From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.sh.mvista.com (unknown [63.81.120.155]) by ozlabs.org (Postfix) with ESMTP id EF505DDF5A for ; Fri, 11 Apr 2008 04:25:37 +1000 (EST) Message-ID: <47FE5B76.40409@ru.mvista.com> Date: Thu, 10 Apr 2008 22:24:54 +0400 From: Sergei Shtylyov MIME-Version: 1.0 To: Kumar Gala 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> <47FE46AC.5000901@ru.mvista.com> <59A939C7-75AF-4C0F-8199-4C31D174AEA9@kernel.crashing.org> In-Reply-To: <59A939C7-75AF-4C0F-8199-4C31D174AEA9@kernel.crashing.org> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Tejun Heo , linux-ide@vger.kernel.org, gregkh@suse.de, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.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: , Kumar Gala wrote: >>>>> Those functions are going to break on 32-bit platforms with >>>>> extended physical address (well, that's starting with Pentiums >>>>> which had 36-bit PAE :-) AND devices mapped beyond 4 GB (e.g. >>>>> PowerPC 44x). You should have used resource_size_t for the >>>>> 'offset' parameter. As this most probably means that libata is >>>>> broken on such platforms, I'm going to submit a patch... >>> It's broken with drivers using MMIO, I meant to say. >> Oops, I meant PCI drivers here, at least for the time being. And it >> looks like that was a false alarm. :-] >>>> 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. >> I thought that pcim_iomap() used devm_ioremap() or something -- >> which of course turned to be wrong. devm_ioremap() alone is yet safe >> since there are no users for it amongst PPC 44x platform device >> drivers... > but there is no reason not to make it work properly. For example I > believe libata uses devm_* and the fsl SATA driver (non-PCI) will need > to work in cases similar to the 44x. Well, as for sata_fsl, it calls of_iomap() which does The Right Thing. > - k WBR, Sergei