[NET]: Split skb->csum

... into anonymous union of __wsum and __u32 (csum and csum_offset resp.)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cassini.c b/drivers/net/cassini.c
index 521c5b7..fd2cc13 100644
--- a/drivers/net/cassini.c
+++ b/drivers/net/cassini.c
@@ -2825,7 +2825,7 @@
 		u64 csum_start_off, csum_stuff_off;
 
 		csum_start_off = (u64) (skb->h.raw - skb->data);
-		csum_stuff_off = (u64) ((skb->h.raw + skb->csum) - skb->data);
+		csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		ctrl =  TX_DESC_CSUM_EN |
 			CAS_BASE(TX_DESC_CSUM_START, csum_start_off) |
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 7a08288..32dde0a 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -2826,7 +2826,7 @@
 		context_desc = E1000_CONTEXT_DESC(*tx_ring, i);
 
 		context_desc->upper_setup.tcp_fields.tucss = css;
-		context_desc->upper_setup.tcp_fields.tucso = css + skb->csum;
+		context_desc->upper_setup.tcp_fields.tucso = css + skb->csum_offset;
 		context_desc->upper_setup.tcp_fields.tucse = 0;
 		context_desc->tcp_seg_setup.data = 0;
 		context_desc->cmd_and_length = cpu_to_le32(E1000_TXD_CMD_DEXT);
diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index e09f575..7b12721 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1249,7 +1249,7 @@
 	if(likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
 		struct ixgb_buffer *buffer_info;
 		css = skb->h.raw - skb->data;
-		cso = (skb->h.raw + skb->csum) - skb->data;
+		cso = css + skb->csum_offset;
 
 		i = adapter->tx_ring.next_to_use;
 		context_desc = IXGB_CONTEXT_DESC(adapter->tx_ring, i);
diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index 806081b..36350e6 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -1955,7 +1955,7 @@
 	flags = (MXGEFW_FLAGS_NO_TSO | MXGEFW_FLAGS_FIRST);
 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
 		cksum_offset = (skb->h.raw - skb->data);
-		pseudo_hdr_offset = (skb->h.raw + skb->csum) - skb->data;
+		pseudo_hdr_offset = cksum_offset + skb->csum_offset;
 		/* If the headers are excessively large, then we must
 		 * fall back to a software checksum */
 		if (unlikely(cksum_offset > 255 || pseudo_hdr_offset > 127)) {
diff --git a/drivers/net/sk98lin/skge.c b/drivers/net/sk98lin/skge.c
index a5d41eb..12cbfd1 100644
--- a/drivers/net/sk98lin/skge.c
+++ b/drivers/net/sk98lin/skge.c
@@ -1562,7 +1562,7 @@
 
 	if (pMessage->ip_summed == CHECKSUM_PARTIAL) {
 		u16 hdrlen = pMessage->h.raw - pMessage->data;
-		u16 offset = hdrlen + pMessage->csum;
+		u16 offset = hdrlen + pMessage->csum_offset;
 
 		if ((pMessage->h.ipiph->protocol == IPPROTO_UDP ) &&
 			(pAC->GIni.GIChipRev == 0) &&
@@ -1681,7 +1681,7 @@
 	*/
 	if (pMessage->ip_summed == CHECKSUM_PARTIAL) {
 		u16 hdrlen = pMessage->h.raw - pMessage->data;
-		u16 offset = hdrlen + pMessage->csum;
+		u16 offset = hdrlen + pMessage->csum_offset;
 
 		Control = BMU_STFWD;
 
diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index 27b537c..5513907 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -2565,7 +2565,7 @@
 
 		td->csum_offs = 0;
 		td->csum_start = offset;
-		td->csum_write = offset + skb->csum;
+		td->csum_write = offset + skb->csum_offset;
 	} else
 		control = BMU_CHECK;
 
