[PATCH v3 04/15] device property: Introduce device_for_each_child_node_scoped()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Similar to recently propose for_each_child_of_node_scoped() this
new version of the loop macro instantiates a new local
struct fwnode_handle * that uses the __free(fwnode_handle) auto
cleanup handling so that if a reference to a node is held on early
exit from the loop the reference will be released. If the loop
runs to completion, the child pointer will be NULL and no action will
be taken.

The reason this is useful is that it removes the need for
fwnode_handle_put() on early loop exits.  If there is a need
to retain the reference, then return_ptr(child) or no_free_ptr(child)
may be used to safely disable the auto cleanup.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
 include/linux/property.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/property.h b/include/linux/property.h
index 9e67c3c4df6e..421ccfd43fb1 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -182,6 +182,11 @@ struct fwnode_handle *device_get_next_child_node(const struct device *dev,
 	for (child = device_get_next_child_node(dev, NULL); child;	\
 	     child = device_get_next_child_node(dev, child))
 
+#define device_for_each_child_node_scoped(dev, child)\
+	for (struct fwnode_handle *child __free(fwnode_handle) = \
+	     device_get_next_child_node(dev, NULL); child; \
+	     child = device_get_next_child_node(dev, child))
+
 struct fwnode_handle *fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
 						  const char *childname);
 struct fwnode_handle *device_get_named_child_node(const struct device *dev,
-- 
2.43.2





[Index of Archives]     [Linux IBM ACPI]     [Linux Power Management]     [Linux Kernel]     [Linux Laptop]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]
  Powered by Linux