From: Daniel Scally <djrscally@gmail.com>
To: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
linux-media@vger.kernel.org, devel@acpica.org
Cc: rjw@rjwysocki.net, lenb@kernel.org, gregkh@linuxfoundation.org,
yong.zhi@intel.com, sakari.ailus@linux.intel.com,
bingbu.cao@intel.com, tian.shu.qiu@intel.com, mchehab@kernel.org,
robert.moore@intel.com, erik.kaneda@intel.com, pmladek@suse.com,
rostedt@goodmis.org, sergey.senozhatsky@gmail.com,
andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk,
laurent.pinchart+renesas@ideasonboard.com,
jacopo+renesas@jmondi.org,
kieran.bingham+renesas@ideasonboard.com,
hverkuil-cisco@xs4all.nl, m.felsch@pengutronix.de,
niklas.soderlund+renesas@ragnatech.se, slongerbeam@gmail.com,
heikki.krogerus@linux.intel.com, linus.walleij@linaro.org,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: [PATCH v3 04/14] software_node: Enforce parent before child ordering of nodes arrays
Date: Thu, 24 Dec 2020 01:08:57 +0000 [thread overview]
Message-ID: <20201224010907.263125-5-djrscally@gmail.com> (raw)
In-Reply-To: <20201224010907.263125-1-djrscally@gmail.com>
Registering software_nodes with the .parent member set to point to a
currently unregistered software_node has the potential for problems,
so enforce parent -> child ordering in arrays passed in to
software_node_register_nodes().
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, reverse the order in which
software_node_unregister_nodes() unregisters software_nodes.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
---
Changes in v3
- kerneldoc comment cleanup
drivers/base/swnode.c | 42 ++++++++++++++++++++++++++++++------------
1 file changed, 30 insertions(+), 12 deletions(-)
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 615a0c93e116..ade49173ff8d 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -692,7 +692,11 @@ swnode_register(const struct software_node *node, struct swnode *parent,
* software_node_register_nodes - Register an array of software nodes
* @nodes: Zero terminated array of software nodes to be registered
*
- * Register multiple software nodes at once.
+ * Register multiple software nodes at once. If any node in the array
+ * has its .parent pointer set (which can only be to another software_node),
+ * then its parent **must** have been registered before it is; either outside
+ * of this function or by ordering the array such that parent comes before
+ * child.
*/
int software_node_register_nodes(const struct software_node *nodes)
{
@@ -700,14 +704,23 @@ int software_node_register_nodes(const struct software_node *nodes)
int i;
for (i = 0; nodes[i].name; i++) {
- ret = software_node_register(&nodes[i]);
- if (ret) {
- software_node_unregister_nodes(nodes);
- return ret;
+ const struct software_node *parent = nodes[i].parent;
+
+ if (parent && !software_node_to_swnode(parent)) {
+ ret = -EINVAL;
+ goto err_unregister_nodes;
}
+
+ ret = software_node_register(&nodes[i]);
+ if (ret)
+ goto err_unregister_nodes;
}
return 0;
+
+err_unregister_nodes:
+ software_node_unregister_nodes(nodes);
+ return ret;
}
EXPORT_SYMBOL_GPL(software_node_register_nodes);
@@ -715,18 +728,23 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes);
* software_node_unregister_nodes - Unregister an array of software nodes
* @nodes: Zero terminated array of software nodes to be unregistered
*
- * Unregister multiple software nodes at once.
+ * Unregister multiple software nodes at once. If parent pointers are set up
+ * in any of the software nodes then the array **must** be ordered such that
+ * parents come before their children.
*
- * NOTE: Be careful using this call if the nodes had parent pointers set up in
- * them before registering. If so, it is wiser to remove the nodes
- * individually, in the correct order (child before parent) instead of relying
- * on the sequential order of the list of nodes in the array.
+ * NOTE: If you are uncertain whether the array is ordered such that
+ * parents will be unregistered before their children, it is wiser to
+ * remove the nodes individually, in the correct order (child before
+ * parent).
