From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751958AbXBBLH6 (ORCPT ); Fri, 2 Feb 2007 06:07:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751981AbXBBLH6 (ORCPT ); Fri, 2 Feb 2007 06:07:58 -0500 Received: from srv5.dvmed.net ([207.36.208.214]:47533 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751958AbXBBLH5 (ORCPT ); Fri, 2 Feb 2007 06:07:57 -0500 Message-ID: <45C31B86.6070009@garzik.org> Date: Fri, 02 Feb 2007 06:07:50 -0500 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.9 (X11/20061219) MIME-Version: 1.0 To: "H. Peter Anvin" CC: "Michael K. Edwards" , Linux Kernel List Subject: Re: Should io(read|write)(8|16|32)_rep take (const|) volatile u(8|16|32) __iomem *addr? References: <45C2D47A.9080001@garzik.org> <45C2DA8D.4050007@zytor.com> In-Reply-To: <45C2DA8D.4050007@zytor.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.7 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org H. Peter Anvin wrote: > Jeff Garzik wrote: >> Volatile is usually reserved for a specific need on a specific arch. >> I doubt it is correct to force it on all arches. > > They already are volatile; the issue is adding "const". > > All io(read|write)* pointers are volatile, IIRC. No, none are volatile, hence my comment. > [jgarzik@pretzel linux-2.6]$ grep volatile lib/iomap.c include/asm-generic/iomap.h > [jgarzik@pretzel linux-2.6]$ Maybe you were thinking about writel() and friends, whose implementation (not prototype!) includes use of volatile. Regards, Jeff