[PATCH V2 02/11] opp: Relocate few routines

[PATCH V2 02/11] opp: Relocate few routines

[Viresh Kumar]

In order to prepare for the later commits, this relocates few routines
towards the top as they will be used earlier in the code.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 277 ++++++++++++++++++++++++-----------------------
 1 file changed, 139 insertions(+), 138 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 677fb2843553..8c3fd57975fb 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -438,6 +438,102 @@ static struct device_opp *_add_device_opp(struct device *dev)
 }
 
 /**
+ * _kfree_device_rcu() - Free device_opp RCU handler
+ * @head:	RCU head
+ */
+static void _kfree_device_rcu(struct rcu_head *head)
+{
+	struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
+
+	kfree_rcu(device_opp, rcu_head);
+}
+
+/**
+ * _kfree_opp_rcu() - Free OPP RCU handler
+ * @head:	RCU head
+ */
+static void _kfree_opp_rcu(struct rcu_head *head)
+{
+	struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
+
+	kfree_rcu(opp, rcu_head);
+}
+
+/**
+ * _opp_remove()  - Remove an OPP from a table definition
+ * @dev_opp:	points back to the device_opp struct this opp belongs to
+ * @opp:	pointer to the OPP to remove
+ *
+ * This function removes an opp definition from the opp list.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * It is assumed that the caller holds required mutex for an RCU updater
+ * strategy.
+ */
+static void _opp_remove(struct device_opp *dev_opp,
+			struct dev_pm_opp *opp)
+{
+	/*
+	 * Notify the changes in the availability of the operable
+	 * frequency/voltage list.
+	 */
+	srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
+	list_del_rcu(&opp->node);
+	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
+
+	if (list_empty(&dev_opp->opp_list)) {
+		list_del_rcu(&dev_opp->node);
+		call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
+			  _kfree_device_rcu);
+	}
+}
+
+/**
+ * dev_pm_opp_remove()  - Remove an OPP from OPP list
+ * @dev:	device for which we do this operation
+ * @freq:	OPP to remove with matching 'freq'
+ *
+ * This function removes an opp from the opp list.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_remove(struct device *dev, unsigned long freq)
+{
+	struct dev_pm_opp *opp;
+	struct device_opp *dev_opp;
+	bool found = false;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp))
+		goto unlock;
+
+	list_for_each_entry(opp, &dev_opp->opp_list, node) {
+		if (opp->rate == freq) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
+			 __func__, freq);
+		goto unlock;
+	}
+
+	_opp_remove(dev_opp, opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
+
+/**
  * _opp_add_dynamic() - Allocate a dynamic OPP.
  * @dev:	device for which we do this operation
  * @freq:	Frequency in Hz for this OPP
@@ -570,102 +666,6 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 EXPORT_SYMBOL_GPL(dev_pm_opp_add);
 
 /**
- * _kfree_opp_rcu() - Free OPP RCU handler
- * @head:	RCU head
- */
-static void _kfree_opp_rcu(struct rcu_head *head)
-{
-	struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
-
-	kfree_rcu(opp, rcu_head);
-}
-
-/**
- * _kfree_device_rcu() - Free device_opp RCU handler
- * @head:	RCU head
- */
-static void _kfree_device_rcu(struct rcu_head *head)
-{
-	struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
-
-	kfree_rcu(device_opp, rcu_head);
-}
-
-/**
- * _opp_remove()  - Remove an OPP from a table definition
- * @dev_opp:	points back to the device_opp struct this opp belongs to
- * @opp:	pointer to the OPP to remove
- *
- * This function removes an opp definition from the opp list.
- *
- * Locking: The internal device_opp and opp structures are RCU protected.
- * It is assumed that the caller holds required mutex for an RCU updater
- * strategy.
- */
-static void _opp_remove(struct device_opp *dev_opp,
-			struct dev_pm_opp *opp)
-{
-	/*
-	 * Notify the changes in the availability of the operable
-	 * frequency/voltage list.
-	 */
-	srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
-	list_del_rcu(&opp->node);
-	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
-
-	if (list_empty(&dev_opp->opp_list)) {
-		list_del_rcu(&dev_opp->node);
-		call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
-			  _kfree_device_rcu);
-	}
-}
-
-/**
- * dev_pm_opp_remove()  - Remove an OPP from OPP list
- * @dev:	device for which we do this operation
- * @freq:	OPP to remove with matching 'freq'
- *
- * This function removes an opp from the opp list.
- *
- * Locking: The internal device_opp and opp structures are RCU protected.
- * Hence this function internally uses RCU updater strategy with mutex locks
- * to keep the integrity of the internal data structures. Callers should ensure
- * that this function is *NOT* called under RCU protection or in contexts where
- * mutex cannot be locked.
- */
-void dev_pm_opp_remove(struct device *dev, unsigned long freq)
-{
-	struct dev_pm_opp *opp;
-	struct device_opp *dev_opp;
-	bool found = false;
-
-	/* Hold our list modification lock here */
-	mutex_lock(&dev_opp_list_lock);
-
-	dev_opp = _find_device_opp(dev);
-	if (IS_ERR(dev_opp))
-		goto unlock;
-
-	list_for_each_entry(opp, &dev_opp->opp_list, node) {
-		if (opp->rate == freq) {
-			found = true;
-			break;
-		}
-	}
-
-	if (!found) {
-		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
-			 __func__, freq);
-		goto unlock;
-	}
-
-	_opp_remove(dev_opp, opp);
-unlock:
-	mutex_unlock(&dev_opp_list_lock);
-}
-EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
-
-/**
  * _opp_set_availability() - helper to set the availability of an opp
  * @dev:		device for which we do this operation
  * @freq:		OPP frequency to modify availability
@@ -825,6 +825,49 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);
 
 #ifdef CONFIG_OF
 /**
+ * of_free_opp_table() - Free OPP table entries created from static DT entries
+ * @dev:	device pointer used to lookup device OPPs.
+ *
+ * Free OPPs created using static entries present in DT.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function indirectly uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void of_free_opp_table(struct device *dev)
+{
+	struct device_opp *dev_opp;
+	struct dev_pm_opp *opp, *tmp;
+
+	/* Check for existing list for 'dev' */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		int error = PTR_ERR(dev_opp);
+
+		if (error != -ENODEV)
+			WARN(1, "%s: dev_opp: %d\n",
+			     IS_ERR_OR_NULL(dev) ?
+					"Invalid device" : dev_name(dev),
+			     error);
+		return;
+	}
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Free static OPPs */
+	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
+		if (!opp->dynamic)
+			_opp_remove(dev_opp, opp);
+	}
+
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(of_free_opp_table);
+
+/**
  * of_init_opp_table() - Initialize opp table from device tree
  * @dev:	device pointer used to lookup device OPPs.
  *
@@ -882,46 +925,4 @@ int of_init_opp_table(struct device *dev)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_init_opp_table);
-
-/**
- * of_free_opp_table() - Free OPP table entries created from static DT entries
- * @dev:	device pointer used to lookup device OPPs.
- *
- * Free OPPs created using static entries present in DT.
- *
- * Locking: The internal device_opp and opp structures are RCU protected.
- * Hence this function indirectly uses RCU updater strategy with mutex locks
- * to keep the integrity of the internal data structures. Callers should ensure
- * that this function is *NOT* called under RCU protection or in contexts where
- * mutex cannot be locked.
- */
-void of_free_opp_table(struct device *dev)
-{
-	struct device_opp *dev_opp;
-	struct dev_pm_opp *opp, *tmp;
-
-	/* Check for existing list for 'dev' */
-	dev_opp = _find_device_opp(dev);
-	if (IS_ERR(dev_opp)) {
-		int error = PTR_ERR(dev_opp);
-		if (error != -ENODEV)
-			WARN(1, "%s: dev_opp: %d\n",
-			     IS_ERR_OR_NULL(dev) ?
-					"Invalid device" : dev_name(dev),
-			     error);
-		return;
-	}
-
-	/* Hold our list modification lock here */
-	mutex_lock(&dev_opp_list_lock);
-
-	/* Free static OPPs */
-	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
-		if (!opp->dynamic)
-			_opp_remove(dev_opp, opp);
-	}
-
-	mutex_unlock(&dev_opp_list_lock);
-}
-EXPORT_SYMBOL_GPL(of_free_opp_table);
 #endif
-- 
2.4.0

[PATCH V2 03/11] OPP: Create _remove_device_opp() for freeing dev_opp

[Viresh Kumar]

This will be used from multiple places later. Lets create a separate
routine for that.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 8c3fd57975fb..7895fdd64192 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -449,6 +449,22 @@ static void _kfree_device_rcu(struct rcu_head *head)
 }
 