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 0ef1848..842abd9 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1350,7 +1350,7 @@
 		u32 tcpsum;
 
 		tcpsum = offset << 16;		/* sum start */
-		tcpsum |= offset + skb->csum;	/* sum write */
+		tcpsum |= offset + skb->csum_offset;	/* sum write */
 
 		ctrl = CALSUM | WR_SUM | INIT_SUM | LOCK_SUM;
 		if (skb->nh.iph->protocol == IPPROTO_UDP)
diff --git a/drivers/net/sungem.c b/drivers/net/sungem.c
index 253e96e..334c6cf 100644
--- a/drivers/net/sungem.c
+++ b/drivers/net/sungem.c
@@ -1030,7 +1030,7 @@
 		u64 csum_start_off, csum_stuff_off;
 
 		csum_start_off = (u64) (skb->h.raw - skb->data);
-		csum_stuff_off = (u64) ((skb->h.raw + skb->csum) - skb->data);
+		csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		ctrl = (TXDCTRL_CENAB |
 			(csum_start_off << 15) |
diff --git a/drivers/net/sunhme.c b/drivers/net/sunhme.c
index 9d7cd13..ec432ea 100644
--- a/drivers/net/sunhme.c
+++ b/drivers/net/sunhme.c
@@ -2272,7 +2272,7 @@
 		u32 csum_start_off, csum_stuff_off;
 
 		csum_start_off = (u32) (skb->h.raw - skb->data);
-		csum_stuff_off = (u32) ((skb->h.raw + skb->csum) - skb->data);
+		csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		tx_flags = (TXFLAG_OWN | TXFLAG_CSENABLE |
 			    ((csum_start_off << 14) & TXFLAG_CSBUFBEGIN) |
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index fcab543..14ec16d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -274,7 +274,10 @@
 	unsigned int		len,
 				data_len,
 				mac_len;
-	__wsum			csum;
+	union {
+		__wsum		csum;
+		__u32		csum_offset;
+	};
 	__u32			priority;
 	__u8			local_df:1,
 				cloned:1,
diff --git a/net/core/dev.c b/net/core/dev.c
index 1a36b17..59d058a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1191,9 +1191,9 @@
 
 	offset = skb->tail - skb->h.raw;
 	BUG_ON(offset <= 0);
-	BUG_ON(skb->csum + 2 > offset);
+	BUG_ON(skb->csum_offset + 2 > offset);
 
-	*(__sum16*)(skb->h.raw + skb->csum) = csum_fold(csum);
+	*(__sum16*)(skb->h.raw + skb->csum_offset) = csum_fold(csum);
 
 out_set_summed:
 	skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 07c25d6..a90bc43 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1414,7 +1414,7 @@
 					      skb->len - csstart, 0);
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		long csstuff = csstart + skb->csum;
+		long csstuff = csstart + skb->csum_offset;
 
 		*((__sum16 *)(to + csstuff)) = csum_fold(csum);
 	}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e9d4671..4913f25 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -504,7 +504,7 @@
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		th->check = ~tcp_v4_check(th, len,
 					  inet->saddr, inet->daddr, 0);
-		skb->csum = offsetof(struct tcphdr, check);
+		skb->csum_offset = offsetof(struct tcphdr, check);
 	} else {
 		th->check = tcp_v4_check(th, len, inet->saddr, inet->daddr,
 					 csum_partial((char *)th,
@@ -526,7 +526,7 @@
 
 	th->check = 0;
 	th->check = ~tcp_v4_check(th, skb->len, iph->saddr, iph->daddr, 0);
-	skb->csum = offsetof(struct tcphdr, check);
+	skb->csum_offset = offsetof(struct tcphdr, check);
 	skb->ip_summed = CHECKSUM_PARTIAL;
 	return 0;
 }
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 28e4cf6..1807a30 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -422,7 +422,7 @@
 		/*
 		 * Only one fragment on the socket.
 		 */
-		skb->csum = offsetof(struct udphdr, check);
+		skb->csum_offset = offsetof(struct udphdr, check);
 		uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
 	} else {
 		/*
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0adb337..517c5002 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -948,7 +948,7 @@
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
-		skb->csum = offsetof(struct tcphdr, check);
+		skb->csum_offset = offsetof(struct tcphdr, check);
 	} else {
 		th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP, 
 					    csum_partial((char *)th, th->doff<<2, 
@@ -970,7 +970,7 @@
 	th->check = 0;
 	th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 				     IPPROTO_TCP, 0);
-	skb->csum = offsetof(struct tcphdr, check);
+	skb->csum_offset = offsetof(struct tcphdr, check);
 	skb->ip_summed = CHECKSUM_PARTIAL;
 	return 0;
 }