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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 F30A0C54FD0 for ; Wed, 25 Mar 2020 09:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D41262077D for ; Wed, 25 Mar 2020 09:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727606AbgCYJyi (ORCPT ); Wed, 25 Mar 2020 05:54:38 -0400 Received: from verein.lst.de ([213.95.11.211]:40008 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726225AbgCYJyi (ORCPT ); Wed, 25 Mar 2020 05:54:38 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id AEB4368AFE; Wed, 25 Mar 2020 10:54:35 +0100 (CET) Date: Wed, 25 Mar 2020 10:54:35 +0100 From: Christoph Hellwig To: Fredrik Noring Cc: Christoph Hellwig , "Maciej W. Rozycki" , Thomas Bogendoerfer , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] MIPS: remove cpu_has_64bit_gp_regs and cpu_has_64bit_addresses Message-ID: <20200325095435.GA27807@lst.de> References: <20200324161525.754181-1-hch@lst.de> <20200324161525.754181-2-hch@lst.de> <20200325083012.GA21605@lst.de> <20200325085524.GA28706@sx9> <20200325085852.GA23786@lst.de> <20200325092446.GB28706@sx9> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200325092446.GB28706@sx9> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 25, 2020 at 10:24:46AM +0100, Fredrik Noring wrote: > > > The (slightly outdated) patch series under review > > > is available here: > > > > > > https://lore.kernel.org/linux-mips/cover.1567326213.git.noring@nocrew.org/T/ > > > > You don't happen to have a git tree available somewhere? > > https://github.com/frno7/linux/tree/ps2-v5.4 > > is stable at v5.4, > > https://github.com/frno7/linux/tree/ps2-master > > has more experimental stuff (also at v5.4 at the moment). There are some > (work-in-progress) notes on the R5900 psABI, that may be of interest, here: > > https://github.com/frno7/linux/wiki/R5900-processor-specific-ABI-(psABI) So from what I can tell this uses a 32-bit kernel and 32-bit userspace, and sets both pu_has_64bit_gp_regs and cpu_has_64bit_addresses to 0. Now if you ever wanted to make use of the 64-bit registeres it would require quite some changes, which probably really should have a new Kconfig option. In fact a lot of the workaround for the 64-bit registeres that are in the code already should be keyed off such an option rather than CONFIG_CPU_R5900.