 /**
+ * _remove_device_opp() - Removes a device OPP table
+ * @dev_opp: device OPP table to be removed.
+ *
+ * Removes/frees device OPP table it it doesn't contain any OPPs.
+ */
+static void _remove_device_opp(struct device_opp *dev_opp)
+{
+	if (!list_empty(&dev_opp->opp_list))
+		return;
+
+	list_del_rcu(&dev_opp->node);
+	call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
+		  _kfree_device_rcu);
+}
+
+/**
  * _kfree_opp_rcu() - Free OPP RCU handler
  * @head:	RCU head
  */
@@ -481,11 +497,7 @@ static void _opp_remove(struct device_opp *dev_opp,
 	list_del_rcu(&opp->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
 
-	if (list_empty(&dev_opp->opp_list)) {
-		list_del_rcu(&dev_opp->node);
-		call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
-			  _kfree_device_rcu);
-	}
+	_remove_device_opp(dev_opp);
 }
 
 /**
-- 
2.4.0

[PATCH V2 04/11] OPP: Allocate dev_opp from _add_device_opp()

[Viresh Kumar]

There is no need to complicate _opp_add_dynamic() with allocation of
dev_opp as well. Allocate it from _add_device_opp() instead.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 41 ++++++++++++++++++-----------------------
 1 file changed, 18 insertions(+), 23 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 7895fdd64192..901b6c77a791 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -408,11 +408,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
 /**
- * _add_device_opp() - Allocate a new device OPP table
+ * _add_device_opp() - Find device OPP table or allocate a new one
  * @dev:	device for which we do this operation
  *
- * New device node which uses OPPs - used when multiple devices with OPP tables
- * are maintained.
+ * It tries to find an existing table first, if it couldn't find one, it
+ * allocates a new OPP table and returns that.
  *
  * Return: valid device_opp pointer if success, else NULL.
  */
@@ -420,6 +420,11 @@ static struct device_opp *_add_device_opp(struct device *dev)
 {
 	struct device_opp *dev_opp;
 
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (!IS_ERR(dev_opp))
+		return dev_opp;
+
 	/*
 	 * Allocate a new device OPP table. In the infrequent case where a new
 	 * device is needed to be added, we pay this penalty.
@@ -575,7 +580,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 			    long u_volt, bool dynamic)
 {
-	struct device_opp *dev_opp = NULL;
+	struct device_opp *dev_opp;
 	struct dev_pm_opp *opp, *new_opp;
 	struct list_head *head;
 	int ret;
@@ -592,19 +597,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	new_opp->rate = freq;
 	new_opp->u_volt = u_volt;
 	new_opp->available = true;
-	new_opp->dynamic = dynamic;
-
-	/* Check for existing list for 'dev' */
-	dev_opp = _find_device_opp(dev);
-	if (IS_ERR(dev_opp)) {
-		dev_opp = _add_device_opp(dev);
-		if (!dev_opp) {
-			ret = -ENOMEM;
-			goto free_opp;
-		}
 
-		head = &dev_opp->opp_list;
-		goto list_add;
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto free_opp;
 	}
 
 	/*
@@ -613,14 +610,12 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	 */
 	head = &dev_opp->opp_list;
 	list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
-		if (new_opp->rate <= opp->rate)
-			break;
-		else
+		if (new_opp->rate > opp->rate)
 			head = &opp->node;
-	}
+		else if (new_opp->rate < opp->rate)
+			break;
 
-	/* Duplicate OPPs ? */
-	if (new_opp->rate == opp->rate) {
+		/* Duplicate OPPs */
 		ret = opp->available && new_opp->u_volt == opp->u_volt ?
 			0 : -EEXIST;
 
@@ -630,7 +625,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 		goto free_opp;
 	}
 
-list_add:
+	new_opp->dynamic = dynamic;
 	new_opp->dev_opp = dev_opp;
 	list_add_rcu(&new_opp->node, head);
 	mutex_unlock(&dev_opp_list_lock);
-- 
2.4.0

[PATCH V2 05/11] OPP: Break _opp_add_dynamic() into smaller functions

[Viresh Kumar]

Later commits would add support for new OPP bindings and this would be
required then. So, lets do it in a separate patch to make it easily
reviewable.

Another change worth noticing is INIT_LIST_HEAD(&opp->node). We weren't
doing it earlier as we never tried to delete a list node before it is
added to list. But this wouldn't be the case anymore. We might try to
delete a node (just to reuse the same code paths), without it being
getting added to the list.

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 109 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 69 insertions(+), 40 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 901b6c77a791..962d62316b80 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -484,6 +484,7 @@ static void _kfree_opp_rcu(struct rcu_head *head)
  * _opp_remove()  - Remove an OPP from a table definition
  * @dev_opp:	points back to the device_opp struct this opp belongs to
  * @opp:	pointer to the OPP to remove
+ * @notify:	OPP_EVENT_REMOVE notification should be sent or not
  *
  * This function removes an opp definition from the opp list.
  *
@@ -492,13 +493,14 @@ static void _kfree_opp_rcu(struct rcu_head *head)
  * strategy.
  */
 static void _opp_remove(struct device_opp *dev_opp,
-			struct dev_pm_opp *opp)
+			struct dev_pm_opp *opp, bool notify)
 {
 	/*
 	 * Notify the changes in the availability of the operable
 	 * frequency/voltage list.
 	 */
-	srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
+	if (notify)
+		srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
 	list_del_rcu(&opp->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
 
@@ -544,12 +546,63 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 		goto unlock;
 	}
 
-	_opp_remove(dev_opp, opp);
+	_opp_remove(dev_opp, opp, true);
 unlock:
 	mutex_unlock(&dev_opp_list_lock);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 
+static struct dev_pm_opp *_allocate_opp(struct device *dev,
+					struct device_opp **dev_opp)
+{
+	struct dev_pm_opp *opp;
+
+	/* allocate new OPP node */
+	opp = kzalloc(sizeof(*opp), GFP_KERNEL);
+	if (!opp)
+		return NULL;
+
+	INIT_LIST_HEAD(&opp->node);
+
+	*dev_opp = _add_device_opp(dev);
+	if (!*dev_opp) {
+		kfree(opp);
+		return NULL;
+	}
+
+	return opp;
+}
+
+static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
+{
+	struct dev_pm_opp *opp;
+	struct list_head *head = &dev_opp->opp_list;
+
+	/*
+	 * Insert new OPP in order of increasing frequency
+	 * and discard if already present.
+	 */
+	list_for_each_entry_rcu(opp, head, node) {
+		if (new_opp->rate > opp->rate)
+			head = &opp->node;
+		else if (new_opp->rate < opp->rate)
+			break;
+
+		/* Duplicate OPPs */
+		dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
+			 __func__, opp->rate, opp->u_volt, opp->available,
+			 new_opp->rate, new_opp->u_volt, new_opp->available);
+
+		return opp->available && new_opp->u_volt == opp->u_volt ?
+			0 : -EEXIST;
+	}
+
+	new_opp->dev_opp = dev_opp;
+	list_add_rcu(&new_opp->node, head);
+
+	return 0;
+}
+
 /**
  * _opp_add_dynamic() - Allocate a dynamic OPP.
  * @dev:	device for which we do this operation
@@ -581,53 +634,28 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 			    long u_volt, bool dynamic)
 {
 	struct device_opp *dev_opp;
-	struct dev_pm_opp *opp, *new_opp;
-	struct list_head *head;
+	struct dev_pm_opp *new_opp;
 	int ret;
 
-	/* allocate new OPP node */
-	new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL);
-	if (!new_opp)
-		return -ENOMEM;
-
 	/* Hold our list modification lock here */
 	mutex_lock(&dev_opp_list_lock);
 
+	new_opp = _allocate_opp(dev, &dev_opp);
+	if (!new_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
 	/* populate the opp table */
 	new_opp->rate = freq;
 	new_opp->u_volt = u_volt;
 	new_opp->available = true;
+	new_opp->dynamic = dynamic;
 
-	dev_opp = _add_device_opp(dev);
-	if (!dev_opp) {
-		ret = -ENOMEM;
-		goto free_opp;
-	}
-
-	/*
-	 * Insert new OPP in order of increasing frequency
-	 * and discard if already present
-	 */
-	head = &dev_opp->opp_list;
-	list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
-		if (new_opp->rate > opp->rate)
-			head = &opp->node;
-		else if (new_opp->rate < opp->rate)
-			break;
-
-		/* Duplicate OPPs */
-		ret = opp->available && new_opp->u_volt == opp->u_volt ?
-			0 : -EEXIST;
-
-		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
-			 __func__, opp->rate, opp->u_volt, opp->available,
-			 new_opp->rate, new_opp->u_volt, new_opp->available);
+	ret = _opp_add(new_opp, dev_opp);
+	if (ret)
 		goto free_opp;
-	}
 
-	new_opp->dynamic = dynamic;
-	new_opp->dev_opp = dev_opp;
-	list_add_rcu(&new_opp->node, head);
 	mutex_unlock(&dev_opp_list_lock);
 
 	/*
@@ -638,8 +666,9 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	return 0;
 
 free_opp:
+	_opp_remove(dev_opp, new_opp, false);
+unlock:
 	mutex_unlock(&dev_opp_list_lock);
-	kfree(new_opp);
 	return ret;
 }
 
@@ -867,7 +896,7 @@ void of_free_opp_table(struct device *dev)
 	/* Free static OPPs */
 	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
 		if (!opp->dynamic)
-			_opp_remove(dev_opp, opp);
+			_opp_remove(dev_opp, opp, true);
 	}
 
 	mutex_unlock(&dev_opp_list_lock);
-- 
2.4.0

[PATCH V2 06/11] opp: Add support to parse "operating-points-v2" bindings

[Viresh Kumar]

This adds support in OPP library to parse and create list of OPPs from
operating-points-v2 bindings. It takes care of most of the properties of
new bindings (except shared-opp, which will be handled separately).

