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 220D4CAC5A8 for ; Fri, 19 Sep 2025 21:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=A1AYJz8YUP/Vhoxa5GdJssOAmcvIGIVOWPwZrgxTxwQ=; b=AcCnN1Y9nIJOitnc+la1r3959t 3GVLnCXwLfO5IZ21iKWA4rDllNgyLi5Ys4MlU5KxBSRQ0BNnyRyP8TbY5wXmB8WYw9gDN6yPDrBSe 7TjgXXvICMzPHJ04pEDqu1a7POC1q0tAKwxTKOGJ66c6muICYxlM5ZCd1+C+uuzt1+I+LG/Ga/s2y iQwzZsR5blgmkDxKOykkSedeDGZXxvZrzW58cgC8tUsMMGfiysYy1s/yrZ7qcgMM7YDduyG1O4Eqb PP8sw9ySg/pO37v4MjM/JK/wgOj3gVuI5e4AED1iMF6M3Djq/X1/6P7E+V2mUREAAA2F7gSFqwp+x Mesba1Qw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uziMv-000000043KI-0kp2; Fri, 19 Sep 2025 21:10:13 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uziMs-000000043Il-1CXD for linux-arm-kernel@lists.infradead.org; Fri, 19 Sep 2025 21:10:11 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 22E8E44F92; Fri, 19 Sep 2025 21:10:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73254C4CEF0; Fri, 19 Sep 2025 21:10:06 +0000 (UTC) Date: Fri, 19 Sep 2025 22:10:04 +0100 From: Catalin Marinas To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , Ard Biesheuvel , Arnd Bergmann , Hanjun Guo , Jonathan Cameron , Guenter Roeck Subject: Re: [PATCH] arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN Message-ID: References: <20250919184025.15416-1-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250919184025.15416-1-will@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250919_141010_351452_1939DE95 X-CRM114-Status: GOOD ( 14.56 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Sep 19, 2025 at 07:40:25PM +0100, Will Deacon wrote: > Big-endian arm64 configurations are vanishingly rare, yet we still claim > to support them in Linux despite very limited testing or visible > interest. Supporting big-endian adds unnecessary burden to reviewers and > contributors which, without any known active users, is hard to justify. > For example, recent work to improve our futex routines and to implement > nested virtualisation support is non-trivially complicated by having to > support both big- and little-endianness. > > Back in 2019 [1], it was claimed that Huawei were using arm64 big-endian > machines in their telecommunication products but I don't know whether > that's still the case and certainly haven't seen any patch contributions > to help support or maintain it. > > Make CPU_BIG_ENDIAN depend on BROKEN as an initial deprecation step > towards its removal. > > Cc: Catalin Marinas > Cc: Marc Zyngier > Cc: Ard Biesheuvel > Cc: Arnd Bergmann > Cc: Hanjun Guo > Cc: Jonathan Cameron > Cc: Guenter Roeck > Link: https://lore.kernel.org/linux-arm-kernel/73701e9f-bee1-7ae8-2277-7a3576171cd4@huawei.com/ [1] > Signed-off-by: Will Deacon Acked-by: Catalin Marinas