switchdev: add offload_fwd_mark generator helper

skb->offload_fwd_mark and dev->offload_fwd_mark are 32-bit and should be
unique for device and may even be unique for a sub-set of ports within
device, so add switchdev helper function to generate unique marks based on
port's switch ID and group_ifindex.  group_ifindex would typically be the
container dev's ifindex, such as the bridge's ifindex.

The generator uses a global hash table to store offload_fwd_marks hashed by
{switch ID, group_ifindex} key.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index d5671f118bfc..89da8934519b 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -157,6 +157,9 @@ int switchdev_port_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
 int switchdev_port_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
                             struct net_device *dev,
                             struct net_device *filter_dev, int idx);
+void switchdev_port_fwd_mark_set(struct net_device *dev,
+                                 struct net_device *group_dev,
+                                 bool joining);
 
 #else
 
@@ -271,6 +274,12 @@ static inline int switchdev_port_fdb_dump(struct sk_buff *skb,
         return -EOPNOTSUPP;
 }
 
+static inline void switchdev_port_fwd_mark_set(struct net_device *dev,
+                                               struct net_device *group_dev,
+                                               bool joining)
+{
+}
+
 #endif
 
 #endif /* _LINUX_SWITCHDEV_H_ */