For backward compatibility, we keep supporting earlier bindings. We try
to search for the new bindings first, in case they aren't present we
look for the old deprecated ones.

There are few things marked as TODO:
- Support for multiple OPP tables
- Support for multiple regulators

They should be fixed separately.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 250 ++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 226 insertions(+), 24 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 962d62316b80..d9ebbd739b23 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -51,10 +51,15 @@
  *		order.
  * @dynamic:	not-created from static DT entries.
  * @available:	true/false - marks if this OPP as available or not
+ * @turbo:	true if turbo (boost) OPP
  * @rate:	Frequency in hertz
- * @u_volt:	Nominal voltage in microvolts corresponding to this OPP
+ * @u_volt:	Target voltage in microvolts corresponding to this OPP
+ * @u_volt_min:	Minimum voltage in microvolts corresponding to this OPP
+ * @u_volt_max:	Maximum voltage in microvolts corresponding to this OPP
+ * @u_amp:	Maximum current drawn by the device in microamperes
  * @dev_opp:	points back to the device_opp struct this opp belongs to
  * @rcu_head:	RCU callback head used for deferred freeing
+ * @np:		OPP's device node.
  *
  * This structure stores the OPP information for a given device.
  */
@@ -63,11 +68,18 @@ struct dev_pm_opp {
 
 	bool available;
 	bool dynamic;
+	bool turbo;
 	unsigned long rate;
+
 	unsigned long u_volt;
+	unsigned long u_volt_min;
+	unsigned long u_volt_max;
+	unsigned long u_amp;
 
 	struct device_opp *dev_opp;
 	struct rcu_head rcu_head;
+
+	struct device_node *np;
 };
 
 /**
@@ -672,6 +684,118 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	return ret;
 }
 
+/* TODO: Support multiple regulators */
+static int opp_get_microvolt(struct dev_pm_opp *opp, struct device *dev)
+{
+	u32 microvolt[3] = {0};
+	int count, ret;
+
+	count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+	if (!count)
+		return 0;
+
+	/* There can be one or three elements here */
+	if (count != 1 && count != 3) {
+		dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",
+			__func__, count);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,
+					 count);
+	if (ret) {
+		dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,
+			ret);
+		return -EINVAL;
+	}
+
+	opp->u_volt = microvolt[0];
+	opp->u_volt_min = microvolt[1];
+	opp->u_volt_max = microvolt[2];
+
+	return 0;
+}
+
+/**
+ * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
+ * @dev:	device for which we do this operation
+ * @np:		device node
+ *
+ * This function adds an opp definition to the opp list and returns status. The
+ * opp can be controlled using dev_pm_opp_enable/disable functions and may be
+ * removed by dev_pm_opp_remove.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ *
+ * Return:
+ * 0		On success OR
+ *		Duplicate OPPs (both freq and volt are same) and opp->available
+ * -EEXIST	Freq are same and volt are different OR
+ *		Duplicate OPPs (both freq and volt are same) and !opp->available
+ * -ENOMEM	Memory allocation failure
+ * -EINVAL	Failed parsing the OPP node
+ */
+static int _opp_add_static_v2(struct device *dev, struct device_node *np)
+{
+	struct device_opp *dev_opp;
+	struct dev_pm_opp *new_opp;
+	int ret;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	new_opp = _allocate_opp(dev, &dev_opp);
+	if (!new_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	ret = of_property_read_u32(np, "opp-hz", (u32 *)&new_opp->rate);
+	if (ret < 0) {
+		dev_err(dev, "%s: opp-hz not found\n", __func__);
+		goto free_opp;
+	}
+
+	new_opp->turbo = of_property_read_bool(np, "turbo-mode");
+
+	new_opp->np = np;
+	new_opp->dynamic = false;
+	new_opp->available = true;
+
+	ret = opp_get_microvolt(new_opp, dev);
+	if (ret)
+		goto free_opp;
+
+	of_property_read_u32(np, "opp-microamp", (u32 *)&new_opp->u_amp);
+
+	ret = _opp_add(new_opp, dev_opp);
+	if (ret)
+		goto free_opp;
+
+	mutex_unlock(&dev_opp_list_lock);
+
+	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu\n",
+		 __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt,
+		 new_opp->u_volt_min, new_opp->u_volt_max);
+
+	/*
+	 * Notify the changes in the availability of the operable
+	 * frequency/voltage list.
+	 */
+	srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADD, new_opp);
+	return 0;
+
+free_opp:
+	_opp_remove(dev_opp, new_opp, false);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+	return ret;
+}
+
 /**
  * dev_pm_opp_add()  - Add an OPP table from a table definitions
  * @dev:	device for which we do this operation
@@ -903,29 +1027,64 @@ void of_free_opp_table(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(of_free_opp_table);
 
-/**
- * of_init_opp_table() - Initialize opp table from device tree
- * @dev:	device pointer used to lookup device OPPs.
- *
- * Register the initial OPP table with the OPP library for given device.
- *
- * Locking: The internal device_opp and opp structures are RCU protected.
- * Hence this function indirectly uses RCU updater strategy with mutex locks
- * to keep the integrity of the internal data structures. Callers should ensure
- * that this function is *NOT* called under RCU protection or in contexts where
- * mutex cannot be locked.
- *
- * Return:
- * 0		On success OR
- *		Duplicate OPPs (both freq and volt are same) and opp->available
- * -EEXIST	Freq are same and volt are different OR
- *		Duplicate OPPs (both freq and volt are same) and !opp->available
- * -ENOMEM	Memory allocation failure
- * -ENODEV	when 'operating-points' property is not found or is invalid data
- *		in device node.
- * -ENODATA	when empty 'operating-points' property is found
- */
-int of_init_opp_table(struct device *dev)
+/* Returns opp descriptor node from its phandle. Caller must do of_node_put() */
+static struct device_node *
+_of_get_opp_desc_node_from_prop(struct device *dev, const struct property *prop)
+{
+	struct device_node *opp_np;
+
+	opp_np = of_find_node_by_phandle(be32_to_cpup(prop->value));
+	if (!opp_np) {
+		dev_err(dev, "%s: Prop: %s contains invalid opp desc phandle\n",
+			__func__, prop->name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return opp_np;
+}
+
+/* Initializes OPP tables based on new bindings */
+static int _of_init_opp_table_v2(struct device *dev,
+				 const struct property *prop)
+{
+	struct device_node *opp_np, *np;
+	int ret = 0, count = 0;
+
+	if (!prop->value)
+		return -ENODATA;
+
+	/* Get opp node */
+	opp_np = _of_get_opp_desc_node_from_prop(dev, prop);
+	if (IS_ERR(opp_np))
+		return PTR_ERR(opp_np);
+
+	/* We have opp-list node now, iterate over it and add OPPs */
+	for_each_available_child_of_node(opp_np, np) {
+		count++;
+
+		ret = _opp_add_static_v2(dev, np);
+		if (ret) {
+			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
+				ret);
+			break;
+		}
+	}
+
+	/* There should be one of more OPP defined */
+	if (WARN_ON(!count))
+		goto put_opp_np;
+
+	if (ret)
+		of_free_opp_table(dev);
+
+put_opp_np:
+	of_node_put(opp_np);
+
+	return ret;
+}
+
+/* Initializes OPP tables based on old-deprecated bindings */
+static int _of_init_opp_table_v1(struct device *dev)
 {
 	const struct property *prop;
 	const __be32 *val;
@@ -960,5 +1119,48 @@ int of_init_opp_table(struct device *dev)
 
 	return 0;
 }
+
+/**
+ * of_init_opp_table() - Initialize opp table from device tree
+ * @dev:	device pointer used to lookup device OPPs.
+ *
+ * Register the initial OPP table with the OPP library for given device.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function indirectly uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ *
+ * Return:
+ * 0		On success OR
+ *		Duplicate OPPs (both freq and volt are same) and opp->available
+ * -EEXIST	Freq are same and volt are different OR
+ *		Duplicate OPPs (both freq and volt are same) and !opp->available
+ * -ENOMEM	Memory allocation failure
+ * -ENODEV	when 'operating-points' property is not found or is invalid data
+ *		in device node.
+ * -ENODATA	when empty 'operating-points' property is found
+ * -EINVAL	when invalid entries are found in opp-v2 table
+ */
+int of_init_opp_table(struct device *dev)
+{
+	const struct property *prop;
+
+	/*
+	 * OPPs have two version of bindings now. The older one is deprecated,
+	 * try for the new binding first.
+	 */
+	prop = of_find_property(dev->of_node, "operating-points-v2", NULL);
+	if (!prop) {
+		/*
+		 * Try old-deprecated bindings for backward compatibility with
+		 * older dtbs.
+		 */
+		return _of_init_opp_table_v1(dev);
+	}
+
+	return _of_init_opp_table_v2(dev, prop);
+}
 EXPORT_SYMBOL_GPL(of_init_opp_table);
 #endif
-- 
2.4.0

Re: [PATCH V2 06/11] opp: Add support to parse "operating-points-v2" bindings

[Bartlomiej Zolnierkiewicz]

Hi,

On Monday, July 27, 2015 10:32:36 AM Viresh Kumar wrote:
> This adds support in OPP library to parse and create list of OPPs from
> operating-points-v2 bindings. It takes care of most of the properties of
> new bindings (except shared-opp, which will be handled separately).
> 
> For backward compatibility, we keep supporting earlier bindings. We try
> to search for the new bindings first, in case they aren't present we
> look for the old deprecated ones.
> 
> There are few things marked as TODO:
> - Support for multiple OPP tables
> - Support for multiple regulators
> 
> They should be fixed separately.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

[PATCH V2 07/11] OPP: Add clock-latency-ns support

[Viresh Kumar]

With "operating-points-v2" bindings, clock-latency is defined per OPP.
Users of this value expect a single value which defines the latency to
switch to any clock rate. Find maximum clock-latency-ns from the OPP
table to service requests from such users.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 41 +++++++++++++++++++++++++++++++++++++++--
 include/linux/pm_opp.h   |  6 ++++++
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index d9ebbd739b23..96d7d1b6730a 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -57,6 +57,8 @@
  * @u_volt_min:	Minimum voltage in microvolts corresponding to this OPP
  * @u_volt_max:	Maximum voltage in microvolts corresponding to this OPP
  * @u_amp:	Maximum current drawn by the device in microamperes
+ * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
+ *		frequency from any other OPP's frequency.
  * @dev_opp:	points back to the device_opp struct this opp belongs to
  * @rcu_head:	RCU callback head used for deferred freeing
  * @np:		OPP's device node.
@@ -75,6 +77,7 @@ struct dev_pm_opp {
 	unsigned long u_volt_min;
 	unsigned long u_volt_max;
 	unsigned long u_amp;
+	unsigned long clock_latency_ns;
 
 	struct device_opp *dev_opp;
 	struct rcu_head rcu_head;
@@ -109,6 +112,8 @@ struct device_opp {
 	struct srcu_notifier_head srcu_head;
 	struct rcu_head rcu_head;
 	struct list_head opp_list;
+
+	unsigned long clock_latency_ns_max;
 };
 
 /*
@@ -226,6 +231,32 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
 
 /**
+ * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds
+ * @dev:	device for which we do this operation
+ *
+ * Return: This function returns the max clock latency in nanoseconds.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
+{
+	struct device_opp *dev_opp;
+	unsigned long clock_latency_ns;
+
+	rcu_read_lock();
+
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp))
+		clock_latency_ns = 0;
+	else
+		clock_latency_ns = dev_opp->clock_latency_ns_max;
+
+	rcu_read_unlock();
+	return clock_latency_ns;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
+
+/**
  * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list
  * @dev:	device for which we do this operation
  *
@@ -765,6 +796,8 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	new_opp->np = np;
 	new_opp->dynamic = false;
 	new_opp->available = true;
+	of_property_read_u32(np, "clock-latency-ns",
+			     (u32 *)&new_opp->clock_latency_ns);
 
 	ret = opp_get_microvolt(new_opp, dev);
 	if (ret)
@@ -776,11 +809,15 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	if (ret)
 		goto free_opp;
 
+	if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max)
+		dev_opp->clock_latency_ns_max = new_opp->clock_latency_ns;
+
 	mutex_unlock(&dev_opp_list_lock);
 
-	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu\n",
+	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
 		 __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt,
-		 new_opp->u_volt_min, new_opp->u_volt_max);
+		 new_opp->u_volt_min, new_opp->u_volt_max,
+		 new_opp->clock_latency_ns);
 
 	/*
 	 * Notify the changes in the availability of the operable
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index cec2d4540914..20324b579adc 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -31,6 +31,7 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp);
 unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp);
 
 int dev_pm_opp_get_opp_count(struct device *dev);
+unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev);
 
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 					      unsigned long freq,
@@ -67,6 +68,11 @@ static inline int dev_pm_opp_get_opp_count(struct device *dev)
 	return 0;
 }
 
+static inline unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
+{
+	return 0;
+}
+
 static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 					unsigned long freq, bool available)
 {
-- 
2.4.0

Re: [PATCH V2 07/11] OPP: Add clock-latency-ns support

[Bartlomiej Zolnierkiewicz]

Hi,

On Monday, July 27, 2015 10:32:37 AM Viresh Kumar wrote:
> With "operating-points-v2" bindings, clock-latency is defined per OPP.
> Users of this value expect a single value which defines the latency to
> switch to any clock rate. Find maximum clock-latency-ns from the OPP
> table to service requests from such users.
> 
> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

[PATCH V2 08/11] opp: Add OPP sharing information to OPP library

[Viresh Kumar]

An opp can be shared by multiple devices, for example its very common
for CPUs to share the OPPs, i.e. when they share clock/voltage rails.

This patch adds support of shared OPPs to the OPP library.

Instead of a single device, dev_opp will not contain a list of devices
that use it. It also senses if the device (we are trying to initialize
OPPs for) shares OPPs with a device added earlier and in that case we
update the list of devices managed by OPPs instead of duplicating OPPs
again.

The same infrastructure will be used for the old OPP bindings, with
later patches.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 174 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 150 insertions(+), 24 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 96d7d1b6730a..d6ab6af7e847 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -86,16 +86,33 @@ struct dev_pm_opp {
 };
 
 /**
+ * struct device_list_opp - devices managed by 'struct device_opp'
+ * @node:	list node
+ * @dev:	device to which the struct object belongs
+ * @rcu_head:	RCU callback head used for deferred freeing
+ *
+ * This is an internal data structure maintaining the list of devices that are
+ * managed by 'struct device_opp'.
+ */
+struct device_list_opp {
+	struct list_head node;
+	const struct device *dev;
+	struct rcu_head rcu_head;
+};
+
+/**
  * struct device_opp - Device opp structure
  * @node:	list node - contains the devices with OPPs that
  *		have been registered. Nodes once added are not modified in this
  *		list.
  *		RCU usage: nodes are not modified in the list of device_opp,
  *		however addition is possible and is secured by dev_opp_list_lock
- * @dev:	device pointer
  * @srcu_head:	notifier head to notify the OPP availability changes.
  * @rcu_head:	RCU callback head used for deferred freeing
+ * @dev_list:	list of devices that share these OPPs
  * @opp_list:	list of opps
+ * @np:		struct device_node pointer for opp's DT node.
+ * @shared_opp: OPP is shared between multiple devices.
  *
  * This is an internal data structure maintaining the link to opps attached to
  * a device. This structure is not meant to be shared to users as it is
@@ -108,12 +125,14 @@ struct dev_pm_opp {
 struct device_opp {
 	struct list_head node;
 
-	struct device *dev;
 	struct srcu_notifier_head srcu_head;
 	struct rcu_head rcu_head;
+	struct list_head dev_list;
 	struct list_head opp_list;
 
+	struct device_node *np;
 	unsigned long clock_latency_ns_max;
+	bool shared_opp;
 };
 
 /*
@@ -133,6 +152,38 @@ do {									\
 			   "dev_opp_list_lock protection");		\
 } while (0)
 
