From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5DEBC3279B for ; Mon, 2 Jul 2018 13:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8416D23F3F for ; Mon, 2 Jul 2018 13:23:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8416D23F3F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752533AbeGBNX4 (ORCPT ); Mon, 2 Jul 2018 09:23:56 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:60320 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752383AbeGBNXx (ORCPT ); Mon, 2 Jul 2018 09:23:53 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EC35118A; Mon, 2 Jul 2018 06:23:52 -0700 (PDT) Received: from [192.168.100.244] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1C6843F5AD; Mon, 2 Jul 2018 06:23:52 -0700 (PDT) Subject: Re: [PATCH] ACPI/PPTT: use ACPI ID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set To: Sudeep Holla , linux-acpi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shunyong.yang@hxt-semitech.com, yu.zheng@hxt-semitech.com, catalin.marinas@arm.com, will.deacon@arm.com, Lorenzo Pieralisi , Andrew Jones , "Rafael J. Wysocki" References: <1530289077-2444-1-git-send-email-sudeep.holla@arm.com> From: Jeremy Linton Message-ID: <2d723ddc-e3c0-6024-8dcf-cdccd50a383e@arm.com> Date: Mon, 2 Jul 2018 08:23:47 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1530289077-2444-1-git-send-email-sudeep.holla@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 06/29/2018 11:17 AM, Sudeep Holla wrote: > Currently we use the ACPI processor ID only for the leaf/processor nodes > as the specification states it must match the value of ACPI processor ID > field in the processor’s entry in the MADT. > > However, if a PPTT structure represents processors group, it match a > processor container UID in the namespace and ACPI_PPTT_ACPI_PROCESSOR_ID_VALID > flag describe whether the ACPI processor ID is valid. > > Lets use UID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set to be > consistent instead of using table offset as it's currently done for non > leaf nodes. > > Cc: "Rafael J. Wysocki" > Signed-off-by: Sudeep Holla > --- > drivers/acpi/pptt.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > Hi, > > There's ongoing discussion on assigning ID based in OS using simple > counters. It can never be consistent with firmware's view. So if the > firmware provides valid UID for non-processors node, we must use it. > > Regards, > Sudeep > > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c > index e5ea1974d1e3..d1e26cb599bf 100644 > --- a/drivers/acpi/pptt.c > +++ b/drivers/acpi/pptt.c > @@ -481,8 +481,14 @@ static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, > if (cpu_node) { > cpu_node = acpi_find_processor_package_id(table, cpu_node, > level, flag); > - /* Only the first level has a guaranteed id */ > - if (level == 0) > + /* > + * As per specification if the processor structure represents > + * an actual processor, then ACPI processor ID must be valid. > + * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID > + * should be set if the UID is valid > + */ > + if (level == 0 || > + cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID) > return cpu_node->acpi_processor_id; > return ACPI_PTR_DIFF(cpu_node, table); > } > Ok sure, Acked-by: Jeremy Linton PS: To table implementers, the spec today mandates that setting the valid flag on a non leaf node means there is a matching _UID processor container in DSDT/SSDT.