From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 4 Sep 2001 13:05:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 4 Sep 2001 13:05:39 -0400 Received: from d12lmsgate-2.de.ibm.com ([195.212.91.200]:49604 "EHLO d12lmsgate-2.de.ibm.com") by vger.kernel.org with ESMTP id ; Tue, 4 Sep 2001 13:05:27 -0400 Importance: Normal Subject: Re: [SOLVED + PATCH]: documented Oops running big-endian reiserfs on parisc architecture To: John Alvord Cc: Jeff Mahoney , Andi Kleen , linux-kernel@vger.kernel.org X-Mailer: Lotus Notes Release 5.0.3 (Intl) 21 March 2000 Message-ID: From: "Ulrich Weigand" Date: Tue, 4 Sep 2001 19:04:37 +0200 X-MIMETrack: Serialize by Router on D12ML028/12/M/IBM(Release 5.0.8 |June 18, 2001) at 04/09/2001 19:04:42 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 John Alvord wrote: >> It is only *atomic* accesses (those implemented using the S/390 >> compare-and-swap instruction) that need to be word aligned; this includes >> the atomic bit operations that reiserfs appears to be using. > >Aren't their some other "must align" instructions like CVB? Or have they >all been relaxed... CVB doesn't have any alignment requirement (I'm not sure it ever had one). Execpt for the 'atomic' operations (CS, CSG, CDS, CDSG, LPQ, STPQ, PLO) I know only of two general-purpose instructions with operand alignment requirement, and that's LAM and STAM. As access registers are not normally used in Linux this shouldn't be a problem. There *is* a whole bunch of privileged system instructions that have various aligment requirements; but here I'd say it's fair to require the user to provide correct aligment in these special cases. Mit freundlichen Gruessen / Best Regards Ulrich Weigand -- Dr. Ulrich Weigand Linux for S/390 Design & Development IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen Phone: +49-7031/16-3727 --- Email: Ulrich.Weigand@de.ibm.com