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 A85A1C433EF for ; Mon, 13 Dec 2021 16:51:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=83KmEBElIhZsOTF2dOuMy05MHqQa36H+tQ9f6ktgPBI=; b=eujx/2Jz/w4ogn nZoTeOaqVkOp08IC3uXM62/qVvc7RlGw5waTNEG/Opm97ZI/fm6Pbpr0PyWECHFRFbhqcl8nNZory YLKwFJ+Hm4p/7LIvVRn0zMsFo5X44hPfrPyuiJV6cnwZlD5ahBqJoPEvObxxeTI6MGqg8WUqoeNZ2 m5DNb5DlRl7vpXqf6Mqh6ZY0+g4UDQN4LC65xc8++mmr4cExgO2Uu2M9VUa/WBi5u5mFWcRVGJKTM kStXiQr4dgpEpWE3zCjyME/VfST4NY6/utTR8ApH5IwJa+c8yGTWTrCJLDUqW49N0sXF8GL9I0Zoy OBJKOynD/UKEE56tpd6A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwoWh-00Ai6N-Gh; Mon, 13 Dec 2021 16:50:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwoWN-00Ai1z-Rd for linux-arm-kernel@lists.infradead.org; Mon, 13 Dec 2021 16:49:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 72DE61FB; Mon, 13 Dec 2021 08:49:50 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.67.68]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7DB813F73B; Mon, 13 Dec 2021 08:49:49 -0800 (PST) Date: Mon, 13 Dec 2021 16:49:46 +0000 From: Mark Rutland To: Peter Zijlstra Cc: linux-arm-kernel@lists.infradead.org, boqun.feng@gmail.com, catalin.marinas@arm.com, will@kernel.org Subject: Re: [PATCH 5/5] arm64: atomics: lse: define RETURN ops in terms of FETCH ops Message-ID: References: <20211210151410.2782645-1-mark.rutland@arm.com> <20211210151410.2782645-6-mark.rutland@arm.com> <20211210221940.GU16608@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211210221940.GU16608@worktop.programming.kicks-ass.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211213_084951_960559_4561F978 X-CRM114-Status: UNSURE ( 9.52 ) X-CRM114-Notice: Please train this message. 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Dec 10, 2021 at 11:19:40PM +0100, Peter Zijlstra wrote: > On Fri, Dec 10, 2021 at 03:14:10PM +0000, Mark Rutland wrote: > > The FEAT_LSE atomic instructions include LD* instructions which return > > the original value of a memory location can be used to directly > > implement FETCH opertations. Each RETURN op is implemented as a copy of > > the corresponding FETCH op with a trailing instruction instruction to > > instruction instruction instruction is probably even more better :-) I've gone the other way and just made that a single `instruction` in the branch. :) Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel