From: Alexander Duyck <alexander.h.duyck@redhat.com>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net
Subject: [PATCH 1/3] etherdev: Avoid unnecessary byte swap in check for Ethertype
Date: Thu, 30 Apr 2015 14:53:48 -0700 [thread overview]
Message-ID: <20150430215348.1798.15509.stgit@ahduyck-vm-fedora22> (raw)
In-Reply-To: <20150430214917.1798.49769.stgit@ahduyck-vm-fedora22>
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 <alexander.h.duyck@redhat.com>
---
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;
/*
next prev parent reply other threads:[~2015-04-30 21:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-30 21:53 [PATCH 0/3] A few minor clean-ups to eth_type_trans Alexander Duyck
2015-04-30 21:53 ` Alexander Duyck [this message]
2015-04-30 23:03 ` [PATCH 1/3] etherdev: Avoid unnecessary byte swap in check for Ethertype Eric Dumazet
2015-04-30 23:24 ` Alexander Duyck
2015-05-01 0:13 ` Eric Dumazet
2015-05-01 0:41 ` Alexander Duyck
2015-04-30 21:53 ` [PATCH 2/3] etherdev: Process is_multicast_ether_addr at same size as other operations Alexander Duyck
2015-04-30 21:53 ` [PATCH 3/3] etherdev: Use skb->data to retrieve Ethernet header instead of eth_hdr Alexander Duyck
2015-04-30 22:35 ` [PATCH 0/3] A few minor clean-ups to eth_type_trans Alexei Starovoitov
2015-04-30 23:11 ` Alexander Duyck
2015-05-01 11:30 ` David Laight
2015-05-01 15:34 ` Alexander Duyck
2015-05-04 2:47 ` David Miller
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