3 files changed, 29 insertions, 142 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index b7445b6ae5a4..c822d72629d5 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -31,23 +31,18 @@ config CPU_FREQ_BOOST_SW
         depends on THERMAL
 
 config CPU_FREQ_STAT
-        tristate "CPU frequency translation statistics"
+        bool "CPU frequency transition statistics"
         default y
         help
-          This driver exports CPU frequency statistics information through sysfs
-          file system.
-
-          To compile this driver as a module, choose M here: the
-          module will be called cpufreq_stats.
+          Export CPU frequency statistics information through sysfs.
 
           If in doubt, say N.
 
 config CPU_FREQ_STAT_DETAILS
-        bool "CPU frequency translation statistics details"
+        bool "CPU frequency transition statistics details"
         depends on CPU_FREQ_STAT
         help
-          This will show detail CPU frequency translation table in sysfs file
-          system.
+          Show detailed CPU frequency transition table in sysfs.
 
           If in doubt, say N.
 
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 198416bc22de..c6a14ba239a2 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -347,6 +347,7 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
                 pr_debug("FREQ: %lu - CPU: %lu\n",
                          (unsigned long)freqs->new, (unsigned long)freqs->cpu);
                 trace_cpu_frequency(freqs->new, freqs->cpu);
+                cpufreq_stats_record_transition(policy, freqs->new);
                 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
                                 CPUFREQ_POSTCHANGE, freqs);
                 if (likely(policy) && likely(policy->cpu == freqs->cpu))
@@ -1108,6 +1109,7 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy, bool notify)
                                              CPUFREQ_REMOVE_POLICY, policy);
 
         down_write(&policy->rwsem);
+        cpufreq_stats_free_table(policy);
         cpufreq_remove_dev_symlink(policy);
         kobj = &policy->kobj;
         cmp = &policy->kobj_unregister;
@@ -1262,6 +1264,8 @@ static int cpufreq_online(unsigned int cpu)
                 ret = cpufreq_add_dev_interface(policy);
                 if (ret)
                         goto out_exit_policy;
+
+                cpufreq_stats_create_table(policy);
                 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
                                 CPUFREQ_CREATE_POLICY, policy);
 
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 5e370a30a964..c6e7f81a0397 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -15,7 +15,7 @@
 #include <linux/slab.h>
 #include <linux/cputime.h>
 
-static spinlock_t cpufreq_stats_lock;
+static DEFINE_SPINLOCK(cpufreq_stats_lock);
 
 struct cpufreq_stats {
         unsigned int total_trans;
@@ -52,6 +52,9 @@ static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
         ssize_t len = 0;
         int i;
 
+        if (policy->fast_switch_enabled)
+                return 0;
+
         cpufreq_stats_update(stats);
         for (i = 0; i < stats->state_num; i++) {
                 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
@@ -68,6 +71,9 @@ static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
         ssize_t len = 0;
         int i, j;
 
+        if (policy->fast_switch_enabled)
+                return 0;
+
         len += snprintf(buf + len, PAGE_SIZE - len, "   From  :    To\n");
         len += snprintf(buf + len, PAGE_SIZE - len, "         : ");
         for (i = 0; i < stats->state_num; i++) {
@@ -130,7 +136,7 @@ static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
         return -1;
 }
 
-static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
+void cpufreq_stats_free_table(struct cpufreq_policy *policy)
 {
         struct cpufreq_stats *stats = policy->stats;
 
@@ -146,20 +152,7 @@ static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
         policy->stats = NULL;
 }
 
-static void cpufreq_stats_free_table(unsigned int cpu)
-{
-        struct cpufreq_policy *policy;
-
-        policy = cpufreq_cpu_get(cpu);
-        if (!policy)
-                return;
-
-        __cpufreq_stats_free_table(policy);
-
-        cpufreq_cpu_put(policy);
-}
-
-static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
+void cpufreq_stats_create_table(struct cpufreq_policy *policy)
 {
         unsigned int i = 0, count = 0, ret = -ENOMEM;
         struct cpufreq_stats *stats;
@@ -170,15 +163,15 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
         /* We need cpufreq table for creating stats table */
         table = cpufreq_frequency_get_table(cpu);
         if (unlikely(!table))
-                return 0;
+                return;
 
