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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45A09C433F5 for ; Mon, 21 Mar 2022 14:16:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349020AbiCUORc (ORCPT ); Mon, 21 Mar 2022 10:17:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349103AbiCUOHy (ORCPT ); Mon, 21 Mar 2022 10:07:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F062B41FB1; Mon, 21 Mar 2022 07:02:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6C777612DC; Mon, 21 Mar 2022 14:02:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 793D5C340E8; Mon, 21 Mar 2022 14:02:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647871336; bh=8mRqTFjNVjmKjv5dCQ4bZtVtCi85jQvwxvTDpXOIhsQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LTAoZj8cRKkKG+jMn1Cgome32cp7f/wYN8uIgV8+KDHekJGcCoHsC/J2wqv1W28xs Y5dqyjfuJGODiuSRTOBEkWD4auJ6ViXUOMUH3MLPrCAbBS82fS//ZDhAKPT/RNkWWw wHNJ1fmcoZyWWbfhdMy6x606M7DbT9Xw7eHl018E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Oltean , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.16 25/37] net: mscc: ocelot: fix backwards compatibility with single-chain tc-flower offload Date: Mon, 21 Mar 2022 14:53:07 +0100 Message-Id: <20220321133222.025147482@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220321133221.290173884@linuxfoundation.org> References: <20220321133221.290173884@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vladimir Oltean [ Upstream commit 8e0341aefcc9133f3f48683873284b169581315b ] ACL rules can be offloaded to VCAP IS2 either through chain 0, or, since the blamed commit, through a chain index whose number encodes a specific PAG (Policy Action Group) and lookup number. The chain number is translated through ocelot_chain_to_pag() into a PAG, and through ocelot_chain_to_lookup() into a lookup number. The problem with the blamed commit is that the above 2 functions don't have special treatment for chain 0. So ocelot_chain_to_pag(0) returns filter->pag = 224, which is in fact -32, but the "pag" field is an u8. So we end up programming the hardware with VCAP IS2 entries having a PAG of 224. But the way in which the PAG works is that it defines a subset of VCAP IS2 filters which should match on a packet. The default PAG is 0, and previous VCAP IS1 rules (which we offload using 'goto') can modify it. So basically, we are installing filters with a PAG on which no packet will ever match. This is the hardware equivalent of adding filters to a chain which has no 'goto' to it. Restore the previous functionality by making ACL filters offloaded to chain 0 go to PAG 0 and lookup number 0. The choice of PAG is clearly correct, but the choice of lookup number isn't "as before" (which was to leave the lookup a "don't care"). However, lookup 0 should be fine, since even though there are ACL actions (policers) which have a requirement to be used in a specific lookup, that lookup is 0. Fixes: 226e9cd82a96 ("net: mscc: ocelot: only install TCAM entries into a specific lookup and PAG") Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20220316192117.2568261-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/mscc/ocelot_flower.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c index 738dd2be79dc..a3f1f1fbaf7d 100644 --- a/drivers/net/ethernet/mscc/ocelot_flower.c +++ b/drivers/net/ethernet/mscc/ocelot_flower.c @@ -54,6 +54,12 @@ static int ocelot_chain_to_block(int chain, bool ingress) */ static int ocelot_chain_to_lookup(int chain) { + /* Backwards compatibility with older, single-chain tc-flower + * offload support in Ocelot + */ + if (chain == 0) + return 0; + return (chain / VCAP_LOOKUP) % 10; } @@ -62,7 +68,15 @@ static int ocelot_chain_to_lookup(int chain) */ static int ocelot_chain_to_pag(int chain) { - int lookup = ocelot_chain_to_lookup(chain); + int lookup; + + /* Backwards compatibility with older, single-chain tc-flower + * offload support in Ocelot + */ + if (chain == 0) + return 0; + + lookup = ocelot_chain_to_lookup(chain); /* calculate PAG value as chain index relative to the first PAG */ return chain - VCAP_IS2_CHAIN(lookup, 0); -- 2.34.1