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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 0570FC43218 for ; Fri, 26 Apr 2019 20:59:45 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C916620679 for ; Fri, 26 Apr 2019 20:59:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AefEDPJ3"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="1CU5hz3n" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C916620679 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lunn.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=pH49zt5jv7WfDvg3B3li8MCqBmryNwV4wFt/0hFIPqM=; b=AefEDPJ3gsyZfe Z+j0qEhRowbhgf3O1GtL7J77XQGfF6vgS8qCa5zblIwn1sHJeRh+M12hU4x6ufa3DNRylZgqOj9g4 6Qip4LPhCTmxvrW0q34DrgqrlPaYY7nWisLcg6tAvYC0Ce/QsyovAGdu/Nj0krhSMtcI5Rh0l0wcJ hLkMeVXs0glzOMjc9dlk2lQMR0bG+3UCDRzZzD5ZyssBFzijzMPwGoHIJJbPL6PONv8E0upSnnA8b 7w1+lTHfWQpdRGnhJZCoKZmfycnJkLIsy3wWVBfyi96jemGB/a2cwVOoV4wKVAV3mO368UKWISOVW 843Oedsl/R+iimzLjBnQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hK7wY-0001Qk-GP; Fri, 26 Apr 2019 20:59:38 +0000 Received: from vps0.lunn.ch ([185.16.172.187]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hK7wU-0001QJ-PJ for linux-arm-kernel@lists.infradead.org; Fri, 26 Apr 2019 20:59:36 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender: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=OCh7hT70whp/+unoMK2jqCVOcBFEvfKRG5b+VUOJD2I=; b=1CU5hz3nVs7ef8TMlXNAhWk/KB Vj2QqJiBl+W/gF58XyYvADOZDqrxI3rRwOJkNmnxn1f+4jFw6p00hkERkOWbAnIDt1iwvAumCTd5q Mjb48qJv4PHQhJctGvPCQIj/cav01dzGvhmBQTXpQSAb6Pt5h3oDcwjCAnLclCs+pJvY=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1hK7w8-0004ty-B9; Fri, 26 Apr 2019 22:59:12 +0200 Date: Fri, 26 Apr 2019 22:59:12 +0200 From: Andrew Lunn To: Jakub Kicinski Subject: Re: [PATCH 03/12] net: ll_temac: Fix support for 64-bit platforms Message-ID: <20190426205912.GI4041@lunn.ch> References: <20190426073231.4008-1-esben@geanix.com> <20190426073231.4008-4-esben@geanix.com> <20190426114013.333e62c8@cakuba.netronome.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190426114013.333e62c8@cakuba.netronome.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190426_135934_969785_DA5E8E36 X-CRM114-Status: GOOD ( 13.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: netdev@vger.kernel.org, Esben Haabendal , YueHaibing , Michal Simek , linux-kernel@vger.kernel.org, Yang Wei , Luis Chamberlain , "David S. Miller" , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 26, 2019 at 11:40:13AM -0700, Jakub Kicinski wrote: > On Fri, 26 Apr 2019 09:32:22 +0200, Esben Haabendal wrote: > > The use of buffer descriptor APP4 field (32-bit) for storing skb pointer > > obviously does not work on 64-bit platforms. > > As APP3 is also unused, we can use that to store the other half of 64-bit > > pointer values. > > > > Contrary to what is hinted at in commit message of commit 15bfe05c8d63 > > ("net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit") > > there are no other pointers stored in cdmac_bd. > > > > Signed-off-by: Esben Haabendal > > This is a bit strange, the driver stores the host's virtual address into > the HW descriptor? Hi Jukub This is reasonably common. You need some sort of cookie which links the hardware descriptor to the skbuf it points to. The hardware makes no use of it, it is just a cookie. Andrew _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 87187C43218 for ; Fri, 26 Apr 2019 20:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47FCA20869 for ; Fri, 26 Apr 2019 20:59:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="1CU5hz3n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbfDZU7h (ORCPT ); Fri, 26 Apr 2019 16:59:37 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:46043 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725966AbfDZU7h (ORCPT ); Fri, 26 Apr 2019 16:59:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender: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=OCh7hT70whp/+unoMK2jqCVOcBFEvfKRG5b+VUOJD2I=; b=1CU5hz3nVs7ef8TMlXNAhWk/KB Vj2QqJiBl+W/gF58XyYvADOZDqrxI3rRwOJkNmnxn1f+4jFw6p00hkERkOWbAnIDt1iwvAumCTd5q Mjb48qJv4PHQhJctGvPCQIj/cav01dzGvhmBQTXpQSAb6Pt5h3oDcwjCAnLclCs+pJvY=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1hK7w8-0004ty-B9; Fri, 26 Apr 2019 22:59:12 +0200 Date: Fri, 26 Apr 2019 22:59:12 +0200 From: Andrew Lunn To: Jakub Kicinski Cc: Esben Haabendal , netdev@vger.kernel.org, "David S. Miller" , Michal Simek , Yang Wei , YueHaibing , Luis Chamberlain , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/12] net: ll_temac: Fix support for 64-bit platforms Message-ID: <20190426205912.GI4041@lunn.ch> References: <20190426073231.4008-1-esben@geanix.com> <20190426073231.4008-4-esben@geanix.com> <20190426114013.333e62c8@cakuba.netronome.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190426114013.333e62c8@cakuba.netronome.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 26, 2019 at 11:40:13AM -0700, Jakub Kicinski wrote: > On Fri, 26 Apr 2019 09:32:22 +0200, Esben Haabendal wrote: > > The use of buffer descriptor APP4 field (32-bit) for storing skb pointer > > obviously does not work on 64-bit platforms. > > As APP3 is also unused, we can use that to store the other half of 64-bit > > pointer values. > > > > Contrary to what is hinted at in commit message of commit 15bfe05c8d63 > > ("net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit") > > there are no other pointers stored in cdmac_bd. > > > > Signed-off-by: Esben Haabendal > > This is a bit strange, the driver stores the host's virtual address into > the HW descriptor? Hi Jukub This is reasonably common. You need some sort of cookie which links the hardware descriptor to the skbuf it points to. The hardware makes no use of it, it is just a cookie. Andrew