From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [PATCH 1/3] etherdev: Avoid unnecessary byte swap in check for Ethertype Date: Thu, 30 Apr 2015 14:53:48 -0700 Message-ID: <20150430215348.1798.15509.stgit@ahduyck-vm-fedora22> References: <20150430214917.1798.49769.stgit@ahduyck-vm-fedora22> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35197 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751722AbbD3Vxt (ORCPT ); Thu, 30 Apr 2015 17:53:49 -0400 In-Reply-To: <20150430214917.1798.49769.stgit@ahduyck-vm-fedora22> Sender: netdev-owner@vger.kernel.org List-ID: This change takes advantage of the fact that ETH_P_802_3_MIN is aligned to 512 so as a result we can actually ignore the lower 8b when comparing the Ethertype to ETH_P_802_3_MIN. This allows us to avoid a byte swap by simply masking the value and comparing it to the byte swapped value for ETH_P_802_3_MIN. Signed-off-by: Alexander Duyck --- net/ethernet/eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index f3bad41d725f..60069318d5d1 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c @@ -178,7 +178,7 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) if (unlikely(netdev_uses_dsa(dev))) return htons(ETH_P_XDSA); - if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN)) + if (likely((eth->h_proto & htons(0xFF00)) >= htons(ETH_P_802_3_MIN))) return eth->h_proto; /*