[NET]: Merge TSO/UFO fields in sk_buff

Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 11daed4..3defe5d 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -3959,8 +3959,8 @@
 	txdp->Control_1 = 0;
 	txdp->Control_2 = 0;
 #ifdef NETIF_F_TSO
-	mss = skb_shinfo(skb)->tso_size;
-	if (mss) {
+	mss = skb_shinfo(skb)->gso_size;
+	if (skb_shinfo(skb)->gso_type == SKB_GSO_TCPV4) {
 		txdp->Control_1 |= TXD_TCP_LSO_EN;
 		txdp->Control_1 |= TXD_TCP_LSO_MSS(mss);
 	}
@@ -3980,10 +3980,10 @@
 	}
 
 	frg_len = skb->len - skb->data_len;
-	if (skb_shinfo(skb)->ufo_size) {
+	if (skb_shinfo(skb)->gso_type == SKB_GSO_UDPV4) {
 		int ufo_size;
 
-		ufo_size = skb_shinfo(skb)->ufo_size;
+		ufo_size = skb_shinfo(skb)->gso_size;
 		ufo_size &= ~7;
 		txdp->Control_1 |= TXD_UFO_EN;
 		txdp->Control_1 |= TXD_UFO_MSS(ufo_size);
@@ -4009,7 +4009,7 @@
 	txdp->Host_Control = (unsigned long) skb;
 	txdp->Control_1 |= TXD_BUFFER0_SIZE(frg_len);
 
-	if (skb_shinfo(skb)->ufo_size)
+	if (skb_shinfo(skb)->gso_type == SKB_GSO_UDPV4)
 		txdp->Control_1 |= TXD_UFO_EN;
 
 	frg_cnt = skb_shinfo(skb)->nr_frags;
@@ -4024,12 +4024,12 @@
 		    (sp->pdev, frag->page, frag->page_offset,
 		     frag->size, PCI_DMA_TODEVICE);
 		txdp->Control_1 = TXD_BUFFER0_SIZE(frag->size);
-		if (skb_shinfo(skb)->ufo_size)
+		if (skb_shinfo(skb)->gso_type == SKB_GSO_UDPV4)
 			txdp->Control_1 |= TXD_UFO_EN;
 	}
 	txdp->Control_1 |= TXD_GATHER_CODE_LAST;
 
-	if (skb_shinfo(skb)->ufo_size)
+	if (skb_shinfo(skb)->gso_type == SKB_GSO_UDPV4)
 		frg_cnt++; /* as Txd0 was used for inband header */
 
 	tx_fifo = mac_control->tx_FIFO_start[queue];
@@ -4043,7 +4043,7 @@
 	if (mss)
 		val64 |= TX_FIFO_SPECIAL_FUNC;
 #endif
-	if (skb_shinfo(skb)->ufo_size)
+	if (skb_shinfo(skb)->gso_type == SKB_GSO_UDPV4)
 		val64 |= TX_FIFO_SPECIAL_FUNC;
 	writeq(val64, &tx_fifo->List_Control);