From 5ca8caff03b2d6940d572238608bd91128b6a39a Mon Sep 17 00:00:00 2001
From: Eric Dumazet <dada1@cosmosbay.com>
Date: Sun, 23 Nov 2008 23:24:32 -0800
Subject: [PATCH] --- yaml --- r: 122111 b: refs/heads/master c:
 1f87e235e6fb92c2968b52b9191de04f1aff8e77 h: refs/heads/master i:   122109:
 da88fafff9d379ff24c0df86f218ff9a72c84b28   122107:
 37c20c1fd63c3ee1284bcdf3923a5d3c75b20e31   122103:
 e52806d2fbe0bba1080ebce80e0fedcd2fc1d290   122095:
 b8f31dfffd97a36431a0e35a191dc7c15c306795   122079:
 979dd2ae7c2a07c4a0bb4508ed54927e26f1a435   122047:
 ad15cc65405231694a45932998f82759ebbc9787   121983:
 52baa544882154647a13f0510d2d893c4cf11b7f   121855:
 189b7f72aa64eecf1b3ee4b8652d4973b4cdeb92 v: v3

---
 [refs]                            |  2 +-
 trunk/include/linux/etherdevice.h | 42 +++++++++++++++++++++++++++++++
 trunk/net/ethernet/eth.c          |  6 ++---
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index c9699c8c68fa..8aa1a3a746ee 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 70eb1bfd52e97120eddf9b5aaabfe1ecdf4eb663
+refs/heads/master: 1f87e235e6fb92c2968b52b9191de04f1aff8e77
diff --git a/trunk/include/linux/etherdevice.h b/trunk/include/linux/etherdevice.h
index 0e5e97060034..1cb0f0b90926 100644
--- a/trunk/include/linux/etherdevice.h
+++ b/trunk/include/linux/etherdevice.h
@@ -27,6 +27,7 @@
 #include <linux/if_ether.h>
 #include <linux/netdevice.h>
 #include <linux/random.h>
+#include <asm/unaligned.h>
 
 #ifdef __KERNEL__
 extern __be16		eth_type_trans(struct sk_buff *skb, struct net_device *dev);
@@ -140,6 +141,47 @@ static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 	BUILD_BUG_ON(ETH_ALEN != 6);
 	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 }
+
+static inline unsigned long zap_last_2bytes(unsigned long value)
+{
+#ifdef __BIG_ENDIAN
+	return value >> 16;
+#else
+	return value << 16;
+#endif
+}
+
+/**
+ * compare_ether_addr_64bits - Compare two Ethernet addresses
+ * @addr1: Pointer to an array of 8 bytes
+ * @addr2: Pointer to an other array of 8 bytes
+ *
+ * Compare two ethernet addresses, returns 0 if equal.
+ * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional
+ * branches, and possibly long word memory accesses on CPU allowing cheap
+ * unaligned memory reads.
+ * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2}
+ *
+ * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits.
+ */
+
+static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
+						 const u8 addr2[6+2])
+{
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	unsigned long fold = ((*(unsigned long *)addr1) ^
+			      (*(unsigned long *)addr2));
+
+	if (sizeof(fold) == 8)
+		return zap_last_2bytes(fold) != 0;
+
+	fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
+				(*(unsigned long *)(addr2 + 4)));
+	return fold != 0;
+#else
+	return compare_ether_addr(addr1, addr2);
+#endif
+}
 #endif	/* __KERNEL__ */
 
 #endif	/* _LINUX_ETHERDEVICE_H */
diff --git a/trunk/net/ethernet/eth.c b/trunk/net/ethernet/eth.c
index a87a171d9914..280352aba403 100644
--- a/trunk/net/ethernet/eth.c
+++ b/trunk/net/ethernet/eth.c
@@ -165,8 +165,8 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
 	skb_pull(skb, ETH_HLEN);
 	eth = eth_hdr(skb);
 
-	if (is_multicast_ether_addr(eth->h_dest)) {
-		if (!compare_ether_addr(eth->h_dest, dev->broadcast))
+	if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
+		if (!compare_ether_addr_64bits(eth->h_dest, dev->broadcast))
 			skb->pkt_type = PACKET_BROADCAST;
 		else
 			skb->pkt_type = PACKET_MULTICAST;
@@ -181,7 +181,7 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
 	 */
 
 	else if (1 /*dev->flags&IFF_PROMISC */ ) {
-		if (unlikely(compare_ether_addr(eth->h_dest, dev->dev_addr)))
+		if (unlikely(compare_ether_addr_64bits(eth->h_dest, dev->dev_addr)))
 			skb->pkt_type = PACKET_OTHERHOST;
 	}