sunvnet: add TSO support

This patch adds TSO support for the sunvnet driver.

Signed-off-by: David L Stevens <david.stevens@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 95 insertions, 9 deletions

diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index d19b3582cdf0..aac7d933319b 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -120,8 +120,15 @@ static int vnet_send_attr(struct vio_driver_state *vio)
                 pkt.mtu = framelen + VLAN_HLEN;
         }
 
-        pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
         pkt.cflags = 0;
+        if (vio_version_after_eq(vio, 1, 7) && port->tso) {
+                pkt.cflags |= VNET_LSO_IPV4_CAPAB;
+                if (!port->tsolen)
+                        port->tsolen = VNET_MAXTSO;
+                pkt.ipv4_lso_maxlen = port->tsolen;
+        }
+
+        pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
 
         viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
                "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
@@ -175,6 +182,26 @@ static int handle_attr_info(struct vio_driver_state *vio,
         }
         port->rmtu = localmtu;
 
+        /* LSO negotiation */
+        if (vio_version_after_eq(vio, 1, 7))
+                port->tso &= !!(pkt->cflags & VNET_LSO_IPV4_CAPAB);
+        else
+                port->tso = false;
+        if (port->tso) {
+                if (!port->tsolen)
+                        port->tsolen = VNET_MAXTSO;
+                port->tsolen = min(port->tsolen, pkt->ipv4_lso_maxlen);
+                if (port->tsolen < VNET_MINTSO) {
+                        port->tso = false;
+                        port->tsolen = 0;
+                        pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
+                }
+                pkt->ipv4_lso_maxlen = port->tsolen;
+        } else {
+                pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
+                pkt->ipv4_lso_maxlen = 0;
+        }
+
         /* for version >= 1.6, ACK packet mode we support */
         if (vio_version_after_eq(vio, 1, 6)) {
                 pkt->xfer_mode = VIO_NEW_DRING_MODE;
@@ -721,6 +748,8 @@ ldc_ctrl:
 
                 if (event == LDC_EVENT_RESET) {
                         port->rmtu = 0;
+                        port->tso = true;
+                        port->tsolen = 0;
                         vio_port_up(vio);
                 }
                 port->rx_event = 0;
@@ -1131,10 +1160,36 @@ static int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb)
         struct net_device *dev = port->vp->dev;
         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
         struct sk_buff *segs;
-        int maclen;
+        int maclen, datalen;
         int status;
+        int gso_size, gso_type, gso_segs;
+        int hlen = skb_transport_header(skb) - skb_mac_header(skb);
+        int proto = IPPROTO_IP;
+
+        if (skb->protocol == htons(ETH_P_IP))
+                proto = ip_hdr(skb)->protocol;
+        else if (skb->protocol == htons(ETH_P_IPV6))
+                proto = ipv6_hdr(skb)->nexthdr;
+
+        if (proto == IPPROTO_TCP)
+                hlen += tcp_hdr(skb)->doff * 4;
+        else if (proto == IPPROTO_UDP)
+                hlen += sizeof(struct udphdr);
+        else {
+                pr_err("vnet_handle_offloads GSO with unknown transport "
+                       "protocol %d tproto %d\n", skb->protocol, proto);
+                hlen = 128; /* XXX */
+        }
+        datalen = port->tsolen - hlen;
+
+        gso_size = skb_shinfo(skb)->gso_size;
+        gso_type = skb_shinfo(skb)->gso_type;
+        gso_segs = skb_shinfo(skb)->gso_segs;
+
+        if (port->tso && gso_size < datalen)
+                gso_segs = DIV_ROUND_UP(skb->len - hlen, datalen);
 
-        if (unlikely(vnet_tx_dring_avail(dr) < skb_shinfo(skb)->gso_segs)) {
+        if (unlikely(vnet_tx_dring_avail(dr) < gso_segs)) {
                 struct netdev_queue *txq;
 
                 txq  = netdev_get_tx_queue(dev, port->q_index);
@@ -1147,7 +1202,19 @@ static int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb)
         maclen = skb_network_header(skb) - skb_mac_header(skb);
         skb_pull(skb, maclen);
 
