s390/qeth: add TSO support for L2 devices

Except for the new HW header id, this works just like TSO6 on L3 devices
and reuses all the existing data path support in qeth_xmit().
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -390,8 +390,9 @@ enum qeth_layer2_frame_flags {
 enum qeth_header_ids {
 	QETH_HEADER_TYPE_LAYER3 = 0x01,
 	QETH_HEADER_TYPE_LAYER2 = 0x02,
-	QETH_HEADER_TYPE_TSO	= 0x03,
+	QETH_HEADER_TYPE_L3_TSO	= 0x03,
 	QETH_HEADER_TYPE_OSN    = 0x04,
+	QETH_HEADER_TYPE_L2_TSO	= 0x06,
 };
 /* flags for qeth_hdr.ext_flags */
 #define QETH_HDR_EXT_VLAN_FRAME       0x01

drivers/s390/net/qeth_l2_main.c

@@ -197,15 +197,19 @@ static void qeth_l2_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
 				struct sk_buff *skb, int ipv, int cast_type,
 				unsigned int data_len)
 {
-	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb_mac_header(skb);
+	struct vlan_ethhdr *veth = vlan_eth_hdr(skb);
 
-	hdr->hdr.l2.id = QETH_HEADER_TYPE_LAYER2;
 	hdr->hdr.l2.pkt_length = data_len;
 
-	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		qeth_tx_csum(skb, &hdr->hdr.l2.flags[1], ipv);
-		if (card->options.performance_stats)
-			card->perf_stats.tx_csum++;
+	if (skb_is_gso(skb)) {
+		hdr->hdr.l2.id = QETH_HEADER_TYPE_L2_TSO;
+	} else {
+		hdr->hdr.l2.id = QETH_HEADER_TYPE_LAYER2;
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
+			qeth_tx_csum(skb, &hdr->hdr.l2.flags[1], ipv);
+			if (card->options.performance_stats)
+				card->perf_stats.tx_csum++;
+		}
 	}
 
 	/* set byte byte 3 to casting flags */
@@ -897,6 +901,20 @@ static int qeth_l2_setup_netdev(struct qeth_card *card)
 		card->dev->hw_features |= NETIF_F_RXCSUM;
 		card->dev->vlan_features |= NETIF_F_RXCSUM;
 	}
+	if (qeth_is_supported(card, IPA_OUTBOUND_TSO)) {
+		card->dev->hw_features |= NETIF_F_TSO;
+		card->dev->vlan_features |= NETIF_F_TSO;
+	}
+	if (qeth_is_supported6(card, IPA_OUTBOUND_TSO)) {
+		card->dev->hw_features |= NETIF_F_TSO6;
+		card->dev->vlan_features |= NETIF_F_TSO6;
+	}
+
+	if (card->dev->hw_features & (NETIF_F_TSO | NETIF_F_TSO6)) {
+		card->dev->needed_headroom = sizeof(struct qeth_hdr_tso);
+		netif_set_gso_max_size(card->dev,
+				       PAGE_SIZE * (QDIO_MAX_ELEMENTS_PER_BUFFER - 1));
+	}
 
 	qeth_l2_request_initial_mac(card);
 	netif_napi_add(card->dev, &card->napi, qeth_poll, QETH_NAPI_WEIGHT);

drivers/s390/net/qeth_l3_main.c

@@ -2037,7 +2037,7 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
 	hdr->hdr.l3.length = data_len;
 
 	if (skb_is_gso(skb)) {
-		hdr->hdr.l3.id = QETH_HEADER_TYPE_TSO;
+		hdr->hdr.l3.id = QETH_HEADER_TYPE_L3_TSO;
 	} else {
 		hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;
 		if (skb->ip_summed == CHECKSUM_PARTIAL) {