mv643xx_eth: fix byte order when checksum offload is enabled

The Marvell Orion system on chips have an integrated mv643xx MAC.  On these
little endian ARM devices mv643xx will oops when checksum offload is
enabled.  Swapping the byte order of the protocol and checksum solves this
problem.

Signed-off-by: Byron Bradley <byron.bbradley@gmail.com>
Cc: Dale Farnsworth <dale@farnsworth.org>
Cc: Manish Lachwani <mlachwani@mvista.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 651c269..b528ce7 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -1652,6 +1652,11 @@
 	}
 }
 
+static inline __be16 sum16_as_be(__sum16 sum)
+{
+	return (__force __be16)sum;
+}
+
 /**
  * eth_tx_submit_descs_for_skb - submit data from an skb to the tx hw
  *
@@ -1689,7 +1694,7 @@
 	desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		BUG_ON(skb->protocol != ETH_P_IP);
+		BUG_ON(skb->protocol != htons(ETH_P_IP));
 
 		cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM |
 			   ETH_GEN_IP_V_4_CHECKSUM  |
@@ -1698,10 +1703,10 @@
 		switch (ip_hdr(skb)->protocol) {
 		case IPPROTO_UDP:
 			cmd_sts |= ETH_UDP_FRAME;
-			desc->l4i_chk = udp_hdr(skb)->check;
+			desc->l4i_chk = ntohs(sum16_as_be(udp_hdr(skb)->check));
 			break;
 		case IPPROTO_TCP:
-			desc->l4i_chk = tcp_hdr(skb)->check;
+			desc->l4i_chk = ntohs(sum16_as_be(tcp_hdr(skb)->check));
 			break;
 		default:
 			BUG();