tcp: Apply device TSO segment limit earlier

Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to
limit the size of TSO skbs.  This avoids the need to fall back to
software GSO for local TCP senders.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index b3730239bf18..72132aef53fc 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -218,6 +218,7 @@ struct cg_proto;
   *     @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
   *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
   *     @sk_gso_max_size: Maximum GSO segment size to build
+  *     @sk_gso_max_segs: Maximum number of GSO segments
   *     @sk_lingertime: %SO_LINGER l_linger setting
   *     @sk_backlog: always used with the per-socket spinlock held
   *     @sk_callback_lock: used with the callbacks in the end of this struct
@@ -338,6 +339,7 @@ struct sock {
         netdev_features_t       sk_route_nocaps;
         int                     sk_gso_type;
         unsigned int            sk_gso_max_size;
+        u16                     sk_gso_max_segs;
         int                     sk_rcvlowat;
         unsigned long           sk_lingertime;
         struct sk_buff_head     sk_error_queue;