = 0, count = 0, ret = -ENOMEM;
+        struct cpufreq_stats *stats;
         unsigned int alloc_size;
         unsigned int cpu = policy->cpu;
         struct cpufreq_frequency_table *pos, *table;
 
+        /* We need cpufreq table for creating stats table */
         table = cpufreq_frequency_get_table(cpu);
         if (unlikely(!table))
                 return 0;
 
-        if (per_cpu(cpufreq_stats_table, cpu))
-                return -EBUSY;
-        stat = kzalloc(sizeof(*stat), GFP_KERNEL);
-        if ((stat) == NULL)
-                return -ENOMEM;
-
-        ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
-        if (ret)
-                goto error_out;
+        /* stats already initialized */
+        if (policy->stats)
+                return -EEXIST;
 
-        stat->cpu = cpu;
-        per_cpu(cpufreq_stats_table, cpu) = stat;
+        stats = kzalloc(sizeof(*stats), GFP_KERNEL);
+        if (!stats)
+                return -ENOMEM;
 
+        /* Find total allocation size */
         cpufreq_for_each_valid_entry(pos, table)
                 count++;
 
@@ -213,32 +189,40 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
 #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_alloc;
-        }
-        stat->freq_table = (unsigned int *)(stat->time_in_state + count);
+
+        /* Allocate memory for time_in_state/freq_table/trans_table in one go */
+        stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
+        if (!stats->time_in_state)
+                goto free_stat;
+
+        stats->freq_table = (unsigned int *)(stats->time_in_state + count);
 
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
-        stat->trans_table = stat->freq_table + count;
+        stats->trans_table = stats->freq_table + count;
 #endif
-        i = 0;
+
+        stats->max_state = count;
+
+        /* Find valid-unique entries */
         cpufreq_for_each_valid_entry(pos, table)
-                if (freq_table_get_index(stat, pos->frequency) == -1)
-                        stat->freq_table[i++] = pos->frequency;
-        stat->state_num = i;
-        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);
-        return 0;
-error_alloc:
-        sysfs_remove_group(&policy->kobj, &stats_attr_group);
-error_out:
-        kfree(stat);
-        per_cpu(cpufreq_stats_table, cpu) = NULL;
+                if (freq_table_get_index(stats, pos->frequency) == -1)
+                        stats->freq_table[i++] = pos->frequency;
+
+        stats->state_num = i;
+        stats->last_time = get_jiffies_64();
+        stats->last_index = freq_table_get_index(stats, policy->cur);
+
+        policy->stats = stats;
+        ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
+        if (!ret)
+                return 0;
+
+        /* We failed, release resources */
+        policy->stats = NULL;
+        kfree(stats->time_in_state);
+free_stat:
+        kfree(stats);
+
         return ret;
 }
 
@@ -259,30 +243,12 @@ static void cpufreq_stats_create_table(unsigned int cpu)
         cpufreq_cpu_put(policy);
 }
 
-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 = 0;
         struct cpufreq_policy *policy = data;
 
-        if (val == CPUFREQ_UPDATE_POLICY_CPU) {
-                cpufreq_stats_update_policy_cpu(policy);
-                return 0;
-        }
-
         if (val == CPUFREQ_CREATE_POLICY)
                 ret = __cpufreq_stats_create_table(policy);
         else if (val == CPUFREQ_REMOVE_POLICY)
@@ -295,35 +261,45 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
                 unsigned long val, void *data)
 {
         struct cpufreq_freqs *freq = data;
-        struct cpufreq_stats *stat;
+        struct cpufreq_policy *policy = cpufreq_cpu_get(freq->cpu);
+        struct cpufreq_stats *stats;
         int old_index, new_index;
 
-        if (val != CPUFREQ_POSTCHANGE)
+        if (!policy) {
+                pr_err("%s: No policy found\n", __func__);
                 return 0;
+        }
 
-        stat = per_cpu(cpufreq_stats_table, freq->cpu);
-        if (!stat)
-                return 0;
+        if (val != CPUFREQ_POSTCHANGE)
+                goto put_policy;
 
-        old_index = stat->last_index;
-        new_index = freq_table_get_index(stat, freq->new);
+        if (!policy->stats) {
+                pr_debug("%s: No stats found\n", __func__);
+                goto put_policy;
+        }
 
-        /* We can't do stat->time_in_state[-1]= .. */
-        if (old_index == -1 || new_index == -1)
-                return 0;
+        stats = policy->stats;
+
+        old_index = stats->last_index;
+        new_index = freq_table_get_index(stats, freq->new);
 
-        cpufreq_stats_update(freq->cpu);
+        /* We can't do stats->time_in_state[-1]= .. */
+        if (old_index == -1 || new_index == -1)
+                goto put_policy;
 
         if (old_index == new_index)
-                return 0;
+                goto put_policy;
 
-        spin_lock(&cpufreq_stats_lock);
-        stat->last_index = new_index;
+        cpufreq_stats_update(stats);
+
+        stats->last_index = new_index;
 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
-        stat->trans_table[old_index * stat->max_state + new_index]++;
+        stats->trans_table[old_index * stats->max_state + new_index]++;
 #endif
-        stat->total_trans++;
-        spin_unlock(&cpufreq_stats_lock);
+        stats->total_trans++;
+
+put_policy:
+        cpufreq_cpu_put(policy);
         return 0;
 }
 
@@ -374,8 +350,7 @@ static void __exit cpufreq_stats_exit(void)
 }
 
 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
-MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
-                                "through sysfs filesystem");
+MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
 MODULE_LICENSE("GPL");
 
 module_init(cpufreq_stats_init);