From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: add TSO support for L2 devices
Patch-mainline: v4.20-rc1
Git-commit: 0aef8392d257288a7b6a905d19d126bc98f14474
References: FATE#326377, LTC#169210, bsc#1115382

Summary:        qeth: Full-blown TCP Segmentation Offload
Description:    As of now, qeth only supports TCP Segmentation Offload (TSO)
                for IPv4 in Layer3 devices. This feature extends the existing
                support to IPv6, and adds support for TSO in both IP variants
                for Layer2.

                To cleanly pull in all the necessary changes to the transmit
                code, update the qeth driver to the current 4.20 level.


Upstream-Description:

             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>

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/net/qeth_core.h    |    3 ++-
 drivers/s390/net/qeth_l2_main.c |   30 ++++++++++++++++++++++++------
 drivers/s390/net/qeth_l3_main.c |    2 +-
 3 files changed, 27 insertions(+), 8 deletions(-)

--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -389,8 +389,9 @@ 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
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -197,15 +197,19 @@ static void qeth_l2_fill_header(struct q
 				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 q
 		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);
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2037,7 +2037,7 @@ static void qeth_l3_fill_header(struct q
 	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) {