From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from yw-out-2324.google.com (yw-out-2324.google.com [74.125.46.30]) by ozlabs.org (Postfix) with ESMTP id 1B573DDE2A for ; Wed, 9 Apr 2008 01:03:55 +1000 (EST) Received: by yw-out-2324.google.com with SMTP id 3so360131ywj.39 for ; Tue, 08 Apr 2008 08:03:44 -0700 (PDT) Message-ID: <47FB8948.9090302@gmail.com> Date: Wed, 09 Apr 2008 00:03:36 +0900 From: Tejun Heo MIME-Version: 1.0 To: Sergei Shtylyov Subject: Re: [PATCH 6/13] devres: implement managed iomap interface References: <11684073371547-git-send-email-htejun@gmail.com> <47FA4FD2.8060808@ru.mvista.com> <47FB85CB.2070506@gmail.com> <47FB8751.3040301@ru.mvista.com> In-Reply-To: <47FB8751.3040301@ru.mvista.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev@ozlabs.org, gregkh@suse.de, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, jgarzik@pobox.com, alan@lxorguk.ukuu.org.uk List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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