+static struct device_list_opp *_find_list_dev(const struct device *dev,
+					      struct device_opp *dev_opp)
+{
+	struct device_list_opp *list_dev;
+
+	list_for_each_entry(list_dev, &dev_opp->dev_list, node)
+		if (list_dev->dev == dev)
+			return list_dev;
+
+	return NULL;
+}
+
+static struct device_opp *_managed_opp(const struct device_node *np)
+{
+	struct device_opp *dev_opp;
+
+	list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) {
+		if (dev_opp->np == np) {
+			/*
+			 * Multiple devices can point to the same OPP table and
+			 * so will have same node-pointer, np.
+			 *
+			 * But the OPPs will be considered as shared only if the
+			 * OPP table contains a "opp-shared" property.
+			 */
+			return dev_opp->shared_opp ? dev_opp : NULL;
+		}
+	}
+
+	return NULL;
+}
+
 /**
  * _find_device_opp() - find device_opp struct using device pointer
  * @dev:	device pointer used to lookup device OPPs
@@ -149,21 +200,18 @@ do {									\
  */
 static struct device_opp *_find_device_opp(struct device *dev)
 {
-	struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV);
+	struct device_opp *dev_opp;
 
 	if (unlikely(IS_ERR_OR_NULL(dev))) {
 		pr_err("%s: Invalid parameters\n", __func__);
 		return ERR_PTR(-EINVAL);
 	}
 
-	list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) {
-		if (tmp_dev_opp->dev == dev) {
-			dev_opp = tmp_dev_opp;
-			break;
-		}
-	}
+	list_for_each_entry_rcu(dev_opp, &dev_opp_list, node)
+		if (_find_list_dev(dev, dev_opp))
+			return dev_opp;
 
-	return dev_opp;
+	return ERR_PTR(-ENODEV);
 }
 
 /**
@@ -450,6 +498,39 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
+/* List-dev Helpers */
+static void _kfree_list_dev_rcu(struct rcu_head *head)
+{
+	struct device_list_opp *list_dev;
+
+	list_dev = container_of(head, struct device_list_opp, rcu_head);
+	kfree_rcu(list_dev, rcu_head);
+}
+
+static void _remove_list_dev(struct device_list_opp *list_dev,
+			     struct device_opp *dev_opp)
+{
+	list_del(&list_dev->node);
+	call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head,
+		  _kfree_list_dev_rcu);
+}
+
+static struct device_list_opp *_add_list_dev(const struct device *dev,
+					     struct device_opp *dev_opp)
+{
+	struct device_list_opp *list_dev;
+
+	list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL);
+	if (!list_dev)
+		return NULL;
+
+	/* Initialize list-dev */
+	list_add_rcu(&list_dev->node, &dev_opp->dev_list);
+	list_dev->dev = dev;
+
+	return list_dev;
+}
+
 /**
  * _add_device_opp() - Find device OPP table or allocate a new one
  * @dev:	device for which we do this operation
@@ -462,6 +543,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 static struct device_opp *_add_device_opp(struct device *dev)
 {
 	struct device_opp *dev_opp;
+	struct device_list_opp *list_dev;
 
 	/* Check for existing list for 'dev' first */
 	dev_opp = _find_device_opp(dev);
@@ -476,7 +558,14 @@ static struct device_opp *_add_device_opp(struct device *dev)
 	if (!dev_opp)
 		return NULL;
 
-	dev_opp->dev = dev;
+	INIT_LIST_HEAD(&dev_opp->dev_list);
+
+	list_dev = _add_list_dev(dev, dev_opp);
+	if (!list_dev) {
+		kfree(dev_opp);
+		return NULL;
+	}
+
 	srcu_init_notifier_head(&dev_opp->srcu_head);
 	INIT_LIST_HEAD(&dev_opp->opp_list);
 
@@ -504,9 +593,19 @@ static void _kfree_device_rcu(struct rcu_head *head)
  */
 static void _remove_device_opp(struct device_opp *dev_opp)
 {
+	struct device_list_opp *list_dev;
+
 	if (!list_empty(&dev_opp->opp_list))
 		return;
 
+	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
+				    node);
+
+	_remove_list_dev(list_dev, dev_opp);
+
+	/* dev_list must be empty now */
+	WARN_ON(!list_empty(&dev_opp->dev_list));
+
 	list_del_rcu(&dev_opp->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
 		  _kfree_device_rcu);
@@ -616,7 +715,8 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev,
 	return opp;
 }
 
-static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
+static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
+		    struct device_opp *dev_opp)
 {
 	struct dev_pm_opp *opp;
 	struct list_head *head = &dev_opp->opp_list;
@@ -632,7 +732,7 @@ static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
 			break;
 
 		/* Duplicate OPPs */
-		dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
+		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
 			 __func__, opp->rate, opp->u_volt, opp->available,
 			 new_opp->rate, new_opp->u_volt, new_opp->available);
 
@@ -695,7 +795,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	new_opp->available = true;
 	new_opp->dynamic = dynamic;
 
-	ret = _opp_add(new_opp, dev_opp);
+	ret = _opp_add(dev, new_opp, dev_opp);
 	if (ret)
 		goto free_opp;
 
@@ -805,7 +905,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 
 	of_property_read_u32(np, "opp-microamp", (u32 *)&new_opp->u_amp);
 
-	ret = _opp_add(new_opp, dev_opp);
+	ret = _opp_add(dev, new_opp, dev_opp);
 	if (ret)
 		goto free_opp;
 
@@ -1038,6 +1138,9 @@ void of_free_opp_table(struct device *dev)
 	struct device_opp *dev_opp;
 	struct dev_pm_opp *opp, *tmp;
 
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
 	/* Check for existing list for 'dev' */
 	dev_opp = _find_device_opp(dev);
 	if (IS_ERR(dev_opp)) {
@@ -1048,18 +1151,21 @@ void of_free_opp_table(struct device *dev)
 			     IS_ERR_OR_NULL(dev) ?
 					"Invalid device" : dev_name(dev),
 			     error);
-		return;
+		goto unlock;
 	}
 
-	/* Hold our list modification lock here */
-	mutex_lock(&dev_opp_list_lock);
-
-	/* Free static OPPs */
-	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
-		if (!opp->dynamic)
-			_opp_remove(dev_opp, opp, true);
+	/* Find if dev_opp manages a single device */
+	if (list_is_singular(&dev_opp->dev_list)) {
+		/* Free static OPPs */
+		list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
+			if (!opp->dynamic)
+				_opp_remove(dev_opp, opp, true);
+		}
+	} else {
+		_remove_list_dev(_find_list_dev(dev, dev_opp), dev_opp);
 	}
 
+unlock:
 	mutex_unlock(&dev_opp_list_lock);
 }
 EXPORT_SYMBOL_GPL(of_free_opp_table);
@@ -1085,6 +1191,7 @@ static int _of_init_opp_table_v2(struct device *dev,
 				 const struct property *prop)
 {
 	struct device_node *opp_np, *np;
+	struct device_opp *dev_opp;
 	int ret = 0, count = 0;
 
 	if (!prop->value)
@@ -1095,6 +1202,14 @@ static int _of_init_opp_table_v2(struct device *dev,
 	if (IS_ERR(opp_np))
 		return PTR_ERR(opp_np);
 
+	dev_opp = _managed_opp(opp_np);
+	if (dev_opp) {
+		/* OPPs are already managed */
+		if (!_add_list_dev(dev, dev_opp))
+			ret = -ENOMEM;
+		goto put_opp_np;
+	}
+
 	/* We have opp-list node now, iterate over it and add OPPs */
 	for_each_available_child_of_node(opp_np, np) {
 		count++;
@@ -1111,8 +1226,19 @@ static int _of_init_opp_table_v2(struct device *dev,
 	if (WARN_ON(!count))
 		goto put_opp_np;
 
-	if (ret)
+	if (!ret) {
+		if (!dev_opp) {
+			dev_opp = _find_device_opp(dev);
+			if (WARN_ON(!dev_opp))
+				goto put_opp_np;
+		}
+
+		dev_opp->np = opp_np;
+		dev_opp->shared_opp = of_property_read_bool(opp_np,
+							    "opp-shared");
+	} else {
 		of_free_opp_table(dev);
+	}
 
 put_opp_np:
 	of_node_put(opp_np);
-- 
2.4.0

Re: [PATCH V2 08/11] opp: Add OPP sharing information to OPP library

[Bartlomiej Zolnierkiewicz]

Hi,

Two very minor nits:

On Monday, July 27, 2015 10:32:38 AM Viresh Kumar wrote:
> An opp can be shared by multiple devices, for example its very common
> for CPUs to share the OPPs, i.e. when they share clock/voltage rails.
> 
> This patch adds support of shared OPPs to the OPP library.
> 
> Instead of a single device, dev_opp will not contain a list of devices

s/will not/will now/ ?

> that use it. It also senses if the device (we are trying to initialize
> OPPs for) shares OPPs with a device added earlier and in that case we
> update the list of devices managed by OPPs instead of duplicating OPPs
> again.
> 
> The same infrastructure will be used for the old OPP bindings, with
> later patches.
> 
> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

[...]

> +static struct device_list_opp *_add_list_dev(const struct device *dev,
> +					     struct device_opp *dev_opp)
> +{
> +	struct device_list_opp *list_dev;
> +
> +	list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL);
> +	if (!list_dev)
> +		return NULL;
> +
> +	/* Initialize list-dev */
> +	list_add_rcu(&list_dev->node, &dev_opp->dev_list);
> +	list_dev->dev = dev;

Probably doesn't matter currently but how's about:

	list_dev->dev = dev;
	list_add_rcu(&list_dev->node, &dev_opp->dev_list);

?

