backports: add devm_add_action()

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/backport/backport-include/linux/device.h b/backport/backport-include/linux/device.h
index e0886f5b..8f282ca6 100644
--- a/backport/backport-include/linux/device.h
+++ b/backport/backport-include/linux/device.h
@@ -125,6 +125,10 @@ static inline struct device *kobj_to_dev(struct kobject *kobj)
 }
 #endif /* LINUX_VERSION_CODE <= KERNEL_VERSION(3,6,0) */
 
+#if LINUX_VERSION_IS_LESS(3,10,0)
+int devm_add_action(struct device *dev, void (*action) (void *), void *data);
+#endif
+
 #if LINUX_VERSION_IS_LESS(3,11,0) && RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(7,0)
 #ifndef DEVICE_ATTR_RO
 #define DEVICE_ATTR_RO(_name) \
diff --git a/backport/compat/backport-3.10.c b/backport/compat/backport-3.10.c
index 5cab709c..0c0e2603 100644
--- a/backport/compat/backport-3.10.c
+++ b/backport/compat/backport-3.10.c
@@ -197,3 +197,41 @@ void split_page(struct page *page, unsigned int order)
 		set_page_refcounted(page + i);
 }
 EXPORT_SYMBOL_GPL(split_page);
+
+struct action_devres {
+	void *data;
+	void (*action)(void *);
+};
+
+static void devm_action_release(struct device *dev, void *res)
+{
+	struct action_devres *devres = res;
+
+	devres->action(devres->data);
+}
+
+/**
+ * devm_add_action() - add a custom action to list of managed resources
+ * @dev: Device that owns the action
+ * @action: Function that should be called
+ * @data: Pointer to data passed to @action implementation
+ *
+ * This adds a custom action to the list of managed resources so that
+ * it gets executed as part of standard resource unwinding.
+ */
+int devm_add_action(struct device *dev, void (*action)(void *), void *data)
+{
+	struct action_devres *devres;
+
+	devres = devres_alloc(devm_action_release,
+			      sizeof(struct action_devres), GFP_KERNEL);
+	if (!devres)
+		return -ENOMEM;
+
+	devres->data = data;
+	devres->action = action;
+
+	devres_add(dev, devres);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_add_action);