From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755617AbaDNX51 (ORCPT ); Mon, 14 Apr 2014 19:57:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22794 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754607AbaDNX5X (ORCPT ); Mon, 14 Apr 2014 19:57:23 -0400 From: Baoquan He To: linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net, lenb@kernel.org, linux-acpi@vger.kernel.org, jiang.liu@linux.intel.com, vgoyal@redhat.com, Baoquan He Subject: [PATCH] acpi: try to trust cpu_index from x86_cpu_to_apicid Date: Tue, 15 Apr 2014 07:55:54 +0800 Message-Id: <1397519754-10205-1-git-send-email-bhe@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In smp with multi cpus, when enter into kdump kernel with only 1 cpu, a warning message is printed out: acpi LNXCPU:0a: BIOS reported wrong ACPI id 0 for the processor In this case kdump kernel use the same ACPI tables as 1st kernel, means lapic information is got from MADT. The acpi_id related to this cpu index and lapic_id may not be 0, so the code to assign value to cpu_index is not correct in this case per cpu0_initialized. cpu index stored in x86_cpu_to_apicid need be respected. Now fix it in this patch per boot_cpu_physical_apicid. When cpu index related to boot_cpu_physical_apicid is not stored in x86_cpu_to_apicid, then we can say this is UP system running SMP kernel with no LAPIC in MADT 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 c29c2c3..1ae460c 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -267,7 +267,7 @@ 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 && (boot_cpu_physical_apicid == pr->apic_id)) { cpu0_initialized = 1; /* Handle UP system running SMP kernel, with no LAPIC in MADT */ if ((cpu_index == -1) && (num_online_cpus() == 1)) -- 1.8.5.3