net: fix netdev_increment_features()

Simplify and fix netdev_increment_features() to conform to what is
stated in netdevice.h comments about NETIF_F_ONE_FOR_ALL.
Include FCoE segmentation and VLAN-challedged flags in computation.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 24 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 3bbb4c2ce92e..7db99b52679f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6164,33 +6164,20 @@ static int dev_cpu_callback(struct notifier_block *nfb,
  */
 u32 netdev_increment_features(u32 all, u32 one, u32 mask)
 {
-        /* If device needs checksumming, downgrade to it. */
-        if (all & NETIF_F_NO_CSUM && !(one & NETIF_F_NO_CSUM))
-                all ^= NETIF_F_NO_CSUM | (one & NETIF_F_ALL_CSUM);
-        else if (mask & NETIF_F_ALL_CSUM) {
-                /* If one device supports v4/v6 checksumming, set for all. */
-                if (one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM) &&
-                    !(all & NETIF_F_GEN_CSUM)) {
-                        all &= ~NETIF_F_ALL_CSUM;
-                        all |= one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
-                }
-
-                /* If one device supports hw checksumming, set for all. */
-                if (one & NETIF_F_GEN_CSUM && !(all & NETIF_F_GEN_CSUM)) {
-                        all &= ~NETIF_F_ALL_CSUM;
-                        all |= NETIF_F_HW_CSUM;
-                }
-        }
+        if (mask & NETIF_F_GEN_CSUM)
+                mask |= NETIF_F_ALL_CSUM;
+        mask |= NETIF_F_VLAN_CHALLENGED;
 
-        /* If device can't no cache copy, don't do for all */
-        if (!(one & NETIF_F_NOCACHE_COPY))
-                all &= ~NETIF_F_NOCACHE_COPY;
+        all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
+        all &= one | ~NETIF_F_ALL_FOR_ALL;
 
-        one |= NETIF_F_ALL_CSUM;
+        /* If device needs checksumming, downgrade to it. */
+        if (all & (NETIF_F_ALL_CSUM & ~NETIF_F_NO_CSUM))
+                all &= ~NETIF_F_NO_CSUM;
 
-        one |= all & NETIF_F_ONE_FOR_ALL;
-        all &= one | NETIF_F_LLTX | NETIF_F_GSO | NETIF_F_UFO;
-        all |= one & mask & NETIF_F_ONE_FOR_ALL;
+        /* If one device supports hw checksumming, set for all. */
+        if (all & NETIF_F_GEN_CSUM)
+                all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
 
         return all;
 }