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__ */