net: dsa: reduce number of protocol hooks

DSA is currently registering one packet_type function per EtherType it
needs to intercept in the receive path of a DSA-enabled Ethernet device.
Right now we have three of them: trailer, DSA and eDSA, and there might
be more in the future, this will not scale to the addition of new
protocols.

This patch proceeds with adding a new layer of abstraction and two new
functions:

dsa_switch_rcv() which will dispatch into the tag-protocol specific
receive function implemented by net/dsa/tag_*.c

dsa_slave_xmit() which will dispatch into the tag-protocol specific
transmit function implemented by net/dsa/tag_*.c

When we do create the per-port slave network devices, we iterate over
the switch protocol to assign the DSA-specific receive and transmit
operations.

A new fake ethertype value is used: ETH_P_XDSA to illustrate the fact
that this is no longer going to look like ETH_P_DSA or ETH_P_TRAILER
like it used to be.

This allows us to greatly simplify the check in eth_type_trans() and
always override the skb->protocol with ETH_P_XDSA for Ethernet switches
tagged protocol, while also reducing the number repetitive slave
netdevice_ops assignments.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c
index e70c43c25e64..6b30abe89183 100644
--- a/net/dsa/tag_edsa.c
+++ b/net/dsa/tag_edsa.c
@@ -17,7 +17,7 @@
 #define DSA_HLEN	4
 #define EDSA_HLEN	8
 
-netdev_tx_t edsa_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t edsa_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct dsa_slave_priv *p = netdev_priv(dev);
 	u8 *edsa_header;
@@ -205,7 +205,7 @@ out:
 	return 0;
 }
 
-struct packet_type edsa_packet_type __read_mostly = {
-	.type	= cpu_to_be16(ETH_P_EDSA),
-	.func	= edsa_rcv,
+const struct dsa_device_ops edsa_netdev_ops = {
+	.xmit	= edsa_xmit,
+	.rcv	= edsa_rcv,
 };