Merge branch 'for-rafael' of https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq into pm-devfreq

Pull devfreq updates for v4.3 from MyungJoo Ham.

* 'for-rafael' of https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
  PM / devfreq: Fix incorrect type issue.
  PM / devfreq: tegra: Update governor to use devfreq_update_stats()
  PM / devfreq: comments for get_dev_status usage updated
  PM / devfreq: drop comment about thermal setting max_freq
  PM / devfreq: cache the last call to get_dev_status()
  PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
  PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
  PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
  PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
  PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding

Conflicts:
	drivers/devfreq/event/exynos-ppmu.c

5 files changed, 54 insertions, 26 deletions

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ca1b362d77e2..3927ed9fdbd5 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -53,7 +53,7 @@ static struct devfreq *find_device_devfreq(struct device *dev)
 {
 	struct devfreq *tmp_devfreq;
 
-	if (unlikely(IS_ERR_OR_NULL(dev))) {
+	if (IS_ERR_OR_NULL(dev)) {
 		pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
 		return ERR_PTR(-EINVAL);
 	}
@@ -133,7 +133,7 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
 {
 	struct devfreq_governor *tmp_governor;
 
-	if (unlikely(IS_ERR_OR_NULL(name))) {
+	if (IS_ERR_OR_NULL(name)) {
 		pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
 		return ERR_PTR(-EINVAL);
 	}
@@ -177,10 +177,10 @@ int update_devfreq(struct devfreq *devfreq)
 		return err;
 
 	/*
-	 * Adjust the freuqency with user freq and QoS.
+	 * Adjust the frequency with user freq and QoS.
 	 *
-	 * List from the highest proiority
-	 * max_freq (probably called by thermal when it's too hot)
+	 * List from the highest priority
+	 * max_freq
 	 * min_freq
 	 */
 
@@ -482,7 +482,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 						devfreq->profile->max_state *
 						devfreq->profile->max_state,
 						GFP_KERNEL);
-	devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) *
+	devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned long) *
 						devfreq->profile->max_state,
 						GFP_KERNEL);
 	devfreq->last_stat_updated = jiffies;
diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
index f9901f52a225..f312485f1451 100644
--- a/drivers/devfreq/event/exynos-ppmu.c
+++ b/drivers/devfreq/event/exynos-ppmu.c
@@ -319,7 +319,8 @@ static int exynos_ppmu_v2_get_event(struct devfreq_event_dev *edev,
 	case PPMU_PMNCNT3:
 		pmcnt_high = __raw_readl(info->ppmu.base + PPMU_V2_PMCNT3_HIGH);
 		pmcnt_low = __raw_readl(info->ppmu.base + PPMU_V2_PMCNT3_LOW);
-		load_count = (u64)((pmcnt_high & 0xff) << 32) + (u64)pmcnt_low;
+		load_count = ((u64)((pmcnt_high & 0xff)) << 32)
+			   + (u64)pmcnt_low;
 		break;
 	}
 	edata->load_count = load_count;
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index 0720ba84ca92..ae72ba5e78df 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -21,17 +21,20 @@
 static int devfreq_simple_ondemand_func(struct devfreq *df,
 					unsigned long *freq)
 {
-	struct devfreq_dev_status stat;
-	int err = df->profile->get_dev_status(df->dev.parent, &stat);
+	int err;
+	struct devfreq_dev_status *stat;
 	unsigned long long a, b;
 	unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
 	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
 	struct devfreq_simple_ondemand_data *data = df->data;
 	unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX;
 
+	err = devfreq_update_stats(df);
 	if (err)
 		return err;
 
+	stat = &df->last_status;
+
 	if (data) {
 		if (data->upthreshold)
 			dfso_upthreshold = data->upthreshold;
@@ -43,41 +46,41 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
 		return -EINVAL;
 
 	/* Assume MAX if it is going to be divided by zero */
-	if (stat.total_time == 0) {
+	if (stat->total_time == 0) {
 		*freq = max;
 		return 0;
 	}
 