> +
> +	return list_dev;
> +}

Otherwise:

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

Re: [PATCH V2 08/11] opp: Add OPP sharing information to OPP library

[Viresh Kumar]

On 27-07-15, 16:48, Bartlomiej Zolnierkiewicz wrote:
> s/will not/will now/ ?

> Probably doesn't matter currently but how's about:
> 
> 	list_dev->dev = dev;
> 	list_add_rcu(&list_dev->node, &dev_opp->dev_list);

> Otherwise:
> 
> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

---------------------8<---------------------
Message-Id: <feac18ce48674ec30a40db9ec65d0dc2e676cff2.1438049409.git.viresh.kumar@linaro.org>
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Wed, 11 Feb 2015 16:16:28 +0800
Subject: [PATCH] opp: Add OPP sharing information to OPP library

An opp can be shared by multiple devices, for example its very common
for CPUs to share the OPPs, i.e. when they share clock/voltage rails.

This patch adds support of shared OPPs to the OPP library.

Instead of a single device, dev_opp will now contain a list of devices
that use it. It also senses if the device (we are trying to initialize
OPPs for) shares OPPs with a device added earlier and in that case we
update the list of devices managed by OPPs instead of duplicating OPPs
again.

The same infrastructure will be used for the old OPP bindings, with
later patches.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 174 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 150 insertions(+), 24 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 96d7d1b6730a..749c36e8141b 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -86,16 +86,33 @@ struct dev_pm_opp {
 };
 
 /**
+ * struct device_list_opp - devices managed by 'struct device_opp'
+ * @node:	list node
+ * @dev:	device to which the struct object belongs
+ * @rcu_head:	RCU callback head used for deferred freeing
+ *
+ * This is an internal data structure maintaining the list of devices that are
+ * managed by 'struct device_opp'.
+ */
+struct device_list_opp {
+	struct list_head node;
+	const struct device *dev;
+	struct rcu_head rcu_head;
+};
+
+/**
  * struct device_opp - Device opp structure
  * @node:	list node - contains the devices with OPPs that
  *		have been registered. Nodes once added are not modified in this
  *		list.
  *		RCU usage: nodes are not modified in the list of device_opp,
  *		however addition is possible and is secured by dev_opp_list_lock
- * @dev:	device pointer
  * @srcu_head:	notifier head to notify the OPP availability changes.
  * @rcu_head:	RCU callback head used for deferred freeing
+ * @dev_list:	list of devices that share these OPPs
  * @opp_list:	list of opps
+ * @np:		struct device_node pointer for opp's DT node.
+ * @shared_opp: OPP is shared between multiple devices.
  *
  * This is an internal data structure maintaining the link to opps attached to
  * a device. This structure is not meant to be shared to users as it is
@@ -108,12 +125,14 @@ struct dev_pm_opp {
 struct device_opp {
 	struct list_head node;
 
-	struct device *dev;
 	struct srcu_notifier_head srcu_head;
 	struct rcu_head rcu_head;
+	struct list_head dev_list;
 	struct list_head opp_list;
 
+	struct device_node *np;
 	unsigned long clock_latency_ns_max;
+	bool shared_opp;
 };
 
 /*
@@ -133,6 +152,38 @@ do {									\
 			   "dev_opp_list_lock protection");		\
 } while (0)
 
+static struct device_list_opp *_find_list_dev(const struct device *dev,
+					      struct device_opp *dev_opp)
+{
+	struct device_list_opp *list_dev;
+
+	list_for_each_entry(list_dev, &dev_opp->dev_list, node)
+		if (list_dev->dev == dev)
+			return list_dev;
+
+	return NULL;
+}
+
+static struct device_opp *_managed_opp(const struct device_node *np)
+{
+	struct device_opp *dev_opp;
+
+	list_for_each_entry_rcu(dev_opp, &dev_opp_list, node) {
+		if (dev_opp->np == np) {
+			/*
+			 * Multiple devices can point to the same OPP table and
+			 * so will have same node-pointer, np.
+			 *
+			 * But the OPPs will be considered as shared only if the
+			 * OPP table contains a "opp-shared" property.
+			 */
+			return dev_opp->shared_opp ? dev_opp : NULL;
+		}
+	}
+
+	return NULL;
+}
+
 /**
  * _find_device_opp() - find device_opp struct using device pointer
  * @dev:	device pointer used to lookup device OPPs
@@ -149,21 +200,18 @@ do {									\
  */
 static struct device_opp *_find_device_opp(struct device *dev)
 {
-	struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV);
+	struct device_opp *dev_opp;
 
 	if (unlikely(IS_ERR_OR_NULL(dev))) {
 		pr_err("%s: Invalid parameters\n", __func__);
 		return ERR_PTR(-EINVAL);
 	}
 
-	list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) {
-		if (tmp_dev_opp->dev == dev) {
-			dev_opp = tmp_dev_opp;
-			break;
-		}
-	}
+	list_for_each_entry_rcu(dev_opp, &dev_opp_list, node)
+		if (_find_list_dev(dev, dev_opp))
+			return dev_opp;
 
-	return dev_opp;
+	return ERR_PTR(-ENODEV);
 }
 
 /**
@@ -450,6 +498,39 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
+/* List-dev Helpers */
+static void _kfree_list_dev_rcu(struct rcu_head *head)
+{
+	struct device_list_opp *list_dev;
+
+	list_dev = container_of(head, struct device_list_opp, rcu_head);
+	kfree_rcu(list_dev, rcu_head);
+}
+
+static void _remove_list_dev(struct device_list_opp *list_dev,
+			     struct device_opp *dev_opp)
+{
+	list_del(&list_dev->node);
+	call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head,
+		  _kfree_list_dev_rcu);
+}
+
+static struct device_list_opp *_add_list_dev(const struct device *dev,
+					     struct device_opp *dev_opp)
+{
+	struct device_list_opp *list_dev;
+
+	list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL);
+	if (!list_dev)
+		return NULL;
+
+	/* Initialize list-dev */
+	list_dev->dev = dev;
+	list_add_rcu(&list_dev->node, &dev_opp->dev_list);
+
+	return list_dev;
+}
+
 /**
  * _add_device_opp() - Find device OPP table or allocate a new one
  * @dev:	device for which we do this operation
@@ -462,6 +543,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 static struct device_opp *_add_device_opp(struct device *dev)
 {
 	struct device_opp *dev_opp;
+	struct device_list_opp *list_dev;
 
 	/* Check for existing list for 'dev' first */
 	dev_opp = _find_device_opp(dev);
@@ -476,7 +558,14 @@ static struct device_opp *_add_device_opp(struct device *dev)
 	if (!dev_opp)
 		return NULL;
 
-	dev_opp->dev = dev;
+	INIT_LIST_HEAD(&dev_opp->dev_list);
+
+	list_dev = _add_list_dev(dev, dev_opp);
+	if (!list_dev) {
+		kfree(dev_opp);
+		return NULL;
+	}
+
 	srcu_init_notifier_head(&dev_opp->srcu_head);
 	INIT_LIST_HEAD(&dev_opp->opp_list);
 
@@ -504,9 +593,19 @@ static void _kfree_device_rcu(struct rcu_head *head)
  */
 static void _remove_device_opp(struct device_opp *dev_opp)
 {
+	struct device_list_opp *list_dev;
+
 	if (!list_empty(&dev_opp->opp_list))
 		return;
 
+	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
+				    node);
+
+	_remove_list_dev(list_dev, dev_opp);
+
+	/* dev_list must be empty now */
+	WARN_ON(!list_empty(&dev_opp->dev_list));
+
 	list_del_rcu(&dev_opp->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
 		  _kfree_device_rcu);
@@ -616,7 +715,8 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev,
 	return opp;
 }
 
-static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
+static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
+		    struct device_opp *dev_opp)
 {
 	struct dev_pm_opp *opp;
 	struct list_head *head = &dev_opp->opp_list;
@@ -632,7 +732,7 @@ static int _opp_add(struct dev_pm_opp *new_opp, struct device_opp *dev_opp)
 			break;
 
 		/* Duplicate OPPs */
-		dev_warn(dev_opp->dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
+		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
 			 __func__, opp->rate, opp->u_volt, opp->available,
 			 new_opp->rate, new_opp->u_volt, new_opp->available);
 
@@ -695,7 +795,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
 	new_opp->available = true;
 	new_opp->dynamic = dynamic;
 
-	ret = _opp_add(new_opp, dev_opp);
+	ret = _opp_add(dev, new_opp, dev_opp);
 	if (ret)
 		goto free_opp;
 
