From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755095AbcEQOCA (ORCPT ); Tue, 17 May 2016 10:02:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47128 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751948AbcEQOB6 (ORCPT ); Tue, 17 May 2016 10:01:58 -0400 From: Jes Sorensen To: Greg KH 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 References: <1463470081-24223-1-git-send-email-david.kershner@unisys.com> <20160517135133.GC18227@kroah.com> Date: Tue, 17 May 2016 10:01:55 -0400 In-Reply-To: <20160517135133.GC18227@kroah.com> (Greg KH's message of "Tue, 17 May 2016 06:51:33 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 17 May 2016 14:01:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Jes