Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753954Ab2KTXwL (ORCPT ); Tue, 20 Nov 2012 18:52:11 -0500 Received: from mail-oa0-f46.google.com ([209.85.219.46]:36657 "EHLO mail-oa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752089Ab2KTXwI (ORCPT ); Tue, 20 Nov 2012 18:52:08 -0500 Message-ID: <50AC17A4.2040507@gmail.com> Date: Tue, 20 Nov 2012 17:52:04 -0600 From: Rob Herring User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121028 Thunderbird/16.0.2 MIME-Version: 1.0 To: Stephen Warren CC: John Stultz , Thomas Gleixner , Grant Likely , Rob Herring , Thomas Petazzoni , Josh Cartwright , Stephen Warren , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Olof Johansson , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH V4 1/3] of: introduce for_each_matching_node_and_match() References: <1353453142-4973-1-git-send-email-swarren@wwwdotorg.org> In-Reply-To: <1353453142-4973-1-git-send-email-swarren@wwwdotorg.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4722 Lines: 118 On 11/20/2012 05:12 PM, Stephen Warren wrote: > 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. Agreed. I will apply for 3.8 assuming no further comments in the next few days. Rob > 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); > -- 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/