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 2F741C79F82 for ; Tue, 8 Sep 2026 15:08:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject: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=k4vXbWuRfzO/MusqbPkktBl/EFRxYMbIBerOhaVzBug=; b=gI6NcrCesf7g+n8EYwoV7YGk9w ZBGwjo55fT9556n60Vy9UD4bfqY+0W/Tko9S/0CNZoFbGlgiGxGyMO7AvbsX3Izm2tlcTpKpfb17J OD5FRaoLhEBwY1fxTKjZD9b2xpnbdttd725EQWzgr0NJ7vs/S8Dr1GpNHbtXudP4zxwULhgoFGOXa CmfmVcBQdanHzjp4/Y60w6V2OBq/gbtmEqAIlPOcmY1yr9hlL4cmgIWUIwjphjFmtM203/EZDnrCw kZqp/pZsJwb1lk7TijXULjCKzknLAYgU0MUKOZdA5WntGBG8M9vW2TRErP39i13IPGghwDLGLFp3r yx7ohBBQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3xQL-00000009PJD-3Src; Tue, 08 Sep 2026 15:07:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3xQJ-00000009PIY-2xC8 for linux-arm-kernel@lists.infradead.org; Tue, 08 Sep 2026 15:07:48 +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 523681476; Tue, 8 Sep 2026 08:07:41 -0700 (PDT) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9B8CB3F7B4; Tue, 8 Sep 2026 08:07:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788880065; bh=F61H69mF3VruYwfQfBXakM+FEgay4xnK235Alpe4aoM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QoWVPHf3TavwxFTtgnVEyELJjRbP3NinnNCLDdKrB4tTPfhhSaiI9Dv5m+cuqbs5c 6A4UZVT4jCFT5UoqOYgw5HqhFx+QATcMzDM7TeYSbbVUYO0rTxiCgImQ7mpKT44N0p OSWoWaZXcddyG//soN84UEUHOWhs9eahQeJsU8Os= Date: Tue, 8 Sep 2026 16:07:40 +0100 From: Mark Rutland To: David Laight Subject: Re: [PATCH v3 16/21] arm64: percpu: Implement preemptible void RMW ops Message-ID: References: <20260904161758.376504-1-mark.rutland@arm.com> <20260904161758.376504-17-mark.rutland@arm.com> <20260905100319.0a50c17f@pumpkin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260905100319.0a50c17f@pumpkin> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260908_080747_784542_AA3334AF X-CRM114-Status: GOOD ( 14.40 ) 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: , Cc: vladimir.murzin@arm.com, usama.anjum@arm.com, peterz@infradead.org, catalin.marinas@arm.com, ruanjinjie@huawei.com, stable@vger.kernel.org, james.morse@arm.com, yang@os.amperecomputing.com, cl@gentwo.org, maz@kernel.org, will@kernel.org, ardb@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Sep 05, 2026 at 10:03:19AM +0100, David Laight wrote: > On Fri, 4 Sep 2026 17:17:53 +0100 > Mark Rutland wrote: > > > Use the PCPU GPR infrastructure to implement all of the RMW ops which do > > not return a value. > ... > > #define __PERCPU_OP_CASE(w, sfx, name, sz, op_llsc, op_lse) \ > > Isn't this definition exactly the same as __PERCPU_RET_OP_CASE() except > for s/tmp/ret/ and the 'return ret'? Not exactly the same; the __PERCPU_RET_OP_CASE() assembly also performs an additional instruction at the end in order to generate the RETURN value. > Since the compiler will just ignore the unwanted return value > there is not point replicating the definition. We could consider sharing the assembly, but it's not quite that simple, so I'm going to leave this as-is for now. Mark.