6 files changed, 73 insertions, 6 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 16d6fe954695..b51e021354b5 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1407,7 +1407,7 @@ static int bond_compute_features(struct bonding *bond)
         int i;
 
         features &= ~(NETIF_F_ALL_CSUM | BOND_VLAN_FEATURES);
-        features |=  NETIF_F_GSO_MASK | NETIF_F_NO_CSUM;
+        features |=  NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_NOCACHE_COPY;
 
         if (!bond->first_slave)
                 goto done;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a4664cc68e2b..09d262415769 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1066,6 +1066,7 @@ struct net_device {
 #define NETIF_F_NTUPLE          (1 << 27) /* N-tuple filters supported */
 #define NETIF_F_RXHASH          (1 << 28) /* Receive hashing offload */
 #define NETIF_F_RXCSUM          (1 << 29) /* Receive checksumming offload */
+#define NETIF_F_NOCACHE_COPY    (1 << 30) /* Use no-cache copyfromuser */
 
         /* Segmentation offload features */
 #define NETIF_F_GSO_SHIFT       16
@@ -1081,7 +1082,7 @@ struct net_device {
         /* = all defined minus driver/device-class-related */
 #define NETIF_F_NEVER_CHANGE    (NETIF_F_HIGHDMA | NETIF_F_VLAN_CHALLENGED | \
                                   NETIF_F_LLTX | NETIF_F_NETNS_LOCAL)
-#define NETIF_F_ETHTOOL_BITS    (0x3f3fffff & ~NETIF_F_NEVER_CHANGE)
+#define NETIF_F_ETHTOOL_BITS    (0x7f3fffff & ~NETIF_F_NEVER_CHANGE)
 
         /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE    (NETIF_F_TSO | NETIF_F_TSO_ECN | \
diff --git a/include/net/sock.h b/include/net/sock.h
index da0534d3401c..43bd515e92fd 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -52,6 +52,7 @@
 #include <linux/mm.h>
 #include <linux/security.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 
 #include <linux/filter.h>
 #include <linux/rculist_nulls.h>
@@ -1389,6 +1390,58 @@ static inline void sk_nocaps_add(struct sock *sk, int flags)
         sk->sk_route_caps &= ~flags;
 }
 
+static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                           char __user *from, char *to,
+                                           int copy)
+{
+        if (skb->ip_summed == CHECKSUM_NONE) {
+                int err = 0;
+                __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
+                if (err)
+                        return err;
+                skb->csum = csum_block_add(skb->csum, csum, skb->len);
+        } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
+                if (!access_ok(VERIFY_READ, from, copy) ||
+                    __copy_from_user_nocache(to, from, copy))
+                        return -EFAULT;
+        } else if (copy_from_user(to, from, copy))
+                return -EFAULT;
+
+        return 0;
+}
+
+static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                       char __user *from, int copy)
+{
+        int err;
+
+        err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), copy);
+        if (err)
+                __skb_trim(skb, skb->len);
+
+        return err;
+}
+
+static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
+                                           struct sk_buff *skb,
+                                           struct page *page,
+                                           int off, int copy)
+{
+        int err;
+
+        err = skb_do_copy_data_nocache(sk, skb, from,
+                                       page_address(page) + off, copy);
+        if (err)
+                return err;
+
+        skb->len             += copy;
+        skb->data_len        += copy;
+        skb->truesize        += copy;
+        sk->sk_wmem_queued   += copy;
+        sk_mem_charge(sk, copy);
+        return 0;
+}
+
 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
                                    struct sk_buff *skb, struct page *page,
                                    int off, int copy)
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.