 	/* Prevent overflow */
-	if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) {
-		stat.busy_time >>= 7;
-		stat.total_time >>= 7;
+	if (stat->busy_time >= (1 << 24) || stat->total_time >= (1 << 24)) {
+		stat->busy_time >>= 7;
+		stat->total_time >>= 7;
 	}
 
 	/* Set MAX if it's busy enough */
-	if (stat.busy_time * 100 >
-	    stat.total_time * dfso_upthreshold) {
+	if (stat->busy_time * 100 >
+	    stat->total_time * dfso_upthreshold) {
 		*freq = max;
 		return 0;
 	}
 
 	/* Set MAX if we do not know the initial frequency */
-	if (stat.current_frequency == 0) {
+	if (stat->current_frequency == 0) {
 		*freq = max;
 		return 0;
 	}
 
 	/* Keep the current frequency */
-	if (stat.busy_time * 100 >
-	    stat.total_time * (dfso_upthreshold - dfso_downdifferential)) {
-		*freq = stat.current_frequency;
+	if (stat->busy_time * 100 >
+	    stat->total_time * (dfso_upthreshold - dfso_downdifferential)) {
+		*freq = stat->current_frequency;
 		return 0;
 	}
 
 	/* Set the desired frequency based on the load */
-	a = stat.busy_time;
-	a *= stat.current_frequency;
-	b = div_u64(a, stat.total_time);
+	a = stat->busy_time;
+	a *= stat->current_frequency;
+	b = div_u64(a, stat->total_time);
 	b *= 100;
 	b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
 	*freq = (unsigned long) b;
diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 13a1a6e8108c..848b93ee930f 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -541,18 +541,20 @@ static struct devfreq_dev_profile tegra_devfreq_profile = {
 static int tegra_governor_get_target(struct devfreq *devfreq,
 				     unsigned long *freq)
 {
-	struct devfreq_dev_status stat;
+	struct devfreq_dev_status *stat;
 	struct tegra_devfreq *tegra;
 	struct tegra_devfreq_device *dev;
 	unsigned long target_freq = 0;
 	unsigned int i;
 	int err;
 
-	err = devfreq->profile->get_dev_status(devfreq->dev.parent, &stat);
+	err = devfreq_update_stats(devfreq);
 	if (err)
 		return err;
 
-	tegra = stat.private_data;
+	stat = &devfreq->last_status;
+
+	tegra = stat->private_data;
 
 	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
 		dev = &tegra->devices[i];
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index ce447f0f1bad..68030e22af35 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -65,7 +65,10 @@ struct devfreq_dev_status {
  *			The "flags" parameter's possible values are
  *			explained above with "DEVFREQ_FLAG_*" macros.
  * @get_dev_status:	The device should provide the current performance
- *			status to devfreq, which is used by governors.
+ *			status to devfreq. Governors are recommended not to
+ *			use this directly. Instead, governors are recommended
+ *			to use devfreq_update_stats() along with
+ *			devfreq.last_status.
  * @get_cur_freq:	The device should provide the current frequency
  *			at which it is operating.
  * @exit:		An optional callback that is called when devfreq
@@ -161,6 +164,7 @@ struct devfreq {
 	struct delayed_work work;
 
 	unsigned long previous_freq;
+	struct devfreq_dev_status last_status;
 
 	void *data; /* private data for governors */
 
@@ -204,6 +208,19 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 						struct devfreq *devfreq);
 
+/**
+ * devfreq_update_stats() - update the last_status pointer in struct devfreq
+ * @df:		the devfreq instance whose status needs updating
+ *
+ *  Governors are recommended to use this function along with last_status,
+ * which allows other entities to reuse the last_status without affecting
+ * the values fetched later by governors.
+ */
+static inline int devfreq_update_stats(struct devfreq *df)
+{
+	return df->profile->get_dev_status(df->dev.parent, &df->last_status);
+}
+
 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
@@ -289,6 +306,11 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
 							struct devfreq *devfreq)
 {
 }
+
+static inline int devfreq_update_stats(struct devfreq *df)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_PM_DEVFREQ */
 
 #endif /* __LINUX_DEVFREQ_H__ */