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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0275EC77B73 for ; Fri, 19 May 2023 00:38:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230339AbjESAi4 (ORCPT ); Thu, 18 May 2023 20:38:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229493AbjESAiy (ORCPT ); Thu, 18 May 2023 20:38:54 -0400 Received: from mail-il1-x135.google.com (mail-il1-x135.google.com [IPv6:2607:f8b0:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C027115 for ; Thu, 18 May 2023 17:38:53 -0700 (PDT) Received: by mail-il1-x135.google.com with SMTP id e9e14a558f8ab-3352b8b9b70so972635ab.0 for ; Thu, 18 May 2023 17:38:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1684456732; x=1687048732; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=7/jPM0KnH+FwZjtmXcaKFjOjxDtUtKIRA4syAmgc008=; b=fmjVDjbt+kVlfJJwbXQK46gG++Iuw6KXHsivhDuvDS1k3OJpQOQpec2T2c0ma/iqQN 9WeSajyeQsFTZLYH+IeZpzrbcJzTbvXie0lgLosHMSjhrMgYpvYY00G4EHMPgrvi/Iu7 tenMCSZl7X6Sx3vKHFEsDse1sK6aOo9BlIjqXMsUfRbjFkGXnAzDm9lEdyUKq9mlWbah zASFPie7alKP0oNfedYyG7FvDteT1lmEtAWg4J3HHFpfWvz6xut2TzwAIjl2xAf9qhFd ud+gIUTwV59X4gLBAG8ikBAGXop4+zMT79TM2ItusYqCkJffT4YMR2Qhr2yOj532k4Uo p0WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684456732; x=1687048732; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7/jPM0KnH+FwZjtmXcaKFjOjxDtUtKIRA4syAmgc008=; b=XryiMQcSzFsDGrOBhRoDkZwjB4EK8j6Aiscs1gkRYkkqNnoA4lJ4F04xjuyLYPcf3U Jycc1x3fcP3rf34H5BOrvaffghGvPJoW1OqMHDaOUuWgmy8atfLpyiB5sHZ7fL7ZiIGA Ull5G/nIbY86CYtEO2VglICz8F8ZKjNCaFcVddTO+ODeHXcc4vFJN8VU+ukgkRggcIu0 hVX7o4WgiZA+XZBGH+/aueGH0RzWyTEtPBcynR4KnX4m4YPxqXN83QCcrGQrR8g8g+vN BtHCML3ouNPCwuRdFC4unPeMfIN5r2RyiL/zNMcl0POYFgZ72NPJnRmKcNe6/UTra6l/ IeGQ== X-Gm-Message-State: AC+VfDzaKl+L52yTWSH2sxkRGFSotIUGJOyuYn1dClQ5KOTnyNhyIG6g 8oBgZvZELZR3476cJjt6LmliPA== X-Google-Smtp-Source: ACHHUZ5LcaA26lj0MuLputKQFfYR1Y7nG2KPFDIiKERvOLPuxhn7bS0bUuvXzticQqEP+j2ZkW7d9w== X-Received: by 2002:a92:c707:0:b0:335:8542:440c with SMTP id a7-20020a92c707000000b003358542440cmr530202ilp.12.1684456732398; Thu, 18 May 2023 17:38:52 -0700 (PDT) Received: from localhost (c-98-32-39-159.hsd1.nm.comcast.net. [98.32.39.159]) by smtp.gmail.com with ESMTPSA id m20-20020a92c534000000b00337b078ce44sm669216ili.0.2023.05.18.17.38.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 May 2023 17:38:51 -0700 (PDT) Date: Thu, 18 May 2023 17:38:50 -0700 (PDT) From: Paul Walmsley To: Arnd Bergmann cc: Palmer Dabbelt , guoren , Thomas Gleixner , Peter Zijlstra , Andy Lutomirski , "Conor.Dooley" , =?ISO-8859-15?Q?Heiko_St=FCbner?= , Jisheng Zhang , Huacai Chen , Anup Patel , Atish Patra , Mark Rutland , =?ISO-8859-15?Q?Bj=F6rn_T=F6pel?= , Catalin Marinas , Will Deacon , Mike Rapoport , Anup Patel , shihua@iscas.ac.cn, jiawei@iscas.ac.cn, liweiwei@iscas.ac.cn, luxufan@iscas.ac.cn, chunyu@iscas.ac.cn, tsu.yubo@gmail.com, wefu@redhat.com, wangjunqiang@iscas.ac.cn, kito.cheng@sifive.com, Andy Chiu , Vincent Chen , Greentime Hu , Jonathan Corbet , wuwei2016@iscas.ac.cn, Jessica Clarke , Linux-Arch , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Guo Ren Subject: Re: [RFC PATCH 00/22] riscv: s64ilp32: Running 32-bit Linux kernel on 64-bit supervisor mode In-Reply-To: <556bebad-3150-4fd5-8725-e4973fd6edd1@app.fastmail.com> Message-ID: <454dede3-5f20-74fc-975a-e11e4d8b5648@sifive.com> References: <556bebad-3150-4fd5-8725-e4973fd6edd1@app.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 18 May 2023, Arnd Bergmann wrote: > We have had long discussions about supporting ilp32 userspace on > arm64, and I think almost everyone is glad we never merged it into > the mainline kernel, so we don't have to worry about supporting it > in the future. The cost of supporting an extra user space ABI > is huge, and I'm sure you don't want to go there. The other two > cited examples (mips-n32 and x86-x32) are pretty much unused now > as well, but still have a maintenance burden until they can finally > get removed. There probably hasn't been much pressure to support Aarch64 ILP32 since ARM still has hardware support for Aarch32. Will be interesting to see if that's still the case after ARM drops Aarch32 support for future designs. - Paul