*/
void software_node_unregister_nodes(const struct software_node *nodes)
{
- int i;
+ unsigned int i = 0;
+
+ while (nodes[i].name)
+ i++;
- for (i = 0; nodes[i].name; i++)
+ while (i--)
software_node_unregister(&nodes[i]);
}
EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
--
2.25.1
next prev parent reply other threads:[~2020-12-24 1:10 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-24 1:08 [PATCH v3 00/14] Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows Daniel Scally
2020-12-24 1:08 ` [PATCH v3 01/14] software_node: Fix refcounts in software_node_get_next_child() Daniel Scally
2020-12-24 1:08 ` [PATCH v3 02/14] property: Return true in fwnode_device_is_available for NULL ops Daniel Scally
2020-12-24 1:08 ` [PATCH v3 03/14] property: Call fwnode_graph_get_endpoint_by_id() for fwnode->secondary Daniel Scally
2020-12-24 1:08 ` Daniel Scally [this message]
2020-12-24 1:08 ` [PATCH v3 05/14] software_node: unregister software_nodes in reverse order Daniel Scally
2020-12-24 12:13 ` Andy Shevchenko
2020-12-24 14:00 ` Daniel Scally
2020-12-24 14:12 ` Andy Shevchenko
2020-12-24 14:14 ` Daniel Scally
2020-12-24 18:36 ` David Laight
2020-12-28 10:15 ` Andy Shevchenko
2020-12-28 21:17 ` Daniel Scally
2020-12-28 16:34 ` Sakari Ailus
2020-12-28 17:47 ` Andy Shevchenko
2020-12-24 1:08 ` [PATCH v3 06/14] include: fwnode.h: Define format macros for ports and endpoints Daniel Scally
2020-12-24 12:17 ` Andy Shevchenko
2020-12-24 12:41 ` Laurent Pinchart
2020-12-28 16:30 ` Sakari Ailus
2020-12-28 17:11 ` Sakari Ailus
2020-12-28 21:36 ` Daniel Scally
2020-12-24 1:09 ` [PATCH v3 07/14] software_node: Add support for fwnode_graph*() family of functions Daniel Scally
2020-12-24 12:24 ` Andy Shevchenko
2020-12-24 12:55 ` Laurent Pinchart
2020-12-24 13:03 ` Andy Shevchenko
2020-12-24 14:21 ` Daniel Scally
2020-12-28 16:41 ` Sakari Ailus
2020-12-28 21:37 ` Daniel Scally
2020-12-26 23:47 ` Daniel Scally
2020-12-24 12:53 ` Laurent Pinchart
2020-12-24 14:24 ` Daniel Scally
2020-12-24 1:09 ` [PATCH v3 08/14] lib/test_printf.c: Use helper function to unwind array of software_nodes Daniel Scally
2020-12-24 1:09 ` [PATCH v3 09/14] ipu3-cio2: Add T: entry to MAINTAINERS Daniel Scally
2020-12-24 1:09 ` [PATCH v3 10/14] ipu3-cio2: Rename ipu3-cio2.c Daniel Scally
2020-12-24 1:09 ` [PATCH v3 11/14] media: v4l2-core: v4l2-async: Check sd->fwnode->secondary in match_fwnode() Daniel Scally
2020-12-24 1:09 ` [PATCH v3 12/14] acpi: Add acpi_dev_get_next_match_dev() and helper macro Daniel Scally
2020-12-24 1:09 ` [PATCH v3 13/14] include: media: v4l2-fwnode: Include v4l2_fwnode_bus_type Daniel Scally
2020-12-24 12:32 ` Andy Shevchenko
2020-12-26 23:14 ` Daniel Scally
2020-12-24 12:58 ` Laurent Pinchart
2020-12-24 1:09 ` [PATCH v3 14/14] ipu3-cio2: Add cio2-bridge to ipu3-cio2 driver Daniel Scally
2020-12-24 12:54 ` Andy Shevchenko
2020-12-26 23:23 ` Daniel Scally
2020-12-28 17:05 ` Sakari Ailus
2020-12-28 22:37 ` Daniel Scally
2020-12-28 22:55 ` Andy Shevchenko
2020-12-28 22:56 ` Andy Shevchenko
2020-12-28 23:07 ` Laurent Pinchart
2020-12-28 23:54 ` Andy Shevchenko
2020-12-29 0:07 ` Laurent Pinchart
2020-12-30 20:47 ` Andy Shevchenko
2020-12-28 23:30 ` Daniel Scally
2020-12-28 23:47 ` Andy Shevchenko
2021-01-02 17:07 ` Sakari Ailus
2021-01-02 17:12 ` Daniel Scally
2021-01-02 17:21 ` Sakari Ailus
2021-01-02 17:24 ` Sakari Ailus
2021-01-02 21:23 ` Daniel Scally
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