linux-kernel - [PATCH 1/5] pinctrl: Export pinctrl_unregister

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Message-Id: <20191215163810.52356-2-hdegoede@redhat.com>
Date:   Sun, 15 Dec 2019 17:38:06 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>, Lee Jones <lee.jones@...aro.org>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        intel-gfx <intel-gfx@...ts.freedesktop.org>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linux-gpio@...r.kernel.org
Subject: [PATCH 1/5] pinctrl: Export pinctrl_unregister_mappings

Rename pinctrl_unregister_map to pinctrl_unregister_mappings so that
its naming matches its pinctrl_register_mappings counter-part and
export it.

The purpose of this patch is to allow non-dt platforms to register
pinctrl mappings from code which is build as a module, which requires
being able to unregister the mapping when the module is unloaded to
avoid dangling pointers; and to avoid registering the mapping multiple
times, when the module gets reloaded later.

Signed-off-by: Hans de Goede <hdegoede@...hat.com>
---
 drivers/pinctrl/core.c          | 11 ++++++++++-
 drivers/pinctrl/core.h          |  3 ++-
 drivers/pinctrl/devicetree.c    |  2 +-
 include/linux/pinctrl/machine.h |  5 +++++
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2bbd8ee93507..c98f8cc9c7ca 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1431,6 +1431,7 @@ int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps,
 		return -ENOMEM;
 
 	maps_node->num_maps = num_maps;
+	maps_node->dup = dup;
 	if (dup) {
 		maps_node->maps = kmemdup(maps, sizeof(*maps) * num_maps,
 					  GFP_KERNEL);
@@ -1463,7 +1464,12 @@ int pinctrl_register_mappings(const struct pinctrl_map *maps,
 }
 EXPORT_SYMBOL_GPL(pinctrl_register_mappings);
 
-void pinctrl_unregister_map(const struct pinctrl_map *map)
+/**
+ * pinctrl_unregister_mappings() - unregister a set of pin controller mappings
+ * @maps: the pincontrol mappings table passed to pinctrl_register_mappings()
+ *	when registering the mappings.
+ */
+void pinctrl_unregister_mappings(const struct pinctrl_map *map)
 {
 	struct pinctrl_maps *maps_node;
 
@@ -1471,6 +1477,8 @@ void pinctrl_unregister_map(const struct pinctrl_map *map)
 	list_for_each_entry(maps_node, &pinctrl_maps, node) {
 		if (maps_node->maps == map) {
 			list_del(&maps_node->node);
+			if (maps_node->dup)
+				kfree(maps_node->maps);
 			kfree(maps_node);
 			mutex_unlock(&pinctrl_maps_mutex);
 			return;
@@ -1478,6 +1486,7 @@ void pinctrl_unregister_map(const struct pinctrl_map *map)
 	}
 	mutex_unlock(&pinctrl_maps_mutex);
 }
+EXPORT_SYMBOL_GPL(pinctrl_unregister_mappings);
 
 /**
  * pinctrl_force_sleep() - turn a given controller device into sleep state
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 7f34167a0405..cba38ef13b1d 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -175,11 +175,13 @@ struct pin_desc {
  * @node: mapping table list node
  * @maps: array of mapping table entries
  * @num_maps: the number of entries in @maps
+ * @dup: has the mapping table been memdup-ed by us?
  */
 struct pinctrl_maps {
 	struct list_head node;
 	const struct pinctrl_map *maps;
 	unsigned num_maps;
+	bool dup;
 };
 
 #ifdef CONFIG_GENERIC_PINCTRL_GROUPS
@@ -238,7 +240,6 @@ pinctrl_find_gpio_range_from_pin_nolock(struct pinctrl_dev *pctldev,
 
 int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps,
 			 bool dup);
-void pinctrl_unregister_map(const struct pinctrl_map *map);
 
 extern int pinctrl_force_sleep(struct pinctrl_dev *pctldev);
 extern int pinctrl_force_default(struct pinctrl_dev *pctldev);
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index 674920daac26..a1925962a3e2 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -51,7 +51,7 @@ void pinctrl_dt_free_maps(struct pinctrl *p)
 	struct pinctrl_dt_map *dt_map, *n1;
 
 	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
-		pinctrl_unregister_map(dt_map->map);
+		pinctrl_unregister_mappings(dt_map->map);
 		list_del(&dt_map->node);
 		dt_free_map(dt_map->pctldev, dt_map->map,
 			    dt_map->num_maps);
diff --git a/include/linux/pinctrl/machine.h b/include/linux/pinctrl/machine.h
index ddd1b2773431..e987dc9fd2af 100644
--- a/include/linux/pinctrl/machine.h
+++ b/include/linux/pinctrl/machine.h
@@ -153,6 +153,7 @@ struct pinctrl_map {
 
 extern int pinctrl_register_mappings(const struct pinctrl_map *map,
 				unsigned num_maps);
+extern void pinctrl_unregister_mappings(const struct pinctrl_map *map);
 extern void pinctrl_provide_dummies(void);
 #else
 
@@ -162,6 +163,10 @@ static inline int pinctrl_register_mappings(const struct pinctrl_map *map,
 	return 0;
 }
 
+static inline void pinctrl_unregister_mappings(const struct pinctrl_map *map)
+{
+}
+
 static inline void pinctrl_provide_dummies(void)
 {
 }
-- 
2.23.0