From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 43EC41FC4 for ; Fri, 8 Sep 2023 08:36:36 +0000 (UTC) Received: from pandora.armlinux.org.uk (unknown [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB26C173B; Fri, 8 Sep 2023 01:36:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc: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-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=bAIlNlhSV1vyCOAvZ0nrlCVU+qTundSRL1Lq1G06UzQ=; b=gTaNmUqodxA7w0bp9tF29M1hyU ChQH1P4/YxuWR5GtCnihZaBtrzFmFc4r9ix/MbSbSERy078XQHUTEbxJn0L3vb0hQsKy/ishrdGrp PbedoLIyM/F3CEunWh+oFhVx7aD4TxZ0ZroRkj+tjsdE8c925Y62zebaSWEjiUYzxU8MJHr7Z0day M9XB22CVADPIZUGLDTtwyDOMXpMiQYjPnTvfO8lghM0kaNqVMtasooz+rLxnxWhFv6rvUQYiVEkM/ AS4pZasAnWNCQ2Ao4Gr16ZCxqIzYo1MNHIBtw2AM4B7nP/FntCZhHiTGZOMZplg7COE18ojqj9wFK hNaIBJ7g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:60418) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qeWyT-0004jo-0U; Fri, 08 Sep 2023 09:36:21 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qeWyT-0006jV-7w; Fri, 08 Sep 2023 09:36:21 +0100 Date: Fri, 8 Sep 2023 09:36:21 +0100 From: "Russell King (Oracle)" To: Puranjay Mohan Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shubham Bansal , Mykola Lysenko , Shuah Khan , bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH bpf-next v3 6/9] arm32, bpf: add support for 64 bit division instruction Message-ID: References: <20230907230550.1417590-1-puranjay12@gmail.com> <20230907230550.1417590-7-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230907230550.1417590-7-puranjay12@gmail.com> Sender: Russell King (Oracle) X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED,RDNS_NONE, SPF_HELO_NONE,SPF_NONE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Thu, Sep 07, 2023 at 11:05:47PM +0000, Puranjay Mohan wrote: > ARM32 doesn't have instructions to do 64-bit/64-bit divisions. So, to > implement the following instructions: > BPF_ALU64 | BPF_DIV > BPF_ALU64 | BPF_MOD > BPF_ALU64 | BPF_SDIV > BPF_ALU64 | BPF_SMOD > > We implement the above instructions by doing function calls to div64_u64() > and div64_u64_rem() for unsigned division/mod and calls to div64_s64() > for signed division/mod. > > Signed-off-by: Puranjay Mohan Reviewed-by: Russell King (Oracle) Thanks! -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!