Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753792Ab2KTXMf (ORCPT ); Tue, 20 Nov 2012 18:12:35 -0500 Received: from avon.wwwdotorg.org ([70.85.31.133]:58639 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753423Ab2KTXMe (ORCPT ); Tue, 20 Nov 2012 18:12:34 -0500 From: Stephen Warren To: Stephen Warren , John Stultz , Thomas Gleixner , Grant Likely , Rob Herring Cc: Arnd Bergmann , Olof Johansson , Josh Cartwright , Thomas Petazzoni , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Stephen Warren Subject: [PATCH V4 1/3] of: introduce for_each_matching_node_and_match() Date: Tue, 20 Nov 2012 16:12:20 -0700 Message-Id: <1353453142-4973-1-git-send-email-swarren@wwwdotorg.org> X-Mailer: git-send-email 1.7.10.4 X-NVConfidentiality: public Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4392 Lines: 113 From: Stephen Warren 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 --- v4: New patch. This series is based on the ARM sys_timer rework that I posted yesterday, although patch 1/3 should be completely independant of that, and could perhaps even be applied for 3.8 right now. I hope that these patches can be taken through arm-soc tree for 3.9; I will repost them based on 3.8-rc1 at the appropriate time. --- drivers/of/base.c | 18 +++++++++++++----- include/linux/of.h | 15 +++++++++++++-- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index f2f63c8..094271e 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -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); diff --git a/include/linux/of.h b/include/linux/of.h index 681a6c8..1000496 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -180,11 +180,22 @@ extern struct device_node *of_find_compatible_node(struct device_node *from, #define for_each_compatible_node(dn, type, compatible) \ for (dn = of_find_compatible_node(NULL, type, compatible); dn; \ dn = of_find_compatible_node(dn, type, compatible)) -extern struct device_node *of_find_matching_node(struct device_node *from, - const struct of_device_id *matches); +extern 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); +static inline struct device_node *of_find_matching_node( + struct device_node *from, + const struct of_device_id *matches) +{ + return of_find_matching_node_and_match(from, matches, NULL); +} #define for_each_matching_node(dn, matches) \ for (dn = of_find_matching_node(NULL, matches); dn; \ dn = of_find_matching_node(dn, matches)) +#define for_each_matching_node_and_match(dn, matches, match) \ + for (dn = of_find_matching_node_and_match(NULL, matches, match); \ + dn; dn = of_find_matching_node_and_match(dn, matches, match)) extern struct device_node *of_find_node_by_path(const char *path); extern struct device_node *of_find_node_by_phandle(phandle handle); extern struct device_node *of_get_parent(const struct device_node *node); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/