Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261263AbVDDQBm (ORCPT ); Mon, 4 Apr 2005 12:01:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261264AbVDDQBm (ORCPT ); Mon, 4 Apr 2005 12:01:42 -0400 Received: from alog0386.analogic.com ([208.224.222.162]:64968 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S261263AbVDDQBk (ORCPT ); Mon, 4 Apr 2005 12:01:40 -0400 Date: Mon, 4 Apr 2005 12:00:34 -0400 (EDT) From: "Richard B. Johnson" Reply-To: linux-os@analogic.com To: David Vrabel cc: James Bottomley , Benjamin Herrenschmidt , "David S. Miller" , matthew@wil.cx, Linux Kernel list Subject: Re: iomapping a big endian area In-Reply-To: <42516034.7000802@arcom.com> Message-ID: References: <1112475134.5786.29.camel@mulgrave> <20050403013757.GB24234@parcelfarce.linux.theplanet.co.uk> <20050402183805.20a0cf49.davem@davemloft.net> <20050403031000.GC24234@parcelfarce.linux.theplanet.co.uk> <1112499639.5786.34.camel@mulgrave> <20050402200858.37347bec.davem@davemloft.net> <1112502477.5786.38.camel@mulgrave> <1112601039.26086.49.camel@gaston> <1112623143.5813.5.camel@mulgrave> <42516034.7000802@arcom.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1322 Lines: 35 On Mon, 4 Apr 2005, David Vrabel wrote: > James Bottomley wrote: >> so can you provide an example of a BE bus (or device) used on a LE >> platform that would actually benefit from this abstraction? > > The Network Processing Engines in the Intel IXP425 are big-endian and > its XScale core may be run in little-endian mode. There's a bunch of > gotchas related to running in little-endian mode so you typically run > the IXP425 in big-endian mode, though. > But the Linux interface (on the CPU side of the PCI bus interface) doesn't care about the implimentation details in the XScale Core. That's why it's a complete subsystem, isolated from the ix86 by the PCI/Bus interface. > David Vrabel > -- > David Vrabel, Design Engineer > > Arcom, Clifton Road Tel: +44 (0)1223 411200 ext. 3233 > Cambridge CB1 7EA, UK Web: http://www.arcom.com/ Cheers, Dick Johnson Penguin : Linux version 2.6.11 on an i686 machine (5537.79 BogoMips). Notice : All mail here is now cached for review by Dictator Bush. 98.36% of all statistics are fiction. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/