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 4D58CC7EE2C for ; Wed, 24 May 2023 09:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230402AbjEXJlB (ORCPT ); Wed, 24 May 2023 05:41:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229884AbjEXJkp (ORCPT ); Wed, 24 May 2023 05:40:45 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42957E4B; Wed, 24 May 2023 02:40:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+7rsgv7m8GCnzFvm19d5DgMqjyzShFESP6prEZ6wJl0=; b=KHb/vRVq9nPWkyfrDVNCJCbRnU r02TvBlK6AG32SCrGO3KSNfCQvZa6N5eizVD6/ZBLpDNCLMKfuMfrS4hduHPYAbyOmmbEzebI/piP ICAizbPhwdM/CwYkH1nxdI5vtyJFFJAFJRvdE4VUHuj9KnBcC1pt4YWa9bkYDrt6ffrCo7dZPG5fd n4XHfnYBqz1dbZcOQ2RKg9i1j8/RoKwozKZOPL2GaDvLeog3nVR8gjCA49TA9Zs81ZN3qdHSggcl/ mOgvg9GjEuf3ThX5Adu5GGG/Vg2xvMQR9OkTo2+c422YYvnUI+qRsLMg6rxL9hiD+0gC7iLGyo4xD QiQO7D7A==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1q1kyC-00B4OS-Rp; Wed, 24 May 2023 09:39:48 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7126D3002C5; Wed, 24 May 2023 11:39:47 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4112D241F8382; Wed, 24 May 2023 11:39:47 +0200 (CEST) Date: Wed, 24 May 2023 11:39:47 +0200 From: Peter Zijlstra To: Arnd Bergmann Cc: Linus Torvalds , Jonathan Corbet , Will Deacon , Boqun Feng , Mark Rutland , Catalin Marinas , dennis@kernel.org, Tejun Heo , Christoph Lameter , Heiko Carstens , gor@linux.ibm.com, Alexander Gordeev , borntraeger@linux.ibm.com, Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Joerg Roedel , suravee.suthikulpanit@amd.com, Robin Murphy , David Woodhouse , Baolu Lu , Herbert Xu , "David S . Miller" , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, iommu@lists.linux.dev, Linux-Arch , linux-crypto@vger.kernel.org, mpe@ellerman.id.au Subject: Re: [PATCH v3 00/11] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Message-ID: <20230524093947.GQ83892@hirez.programming.kicks-ass.net> References: <20230515075659.118447996@infradead.org> <4975b92f-92f6-4d50-8386-9add12ddfd61@app.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4975b92f-92f6-4d50-8386-9add12ddfd61@app.fastmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Mon, May 15, 2023 at 11:42:23AM +0200, Arnd Bergmann wrote: > The need for runtime feature checking in the callers on x86-64 is still > a bit awkward, but this is no worse than before. I understand that > turning this into a compile-time choice would require first settling > a larger debate about raising the default target for distros beyond > the current CONFIG_GENERIC_CPU. Looks like Power is going to be in the same boat, they can do cmpxchg128, but only for Power8+.