[I/OAT]: TCP recv offload to I/OAT

Locks down user pages and sets up for DMA in tcp_recvmsg, then calls
dma_async_try_early_copy in tcp_v4_do_rcv

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 1 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 672950e54c49..25ecc6e2478b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -71,6 +71,7 @@
 #include <net/inet_common.h>
 #include <net/timewait_sock.h>
 #include <net/xfrm.h>
+#include <net/netdma.h>
 
 #include <linux/inet.h>
 #include <linux/ipv6.h>
@@ -1091,8 +1092,18 @@ process:
         bh_lock_sock(sk);
         ret = 0;
         if (!sock_owned_by_user(sk)) {
-                if (!tcp_prequeue(sk, skb))
+#ifdef CONFIG_NET_DMA
+                struct tcp_sock *tp = tcp_sk(sk);
+                if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
+                        tp->ucopy.dma_chan = get_softnet_dma();
+                if (tp->ucopy.dma_chan)
                         ret = tcp_v4_do_rcv(sk, skb);
+                else
+#endif
+                {
+                        if (!tcp_prequeue(sk, skb))
+                        ret = tcp_v4_do_rcv(sk, skb);
+                }
         } else
                 sk_add_backlog(sk, skb);
         bh_unlock_sock(sk);
@@ -1296,6 +1307,11 @@ int tcp_v4_destroy_sock(struct sock *sk)
         /* Cleans up our, hopefully empty, out_of_order_queue. */
         __skb_queue_purge(&tp->out_of_order_queue);
 
+#ifdef CONFIG_NET_DMA
+        /* Cleans up our sk_async_wait_queue */
+        __skb_queue_purge(&sk->sk_async_wait_queue);
+#endif
+
         /* Clean prequeue, it must be empty really */
         __skb_queue_purge(&tp->ucopy.prequeue);