From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751202AbdGYJ1f (ORCPT ); Tue, 25 Jul 2017 05:27:35 -0400 Received: from foss.arm.com ([217.140.101.70]:43336 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750860AbdGYJ1e (ORCPT ); Tue, 25 Jul 2017 05:27:34 -0400 Subject: Re: [PATCH v2 2/6] of: Add helper for mapping device node to logical CPU number To: Sudeep Holla , linux-arm-kernel@lists.infradead.org References: <1500892161-17634-1-git-send-email-suzuki.poulose@arm.com> <1500892161-17634-3-git-send-email-suzuki.poulose@arm.com> <7ec47d12-3b6b-82c0-ba15-5664b5169974@arm.com> Cc: mark.rutland@arm.com, peterz@infradead.org, will.deacon@arm.com, linux-kernel@vger.kernel.org, Rob Herring From: Suzuki K Poulose Message-ID: <18f06d4c-f063-30f7-70e8-aacd6e7a129b@arm.com> Date: Tue, 25 Jul 2017 10:27:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <7ec47d12-3b6b-82c0-ba15-5664b5169974@arm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/07/17 17:42, Sudeep Holla wrote: > > > On 24/07/17 11:29, Suzuki K Poulose wrote: >> Add a helper to map a device node to a logical CPU number to avoid >> duplication. Currently this is open coded in different places (e.g >> gic-v3, coresight). The helper tries to map device node to a "possible" >> logical CPU id, which may not be online yet. It is the responsibility >> of the user to make sure that the CPU is online. The helper uses >> of_get_cpu_node() which uses arch specific backends to match the phyiscal >> ids. >> >> Cc: Rob Herring >> Cc: Mark Rutland >> Signed-off-by: Suzuki K Poulose >> --- >> drivers/of/base.c | 26 ++++++++++++++++++++++++++ >> include/linux/of_device.h | 7 +++++++ >> 2 files changed, 33 insertions(+) >> >> diff --git a/drivers/of/base.c b/drivers/of/base.c >> index 686628d..639af23 100644 >> --- a/drivers/of/base.c >> +++ b/drivers/of/base.c >> @@ -420,6 +420,32 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) >> EXPORT_SYMBOL(of_get_cpu_node); >> >> /** >> + * of_device_node_get_cpu: Get the logical CPU number for a given device_node >> + * >> + * @cpu_node: Pointer to the device_node for CPU. >> + * >> + * Returns the logical CPU number of the given CPU device_node. >> + * Returns >= nr_cpu_ids if CPU is not found. >> + */ >> +int of_device_node_get_cpu(struct device_node *cpu_node) >> +{ >> + int cpu, thread; >> + bool found = false; >> + struct device_node *np; >> + >> + for_each_possible_cpu(cpu) { >> + np = of_get_cpu_node(cpu, &thread); > > Ideally, we should be able to use of_cpu_device_node_get instead of > of_get_cpu_node which parses the device tree. Not sure if that's the > case here too. > > Sorry for following up on this so late. I had a patch in my tree > for-a-while to address that. Just posted it[1] now seeing this patch now. > > You can move to of_cpu_device_node_get if all users of this function are > called after CPU's are registered. Otherwise, you can keep it as is for > now and it can be changed once [1] lands. As you mentioned offline, since GIC uses this, we need to stick to of_get_cpu_node. In fact, I started off with the of_cpu_device_node_get() and switched to the former. It would be really nice to have your patch, which streamlines the interface and we could switch to that. Cheers Suzuki >