net: dsa: tag_8021q: merge RX and TX VLANs

In the old Shared VLAN Learning mode of operation that tag_8021q
previously used for forwarding, we needed to have distinct concepts for
an RX and a TX VLAN.

An RX VLAN could be installed on all ports that were members of a given
bridge, so that autonomous forwarding could still work, while a TX VLAN
was dedicated for precise packet steering, so it just contained the CPU
port and one egress port.

Now that tag_8021q uses Independent VLAN Learning and imprecise RX/TX
all over, those lines have been blurred and we no longer have the need
to do precise TX towards a port that is in a bridge. As for standalone
ports, it is fine to use the same VLAN ID for both RX and TX.

This patch changes the tag_8021q format by shifting the VLAN range it
reserves, and halving it. Previously, our DIR bits were encoding the
VLAN direction (RX/TX) and were set to either 1 or 2. This meant that
tag_8021q reserved 2K VLANs, or 50% of the available range.

Change the DIR bits to a hardcoded value of 3 now, which makes tag_8021q
reserve only 1K VLANs, and a different range now (the last 1K). This is
done so that we leave the old format in place in case we need to return
to it.

In terms of code, the vid_is_dsa_8021q_rxvlan and vid_is_dsa_8021q_txvlan
functions go away. Any vid_is_dsa_8021q is both a TX and an RX VLAN, and
they are no longer distinct. For example, felix which did different
things for different VLAN types, now needs to handle the RX and the TX
logic for the same VLAN.

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

1 files changed, 1 insertions, 7 deletions

diff --git a/include/linux/dsa/8021q.h b/include/linux/dsa/8021q.h
index 92f5243b841e..b4e2862633f6 100644
--- a/include/linux/dsa/8021q.h
+++ b/include/linux/dsa/8021q.h
@@ -49,18 +49,12 @@ struct net_device *dsa_tag_8021q_find_port_by_vbid(struct net_device *master,
 
 u16 dsa_8021q_bridge_tx_fwd_offload_vid(unsigned int bridge_num);
 
-u16 dsa_tag_8021q_tx_vid(const struct dsa_port *dp);
-
-u16 dsa_tag_8021q_rx_vid(const struct dsa_port *dp);
+u16 dsa_tag_8021q_standalone_vid(const struct dsa_port *dp);
 
 int dsa_8021q_rx_switch_id(u16 vid);
 
 int dsa_8021q_rx_source_port(u16 vid);
 
-bool vid_is_dsa_8021q_rxvlan(u16 vid);
-
-bool vid_is_dsa_8021q_txvlan(u16 vid);
-
 bool vid_is_dsa_8021q(u16 vid);
 
 #endif /* _NET_DSA_8021Q_H */