From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965352AbXBLTuH (ORCPT ); Mon, 12 Feb 2007 14:50:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965353AbXBLTuH (ORCPT ); Mon, 12 Feb 2007 14:50:07 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:46719 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965352AbXBLTuE (ORCPT ); Mon, 12 Feb 2007 14:50:04 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Andi Kleen Cc: Benjamin Romer , Vivek Goyal , patches@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH x86 for review III] [7/29] x86_64: update IO-APIC dest field to 8-bit for xAPIC References: <20070212551.664370000@suse.de> <20070212165127.1790A13FAE@wotan.suse.de> Date: Mon, 12 Feb 2007 12:49:28 -0700 In-Reply-To: <20070212165127.1790A13FAE@wotan.suse.de> (Andi Kleen's message of "Mon, 12 Feb 2007 17:51:27 +0100 (CET)") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen writes: > From: Benjamin Romer > > On the Unisys ES7000/ONE system, we encountered a problem where performing > a kexec reboot or dump on any cell other than cell 0 causes the system > timer to stop working, resulting in a hang during timer calibration in the > new kernel. > > We traced the problem to one line of code in disable_IO_APIC(), which needs > to restore the timer's IO-APIC configuration before rebooting. The code is > currently using the 4-bit physical destination field, rather than using the > 8-bit logical destination field, and it cuts off the upper 4 bits of the > timer's APIC ID. If we change this to use the logical destination field, > the timer works and we can kexec on the upper cells. This was tested on > two different cells (0 and 2) in an ES7000/ONE system. > > For reference, the relevant Intel xAPIC spec is kept at > ftp://download.intel.com/design/chipsets/e8501/datashts/30962001.pdf, > specifically on page 334. > > Signed-off-by: Benjamin M Romer > Signed-off-by: Andi Kleen > Cc: Andi Kleen > Cc: "Eric W. Biederman" > Cc: Vivek Goyal > Signed-off-by: Andrew Morton Acked-by: Eric W. Biederman"