From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH] Prevent reserving RAM in the region already reserved by BIOS Date: Wed, 19 May 2010 16:00:43 -0700 Message-ID: <4BF46D9B.4090806@zytor.com> References: <4BF42296.1030905@oracle.com> <4BF4235D.3080904@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:54406 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891Ab0ESXBf (ORCPT ); Wed, 19 May 2010 19:01:35 -0400 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Mathieu Rondonneau Cc: Yinghai , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Ingo Molnar , Linus Torvalds On 05/19/2010 03:58 PM, Mathieu Rondonneau wrote: > Thanks for the feedback. > > No, I don' t see any changes in the /proc/iomem. > > I am trying to prevent a ioremap of a 4K size on a non aligned 4K > address that is below the ISA_START_ADDRESS. > > The problem generates a oops about overlapping. > I have a fix which instruct to not to do any re-map if the section > name is "reserved". > Which is not really clean. > I am looking for a clean way to tell the ioremap function to not remap > bios reserved memory. > That' s why I thought the e820 would be a good start. > > I will continue looking into this. It does not crash the systems. A > warning generates the oops. > Why are you mapping a fixed-address in ISA space to begin with? Requests to a fixed address (as opposed to dynamic allocation) have to be granted even in reserved space -- after all, that's what the address might be reserved for! -hpa