@@ -805,7 +905,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 
 	of_property_read_u32(np, "opp-microamp", (u32 *)&new_opp->u_amp);
 
-	ret = _opp_add(new_opp, dev_opp);
+	ret = _opp_add(dev, new_opp, dev_opp);
 	if (ret)
 		goto free_opp;
 
@@ -1038,6 +1138,9 @@ void of_free_opp_table(struct device *dev)
 	struct device_opp *dev_opp;
 	struct dev_pm_opp *opp, *tmp;
 
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
 	/* Check for existing list for 'dev' */
 	dev_opp = _find_device_opp(dev);
 	if (IS_ERR(dev_opp)) {
@@ -1048,18 +1151,21 @@ void of_free_opp_table(struct device *dev)
 			     IS_ERR_OR_NULL(dev) ?
 					"Invalid device" : dev_name(dev),
 			     error);
-		return;
+		goto unlock;
 	}
 
-	/* Hold our list modification lock here */
-	mutex_lock(&dev_opp_list_lock);
-
-	/* Free static OPPs */
-	list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
-		if (!opp->dynamic)
-			_opp_remove(dev_opp, opp, true);
+	/* Find if dev_opp manages a single device */
+	if (list_is_singular(&dev_opp->dev_list)) {
+		/* Free static OPPs */
+		list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
+			if (!opp->dynamic)
+				_opp_remove(dev_opp, opp, true);
+		}
+	} else {
+		_remove_list_dev(_find_list_dev(dev, dev_opp), dev_opp);
 	}
 
+unlock:
 	mutex_unlock(&dev_opp_list_lock);
 }
 EXPORT_SYMBOL_GPL(of_free_opp_table);
@@ -1085,6 +1191,7 @@ static int _of_init_opp_table_v2(struct device *dev,
 				 const struct property *prop)
 {
 	struct device_node *opp_np, *np;
+	struct device_opp *dev_opp;
 	int ret = 0, count = 0;
 
 	if (!prop->value)
@@ -1095,6 +1202,14 @@ static int _of_init_opp_table_v2(struct device *dev,
 	if (IS_ERR(opp_np))
 		return PTR_ERR(opp_np);
 
+	dev_opp = _managed_opp(opp_np);
+	if (dev_opp) {
+		/* OPPs are already managed */
+		if (!_add_list_dev(dev, dev_opp))
+			ret = -ENOMEM;
+		goto put_opp_np;
+	}
+
 	/* We have opp-list node now, iterate over it and add OPPs */
 	for_each_available_child_of_node(opp_np, np) {
 		count++;
@@ -1111,8 +1226,19 @@ static int _of_init_opp_table_v2(struct device *dev,
 	if (WARN_ON(!count))
 		goto put_opp_np;
 
-	if (ret)
+	if (!ret) {
+		if (!dev_opp) {
+			dev_opp = _find_device_opp(dev);
+			if (WARN_ON(!dev_opp))
+				goto put_opp_np;
+		}
+
+		dev_opp->np = opp_np;
+		dev_opp->shared_opp = of_property_read_bool(opp_np,
+							    "opp-shared");
+	} else {
 		of_free_opp_table(dev);
+	}
 
 put_opp_np:
 	of_node_put(opp_np);

[PATCH V2 09/11] OPP: Add support for opp-suspend

[Viresh Kumar]

With "operating-points-v2" bindings, its possible to specify the OPP to
which the device must be switched, before suspending.

This patch adds support for getting that information.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index d6ab6af7e847..22b1e6ae7a94 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -133,6 +133,7 @@ struct device_opp {
 	struct device_node *np;
 	unsigned long clock_latency_ns_max;
 	bool shared_opp;
+	struct dev_pm_opp *suspend_opp;
 };
 
 /*
@@ -909,6 +910,16 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	if (ret)
 		goto free_opp;
 
+	/* OPP to select on device suspend */
+	if (of_property_read_bool(np, "opp-suspend")) {
+		if (dev_opp->suspend_opp)
+			dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
+				 __func__, dev_opp->suspend_opp->rate,
+				 new_opp->rate);
+		else
+			dev_opp->suspend_opp = new_opp;
+	}
+
 	if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max)
 		dev_opp->clock_latency_ns_max = new_opp->clock_latency_ns;
 
-- 
2.4.0

Re: [PATCH V2 09/11] OPP: Add support for opp-suspend

[Bartlomiej Zolnierkiewicz]

Hi,

On Monday, July 27, 2015 10:32:39 AM Viresh Kumar wrote:
> With "operating-points-v2" bindings, its possible to specify the OPP to
> which the device must be switched, before suspending.
> 
> This patch adds support for getting that information.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

[PATCH V2 10/11] opp: Add helpers for initializing CPU OPPs

[Viresh Kumar]

With "operating-points-v2" its possible to tell which devices share
OPPs. We already have infrastructure to decode that information.

This patch adds following APIs:
- of_get_cpus_sharing_opps: Returns cpumask of CPUs sharing OPPs (only
  valid with v2 bindings).
- of_cpumask_init_opp_table: Initializes OPPs for all CPUs present in
  cpumask.
- of_cpumask_free_opp_table: Frees OPPs for all CPUs present in cpumask.

- set_cpus_sharing_opps: Sets which CPUs share OPPs (only valid with old
  OPP bindings, as this information isn't present in DT).

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pm_opp.h   |  23 +++++++
 2 files changed, 198 insertions(+)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 22b1e6ae7a94..976c839cb238 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -11,6 +11,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/err.h>
@@ -1181,6 +1182,26 @@ void of_free_opp_table(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(of_free_opp_table);
 
+void of_cpumask_free_opp_table(cpumask_var_t cpumask)
+{
+	struct device *cpu_dev;
+	int cpu;
+
+	WARN_ON(cpumask_empty(cpumask));
+
+	for_each_cpu(cpu, cpumask) {
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			pr_err("%s: failed to get cpu%d device\n", __func__,
+			       cpu);
+			continue;
+		}
+
+		of_free_opp_table(cpu_dev);
+	}
+}
+EXPORT_SYMBOL_GPL(of_cpumask_free_opp_table);
+
 /* Returns opp descriptor node from its phandle. Caller must do of_node_put() */
 static struct device_node *
 _of_get_opp_desc_node_from_prop(struct device *dev, const struct property *prop)
@@ -1197,6 +1218,31 @@ _of_get_opp_desc_node_from_prop(struct device *dev, const struct property *prop)
 	return opp_np;
 }
 