         /* stats already initialized */
         if (policy->stats)
-                return -EEXIST;
+                return;
 
         stats = kzalloc(sizeof(*stats), GFP_KERNEL);
         if (!stats)
-                return -ENOMEM;
+                return;
 
         /* Find total allocation size */
         cpufreq_for_each_valid_entry(pos, table)
@@ -215,80 +208,32 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy)
         policy->stats = stats;
         ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
         if (!ret)
-                return 0;
+                return;
 
         /* We failed, release resources */
         policy->stats = NULL;
         kfree(stats->time_in_state);
 free_stat:
         kfree(stats);
-
-        return ret;
-}
-
-static void cpufreq_stats_create_table(unsigned int cpu)
-{
-        struct cpufreq_policy *policy;
-
-        /*
-         * "likely(!policy)" because normally cpufreq_stats will be registered
-         * before cpufreq driver
-         */
-        policy = cpufreq_cpu_get(cpu);
-        if (likely(!policy))
-                return;
-
-        __cpufreq_stats_create_table(policy);
-
-        cpufreq_cpu_put(policy);
 }
 
-static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
-                unsigned long val, void *data)
+void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
+                                     unsigned int new_freq)
 {
-        int ret = 0;
-        struct cpufreq_policy *policy = data;
-
-        if (val == CPUFREQ_CREATE_POLICY)
-                ret = __cpufreq_stats_create_table(policy);
-        else if (val == CPUFREQ_REMOVE_POLICY)
-                __cpufreq_stats_free_table(policy);
-
-        return ret;
-}
-
-static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
-                unsigned long val, void *data)
-{
-        struct cpufreq_freqs *freq = data;
-        struct cpufreq_policy *policy = cpufreq_cpu_get(freq->cpu);
-        struct cpufreq_stats *stats;
+        struct cpufreq_stats *stats = policy->stats;
         int old_index, new_index;
 
-        if (!policy) {
-                pr_err("%s: No policy found\n", __func__);
-                return 0;
-        }
-
-        if (val != CPUFREQ_POSTCHANGE)
-                goto put_policy;
-
-        if (!policy->stats) {
+        if (!stats) {
                 pr_debug("%s: No stats found\n", __func__);
-                goto put_policy;
+                return;
         }
 
-        stats = policy->stats;
-
         old_index = stats->last_index;
-        new_index = freq_table_get_index(stats, freq->new);
+        new_index = freq_table_get_index(stats, new_freq);
 
         /* We can't do stats->time_in_state[-1]= .. */
-        if (old_index == -1 || new_index == -1)
-                goto put_policy;
-
-        if (old_index == new_index)
-                goto put_policy;
+        if (old_index == -1 || new_index == -1 || old_index == new_index)
+                return;
 
         cpufreq_stats_update(stats);
 
@@ -297,61 +242,4 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
         stats->trans_table[old_index * stats->max_state + new_index]++;
 #endif
         stats->total_trans++;
-
-put_policy:
-        cpufreq_cpu_put(policy);
-        return 0;
 }
-
-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;
-
-        for_each_online_cpu(cpu)
-                cpufreq_stats_create_table(cpu);
-
-        ret = cpufreq_register_notifier(&notifier_trans_block,
-                                CPUFREQ_TRANSITION_NOTIFIER);
-        if (ret) {
-                cpufreq_unregister_notifier(&notifier_policy_block,
-                                CPUFREQ_POLICY_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);
-        for_each_online_cpu(cpu)
-                cpufreq_stats_free_table(cpu);
-}
-
-MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
-MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
-MODULE_LICENSE("GPL");
-
-module_init(cpufreq_stats_init);
-module_exit(cpufreq_stats_exit);