3 files changed, 17 insertions, 4 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 02f56376fe99..5d0b4f6f1a72 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5425,6 +5425,14 @@ int register_netdevice(struct net_device *dev)
                 dev->features &= ~NETIF_F_GSO;
         }
 
+        /* Turn on no cache copy if HW is doing checksum */
+        dev->hw_features |= NETIF_F_NOCACHE_COPY;
+        if ((dev->features & NETIF_F_ALL_CSUM) &&
+            !(dev->features & NETIF_F_NO_CSUM)) {
+                dev->wanted_features |= NETIF_F_NOCACHE_COPY;
+                dev->features |= NETIF_F_NOCACHE_COPY;
+        }
+
         /* Enable GRO and NETIF_F_HIGHDMA for vlans by default,
          * vlan_dev_init() will do the dev->features check, so these features
          * are enabled only if supported by underlying device.
@@ -6182,6 +6190,10 @@ u32 netdev_increment_features(u32 all, u32 one, u32 mask)
                 }
         }
 
+        /* If device can't no cache copy, don't do for all */
+        if (!(one & NETIF_F_NOCACHE_COPY))
+                all &= ~NETIF_F_NOCACHE_COPY;
+
         one |= NETIF_F_ALL_CSUM;
 
         one |= all & NETIF_F_ONE_FOR_ALL;
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 439e4b0e1312..719670ae199c 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -359,7 +359,7 @@ static const char netdev_features_strings[ETHTOOL_DEV_FEATURE_WORDS * 32][ETH_GS
         /* NETIF_F_NTUPLE */          "rx-ntuple-filter",
         /* NETIF_F_RXHASH */          "rx-hashing",
         /* NETIF_F_RXCSUM */          "rx-checksum",
-        "",
+        /* NETIF_F_NOCACHE_COPY */    "tx-nocache-copy"
         "",
 };
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b22d45010545..054a59d21eb0 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -999,7 +999,8 @@ new_segment:
                                 /* We have some space in skb head. Superb! */
                                 if (copy > skb_tailroom(skb))
                                         copy = skb_tailroom(skb);
-                                if ((err = skb_add_data(skb, from, copy)) != 0)
+                                err = skb_add_data_nocache(sk, skb, from, copy);
+                                if (err)
                                         goto do_fault;
                         } else {
                                 int merge = 0;
@@ -1042,8 +1043,8 @@ new_segment:
 
                                 /* Time to copy data. We are close to
                                  * the end! */
-                                err = skb_copy_to_page(sk, from, skb, page,
-                                                       off, copy);
+                                err = skb_copy_to_page_nocache(sk, from, skb,
+                                                               page, off, copy);
                                 if (err) {
                                         /* If this page was new, give it to the
                                          * socket so it does not get leaked.