Revert "net: dsa: Allow drivers to filter packets they can decode source port from"

This reverts commit cc1939e4b3.

Currently 2 classes of DSA drivers are able to send/receive packets
directly through the DSA master:
- drivers with DSA_TAG_PROTO_NONE
- sja1105

Now that sja1105 has gained the ability to perform traffic termination
even under the tricky case (VLAN-aware bridge), and that is much more
functional (we can perform VLAN-aware bridging with foreign interfaces),
there is no reason to keep this code in the receive path of the network
core. So delete it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -88,11 +88,6 @@ struct dsa_device_ops {
 			       struct packet_type *pt);
 	void (*flow_dissect)(const struct sk_buff *skb, __be16 *proto,
 			     int *offset);
-	/* Used to determine which traffic should match the DSA filter in
-	 * eth_type_trans, and which, if any, should bypass it and be processed
-	 * as regular on the master net device.
-	 */
-	bool (*filter)(const struct sk_buff *skb, struct net_device *dev);
 	unsigned int needed_headroom;
 	unsigned int needed_tailroom;
 	const char *name;
@@ -246,7 +241,6 @@ struct dsa_port {
 	struct dsa_switch_tree *dst;
 	struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev,
 			       struct packet_type *pt);
-	bool (*filter)(const struct sk_buff *skb, struct net_device *dev);
 
 	enum {
 		DSA_PORT_TYPE_UNUSED = 0,
@@ -985,15 +979,6 @@ static inline bool netdev_uses_dsa(const struct net_device *dev)
 	return false;
 }
 
-static inline bool dsa_can_decode(const struct sk_buff *skb,
-				  struct net_device *dev)
-{
-#if IS_ENABLED(CONFIG_NET_DSA)
-	return !dev->dsa_ptr->filter || dev->dsa_ptr->filter(skb, dev);
-#endif
-	return false;
-}
-
 /* All DSA tags that push the EtherType to the right (basically all except tail
  * tags, which don't break dissection) can be treated the same from the
  * perspective of the flow dissector.