From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753949AbaE1VmQ (ORCPT ); Wed, 28 May 2014 17:42:16 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42155 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751132AbaE1VmP (ORCPT ); Wed, 28 May 2014 17:42:15 -0400 Message-ID: <53865820.7010309@zytor.com> Date: Wed, 28 May 2014 14:41:52 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Arnd Bergmann , josh@joshtriplett.org CC: Greg Kroah-Hartman , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH] drivers/char/mem.c: Add /dev/ioports, supporting 16-bit and 32-bit ports References: <20140509191914.GA7286@jtriplet-mobl1> <53729873.2030805@zytor.com> <20140515215646.GA16326@cloud> <63645237.lSKEVJUKkQ@wuerfel> In-Reply-To: <63645237.lSKEVJUKkQ@wuerfel> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/19/2014 05:36 AM, Arnd Bergmann wrote: > > My feeling is that all devices we can think of fall into at least one > of these categories: > > * legacy PC stuff that needs only byte access > * PCI devices that can be accessed through sysfs > * devices on x86 that can be accessed using iopl > I don't believe PCI I/O space devices can be accessed through sysfs, but perhaps I'm wrong? (mmapping I/O space is not portable.) -hpa