Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757418Ab3GVPGx (ORCPT ); Mon, 22 Jul 2013 11:06:53 -0400 Received: from service87.mimecast.com ([91.220.42.44]:45686 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757084Ab3GVPGu convert rfc822-to-8bit (ORCPT ); Mon, 22 Jul 2013 11:06:50 -0400 Message-ID: <51ED4A99.3030403@arm.com> Date: Mon, 22 Jul 2013 16:07:05 +0100 From: Sudeep KarkadaNagesha User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: Nicolas Pitre CC: Sudeep KarkadaNagesha , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , "devicetree@vger.kernel.org" , Russell King , Shawn Guo , Gregory Clement , Greg Kroah-Hartman , Viresh Kumar , "Rafael J. Wysocki" , "grant.likely@linaro.org" , "rob.herring@calxeda.com" , Lorenzo Pieralisi , Olof Johansson , Arnd Bergmann Subject: Re: [PATCH v3 01/16] of: add support for retrieving cpu node for a given logical cpu index References: <1374069984-20567-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1374492747-13879-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1374492747-13879-2-git-send-email-Sudeep.KarkadaNagesha@arm.com> In-Reply-To: X-OriginalArrivalTime: 22 Jul 2013 15:06:45.0026 (UTC) FILETIME=[1489A820:01CE86ED] X-MC-Unique: 113072216064801801 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3104 Lines: 80 Hi Nico, On 22/07/13 15:14, Nicolas Pitre wrote: > On Mon, 22 Jul 2013, Sudeep KarkadaNagesha wrote: > >> From: Sudeep KarkadaNagesha >> >> Currently different drivers requiring to access cpu device node are >> parsing the device tree themselves. Since the ordering in the DT need >> not match the logical cpu ordering, the parsing logic needs to consider >> that. However, this has resulted in lots of code duplication and in some >> cases even incorrect logic. >> >> It's better to consolidate them by adding support for getting cpu >> device node for a given logical cpu index in DT core library. However >> logical to physical index mapping can be architecture specific. >> >> This patch adds of_get_cpu_node to retrieve a cpu device node for a >> given logical cpu index. The default matching of the physical id to the >> logical cpu index can be overridden by architecture specific code. >> >> It is recommended to use these helper function only in pre-SMP/early >> initialisation stages to retrieve CPU device node pointers in logical >> ordering. Once the cpu devices are registered, it can be retrieved easily >> from cpu device of_node which avoids unnecessary parsing and matching. >> >> Acked-by: Rob Herring >> Signed-off-by: Sudeep KarkadaNagesha > > Minor nits below. Otherwise... > > Acked-by: Nicolas Pitre > Thanks for all the Acks. >> --- >> drivers/of/base.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/of.h | 6 +++++ >> 2 files changed, 78 insertions(+) >> >> diff --git a/drivers/of/base.c b/drivers/of/base.c >> index 5c54279..1e690bf 100644 >> --- a/drivers/of/base.c >> +++ b/drivers/of/base.c >> @@ -230,6 +230,78 @@ const void *of_get_property(const struct device_node *np, const char *name, >> } >> EXPORT_SYMBOL(of_get_property); >> >> +/* >> + * arch_match_cpu_phys_id - Match the given logical CPU and physical id >> + * >> + * @cpu: logical index of a cpu >> + * @phys_id: physical identifier of a cpu >> + * >> + * CPU logical to physical index mapping is architecture specific. >> + * However this __weak function provides a default match of physical >> + * id to logical cpu index. >> + * >> + * Returns true if the physical identifier and the logical index correspond >> + * to the same cpu, false otherwise. >> + */ >> +bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id) > > Maybe a prototype declaration for this function should be added to > include/linux/of.h to avoid mismatch with architecture provided > versions. > Agreed, but include/linux/of.h doesn't seem to be right choice for me as this function is not really related to OF/DT. I can't choose any better place either. I don't have a strong opinion on that, just a thought. Regards, Sudeep -- 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/