-        segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
+        if (port->tso && gso_size < datalen) {
+                /* segment to TSO size */
+                skb_shinfo(skb)->gso_size = datalen;
+                skb_shinfo(skb)->gso_segs = gso_segs;
+
+                segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
+
+                /* restore gso_size & gso_segs */
+                skb_shinfo(skb)->gso_size = gso_size;
+                skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len - hlen,
+                                                         gso_size);
+        } else
+                segs = skb_gso_segment(skb, dev->features & ~NETIF_F_TSO);
         if (IS_ERR(segs)) {
                 dev->stats.tx_dropped++;
                 return NETDEV_TX_OK;
@@ -1162,6 +1229,13 @@ static int vnet_handle_offloads(struct vnet_port *port, struct sk_buff *skb)
 
                 segs = segs->next;
                 curr->next = NULL;
+                if (port->tso && curr->len > dev->mtu) {
+                        skb_shinfo(curr)->gso_size = gso_size;
+                        skb_shinfo(curr)->gso_type = gso_type;
+                        skb_shinfo(curr)->gso_segs =
+                                DIV_ROUND_UP(curr->len - hlen, gso_size);
+                } else
+                        skb_shinfo(curr)->gso_size = 0;
 
                 skb_push(curr, maclen);
                 skb_reset_mac_header(curr);
@@ -1203,13 +1277,13 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 goto out_dropped;
         }
 
-        if (skb_is_gso(skb)) {
+        if (skb_is_gso(skb) && skb->len > port->tsolen) {
                 err = vnet_handle_offloads(port, skb);
                 rcu_read_unlock();
                 return err;
         }
 
-        if (skb->len > port->rmtu) {
+        if (!skb_is_gso(skb) && skb->len > port->rmtu) {
                 unsigned long localmtu = port->rmtu - ETH_HLEN;
 
                 if (vio_version_after_eq(&port->vio, 1, 3))
@@ -1306,6 +1380,11 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 struct vio_net_dext *dext = vio_net_ext(d);
 
                 memset(dext, 0, sizeof(*dext));
+                if (skb_is_gso(port->tx_bufs[txi].skb)) {
+                        dext->ipv4_lso_mss = skb_shinfo(port->tx_bufs[txi].skb)
+                                             ->gso_size;
+                        dext->flags |= VNET_PKT_IPV4_LSO;
+                }
                 if (vio_version_after_eq(&port->vio, 1, 8) &&
                     !port->switch_port) {
                         dext->flags |= VNET_PKT_HCK_IPV4_HDRCKSUM_OK;
@@ -1712,7 +1791,7 @@ static struct vnet *vnet_new(const u64 *local_mac)
         dev->ethtool_ops = &vnet_ethtool_ops;
         dev->watchdog_timeo = VNET_TX_TIMEOUT;
 
-        dev->hw_features = NETIF_F_GSO | NETIF_F_GSO_SOFTWARE |
+        dev->hw_features = NETIF_F_TSO | NETIF_F_GSO | NETIF_F_GSO_SOFTWARE |
                            NETIF_F_HW_CSUM | NETIF_F_SG;
         dev->features = dev->hw_features;
 
@@ -1892,6 +1971,8 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
         if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL) != NULL)
                 switch_port = 1;
         port->switch_port = switch_port;
+        port->tso = true;
+        port->tsolen = 0;
 
         spin_lock_irqsave(&vp->lock, flags);
         if (switch_port)
diff --git a/drivers/net/ethernet/sun/sunvnet.h b/drivers/net/ethernet/sun/sunvnet.h
index cd5d343ea232..01ca78191683 100644
--- a/drivers/net/ethernet/sun/sunvnet.h
+++ b/drivers/net/ethernet/sun/sunvnet.h
@@ -20,6 +20,9 @@
 #define VNET_TX_RING_SIZE               512
 #define VNET_TX_WAKEUP_THRESH(dr)       ((dr)->pending / 4)
 
+#define VNET_MINTSO      2048   /* VIO protocol's minimum TSO len */
+#define VNET_MAXTSO     65535   /* VIO protocol's maximum TSO len */
+
 /* VNET packets are sent in buffers with the first 6 bytes skipped
  * so that after the ethernet header the IPv4/IPv6 headers are aligned
  * properly.
@@ -40,8 +43,9 @@ struct vnet_port {
 
         struct hlist_node       hash;
         u8                      raddr[ETH_ALEN];
-        u8                      switch_port;
-        u8                      __pad;
+        unsigned                switch_port:1;
+        unsigned                tso:1;
+        unsigned                __pad:14;
 
         struct vnet             *vp;
 
@@ -56,6 +60,7 @@ struct vnet_port {
         struct timer_list       clean_timer;
 
         u64                     rmtu;
+        u16                     tsolen;
 
         struct napi_struct      napi;
         u32                     napi_stop_idx;