[PATCH] opp: Prepare for ->set_opp() helper to work without regulators

[Viresh Kumar <viresh.kumar@linaro.org>]

Until now the ->set_opp() helper (i.e. special implementation for
setting the OPPs for platforms) was implemented only to take care of
multiple regulators case, but going forward we would need that for other
use cases as well.

This patch prepares for that by allocating the regulator specific part
from dev_pm_opp_set_regulators() and the opp helper part from
dev_pm_opp_register_set_opp_helper().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
Dmitry,

I haven't tested this patch, can you please help with that ?

 drivers/opp/core.c | 81 ++++++++++++++++++++++++----------------------
 drivers/opp/opp.h  |  2 ++
 2 files changed, 45 insertions(+), 38 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index b1a2296f3065..f80b6f1ca108 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1817,38 +1817,6 @@ void dev_pm_opp_put_prop_name(struct opp_table *opp_table)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
 
-static int _allocate_set_opp_data(struct opp_table *opp_table)
-{
-	struct dev_pm_set_opp_data *data;
-	int len, count = opp_table->regulator_count;
-
-	if (WARN_ON(!opp_table->regulators))
-		return -EINVAL;
-
-	/* space for set_opp_data */
-	len = sizeof(*data);
-
-	/* space for old_opp.supplies and new_opp.supplies */
-	len += 2 * sizeof(struct dev_pm_opp_supply) * count;
-
-	data = kzalloc(len, GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	data->old_opp.supplies = (void *)(data + 1);
-	data->new_opp.supplies = data->old_opp.supplies + count;
-
-	opp_table->set_opp_data = data;
-
-	return 0;
-}
-
-static void _free_set_opp_data(struct opp_table *opp_table)
-{
-	kfree(opp_table->set_opp_data);
-	opp_table->set_opp_data = NULL;
-}
-
 /**
  * dev_pm_opp_set_regulators() - Set regulator names for the device
  * @dev: Device for which regulator name is being set.
@@ -1865,6 +1833,8 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
 					    const char * const names[],
 					    unsigned int count)
 {
+	struct dev_pm_opp_supply *supplies;
+	struct dev_pm_set_opp_data *data;
 	struct opp_table *opp_table;
 	struct regulator *reg;
 	int ret, i;
@@ -1906,10 +1876,20 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
 
 	opp_table->regulator_count = count;
 
-	/* Allocate block only once to pass to set_opp() routines */
-	ret = _allocate_set_opp_data(opp_table);
-	if (ret)
+	supplies = kmalloc_array(count * 2, sizeof(*supplies), GFP_KERNEL);
+	if (!supplies) {
+		ret = -ENOMEM;
 		goto free_regulators;
+	}
+
+	mutex_lock(&opp_table->lock);
+	opp_table->sod_supplies = supplies;
+	if (opp_table->set_opp_data) {
+		data = opp_table->set_opp_data;
+		data->old_opp.supplies = supplies;
+		data->new_opp.supplies = supplies + count;
+	}
+	mutex_unlock(&opp_table->lock);
 
 	return opp_table;
 
@@ -1952,9 +1932,16 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
 	for (i = opp_table->regulator_count - 1; i >= 0; i--)
 		regulator_put(opp_table->regulators[i]);
 
-	_free_set_opp_data(opp_table);
+	mutex_lock(&opp_table->lock);
+	if (opp_table->sod_supplies) {
+		opp_table->set_opp_data->old_opp.supplies = NULL;
+		opp_table->set_opp_data->new_opp.supplies = NULL;
+	}
+	mutex_unlock(&opp_table->lock);
 
+	kfree(opp_table->sod_supplies);
 	kfree(opp_table->regulators);
+	opp_table->sod_supplies = NULL;
 	opp_table->regulators = NULL;
 	opp_table->regulator_count = -1;
 
@@ -2046,6 +2033,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_put_clkname);
 struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev,
 			int (*set_opp)(struct dev_pm_set_opp_data *data))
 {
+	struct dev_pm_set_opp_data *data;
 	struct opp_table *opp_table;
 
 	if (!set_opp)
@@ -2062,8 +2050,23 @@ struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev,
 	}
 
 	/* Another CPU that shares the OPP table has set the helper ? */
-	if (!opp_table->set_opp)
-		opp_table->set_opp = set_opp;
+	if (opp_table->set_opp)
+		return opp_table;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&opp_table->lock);
+	opp_table->set_opp_data = data;
+	if (opp_table->sod_supplies) {
+		data->old_opp.supplies = opp_table->sod_supplies;
+		data->new_opp.supplies = opp_table->sod_supplies +
+					 opp_table->regulator_count;
+	}
+	mutex_unlock(&opp_table->lock);
+
+	opp_table->set_opp = set_opp;
 
 	return opp_table;
 }
@@ -2085,6 +2088,8 @@ void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table)
 	WARN_ON(!list_empty(&opp_table->opp_list));
 
 	opp_table->set_opp = NULL;
+	kfree(opp_table->set_opp_data);
+	opp_table->set_opp_data = NULL;
 	dev_pm_opp_put_opp_table(opp_table);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_set_opp_helper);
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 4ced7ffa8158..4408cfcb0f31 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -155,6 +155,7 @@ enum opp_table_access {
  * @genpd_performance_state: Device's power domain support performance state.
  * @is_genpd: Marks if the OPP table belongs to a genpd.
  * @set_opp: Platform specific set_opp callback
+ * @sod_supplies: Set opp data supplies
  * @set_opp_data: Data to be passed to set_opp callback
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
@@ -202,6 +203,7 @@ struct opp_table {
 	bool is_genpd;
 
 	int (*set_opp)(struct dev_pm_set_opp_data *data);
+	struct dev_pm_opp_supply *sod_supplies;
 	struct dev_pm_set_opp_data *set_opp_data;
 
 #ifdef CONFIG_DEBUG_FS
-- 
2.25.0.rc1.19.g042ed3e048af