[PATCH v4] PM / devfreq: Move statistics to separate struct devfreq_stats

[Chanwoo Choi <cw00.choi@samsung.com>]

From: Kamil Konieczny <k.konieczny@samsung.com>

Count time and transitions between devfreq frequencies in separate
struct devfreq_stats for improved code readability and maintenance.

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
[cw00.choi: Fix the merge conflict in trasn_stat_store]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c | 44 ++++++++++++++++++++-------------------
 include/linux/devfreq.h   | 26 +++++++++++++++--------
 2 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index df31f430051d..1786a86b1779 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -214,8 +214,8 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 		goto out;
 	}
 
-	devfreq->time_in_state[prev_lev] +=
-			 cur_time - devfreq->last_stat_updated;
+	devfreq->stats.time_in_state[prev_lev] +=
+			cur_time - devfreq->stats.last_update;
 
 	lev = devfreq_get_freq_level(devfreq, freq);
 	if (lev < 0) {
@@ -224,13 +224,13 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
 	}
 
 	if (lev != prev_lev) {
-		devfreq->trans_table[(prev_lev *
-				devfreq->profile->max_state) + lev]++;
-		devfreq->total_trans++;
+		devfreq->stats.trans_table[
+			(prev_lev * devfreq->profile->max_state) + lev]++;
+		devfreq->stats.total_trans++;
 	}
 
 out:
-	devfreq->last_stat_updated = cur_time;
+	devfreq->stats.last_update = cur_time;
 	return ret;
 }
 EXPORT_SYMBOL(devfreq_update_status);
@@ -525,7 +525,7 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
 			msecs_to_jiffies(devfreq->profile->polling_ms));
 
 out_update:
-	devfreq->last_stat_updated = get_jiffies_64();
+	devfreq->stats.last_update = get_jiffies_64();
 	devfreq->stop_polling = false;
 
 	if (devfreq->profile->get_cur_freq &&
@@ -735,28 +735,29 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		goto err_out;
 	}
 
-	devfreq->trans_table = devm_kzalloc(&devfreq->dev,
+	devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
 			array3_size(sizeof(unsigned int),
 				    devfreq->profile->max_state,
 				    devfreq->profile->max_state),
 			GFP_KERNEL);
-	if (!devfreq->trans_table) {
+	if (!devfreq->stats.trans_table) {
 		mutex_unlock(&devfreq->lock);
 		err = -ENOMEM;
 		goto err_devfreq;
 	}
 
-	devfreq->time_in_state = devm_kcalloc(&devfreq->dev,
+	devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
 			devfreq->profile->max_state,
-			sizeof(*devfreq->time_in_state),
+			sizeof(*devfreq->stats.time_in_state),
 			GFP_KERNEL);
-	if (!devfreq->time_in_state) {
+	if (!devfreq->stats.time_in_state) {
 		mutex_unlock(&devfreq->lock);
 		err = -ENOMEM;
 		goto err_devfreq;
 	}
 
-	devfreq->last_stat_updated = get_jiffies_64();
+	devfreq->stats.total_trans = 0;
+	devfreq->stats.last_update = get_jiffies_64();
 
 	srcu_init_notifier_head(&devfreq->transition_notifier_list);
 
@@ -1469,13 +1470,14 @@ static ssize_t trans_stat_show(struct device *dev,
 				devfreq->profile->freq_table[i]);
 		for (j = 0; j < max_state; j++)
 			len += sprintf(buf + len, "%10u",
-				devfreq->trans_table[(i * max_state) + j]);
+				devfreq->stats.trans_table[(i * max_state) + j]);
+
 		len += sprintf(buf + len, "%10llu\n", (u64)
-			jiffies64_to_msecs(devfreq->time_in_state[i]));
+			jiffies64_to_msecs(devfreq->stats.time_in_state[i]));
 	}
 
 	len += sprintf(buf + len, "Total transition : %u\n",
-					devfreq->total_trans);
+					devfreq->stats.total_trans);
 	return len;
 }
 
@@ -1494,13 +1496,13 @@ static ssize_t trans_stat_store(struct device *dev,
 		return -EINVAL;
 
 	mutex_lock(&df->lock);
-	memset(df->time_in_state, 0, (df->profile->max_state *
-					sizeof(*df->time_in_state)));
-	memset(df->trans_table, 0, array3_size(sizeof(unsigned int),
+	memset(df->stats.time_in_state, 0, (df->profile->max_state *
+					sizeof(*df->stats.time_in_state)));
+	memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
 					df->profile->max_state,
 					df->profile->max_state));
-	df->total_trans = 0;
-	df->last_stat_updated = get_jiffies_64();
+	df->stats.total_trans = 0;
+	df->stats.last_update = get_jiffies_64();
 	mutex_unlock(&df->lock);
 
 	return count;
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 41f15e7a22b8..de2fdc56aa5b 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -106,6 +106,20 @@ struct devfreq_dev_profile {
 	unsigned int max_state;
 };
 
+/**
+ * struct devfreq_stats - Statistics of devfreq device behavior
+ * @total_trans:	Number of devfreq transitions.
+ * @trans_table:	Statistics of devfreq transitions.
+ * @time_in_state:	Statistics of devfreq states.
+ * @last_update:	The last time stats were updated.
+ */
+struct devfreq_stats {
+	unsigned int total_trans;
+	unsigned int *trans_table;
+	u64 *time_in_state;
+	u64 last_update;
+};
+
 /**
  * struct devfreq - Device devfreq structure
  * @node:	list node - contains the devices with devfreq that have been
@@ -131,10 +145,7 @@ struct devfreq_dev_profile {
  * @suspend_freq:	 frequency of a device set during suspend phase.
  * @resume_freq:	 frequency of a device set in resume phase.
  * @suspend_count:	 suspend requests counter for a device.
- * @total_trans:	Number of devfreq transitions
- * @trans_table:	Statistics of devfreq transitions
- * @time_in_state:	Statistics of devfreq states
- * @last_stat_updated:	The last time stat updated
+ * @stats:	Statistics of devfreq device behavior
  * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
  *
  * This structure stores the devfreq information for a give device.
@@ -171,11 +182,8 @@ struct devfreq {
 	unsigned long resume_freq;
 	atomic_t suspend_count;
 
-	/* information for device frequency transition */
-	unsigned int total_trans;
-	unsigned int *trans_table;
-	u64 *time_in_state;
-	u64 last_stat_updated;
+	/* information for device frequency transitions */
+	struct devfreq_stats stats;
 
 	struct srcu_notifier_head transition_notifier_list;
 };
-- 
2.17.1