of: introduce for_each_matching_node_and_match()

The following pattern of code is tempting:

    for_each_matching_node(np, table) {
        match = of_match_node(table, np);

However, this results in iterating over table twice; the second time
inside of_match_node(). The implementation of for_each_matching_node()
already found the match, so this is redundant. Invent new function
of_find_matching_node_and_match() and macro
for_each_matching_node_and_match() to remove the double iteration,
thus transforming the above code to:

    for_each_matching_node_and_match(np, table, &match)

Signed-off-by: Stephen Warren <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
This commit is contained in:
Stephen Warren 2012-11-20 16:12:20 -07:00 • committed by Rob Herring
commit 50c8af4cf9
2 changed files with 26 additions and 7 deletions

View file

@ -594,27 +594,35 @@ const struct of_device_id *of_match_node(const struct of_device_id *matches,
EXPORT_SYMBOL(of_match_node);
/**
* of_find_matching_node - Find a node based on an of_device_id match
* table.
* of_find_matching_node_and_match - Find a node based on an of_device_id
* match table.
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @matches: array of of device match structures to search in
* @match Updated to point at the matches entry which matched
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_matching_node(struct device_node *from,
const struct of_device_id *matches)
struct device_node *of_find_matching_node_and_match(struct device_node *from,
const struct of_device_id *matches,
const struct of_device_id **match)
{
struct device_node *np;
if (match)
*match = NULL;
read_lock(&devtree_lock);
np = from ? from->allnext : allnodes;
for (; np; np = np->allnext) {
if (of_match_node(matches, np) && of_node_get(np))
if (of_match_node(matches, np) && of_node_get(np)) {
if (match)
*match = matches;
break;
}
}
of_node_put(from);
read_unlock(&devtree_lock);