From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 25AFDC433FE for ; Wed, 4 May 2022 21:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=pS8gQTlCYwwnahAUB0EZpVzt5f8PMWXa1kOcXqpA7Xo=; b=W0PQNTxbj0/jcs w6HXPnTA2BMTgxRXPkghNriv0sXvG6ITtZnwB/OzdXqp3ruS+dfJ9CCF5ll30zCPGmmq4fqPW/CLr JvZuVQvwpvCxcWsYC4xfkfUhpiSlu8D6tZXDkmTrsvfnyCV0XrpRqNBI+ZtDFmbFBT0yKWGl/B0Vz eqki4V4pF8O4m8sFsCuqPsMEeMrhZtdKJdxTjUYzcMmCPMDY1/1e5iX4KQZ1UI2MsFVu/Rrkf3ZYp TjpAQJxQah+CvwqyWXyLEW7a1rru1xYWGtlRWsbKpP8UI1r0qNbKLt6KRN83oonQK2bBBrCPMVBXr STZmWXouklgSt9L+sU/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmMEn-00Cimm-W8; Wed, 04 May 2022 21:08:46 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmMEl-00CimD-I0; Wed, 04 May 2022 21:08:44 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DE761616A3; Wed, 4 May 2022 21:08:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F213FC385A4; Wed, 4 May 2022 21:08:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651698522; bh=y1eZ0VyTuh3OSu3SZE5hnm+6Lqgi7WUL9wuM4x9LDoU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=OV+zeMEqAJx67x4OYYs/T+PwaB9EPFjKfNsjZzrWwMVM3NvLvNFpPf0wDtRgV6hPg C/vW0RHXE+D3VHZkPbIlT7vV9H8IzZjwKHGMG7joXJdlZZ7WJg8oDJqQBcpyc4rw/O yxAB78m6HEpQDrzbacEayJr8iiRcV1EWi7mSGZxb5IDhBXSg0dvOB0Jpz0xpdKT8q1 53W71wtG3ZAAJTFq4C2Bw331IYIMqmF+azzr+0ky2kC+20quz/B/hGbW52VPMkvf2m sc7xISbNbAO/Ktfv/RlrnLm3f7ClaHPrrdpfMsEfr0tf1mKOlzAyEBnIbIHem9sEJj ZVekgou/eHQhA== Date: Wed, 4 May 2022 16:08:40 -0500 From: Bjorn Helgaas To: Niklas Schnelle Cc: Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-pci@vger.kernel.org, Arnd Bergmann , Richard Henderson , Ivan Kokshaysky , Matt Turner , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Paul Walmsley , Palmer Dabbelt , Albert Ou , Yoshinori Sato , Rich Felker , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "open list:ALPHA PORT" , "moderated list:ARM PORT" , "open list:IA64 (Itanium) PLATFORM" , "open list:M68K ARCHITECTURE" , "open list:MIPS" , "open list:PARISC ARCHITECTURE" , "open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)" , "open list:RISC-V ARCHITECTURE" , "open list:SUPERH" , "open list:SPARC + UltraSPARC (sparc/sparc64)" Subject: Re: [RFC v2 01/39] Kconfig: introduce HAS_IOPORT option and select it as necessary Message-ID: <20220504210840.GA469916@bhelgaas> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220429135108.2781579-2-schnelle@linux.ibm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220504_140843_705840_56CFAB30 X-CRM114-Status: GOOD ( 13.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 29, 2022 at 03:49:59PM +0200, Niklas Schnelle wrote: > We introduce a new HAS_IOPORT Kconfig option to indicate support for > I/O Port access. In a future patch HAS_IOPORT=n will disable compilation > of the I/O accessor functions inb()/outb() and friends on architectures > which can not meaningfully support legacy I/O spaces such as s390 or > where such support is optional. So you plan to drop inb()/outb() on architectures where I/O port space is optional? So even platforms that have I/O port space may not be able to use it? This feels like a lot of work where the main benefit is to keep Kconfig from offering drivers that aren't of interest on s390. Granted, there may be issues where inb()/outb() does the wrong thing such as dereferencing null pointers when I/O port space isn't implemented. I think that's a defect in inb()/outb() and could be fixed there. Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel