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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 DF701C07E9B for ; Tue, 6 Jul 2021 13:38:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C673E619D4 for ; Tue, 6 Jul 2021 13:38:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231872AbhGFNlS (ORCPT ); Tue, 6 Jul 2021 09:41:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231838AbhGFNlS (ORCPT ); Tue, 6 Jul 2021 09:41:18 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBFD1C061574 for ; Tue, 6 Jul 2021 06:38:39 -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=WyUN3WjTwtguxoOsNeOjyV8R5q/61vt5UcBCdQn0DOk=; b=U1lZuUYgZl67UD/ilk8wT4wrGQ De9sdtxCnJLV4s+BgM95TwJKHdeyVMJVUGN+qUlwvJU0W2AiyK4qTSzKFBA7fT3/1pHu98oVHw+lD 5vDQIhL+vI50DAJ9nrQ7Dn48u3BqCc12Zs973IOoljFXfr1gl3J+KloNqyhMt/8OpzolSvP7wRIeT cvBO5iVR8WbJ/vf8DIVDeVu6zM/ZYA0snFE76HoPhMi1Z4R6kqDKK7/JOkMv9EsE9sGMeCbuwU1WK YnL+aU8hTO+539umDWTqc4cYH5OzlPCopdych0ep62i1bmdvbvws8ziqvHqxqL6GB7tkb+NXELv9G Bwk3j7tw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0lGv-00BQal-T7; Tue, 06 Jul 2021 13:38:00 +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 (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id F3D2A300233; Tue, 6 Jul 2021 15:37:55 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DE963200E6658; Tue, 6 Jul 2021 15:37:55 +0200 (CEST) Date: Tue, 6 Jul 2021 15:37:55 +0200 From: Peter Zijlstra To: Arnd Bergmann Cc: Huacai Chen , Andy Lutomirski , Thomas Gleixner , Andrew Morton , David Airlie , Linus Torvalds , linux-arch , Xuefeng Li , Huacai Chen , Jiaxun Yang Subject: Re: [PATCH 04/19] LoongArch: Add common headers Message-ID: References: <20210706041820.1536502-1-chenhuacai@loongson.cn> <20210706041820.1536502-5-chenhuacai@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Tue, Jul 06, 2021 at 02:59:22PM +0200, Arnd Bergmann wrote: > The specific registers are documented at > https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN#control-and-status-registers Urrrgghhh.... the AMOs are not only fully sequentially consistent, they're specified to be completion barriers. That seems horrifically expensive. Also, AFAICT there is no forward progress specified for LL/SC :/