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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6EDB5C2D0A3 for ; Mon, 9 Nov 2020 12:42:49 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4764520659 for ; Mon, 9 Nov 2020 12:42:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4764520659 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CV9cy3xkGzDqLy for ; Mon, 9 Nov 2020 23:42:42 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4CV9Ws3k5NzDqNj for ; Mon, 9 Nov 2020 23:38:12 +1100 (AEDT) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 0A9CY4kY014413; Mon, 9 Nov 2020 06:34:05 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 0A9CY3EW014410; Mon, 9 Nov 2020 06:34:03 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 9 Nov 2020 06:34:03 -0600 From: Segher Boessenkool To: Gabriel Paubert Subject: Re: [PATCH] powerpc: add compile-time support for lbarx, lwarx Message-ID: <20201109123403.GH2672@gate.crashing.org> References: <20201107032328.2454582-1-npiggin@gmail.com> <20201107071213.GA30735@lt-gp.iram.es> <0810564117125.202011.20201107114257.GG2672@gate.crashing.org> <20201108200152.GA16446@lt-gp.iram.es> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201108200152.GA16446@lt-gp.iram.es> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sun, Nov 08, 2020 at 09:01:52PM +0100, Gabriel Paubert wrote: > On Sat, Nov 07, 2020 at 05:42:57AM -0600, Segher Boessenkool wrote: > > On Sat, Nov 07, 2020 at 08:12:13AM +0100, Gabriel Paubert wrote: > > > On Sat, Nov 07, 2020 at 01:23:28PM +1000, Nicholas Piggin wrote: > > > > ISA v2.06 (POWER7 and up) as well as e6500 support lbarx and lwarx. > > > > > > Hmm, lwarx exists since original Power AFAIR, > > > > Almost: it was new on PowerPC. > > I stand corrected. Does this mean that Power1 (and 2 I believe) had > no SMP support? As I understand it, that's correct. Of course you always can do SMP "by hand" -- you can do all synchronisation via software (perhaps using some knowledge of the specific hardware you're running on), it's just slow (and usually not portable). Compare to SMP on 603 for example. Segher