+/* Returns opp descriptor node for a device. Caller must do of_node_put() */
+static struct device_node *_of_get_opp_desc_node(struct device *dev)
+{
+	const struct property *prop;
+
+	prop = of_find_property(dev->of_node, "operating-points-v2", NULL);
+	if (!prop)
+		return ERR_PTR(-ENODEV);
+	if (!prop->value)
+		return ERR_PTR(-ENODATA);
+
+	/*
+	 * TODO: Support for multiple OPP tables.
+	 *
+	 * There should be only ONE phandle present in "operating-points-v2"
+	 * property.
+	 */
+	if (prop->length != sizeof(__be32)) {
+		dev_err(dev, "%s: Invalid opp desc phandle\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return _of_get_opp_desc_node_from_prop(dev, prop);
+}
+
 /* Initializes OPP tables based on new bindings */
 static int _of_init_opp_table_v2(struct device *dev,
 				 const struct property *prop)
@@ -1337,4 +1383,133 @@ int of_init_opp_table(struct device *dev)
 	return _of_init_opp_table_v2(dev, prop);
 }
 EXPORT_SYMBOL_GPL(of_init_opp_table);
+
+int of_cpumask_init_opp_table(cpumask_var_t cpumask)
+{
+	struct device *cpu_dev;
+	int cpu, ret = 0;
+
+	WARN_ON(cpumask_empty(cpumask));
+
+	for_each_cpu(cpu, cpumask) {
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			pr_err("%s: failed to get cpu%d device\n", __func__,
+			       cpu);
+			continue;
+		}
+
+		ret = of_init_opp_table(cpu_dev);
+		if (ret) {
+			pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
+			       __func__, cpu, ret);
+
+			/* Free all other OPPs */
+			of_cpumask_free_opp_table(cpumask);
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_cpumask_init_opp_table);
+
+/* Required only for V1 bindings, as v2 can manage it from DT itself */
+int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask)
+{
+	struct device_list_opp *list_dev;
+	struct device_opp *dev_opp;
+	struct device *dev;
+	int cpu, ret = 0;
+
+	rcu_read_lock();
+
+	dev_opp = _find_device_opp(cpu_dev);
+	if (IS_ERR(dev_opp)) {
+		ret = -EINVAL;
+		goto out_rcu_read_unlock;
+	}
+
+	for_each_cpu(cpu, cpumask) {
+		if (cpu == cpu_dev->id)
+			continue;
+
+		dev = get_cpu_device(cpu);
+		if (!dev) {
+			dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
+				__func__, cpu);
+			continue;
+		}
+
+		list_dev = _add_list_dev(dev, dev_opp);
+		if (!list_dev) {
+			dev_err(dev, "%s: failed to add list-dev for cpu%d device\n",
+				__func__, cpu);
+			continue;
+		}
+	}
+out_rcu_read_unlock:
+	rcu_read_unlock();
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_cpus_sharing_opps);
+
+/*
+ * Works only for OPP v2 bindings.
+ *
+ * cpumask should be already set to mask of cpu_dev->id.
+ * Returns -ENOENT if operating-points-v2 bindings aren't supported.
+ */
+int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask)
+{
+	struct device_node *np, *tmp_np;
+	struct device *tcpu_dev;
+	int cpu, ret = 0;
+
+	/* Get OPP descriptor node */
+	np = _of_get_opp_desc_node(cpu_dev);
+	if (IS_ERR(np)) {
+		dev_dbg(cpu_dev, "%s: Couldn't find opp node: %ld\n", __func__,
+			PTR_ERR(np));
+		return -ENOENT;
+	}
+
+	/* OPPs are shared ? */
+	if (!of_get_property(np, "opp-shared", NULL))
+		goto put_cpu_node;
+
+	for_each_possible_cpu(cpu) {
+		if (cpu == cpu_dev->id)
+			continue;
+
+		tcpu_dev = get_cpu_device(cpu);
+		if (!tcpu_dev) {
+			dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
+				__func__, cpu);
+			ret = -ENODEV;
+			goto put_cpu_node;
+		}
+
+		/* Get OPP descriptor node */
+		tmp_np = _of_get_opp_desc_node(tcpu_dev);
+		if (IS_ERR(tmp_np)) {
+			dev_info(tcpu_dev, "%s: Couldn't find opp node: %ld\n",
+				 __func__, PTR_ERR(tmp_np));
+			ret = -EINVAL;
+			goto put_cpu_node;
+		}
+
+		/* CPUs are sharing opp node */
+		if (np == tmp_np)
+			cpumask_set_cpu(cpu, cpumask);
+
+		of_node_put(tmp_np);
+	}
+
+put_cpu_node:
+	of_node_put(np);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_get_cpus_sharing_opps);
 #endif
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 20324b579adc..bb52fae5b921 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -121,6 +121,10 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
 int of_init_opp_table(struct device *dev);
 void of_free_opp_table(struct device *dev);
+int of_cpumask_init_opp_table(cpumask_var_t cpumask);
+void of_cpumask_free_opp_table(cpumask_var_t cpumask);
+int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask);
+int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask);
 #else
 static inline int of_init_opp_table(struct device *dev)
 {
@@ -130,6 +134,25 @@ static inline int of_init_opp_table(struct device *dev)
 static inline void of_free_opp_table(struct device *dev)
 {
 }
+
+static inline int of_cpumask_init_opp_table(cpumask_var_t cpumask)
+{
+	return -ENOSYS;
+}
+
+static inline void of_cpumask_free_opp_table(cpumask_var_t cpumask)
+{
+}
+
+static inline int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask)
+{
+	return -ENOSYS;
+}
+
+static inline int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask)
+{
+	return -ENOSYS;
+}
 #endif
 
 #endif		/* __LINUX_OPP_H__ */
-- 
2.4.0

Re: [PATCH V2 10/11] opp: Add helpers for initializing CPU OPPs

[Bartlomiej Zolnierkiewicz]

Hi,

On Monday, July 27, 2015 10:32:40 AM Viresh Kumar wrote:
> With "operating-points-v2" its possible to tell which devices share
> OPPs. We already have infrastructure to decode that information.
> 
> This patch adds following APIs:
> - of_get_cpus_sharing_opps: Returns cpumask of CPUs sharing OPPs (only
>   valid with v2 bindings).
> - of_cpumask_init_opp_table: Initializes OPPs for all CPUs present in
>   cpumask.
> - of_cpumask_free_opp_table: Frees OPPs for all CPUs present in cpumask.
> 
> - set_cpus_sharing_opps: Sets which CPUs share OPPs (only valid with old
>   OPP bindings, as this information isn't present in DT).
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

[PATCH V2 11/11] cpufreq-dt: Add support for operating-points-v2 bindings

[Viresh Kumar]

Support for parsing operating-points-v2 bindings is in place now, lets
modify cpufreq-dt driver to use them.

For backward compatibility we will continue to support earlier bindings.
Special handling for that is required, to make sure OPPs are initialized
for all the CPUs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq-dt.c | 56 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 46 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 528a82bf5038..c6e7033076de 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -184,7 +184,6 @@ static int allocate_resources(int cpu, struct device **cdev,
 
 static int cpufreq_init(struct cpufreq_policy *policy)
 {
-	struct cpufreq_dt_platform_data *pd;
 	struct cpufreq_frequency_table *freq_table;
 	struct device_node *np;
 	struct private_data *priv;
@@ -193,6 +192,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	struct clk *cpu_clk;
 	unsigned long min_uV = ~0, max_uV = 0;
 	unsigned int transition_latency;
+	bool need_update = false;
 	int ret;
 
 	ret = allocate_resources(policy->cpu, &cpu_dev, &cpu_reg, &cpu_clk);
@@ -208,8 +208,47 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 		goto out_put_reg_clk;
 	}
 
-	/* OPPs might be populated at runtime, don't check for error here */
-	of_init_opp_table(cpu_dev);
+	/* Get OPP-sharing information from "operating-points-v2" bindings */
+	ret = of_get_cpus_sharing_opps(cpu_dev, policy->cpus);
+	if (ret) {
+		/*
+		 * operating-points-v2 not supported, fallback to old method of
+		 * finding shared-OPPs for backward compatibility.
+		 */
+		if (ret == -ENOENT)
+			need_update = true;
+		else
+			goto out_node_put;
+	}
+
+	/*
+	 * Initialize OPP tables for all policy->cpus. They will be shared by
+	 * all CPUs which have marked their CPUs shared with OPP bindings.
+	 *
+	 * For platforms not using operating-points-v2 bindings, we do this
+	 * before updating policy->cpus. Otherwise, we will end up creating
+	 * duplicate OPPs for policy->cpus.
+	 *
+	 * OPPs might be populated at runtime, don't check for error here
+	 */
+	of_cpumask_init_opp_table(policy->cpus);
+
+	if (need_update) {
+		struct cpufreq_dt_platform_data *pd = cpufreq_get_driver_data();
+
+		if (!pd || !pd->independent_clocks)
+			cpumask_setall(policy->cpus);
+
+		/*
+		 * OPP tables are initialized only for policy->cpu, do it for
+		 * others as well.
+		 */
+		set_cpus_sharing_opps(cpu_dev, policy->cpus);
+
+		of_property_read_u32(np, "clock-latency", &transition_latency);
+	} else {
+		transition_latency = dev_pm_opp_get_max_clock_latency(cpu_dev);
+	}
 
 	/*
 	 * But we need OPP table to function so if it is not there let's
@@ -230,7 +269,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 
 	of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance);
 
-	if (of_property_read_u32(np, "clock-latency", &transition_latency))
+	if (!transition_latency)
 		transition_latency = CPUFREQ_ETERNAL;
 
 	if (!IS_ERR(cpu_reg)) {
@@ -293,10 +332,6 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 
 	policy->cpuinfo.transition_latency = transition_latency;
 
-	pd = cpufreq_get_driver_data();
-	if (!pd || !pd->independent_clocks)
-		cpumask_setall(policy->cpus);
-
 	of_node_put(np);
 
 	return 0;
@@ -306,7 +341,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 out_free_priv:
 	kfree(priv);
 out_free_opp:
-	of_free_opp_table(cpu_dev);
+	of_cpumask_free_opp_table(policy->cpus);
+out_node_put:
 	of_node_put(np);
 out_put_reg_clk:
 	clk_put(cpu_clk);
@@ -322,7 +358,7 @@ static int cpufreq_exit(struct cpufreq_policy *policy)
 
 	cpufreq_cooling_unregister(priv->cdev);
 	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
-	of_free_opp_table(priv->cpu_dev);
+	of_cpumask_free_opp_table(policy->related_cpus);
 	clk_put(policy->clk);
 	if (!IS_ERR(priv->cpu_reg))
 		regulator_put(priv->cpu_reg);
-- 
2.4.0

Re: [PATCH V2 11/11] cpufreq-dt: Add support for operating-points-v2 bindings

[Bartlomiej Zolnierkiewicz]

Hi,

On Monday, July 27, 2015 10:32:41 AM Viresh Kumar wrote:
> Support for parsing operating-points-v2 bindings is in place now, lets
> modify cpufreq-dt driver to use them.
> 
> For backward compatibility we will continue to support earlier bindings.
> Special handling for that is required, to make sure OPPs are initialized
> for all the CPUs.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics