From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 6/13] devres: implement managed iomap interface Date: Wed, 09 Apr 2008 00:03:36 +0900 Message-ID: <47FB8948.9090302@gmail.com> References: <11684073371547-git-send-email-htejun@gmail.com> <47FA4FD2.8060808@ru.mvista.com> <47FB85CB.2070506@gmail.com> <47FB8751.3040301@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wf-out-1314.google.com ([209.85.200.170]:3120 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752407AbYDHPDo (ORCPT ); Tue, 8 Apr 2008 11:03:44 -0400 Received: by wf-out-1314.google.com with SMTP id 28so2035633wff.4 for ; Tue, 08 Apr 2008 08:03:44 -0700 (PDT) In-Reply-To: <47FB8751.3040301@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Sergei Shtylyov Cc: jgarzik@pobox.com, gregkh@suse.de, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linuxppc-dev@ozlabs.org Sergei Shtylyov wrote: >> Yeah, right please go ahead. But I wonder whether any BIOS was >> actually crazy enough to map mmio region above 4G on 32bit machine. > > This is a *hardware* mapping on some non-x86 platforms (like PPC 44x > or MIPS Alchemy). The arch/ppc/ and arch/mips/ kernels have special > hooks called from ioremap() which help create an illusion that the PCI > memory space on such platforms (not only it) is mapped below 4 GB; > arch/powerpc/ kernel doesn't do this anymore -- hence this newly > encountered issue. Ah... I see. Thanks for the clarification. -- tejun