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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 EC214C433DB for ; Thu, 4 Feb 2021 16:14:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1FB264F4D for ; Thu, 4 Feb 2021 16:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237810AbhBDQOW (ORCPT ); Thu, 4 Feb 2021 11:14:22 -0500 Received: from mga17.intel.com ([192.55.52.151]:9911 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237631AbhBDQIx (ORCPT ); Thu, 4 Feb 2021 11:08:53 -0500 IronPort-SDR: Ne2SAtKc+EH0M1ksC1PlkWB0DaoY9Eedgarc+dfebN3fdcnjNmnfMY1xuz25oM9IRSRttwUj4I nJ/DNawnSp/g== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="161025234" X-IronPort-AV: E=Sophos;i="5.79,401,1602572400"; d="scan'208";a="161025234" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 08:07:22 -0800 IronPort-SDR: c+jdb7JXd2t0VvhuqvSTRHc8VZqvpxiZQkpv5pP/W+iBiIYeiOSskyD9PO9X9b1QCnqysaqy4e 75gUFQ1AB0GQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,401,1602572400"; d="scan'208";a="434006013" Received: from ranger.igk.intel.com ([10.102.21.164]) by orsmga001.jf.intel.com with ESMTP; 04 Feb 2021 08:07:20 -0800 Date: Thu, 4 Feb 2021 16:58:03 +0100 From: Maciej Fijalkowski To: Camelia Groza Cc: kuba@kernel.org, davem@davemloft.net, madalin.bucur@oss.nxp.com, netdev@vger.kernel.org Subject: Re: [PATCH net 2/3] dpaa_eth: reduce data alignment requirements for the A050385 erratum Message-ID: <20210204155803.GC2580@ranger.igk.intel.com> References: <6e534e4b2da14bb57331446e950a49f237f979c0.1612275417.git.camelia.groza@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6e534e4b2da14bb57331446e950a49f237f979c0.1612275417.git.camelia.groza@nxp.com> User-Agent: Mutt/1.12.1 (2019-06-15) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Feb 02, 2021 at 07:34:43PM +0200, Camelia Groza wrote: > The 256 byte data alignment is required for preventing DMA transaction > splits when crossing 4K page boundaries. Since XDP deals only with page > sized buffers or less, this restriction isn't needed. Instead, the data > only needs to be aligned to 64 bytes to prevent DMA transaction splits. > > These lessened restrictions can increase performance by widening the pool > of permitted data alignments and preventing unnecessary realignments. > > Fixes: ae680bcbd06a ("dpaa_eth: implement the A050385 erratum workaround for XDP") > Signed-off-by: Camelia Groza Acked-by: Maciej Fijalkowski > --- > drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > index e1d041c35ad9..78dfa05f6d55 100644 > --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > @@ -2192,7 +2192,7 @@ static int dpaa_a050385_wa_xdpf(struct dpaa_priv *priv, > * byte frame headroom. If the XDP program uses all of it, copy the > * data to a new buffer and make room for storing the backpointer. > */ > - if (PTR_IS_ALIGNED(xdpf->data, DPAA_A050385_ALIGN) && > + if (PTR_IS_ALIGNED(xdpf->data, DPAA_FD_DATA_ALIGNMENT) && > xdpf->headroom >= priv->tx_headroom) { > xdpf->headroom = priv->tx_headroom; > return 0; > -- > 2.17.1 >