From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 1/2] asm-generic/io.h: provide default ioremap/iounmap for !HAS_IOMEM Date: Wed, 30 Mar 2016 08:29:45 -0500 Message-ID: References: <1459275781-3863-1-git-send-email-robh@kernel.org> <6746826.YZLTqKTgkv@wuerfel> <56FB8AC1.4070209@nod.at> <6282729.XLLXSxbzQJ@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <6282729.XLLXSxbzQJ@wuerfel> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: Richard Weinberger , Lee Jones , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , user-mode-linux-devel@lists.sourceforge.net List-Id: linux-arch.vger.kernel.org On Wed, Mar 30, 2016 at 5:03 AM, Arnd Bergmann wrote: > On Wednesday 30 March 2016 10:13:53 Richard Weinberger wrote: >> >> I fully understand your point of view. COMPILE_TEST is a monster that >> can do the heavy lifting for you, but monsters also have claws and fangs. >> >> Having COMPILE_TEST having depend on !UML works for me. But don't >> we have other archs without io mem? At least a few years ago while >> porting nandsim to UML I found s390 that lacks of io mem too. > > s390 gained IOMEM support when they started having PCI attachments. I'm confused how s390 defines HAS_IOMEM and includes it from lib/Kconfig though. > arch/score selects NO_IOMEM, though they do in fact use MMIO, and > I'm sure their architecture has lots of other problems with build > testing that nobody cares about. > > arch/tile can select NO_IOMEM when PCI is disabled, they might > care about this, though I think they also have other build-time > issues. > >> Maybe we depend COMPILE_TEST on HAS_IOMEM? > > That sounds fine with me as well. That or !UML is fine, but I still think we should rid drivers from depending on HAS_IOMEM. We probably still have cases where the only dependency besides the driver's subsystem is HAS_IOMEM. Rob From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:48484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751379AbcC3NaK (ORCPT ); Wed, 30 Mar 2016 09:30:10 -0400 MIME-Version: 1.0 In-Reply-To: <6282729.XLLXSxbzQJ@wuerfel> References: <1459275781-3863-1-git-send-email-robh@kernel.org> <6746826.YZLTqKTgkv@wuerfel> <56FB8AC1.4070209@nod.at> <6282729.XLLXSxbzQJ@wuerfel> From: Rob Herring Date: Wed, 30 Mar 2016 08:29:45 -0500 Message-ID: Subject: Re: [PATCH 1/2] asm-generic/io.h: provide default ioremap/iounmap for !HAS_IOMEM Content-Type: text/plain; charset=UTF-8 Sender: linux-arch-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: Richard Weinberger , Lee Jones , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , user-mode-linux-devel@lists.sourceforge.net Message-ID: <20160330132945.Ij6R2uj2I8uZleHFKRM8qhsCiUt1ghOPQ2cbDJvZU8Y@z> On Wed, Mar 30, 2016 at 5:03 AM, Arnd Bergmann wrote: > On Wednesday 30 March 2016 10:13:53 Richard Weinberger wrote: >> >> I fully understand your point of view. COMPILE_TEST is a monster that >> can do the heavy lifting for you, but monsters also have claws and fangs. >> >> Having COMPILE_TEST having depend on !UML works for me. But don't >> we have other archs without io mem? At least a few years ago while >> porting nandsim to UML I found s390 that lacks of io mem too. > > s390 gained IOMEM support when they started having PCI attachments. I'm confused how s390 defines HAS_IOMEM and includes it from lib/Kconfig though. > arch/score selects NO_IOMEM, though they do in fact use MMIO, and > I'm sure their architecture has lots of other problems with build > testing that nobody cares about. > > arch/tile can select NO_IOMEM when PCI is disabled, they might > care about this, though I think they also have other build-time > issues. > >> Maybe we depend COMPILE_TEST on HAS_IOMEM? > > That sounds fine with me as well. That or !UML is fine, but I still think we should rid drivers from depending on HAS_IOMEM. We probably still have cases where the only dependency besides the driver's subsystem is HAS_IOMEM. Rob