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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 74AF0C433DB for ; Tue, 30 Mar 2021 09:34:19 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 AECA161606 for ; Tue, 30 Mar 2021 09:34:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AECA161606 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; 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=vVDCnTReLUXkgC96pclRpQiFy2bysal0D6P39QiwlsE=; b=ViLWPsPpaQCPr4wbsMKeN7u0I WWXcvhuPvBivNaC+S2cbBb98cLp3aphgk/FljvfZZk2GFYTzqNOGkTswHNJrlkMnaQ3HLWOjd07Tb n0L7F6V6d5+LFIiyBtBwREUohVHQLwrdFxu3ZC4AdWN/NXwDiBgG2Rpi1YLQaFKae+z+a5eZ9l4Fi ur61Ns2TfZROJhCaInUpp+HuWS95+1IACsIE0fqimhon/rBhi0Ol0G8FPGz3nLrPF1t05pTUs7LDu 61QkHAjYDusAl4BoYE3f9pujHs0kvo2kkkWJ44HebaKxNW20BsepBHGBT7m54Wo1TDwUD+XfkW2n6 /9H8Ei3iA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lRAjV-003DuB-0j; Tue, 30 Mar 2021 09:32:21 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lRAj7-003DoF-MB for linux-arm-kernel@lists.infradead.org; Tue, 30 Mar 2021 09:32:03 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 190F86195D; Tue, 30 Mar 2021 09:31:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617096715; bh=BpKzBVeqnwaVwGkM7DZHfqbqAkT3YLrMqWKYlAvZR1M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gvBRyFV/PWB+wQSDwH8nwqBlxgOVa8DUFhq3UF3TVrddNOKU0Wi1QbmuCoA2FI7Q8 i36qG8lZzYsO7Vx4SsRYdOTSm7Jv6RpaKCSDG1OOvjF+E0tbznAltY7VpbA0BfRRuj xV2C6ArN+oJ7+wWyx6RK+6roOUUHmRFc2elS1K6ZAKbCxPwS5XHJRtDOfD1WdaBwMh 0TDZZxLxDDt3lt+YSRzUy/RWr4Rp0V7C4+SJl5ebjCHr2omWfvKTQGb8AGXmP7sq0V l7DVDcThU2qlny0HChdZtRA7RC7kqzHZNHmwwSivcOVD5NiPftTI+NoZ1jt0lw2Axi 9R7NIlxYjKMag== Date: Tue, 30 Mar 2021 10:31:49 +0100 From: Will Deacon To: Jianlin Lv Cc: bpf@vger.kernel.org, zlim.lnx@gmail.com, catalin.marinas@arm.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iecedge@gmail.com Subject: Re: [PATCH bpf-next] bpf: arm64: Redefine MOV consistent with arch insn Message-ID: <20210330093149.GA5281@willie-the-truck> References: <20210330074235.525747-1-Jianlin.Lv@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210330074235.525747-1-Jianlin.Lv@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210330_103158_174647_598CE85E X-CRM114-Status: UNSURE ( 7.72 ) 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 Tue, Mar 30, 2021 at 03:42:35PM +0800, Jianlin Lv wrote: > A64_MOV is currently mapped to Add Instruction. Architecturally MOV > (register) is an alias of ORR (shifted register) and MOV (to or from SP) > is an alias of ADD (immediate). > This patch redefines A64_MOV and uses existing functionality > aarch64_insn_gen_move_reg() in insn.c to encode MOV (register) instruction. > For moving between register and stack pointer, rename macro to A64_MOV_SP. What does this gain us? There's no requirement for a BPF "MOV" to match an arm64 architectural "MOV", so what's the up-side of aligning them like this? Cheers, Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel