From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757161AbaGDOIJ (ORCPT ); Fri, 4 Jul 2014 10:08:09 -0400 Received: from mail.skyhub.de ([78.46.96.112]:37879 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751554AbaGDOIH (ORCPT ); Fri, 4 Jul 2014 10:08:07 -0400 Date: Fri, 4 Jul 2014 16:07:55 +0200 From: Borislav Petkov To: Jason Baron Cc: m.chehab@samsung.com, tony.luck@intel.com, hpa@zytor.com, mingo@kernel.org, dougthompson@xmission.com, mitake@dcl.info.waseda.ac.jp, aris@redhat.com, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q Message-ID: <20140704140755.GA3340@pd.tnic> References: <281f09da7ad01e5cea99737ec34d2399bdbbbf63.1403818526.git.jbaron@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <281f09da7ad01e5cea99737ec34d2399bdbbbf63.1403818526.git.jbaron@akamai.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 26, 2014 at 09:58:28PM +0000, Jason Baron wrote: > Even on x86-64, I've found the need to break up a readq() into 2 readl() > calls. According to the Intel datasheet for the E3-1200 processor: > > " > Software must not access B0/D0/F0 32-bit memory-mapped registers with > requests that cross a DW boundary. > " > > (http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html p. 16) > > I can confirm this is true via several hard machine lockups. > > Thus, add explicit hi_lo_[readq|write]_q and lo_hi_[read|write]_q so that these > uses are spelled out. > > Signed-off-by: Jason Baron Applied, thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --