From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753928AbcERAEG (ORCPT ); Tue, 17 May 2016 20:04:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:40391 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753008AbcERAEB (ORCPT ); Tue, 17 May 2016 20:04:01 -0400 Date: Tue, 17 May 2016 17:03:59 -0700 From: Greg KH To: Jes Sorensen Cc: David Kershner , corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, erik.arfvidson@unisys.com, timothy.sell@unisys.com, hofrat@osadl.org, dzickus@redhat.com, alexander.curtin@unisys.com, janani.rvchndrn@gmail.com, sudipm.mukherjee@gmail.com, prarit@redhat.com, david.binder@unisys.com, nhorman@redhat.com, dan.j.williams@intel.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, driverdev-devel@linuxdriverproject.org, sparmaintainer@unisys.com Subject: Re: [PATCH 0/5] add bus driver for Unisys s-Par paravirtualized devices to arch/x86 Message-ID: <20160518000359.GA325@kroah.com> References: <1463470081-24223-1-git-send-email-david.kershner@unisys.com> <20160517135133.GC18227@kroah.com> <20160517142735.GA19617@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 17, 2016 at 07:49:53PM -0400, Jes Sorensen wrote: > Greg KH writes: > > On Tue, May 17, 2016 at 10:01:55AM -0400, Jes Sorensen wrote: > >> Greg KH writes: > >> > On Tue, May 17, 2016 at 03:27:56AM -0400, David Kershner wrote: > >> >> This patchset moves the visorbus driver > >> >> (fromdrivers/staging/unisys/visorbus) > >> >> and its dependent headers files (from drivers/staging/unisys/include) > >> >> out of staging into the main kernel tree. > >> >> > >> >> The visorbus driver is a bus driver for various paravirtualized devices > >> >> presented within a Unisys s-Par guest environment. Drivers for these > >> >> devices are also currently present under drivers/staging/unisys/, which we > >> >> intend to also move out of staging immediately after visorbus. All of > >> >> these other drivers are dependent upon visorbus and the include directory, > >> >> which is why we would like to move these first. > >> >> > >> >> Our initial consultations with various members of the community have led us > >> >> to the conclusion that the most appropriate locations for these is: > >> >> arch/x86/visorbus/ (driver) > >> >> include/linux/visorbus/ (header files) > >> >> > >> >> The rationale is that visorbus is dependent on x86-64 architecture. > >> > > >> > What makes it dependent on x86? What prevents it from running on some > >> > other architecture (not the fact that no one has made such hardware, > >> > just the code reasons please.) > >> > >> It's dependent on system firmware which is only available on the S-Par > >> platform which is x86_64 only. The closest similarity is probably what > >> you find on the PPC and Sparc platforms. > > > > Ok, but still no need to put it under arch/ anything, it should go in > > drivers/ like all other drivers and busses are, no matter what the arch > > it happens to run on is. > > I don't think thats obvious. arch/x86/kvm is an example of this, Sparc > and PPC also have their stuff under arch/. For some things, yes, but let's not make the same mistakes as others :) Look at drivers/hv/ for an example of a very x86-only bus and driver subsystem living in drivers/ Please don't burry driver stuff in arch/ the ARM developers are trying to fix their mistakes of the past and move all of their cruft out of arch/ for that reason. thanks, greg k-h