cxgb - fix T2 GSO

The patch ensures that a GSO skb has enough headroom
to push an encapsulating cpl_tx_pkt_lso header.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

3 files changed, 18 insertions, 20 deletions

diff --git a/drivers/net/chelsio/cxgb2.c b/drivers/net/chelsio/cxgb2.c
index 2dbf8dc116c6..2461f91b0996 100644..100755
--- a/drivers/net/chelsio/cxgb2.c
+++ b/drivers/net/chelsio/cxgb2.c
@@ -401,7 +401,8 @@ static char stats_strings[][ETH_GSTRING_LEN] = {
         "TxTso",
         "RxVlan",
         "TxVlan",
-
+        "TxNeedHeadroom", 
+        
         /* Interrupt stats */
         "rx drops",
         "pure_rsps",
diff --git a/drivers/net/chelsio/sge.c b/drivers/net/chelsio/sge.c
index 443666292a5c..e8b1036672ae 100644..100755
--- a/drivers/net/chelsio/sge.c
+++ b/drivers/net/chelsio/sge.c
@@ -991,6 +991,7 @@ void t1_sge_get_port_stats(const struct sge *sge, int port,
                 ss->tx_packets += st->tx_packets;
                 ss->tx_cso += st->tx_cso;
                 ss->tx_tso += st->tx_tso;
+                ss->tx_need_hdrroom += st->tx_need_hdrroom;
                 ss->vlan_xtract += st->vlan_xtract;
                 ss->vlan_insert += st->vlan_insert;
         }
@@ -1848,7 +1849,8 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct adapter *adapter = dev->priv;
         struct sge *sge = adapter->sge;
-        struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[dev->if_port], smp_processor_id());
+        struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[dev->if_port],
+                                                smp_processor_id());
         struct cpl_tx_pkt *cpl;
         struct sk_buff *orig_skb = skb;
         int ret;
@@ -1856,6 +1858,18 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
         if (skb->protocol == htons(ETH_P_CPL5))
                 goto send;
 
+        /*
+         * We are using a non-standard hard_header_len.
+         * Allocate more header room in the rare cases it is not big enough.
+         */
+        if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
+                skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
+                ++st->tx_need_hdrroom;
+                dev_kfree_skb_any(orig_skb);
+                if (!skb)
+                        return NETDEV_TX_OK;
+        }
+
         if (skb_shinfo(skb)->gso_size) {
                 int eth_type;
                 struct cpl_tx_pkt_lso *hdr;
@@ -1889,24 +1903,6 @@ int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
                         return NETDEV_TX_OK;
                 }
 
-                /*
-                 * We are using a non-standard hard_header_len and some kernel
-                 * components, such as pktgen, do not handle it right.
-                 * Complain when this happens but try to fix things up.
-                 */
-                if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
-                        pr_debug("%s: headroom %d header_len %d\n", dev->name,
-                                 skb_headroom(skb), dev->hard_header_len);
-
-                        if (net_ratelimit())
-                                printk(KERN_ERR "%s: inadequate headroom in "
-                                       "Tx packet\n", dev->name);
-                        skb = skb_realloc_headroom(skb, sizeof(*cpl));
-                        dev_kfree_skb_any(orig_skb);
-                        if (!skb)
-                                return NETDEV_TX_OK;
-                }
-
                 if (!(adapter->flags & UDP_CSUM_CAPABLE) &&
                     skb->ip_summed == CHECKSUM_PARTIAL &&
                     ip_hdr(skb)->protocol == IPPROTO_UDP) {
diff --git a/drivers/net/chelsio/sge.h b/drivers/net/chelsio/sge.h
index 713d9c55f24d..285bbb272ed5 100644..100755
--- a/drivers/net/chelsio/sge.h
+++ b/drivers/net/chelsio/sge.h
@@ -64,6 +64,7 @@ struct sge_port_stats {
         u64 tx_tso;          /* # of TSO requests */
         u64 vlan_xtract;     /* # of VLAN tag extractions */
         u64 vlan_insert;     /* # of VLAN tag insertions */
+        u64 tx_need_hdrroom; /* # of TX skbs in need of more header room */
 };
 
 struct sk_buff;