From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 28 Jun 2001 12:03:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 28 Jun 2001 12:03:42 -0400 Received: from smtp1.cern.ch ([137.138.128.38]:47885 "EHLO smtp1.cern.ch") by vger.kernel.org with ESMTP id ; Thu, 28 Jun 2001 12:03:31 -0400 To: David Woodhouse Cc: Alan Cox , dhowells@redhat.com (David Howells), linux-kernel@vger.kernel.org, arjanv@redhat.com Subject: Re: [RFC] I/O Access Abstractions In-Reply-To: <7040.993736538@redhat.com> From: Jes Sorensen Date: 28 Jun 2001 18:02:35 +0200 In-Reply-To: David Woodhouse's message of "Thu, 28 Jun 2001 14:55:38 +0100" Message-ID: User-Agent: Gnus/5.070096 (Pterodactyl Gnus v0.96) Emacs/20.4 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 >>>>> "David" == David Woodhouse writes: David> Having per-resource I/O methods would help us to remove some of David> the cruft which is accumulating in various non-x86 code. Note David> that the below is the _core_ routines for _one_ board - I'm not David> even including the extra indirection through the machine vector David> here.... Have you considered the method used by the 8390 Ethernet driver? For each device, add a pointer to the registers and a register shift. I really don't like hacing virtual access functions that makes memory mapped I/O look the same as I/O operations. For memory mapped I/O you want to be able to smart optimizations to reduce the access on the PCI bus (or similar). Jes