s390/qeth: speed-up IPv4 OSA xmit

Move the xmit of offload-eligible (ie IPv4) traffic on OSA over to the
new, copy-free path.
As with L2, we'll need to preserve the skb_orphan() behaviour of the
old code path until TX completion is sufficiently fast.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 0863ffa9ab59013c13f87783dfe27391236abea9..062f62b4929490504f0b341a9c49f2e8c25e5e21 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2050,6 +2050,12 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr,
                hdr->hdr.l3.vlan_id = skb_vlan_tag_get(skb);
        }
 
+       if (!skb_is_gso(skb) && skb->ip_summed == CHECKSUM_PARTIAL) {
+               qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);
+               if (card->options.performance_stats)
+                       card->perf_stats.tx_csum++;
+       }
+
        /* OSA only: */
        if (!ipv) {
                hdr->hdr.l3.flags = QETH_HDR_PASSTHRU;
@@ -2164,8 +2170,8 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,
        unsigned char eth_hdr[ETH_HLEN];
        unsigned int hdr_elements = 0;
        struct qeth_hdr *hdr = NULL;
+       int elements, push_len, rc;
        unsigned int hd_len = 0;
-       int push_len, rc;
 
        /* compress skb to fit into one IO buffer: */
        if (!qeth_get_elements_no(card, skb, 0, 0)) {
@@ -2199,17 +2205,26 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,
                hdr_elements = 1;
        }
 
-       if (!qeth_get_elements_no(card, skb, hdr_elements, 0)) {
+       elements = qeth_get_elements_no(card, skb, hdr_elements, 0);
+       if (!elements) {
                rc = -E2BIG;
                goto out;
        }
+       elements += hdr_elements;
 
        if (skb->protocol == htons(ETH_P_AF_IUCV))
                qeth_l3_fill_af_iucv_hdr(hdr, skb, frame_len);
        else
                qeth_l3_fill_header(card, hdr, skb, ipv, cast_type, frame_len);
 
-       rc = qeth_do_send_packet_fast(queue, skb, hdr, 0, hd_len);
+       if (IS_IQD(card)) {
+               rc = qeth_do_send_packet_fast(queue, skb, hdr, 0, hd_len);
+       } else {
+               /* TODO: drop skb_orphan() once TX completion is fast enough */
+               skb_orphan(skb);
+               rc = qeth_do_send_packet(card, queue, skb, hdr, 0, hd_len,
+                                        elements);
+       }
 out:
        if (!rc) {
                if (card->options.performance_stats && nr_frags) {
@@ -2295,12 +2310,6 @@ static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb,
                hdr = skb_push(new_skb, sizeof(struct qeth_hdr));
                qeth_l3_fill_header(card, hdr, new_skb, ipv, cast_type,
                                    new_skb->len - sizeof(struct qeth_hdr));
-
-               if (new_skb->ip_summed == CHECKSUM_PARTIAL) {
-                       qeth_tx_csum(new_skb, &hdr->hdr.l3.ext_flags, ipv);
-                       if (card->options.performance_stats)
-                               card->perf_stats.tx_csum++;
-               }
        }
 
        elements = use_tso ?
@@ -2384,7 +2393,7 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb,
        }
        netif_stop_queue(dev);
 
-       if (IS_IQD(card))
+       if (IS_IQD(card) || (!skb_is_gso(skb) && ipv == 4))
                rc = qeth_l3_xmit_offload(card, skb, queue, ipv, cast_type);
        else
                rc = qeth_l3_xmit(card, skb, queue, ipv, cast_type);
@@ -2563,9 +2572,7 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
                if (!card->dev)
                        return -ENODEV;
                card->dev->flags |= IFF_NOARP;
-               card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;
                card->dev->netdev_ops = &qeth_l3_netdev_ops;
-               card->dev->needed_headroom = sizeof(struct qeth_hdr) - ETH_HLEN;
 
                rc = qeth_l3_iqd_read_initial_mac(card);
                if (rc)
@@ -2582,6 +2589,8 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
        card->dev->max_mtu = ETH_MAX_MTU;
        card->dev->dev_port = card->info.portno;
        card->dev->ethtool_ops = &qeth_l3_ethtool_ops;
+       card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+       card->dev->needed_headroom = sizeof(struct qeth_hdr) - ETH_HLEN;
        card->dev->features |=  NETIF_F_HW_VLAN_CTAG_TX |
                                NETIF_F_HW_VLAN_CTAG_RX |
                                NETIF_F_HW_VLAN_CTAG_FILTER;