From patchwork Mon May 5 04:48:26 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 4111671 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5ED7CBFF02 for ; Mon, 5 May 2014 04:50:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8BA5E203E6 for ; Mon, 5 May 2014 04:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7DC220256 for ; Mon, 5 May 2014 04:50:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754398AbaEEEt6 (ORCPT ); Mon, 5 May 2014 00:49:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11774 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750882AbaEEEt4 (ORCPT ); Mon, 5 May 2014 00:49:56 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s454nsgj020089 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 5 May 2014 00:49:54 -0400 Received: from dhcp-16-105.nay.redhat.com (dhcp-16-119.nay.redhat.com [10.66.16.119]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s454nkUH025335; Mon, 5 May 2014 00:49:51 -0400 From: Baoquan He To: rjw@rjwysocki.net, linux-acpi@vger.kernel.org, linux-ia64@vger.kernel.org Cc: linux-kernel@vger.kernel.org, dyoung@redhat.com, Baoquan He Subject: [Patch v3 2/2] lapic need be checked if available when initialize acpi processor id Date: Mon, 5 May 2014 12:48:26 +0800 Message-Id: <1399265306-8553-2-git-send-email-bhe@redhat.com> In-Reply-To: <1399265306-8553-1-git-send-email-bhe@redhat.com> References: <1399265306-8553-1-git-send-email-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In acpi_processor_get_info(), acpi processor info is initialized including id, namely cpu index. Currently, if on UP system running SMP kerenl with no LAPIC in MADT, cpu0_initialized is checked if acpi processor id is initialized. However this check maybe is not sufficient for kdump kernel. Most of time only 1 CPU is supported because of known problems in kdump kernel. So in 1st kernel multiple CPUs are present, then crash happened in one specific CPU, say 2nd CPU. Then it jumped into kdump kernel with "nr_cpus=1" specified in cmdline. In this situation, since kdump kernel is warm reset, it will reuse the ACPI resource passed from crashed kernel directly, namely 1st kernel. It means in MADT all LAPIC is enabled while only 1 CPU is present in running system. The kdump kernel usually is the same as the crashed 1st kernel. So now in kdump kernel, x86_cpu_to_apicid stored the apicid and its related cpu id. If only check cpu0_initialized, it will assign 0 to the acpi processor id of 1st CPU, it's not correct. So in this patch, check acpi_lapic too. If acpi_lapic is 0, then LAPIC in MADT is not available, assigne 0 to the handling acpi processor id. If acpi_lapic is 1, then LAPIC in MADT is available, let's get apic processor id from x86_cpu_to_apicid. Signed-off-by: Baoquan He --- drivers/acpi/acpi_processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b06f5f5..bf0cce9 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -268,7 +268,7 @@ static int acpi_processor_get_info(struct acpi_device *device) pr->apic_id = apic_id; cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); - if (!cpu0_initialized) { + if (!cpu0_initialized && !acpi_lapic) { cpu0_initialized = 1; /* Handle UP system running SMP kernel, with no LAPIC in MADT */ if ((cpu_index == -1) && (num_online_cpus() == 1))