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From:   Daniel Scally <djrscally@gmail.com>
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Subject: [RFC PATCH v3 1/9] software_node: Add helper function to unregister arrays of software_nodes ordered parent to child
Date:   Mon, 19 Oct 2020 23:58:55 +0100
Message-Id: <20201019225903.14276-2-djrscally@gmail.com>
In-Reply-To: <20201019225903.14276-1-djrscally@gmail.com>
References: <20201019225903.14276-1-djrscally@gmail.com>
Precedence: bulk

Software nodes that are children of another software node should be
unregistered before their parent. To allow easy unregistering of an array
of software_nodes ordered parent to child, add a helper function to loop
over and unregister nodes in such an array in reverse order.

Suggested-by: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
---
Changes in v3:
	- patch introduced.

 drivers/base/swnode.c    | 21 +++++++++++++++++++++
 include/linux/property.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 010828fc7..f01b1cc61 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -727,6 +727,27 @@ void software_node_unregister_nodes(const struct software_node *nodes)
 }
 EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
 
+/**
+ * software_node_unregister_nodes_reverse - Unregister an array of software
+ * nodes in reverse order.
+ * @nodes: Array of software nodes to be unregistered.
+ *
+ * NOTE: The same warning applies as with software_node_unregister_nodes.
+ * Unless you are _sure_ that the array of nodes is ordered parent to child
+ * it is wiser to remove them individually in the correct order.
+ */
+void software_node_unregister_nodes_reverse(const struct software_node *nodes)
+{
+	unsigned int i = 0;
+
+	while (nodes[i].name)
+		i++;
+
+	while (i--)
+		software_node_unregister(&nodes[i]);
+}
+EXPORT_SYMBOL_GPL(software_node_unregister_nodes_reverse);
+
 /**
  * software_node_register_node_group - Register a group of software nodes
  * @node_group: NULL terminated array of software node pointers to be registered
diff --git a/include/linux/property.h b/include/linux/property.h
index 9f805c442..b6410258b 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -444,6 +444,7 @@ software_node_find_by_name(const struct software_node *parent,
 
 int software_node_register_nodes(const struct software_node *nodes);
 void software_node_unregister_nodes(const struct software_node *nodes);
+void software_node_unregister_nodes_reverse(const struct software_node *nodes);
 
 int software_node_register_node_group(const struct software_node **node_group);
 void software_node_unregister_node_group(const struct software_node **node_group);
-- 
2.17.1