From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757328AbaE2Mpg (ORCPT ); Thu, 29 May 2014 08:45:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1408 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756105AbaE2Mpf (ORCPT ); Thu, 29 May 2014 08:45:35 -0400 Date: Thu, 29 May 2014 08:45:20 -0400 From: Vivek Goyal To: Dave Young Cc: matt.fleming@intel.com, bp@alien8.de, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH] export efi.flags to sysfs Message-ID: <20140529124520.GC14570@redhat.com> References: <20140526083935.GA19682@dhcp-16-198.nay.redhat.com> <20140527133411.GG10994@redhat.com> <20140528021359.GC2820@darkstar.nay.redhat.com> <20140528124029.GF14863@redhat.com> <20140529020837.GB2068@darkstar.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140529020837.GB2068@darkstar.nay.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 29, 2014 at 10:08:37AM +0800, Dave Young wrote: > On 05/28/14 at 08:40am, Vivek Goyal wrote: > > On Wed, May 28, 2014 at 10:13:59AM +0800, Dave Young wrote: > > > On 05/27/14 at 09:34am, Vivek Goyal wrote: > > > > On Mon, May 26, 2014 at 04:39:35PM +0800, Dave Young wrote: > > > > > > > > > > For efi=old_map and any old_map quirks like SGI UV in current > > > > > tree kexec/kdump will fail because it depends on the new 1:1 mapping. > > > > > > > > > > Thus export the mapping method to sysfs so kexec tools can switch > > > > > to original way to boot. > > > > > > > > > > Since we have efi.flags for all efi facilities so let's just export the > > > > > efi.flags itself, it maybe useful for other arches and use cases. > > > > > > > > > > > > > Does it require any documentation in Documentation/ABI/.. > > > > > > Yes, it's necessary. Will do in next version. > > > > > > I'm still discussing with Matt, exporting efi.flags seems not a good way > > > because they are more internal interfaces. > > > > > > Probably I should export only a file 'old_map' instead. > > > > How does /sys/firmware/efi/runtime-map/* look like with old mapping? Can't > > we look at it and figure out if it is 1:1 or not. > > There's phys_addr and virt_addr, (virt_addr - phys_addr) will always be > -64G for 1:1 map, ioremapped addresses space is different. I am curious that what's the meaning of 1:1 mapping here? So far I thought that means virt and physical addresses are same but that does not seem to be the case. So what does it mean? Thanks Vivek