Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261242AbVDDOAX (ORCPT ); Mon, 4 Apr 2005 10:00:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261241AbVDDOAX (ORCPT ); Mon, 4 Apr 2005 10:00:23 -0400 Received: from stat16.steeleye.com ([209.192.50.48]:46814 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S261240AbVDDOAN (ORCPT ); Mon, 4 Apr 2005 10:00:13 -0400 Subject: Re: iomapping a big endian area From: James Bottomley To: Benjamin Herrenschmidt Cc: "David S. Miller" , matthew@wil.cx, SCSI Mailing List , Linux Kernel list In-Reply-To: <1112601039.26086.49.camel@gaston> 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> Content-Type: text/plain Date: Mon, 04 Apr 2005 08:59:03 -0500 Message-Id: <1112623143.5813.5.camel@mulgrave> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-2) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1138 Lines: 26 On Mon, 2005-04-04 at 17:50 +1000, Benjamin Herrenschmidt wrote: > I disagree. The driver will never "know" ... ? the driver has to know. Look at the 53c700 to see exactly how awful it is. This beast has byte and word registers. When used BE, all the byte registers alter their position (to both inb and readb). > I don't think it's sane. You know that your device is BE or LE and use > the appropriate interface. "native" doesn't make sense to me in this > context. Well ... it's like this. Native means "pass through without swapping" and has an easy implementation on both BE and LE platforms. Logically io{read,write}{16,32}be would have to do byte swaps on LE platforms. Being lazy, I'm opposed to doing the work if there's no actual use for it, so can you provide an example of a BE bus (or device) used on a LE platform that would actually benefit from this abstraction? James - 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/