This is very similar to the problem and solution from commit
232deb3f9567 ("net: dsa: avoid refcount warnings when
->port_{fdb,mdb}_del returns error"), except for the
dsa_port_do_tag_8021q_vlan_del() operation.

Fixes: c64b9c05045a ("net: dsa: tag_8021q: add proper cross-chip notifier support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20250414213020.2959021-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The 'dsa_tag_8021q_bridge_join' could be used as a generic implementation
of the 'ds->ops->port_bridge_join()' function. However, it is necessary
to synchronize their arguments.

This patch also moves the 'tx_fwd_offload' flag configuration line into
'dsa_tag_8021q_bridge_join' body. Currently, every (sja1105) driver sets
it, and the future vsc73xx implementation will also need it for
simplification.

Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20240713211620.1125910-11-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A new tagging protocol implementation based on tag_8021q is on the
horizon, and it appears that it also has to open-code the complicated
logic of finding a source port based on a VLAN header.

Create a single dsa_tag_8021q_find_user() and make sja1105 call it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240713211620.1125910-7-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tag_sja1105 has a wrapper over dsa_8021q_rcv(): sja1105_vlan_rcv(),
which determines whether the packet came from a bridge with
vlan_filtering=1 (the case resolved via
dsa_find_designated_bridge_port_by_vid()), or if it contains a tag_8021q
header.

Looking at a new tagger implementation for vsc73xx, based also on
tag_8021q, it is becoming clear that the logic is needed there as well.
So instead of forcing each tagger to wrap around dsa_8021q_rcv(), let's
merge the logic into the core.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Link: https://patch.msgid.link/20240713211620.1125910-5-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In both sja1105_rcv() and sja1110_rcv(), we may have precise source port
information coming from parallel hardware mechanisms, in addition to the
tag_8021q header.

Only sja1105_rcv() has extra logic to not overwrite that precise info
with what's present in the VLAN tag. This is because sja1110_rcv() gets
by, by having a reversed set of checks when assigning skb->dev. When the
source port is imprecise (vbid >=1), source_port and switch_id will be
set to zeroes by dsa_8021q_rcv(), which might be problematic. But by
checking for vbid >= 1 first, sja1110_rcv() fends that off.

We would like to make more code common between sja1105_rcv() and
sja1110_rcv(), and for that, we need to make sure that sja1110_rcv()
also goes through the precise source port preservation logic.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20240713211620.1125910-4-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Use more inclusive terms throughout the DSA subsystem by moving away
from "master" which is replaced by "conduit" and "slave" which is
replaced by "user". No functional changes.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231023181729.1191071-2-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Once commit 6d1ccff62780 ("net: reset mac header in dev_start_xmit()")
will be reverted, it will no longer be true that skb->data points at
skb_mac_header(skb) - since the skb->mac_header will not be set - so
stop saying that, and just say that it points to the MAC header.

I've reviewed vlan_insert_tag() and it does not *actually* depend on
skb_mac_header(), so reword that to avoid the confusion.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge in the left-over fixes before the net-next pull-request.

net/mptcp/subflow.c
  d3295fee3c75 ("mptcp: use proper req destructor for IPv6")
  36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()")

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

If dsa_tag_8021q_setup() fails, for example due to the inability of the
device to install a VLAN, the tag_8021q context of the switch will leak.
Make sure it is freed on the error path.

Fixes: 328621f6131f ("net: dsa: tag_8021q: absorb dsa_8021q_setup into dsa_tag_8021q_{,un}register")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20221209235242.480344-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The last remnants in dsa_priv.h are a netlink-related definition for
which we create a new header, and DSA_MAX_NUM_OFFLOADING_BRIDGES which
is only used from dsa.c, so move it there.

Some inclusions need to be adjusted now that we no longer have headers
included transitively from dsa_priv.h.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>