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 X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04017C433F4 for ; Fri, 21 Sep 2018 06:09:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B107C21531 for ; Fri, 21 Sep 2018 06:09:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="dc2q6qoq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B107C21531 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389302AbeIUL5O (ORCPT ); Fri, 21 Sep 2018 07:57:14 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:47368 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388944AbeIUL5O (ORCPT ); Fri, 21 Sep 2018 07:57:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Transfer-Encoding :Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=cg03QiRjf+HUQPKf/1TFGUUl54s7S7du4g8XL+t6vRk=; b=dc2q6qoqIxXBTE9q6iHSZxC8fR L2vj/KvmnIDkDtqwbwObTedmdHm3RyBP7J+FiXkATIqzjeITQejJpjy2Cp6xHFHN//AFXQB8pORUi +qUAkfLC+9AIEdw5r39uOVrf+ng0J3wwU7v9fiseqtjPSEHOjiM6Fpt1N1EaROP5qvy7YpSDFJtSw NcCO4/G42OVfq+YXydx3/3HZJffEQiGYsV8yR9ZBOlWUn8l3mfjZPUcM2w3tZjeHBfj941+o9cMCZ dFa+UDOsrsHn1Bx72snk6HTHx6dYsXCW4s98nO67BVygNZ1Bh+Mn2MCBYW1y1o6Gzr13GzqJ6J4Ed ZZotdvBQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1g3EdJ-00026K-EN; Fri, 21 Sep 2018 06:09:41 +0000 Date: Thu, 20 Sep 2018 23:09:41 -0700 From: Christoph Hellwig To: Paul Burton Cc: Arnd Bergmann , Firoz Khan , Hauke Mehrtens , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , "open list:RALINK MIPS ARCHITECTURE" , Ralf Baechle , James Hogan , gregkh , Philippe Ombredanne , Thomas Gleixner , Kate Stewart , y2038 Mailman List , Linux Kernel Mailing List , linux-arch , Deepa Dinamani , Marcin Juszkiewicz Subject: Re: [PATCH 0/3] System call table generation support Message-ID: <20180921060941.GB13865@infradead.org> References: <1536914314-5026-1-git-send-email-firoz.khan@linaro.org> <20180917171720.wda5qrl7hyyacmwl@pburton-laptop> <20180920204833.gpypjjxcmxjupls6@pburton-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180920204833.gpypjjxcmxjupls6@pburton-laptop> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 20, 2018 at 08:48:37PM +0000, Paul Burton wrote: > > Speaking of nanoMIPS, what is your plan for the syscall ABI there? > > I can see two ways of approaching it: > > > > a) keep all the MIPSisms in the data structures, and just use a subset of > > o32 that drops all the obsolete entry points > > b) start over and stay as close as possible to the generic ABI, using the > > asm-generic versions of both the syscall table and the uapi header > > files instead of the traditional version. > > We've taken option b in our current downstream kernel & that's what I > hope we'll get upstream too. There's no expectation that we'll ever need > to mix pre-nanoMIPS & nanoMIPS ISAs or their associated ABIs across the > kernel/user boundary so it's felt like a great opportunity to clean up & > standardise. > > Getting nanoMIPS/p32 support submitted upstream is on my to-do list, but > there's a bunch of prep work to get in first & of course that to-do list > is forever growing. Hopefully in the next couple of cycles. p32 is just the ABI name for nanoMIPS or yet another MIPS ABI? Either way, І think if there is yet another ABI even on an existing port we should always aim for the asm-generic syscall table indeed. Especially for mips where o32 has a rather awkward ABI only explained by odd decisions more than 20 years ago.