This reverts commit 965e6b26, reversing
changes made to 4d98bb0d.

After talking with Ido Schimmel, it became clear that rtnl_lock is not
actually required for anything that is done inside the
SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE deferred work handlers.

The reason why it was probably added by Arkadi Sharshevsky in commit
c9eb3e0f ("net: dsa: Add support for learning FDB through
notification") was to offer the same locking/serialization guarantees as
.ndo_fdb_{add,del} and avoid reworking any drivers.

DSA has implemented .ndo_fdb_add and .ndo_fdb_del until commit
b117e1e8 ("net: dsa: delete dsa_legacy_fdb_add and
dsa_legacy_fdb_del") - that is to say, until fairly recently.

But those methods have been deleted, so now we are free to drop the
rtnl_lock as well.

Note that exposing DSA switch drivers to an unlocked method which was
previously serialized by the rtnl_mutex is a potentially dangerous
affair. Driver writers couldn't ensure that their internal locking
scheme does the right thing even if they wanted.

We could err on the side of paranoia and introduce a switch-wide lock
inside the DSA framework, but that seems way overreaching. Instead, we
could check as many drivers for regressions as we can, fix those first,
then let this change go in once it is assumed to be fairly safe.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ever since Vivien's conversion of the ds->ports array into a dst->ports
list, and the introduction of dsa_to_port, iterations through the ports
of a switch became quadratic whenever dsa_to_port was needed.

dsa_to_port can either be called directly, or indirectly through the
dsa_is_{user,cpu,dsa,unused}_port helpers.

Use the newly introduced dsa_switch_for_each_port() iteration macro
that works with the iterator variable being a struct dsa_port *dp
directly, and not an int i. It is an expensive variable to go from i to
dp, but cheap to go from dp to i.

This macro iterates through the entire ds->dst->ports list and filters
by the ports belonging just to the switch provided as argument.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jakub pointed out that we have a new ethtool API for reporting device
statistics in a standardized way, via .get_eth_{phy,mac,ctrl}_stats.
Add a small amount of plumbing to allow DSA drivers to take advantage of
this when exposing statistics.
Suggested-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert from ether_addr_copy() to eth_hw_addr_set():

  @@
  expression dev, np;
  @@
  - ether_addr_copy(dev->dev_addr, np)
  + eth_hw_addr_set(dev, np)
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA supports connecting to a phy-handle, and has a fallback to a non-OF
based method of connecting to an internal PHY on the switch's own MDIO
bus, if no phy-handle and no fixed-link nodes were present.

The -ENODEV error code from the first attempt (phylink_of_phy_connect)
is what triggers the second attempt (phylink_connect_phy).

However, when the first attempt returns a different error code than
-ENODEV, this results in an unbalance of calls to phylink_create and
phylink_destroy by the time we exit the function. The phylink instance
has leaked.

There are many other error codes that can be returned by
phylink_of_phy_connect. For example, phylink_validate returns -EINVAL.
So this is a practical issue too.

Fixes: aab9c406 ("net: dsa: Plug in PHYLINK support")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20210914134331.2303380-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

As explained in commit e358bef7 ("net: dsa: Give drivers the chance
to veto certain upper devices"), the hellcreek driver uses some tricks
to comply with the network stack expectations: it enforces port
separation in standalone mode using VLANs. For untagged traffic,
bridging between ports is prevented by using different PVIDs, and for
VLAN-tagged traffic, it never accepts 8021q uppers with the same VID on
two ports, so packets with one VLAN cannot leak from one port to another.

That is almost fine*, and has worked because hellcreek relied on an
implicit behavior of the DSA core that was changed by the previous
patch: the standalone ports declare the 'rx-vlan-filter' feature as 'on
[fixed]'. Since most of the DSA drivers are actually VLAN-unaware in
standalone mode, that feature was actually incorrectly reflecting the
hardware/driver state, so there was a desire to fix it. This leaves the
hellcreek driver in a situation where it has to explicitly request this
behavior from the DSA framework.

We configure the ports as follows:

- Standalone: 'rx-vlan-filter' is on. An 8021q upper on top of a
  standalone hellcreek port will go through dsa_slave_vlan_rx_add_vid
  and will add a VLAN to the hardware tables, giving the driver the
  opportunity to refuse it through .port_prechangeupper.

- Bridged with vlan_filtering=0: 'rx-vlan-filter' is off. An 8021q upper
  on top of a bridged hellcreek port will not go through
  dsa_slave_vlan_rx_add_vid, because there will not be any attempt to
  offload this VLAN. The driver already disables VLAN awareness, so that
  upper should receive the traffic it needs.

- Bridged with vlan_filtering=1: 'rx-vlan-filter' is on. An 8021q upper
  on top of a bridged hellcreek port will call dsa_slave_vlan_rx_add_vid,
  and can again be vetoed through .port_prechangeupper.

*It is not actually completely fine, because if I follow through
correctly, we can have the following situation:

ip link add br0 type bridge vlan_filtering 0
ip link set lan0 master br0 # lan0 now becomes VLAN-unaware
ip link set lan0 nomaster # lan0 fails to become VLAN-aware again, therefore breaking isolation

This patch fixes that corner case by extending the DSA core logic, based
on this requested attribute, to change the VLAN awareness state of the
switch (port) when it leaves the bridge.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NKurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There have been multiple independent reports about
dsa_slave_vlan_rx_add_vid being called (and consequently calling the
drivers' .port_vlan_add) when it isn't needed, and sometimes (not
always) causing problems in the process.

Case 1:
mv88e6xxx_port_vlan_prepare is stubborn and only accepts VLANs on
bridged ports. That is understandably so, because standalone mv88e6xxx
ports are VLAN-unaware, and VTU entries are said to be a scarce
resource.

Otherwise said, the following fails lamentably on mv88e6xxx:

ip link add br0 type bridge vlan_filtering 1
ip link set lan3 master br0
ip link add link lan10 name lan10.1 type vlan id 1
[485256.724147] mv88e6085 d0032004.mdio-mii:12: p10: hw VLAN 1 already used by port 3 in br0
RTNETLINK answers: Operation not supported

This has become a worse issue since commit 9b236d2a ("net: dsa:
Advertise the VLAN offload netdev ability only if switch supports it").
Up to that point, the driver was returning -EOPNOTSUPP and DSA was
reconverting that error to 0, making the 8021q upper think all is ok
(but obviously the error message was there even prior to this change).
After that change the -EOPNOTSUPP is propagated to vlan_vid_add, and it
is a hard error.

Case 2:
Ports that don't offload the Linux bridge (have a dp->bridge_dev = NULL
because they don't implement .port_bridge_{join,leave}). Understandably,
a standalone port should not offload VLANs either, it should remain VLAN
unaware and any VLAN should be a software VLAN (as long as the hardware
is not quirky, that is).

In fact, dsa_slave_port_obj_add does do the right thing and rejects
switchdev VLAN objects coming from the bridge when that bridge is not
offloaded:

	case SWITCHDEV_OBJ_ID_PORT_VLAN:
		if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
			return -EOPNOTSUPP;

		err = dsa_slave_vlan_add(dev, obj, extack);

But it seems that the bridge is able to trick us. The __vlan_vid_add
from br_vlan.c has:

	/* Try switchdev op first. In case it is not supported, fallback to
	 * 8021q add.
	 */
	err = br_switchdev_port_vlan_add(dev, v->vid, flags, extack);
	if (err == -EOPNOTSUPP)
		return vlan_vid_add(dev, br->vlan_proto, v->vid);

So it says "no, no, you need this VLAN in your life!". And we, naive as
we are, say "oh, this comes from the vlan_vid_add code path, it must be
an 8021q upper, sure, I'll take that". And we end up with that bridge
VLAN installed on our port anyway. But this time, it has the wrong flags:
if the bridge was trying to install VLAN 1 as a pvid/untagged VLAN,
failed via switchdev, retried via vlan_vid_add, we have this comment:

	/* This API only allows programming tagged, non-PVID VIDs */

So what we do makes absolutely no sense.

Backtracing a bit, we see the common pattern. We allow the network stack
to think that our standalone ports are VLAN-aware, but they aren't, for
the vast majority of switches. The quirky ones should not dictate the
norm. The dsa_slave_vlan_rx_add_vid and dsa_slave_vlan_rx_kill_vid
methods exist for drivers that need the 'rx-vlan-filter: on' feature in
ethtool -k, which can be due to any of the following reasons:

1. vlan_filtering_is_global = true, and some ports are under a
   VLAN-aware bridge while others are standalone, and the standalone
   ports would otherwise drop VLAN-tagged traffic. This is described in
   commit 061f6a50 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid
   implementation").

2. the ports that are under a VLAN-aware bridge should also set this
   feature, for 8021q uppers having a VID not claimed by the bridge.
   In this case, the driver will essentially not even know that the VID
   is coming from the 8021q layer and not the bridge.

3. Hellcreek. This driver needs it because in standalone mode, it uses
   unique VLANs per port to ensure separation. For separation of untagged
   traffic, it uses different PVIDs for each port, and for separation of
   VLAN-tagged traffic, it never accepts 8021q uppers with the same vid
   on two ports.

If a driver does not fall under any of the above 3 categories, there is
no reason why it should advertise the 'rx-vlan-filter' feature, therefore
no reason why it should offload the VLANs added through vlan_vid_add.

This commit fixes the problem by removing the 'rx-vlan-filter' feature
from the slave devices when they operate in standalone mode, and when
they offload a VLAN-unaware bridge.

The way it works is that vlan_vid_add will now stop its processing here:

vlan_add_rx_filter_info:
	if (!vlan_hw_filter_capable(dev, proto))
		return 0;

So the VLAN will still be saved in the interface's VLAN RX filtering
list, but because it does not declare VLAN filtering in its features,
the 8021q module will return zero without committing that VLAN to
hardware.

This gives the drivers what they want, since it keeps the 8021q VLANs
away from the VLAN table until VLAN awareness is enabled (point at which
the ports are no longer standalone, hence in the mv88e6xxx case, the
check in mv88e6xxx_port_vlan_prepare passes).

Since the issue predates the existence of the hellcreek driver, case 3
will be dealt with in a separate patch.

The main change that this patch makes is to no longer set
NETIF_F_HW_VLAN_CTAG_FILTER unconditionally, but toggle it dynamically
(for most switches, never).

The second part of the patch addresses an issue that the first part
introduces: because the 'rx-vlan-filter' feature is now dynamically
toggled, and our .ndo_vlan_rx_add_vid does not get called when
'rx-vlan-filter' is off, we need to avoid bugs such as the following by
replaying the VLANs from 8021q uppers every time we enable VLAN
filtering:

ip link add link lan0 name lan0.100 type vlan id 100
ip addr add 192.168.100.1/24 dev lan0.100
ping 192.168.100.2 # should work
ip link add br0 type bridge vlan_filtering 0
ip link set lan0 master br0
ping 192.168.100.2 # should still work
ip link set br0 type bridge vlan_filtering 1
ping 192.168.100.2 # should still work but doesn't

As reported by Florian, some drivers look at ds->vlan_filtering in
their .port_vlan_add() implementation. So this patch also makes sure
that ds->vlan_filtering is committed before calling the driver. This is
the reason why it is first committed, then restored on the failure path.
Reported-by: NTobias Waldekranz <tobias@waldekranz.com>
Reported-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the driver does not implement .port_bridge_{join,leave}, then we must
fall back to standalone operation on that port, and trigger the error
path of dsa_port_bridge_join. This sets dp->bridge_dev = NULL.

In turn, having a non-NULL dp->bridge_dev when there is no offloading
support makes the following things go wrong:

- dsa_default_offload_fwd_mark make the wrong decision in setting
  skb->offload_fwd_mark. It should set skb->offload_fwd_mark = 0 for
  ports that don't offload the bridge, which should instruct the bridge
  to forward in software. But this does not happen, dp->bridge_dev is
  incorrectly set to point to the bridge, so the bridge is told that
  packets have been forwarded in hardware, which they haven't.

- switchdev objects (MDBs, VLANs) should not be offloaded by ports that
  don't offload the bridge. Standalone ports should behave as packet-in,
  packet-out and the bridge should not be able to manipulate the pvid of
  the port, or tag stripping on egress, or ingress filtering. This
  should already work fine because dsa_slave_port_obj_add has:

	case SWITCHDEV_OBJ_ID_PORT_VLAN:
		if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
			return -EOPNOTSUPP;

		err = dsa_slave_vlan_add(dev, obj, extack);

  but since dsa_port_offloads_bridge_port works based on dp->bridge_dev,
  this is again sabotaging us.

All the above work in case the port has an unoffloaded LAG interface, so
this is well exercised code, we should apply it for plain unoffloaded
bridge ports too.
Reported-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net: switchdev: zero-initialize struct switchdev_notifier_fdb_info emitted by drivers towards the bridge

The blamed commit added a new field to struct switchdev_notifier_fdb_info,
but did not make sure that all call paths set it to something valid.
For example, a switchdev driver may emit a SWITCHDEV_FDB_ADD_TO_BRIDGE
notifier, and since the 'is_local' flag is not set, it contains junk
from the stack, so the bridge might interpret those notifications as
being for local FDB entries when that was not intended.

To avoid that now and in the future, zero-initialize all
switchdev_notifier_fdb_info structures created by drivers such that all
newly added fields to not need to touch drivers again.

Fixes: 2c4eca3e ("net: bridge: switchdev: include local flag in FDB notifications")
Reported-by: NIdo Schimmel <idosch@idosch.org>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NIdo Schimmel <idosch@nvidia.com>
Tested-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NLeon Romanovsky <leonro@nvidia.com>
Reviewed-by: NKarsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20210810115024.1629983-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

DSA drives the procedure to flush dynamic FDB entries from a port based
on the change of STP state: whenever we go from a state where address
learning is enabled (LEARNING, FORWARDING) to a state where it isn't
(LISTENING, BLOCKING, DISABLED), we need to flush the existing dynamic
entries.

However, there are cases when this is not needed. Internally, when a
DSA switch interface is not under a bridge, DSA still keeps it in the
"FORWARDING" STP state. And when that interface joins a bridge, the
bridge will meticulously iterate that port through all STP states,
starting with BLOCKING and ending with FORWARDING. Because there is a
state transition from the standalone version of FORWARDING into the
temporary BLOCKING bridge port state, DSA calls the fast age procedure.

Since commit 5e38c158 ("net: dsa: configure better brport flags when
ports leave the bridge"), DSA asks standalone ports to disable address
learning. Therefore, there can be no dynamic FDB entries on a standalone
port. Therefore, it does not make sense to flush dynamic FDB entries on
one.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 08cc83cc ("net: dsa: add support for BRIDGE_MROUTER
attribute") added an option for users to turn off multicast flooding
towards the CPU if they turn off the IGMP querier on a bridge which
already has enslaved ports (echo 0 > /sys/class/net/br0/bridge/multicast_router).

And commit a8b659e7 ("net: dsa: act as passthrough for bridge port flags")
simply papered over that issue, because it moved the decision to flood
the CPU with multicast (or not) from the DSA core down to individual drivers,
instead of taking a more radical position then.

The truth is that disabling multicast flooding to the CPU is simply
something we are not prepared to do now, if at all. Some reasons:

- ICMP6 neighbor solicitation messages are unregistered multicast
  packets as far as the bridge is concerned. So if we stop flooding
  multicast, the outside world cannot ping the bridge device's IPv6
  link-local address.

- There might be foreign interfaces bridged with our DSA switch ports
  (sending a packet towards the host does not necessarily equal
  termination, but maybe software forwarding). So if there is no one
  interested in that multicast traffic in the local network stack, that
  doesn't mean nobody is.

- PTP over L4 (IPv4, IPv6) is multicast, but is unregistered as far as
  the bridge is concerned. This should reach the CPU port.

- The switch driver might not do FDB partitioning. And since we don't
  even bother to do more fine-grained flood disabling (such as "disable
  flooding _from_port_N_ towards the CPU port" as opposed to "disable
  flooding _from_any_port_ towards the CPU port"), this breaks standalone
  ports, or even multiple bridges where one has an IGMP querier and one
  doesn't.

Reverting the logic makes all of the above work.

Fixes: a8b659e7 ("net: dsa: act as passthrough for bridge port flags")
Fixes: 08cc83cc ("net: dsa: add support for BRIDGE_MROUTER attribute")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most users of ndo_do_ioctl are ethernet drivers that implement
the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware
timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP.

Separate these from the few drivers that use ndo_do_ioctl to
implement SIOCBOND, SIOCBR and SIOCWANDEV commands.

This is a purely cosmetic change intended to help readers find
their way through the implementation.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Starting with commit 4f2673b3 ("net: bridge: add helper to replay
port and host-joined mdb entries"), DSA has introduced some bridge
helpers that replay switchdev events (FDB/MDB/VLAN additions and
deletions) that can be lost by the switchdev drivers in a variety of
circumstances:

- an IP multicast group was host-joined on the bridge itself before any
  switchdev port joined the bridge, leading to the host MDB entries
  missing in the hardware database.
- during the bridge creation process, the MAC address of the bridge was
  added to the FDB as an entry pointing towards the bridge device
  itself, but with no switchdev ports being part of the bridge yet, this
  local FDB entry would remain unknown to the switchdev hardware
  database.
- a VLAN/FDB/MDB was added to a bridge port that is a LAG interface,
  before any switchdev port joined that LAG, leading to the hardware
  database missing those entries.
- a switchdev port left a LAG that is a bridge port, while the LAG
  remained part of the bridge, and all FDB/MDB/VLAN entries remained
  installed in the hardware database of the switchdev port.

Also, since commit 0d2cfbd4 ("net: bridge: ignore switchdev events
for LAG ports which didn't request replay"), DSA introduced a method,
based on a const void *ctx, to ensure that two switchdev ports under the
same LAG that is a bridge port do not see the same MDB/VLAN entry being
replayed twice by the bridge, once for every bridge port that joins the
LAG.

With so many ordering corner cases being possible, it seems unreasonable
to expect a switchdev driver writer to get it right from the first try.
Therefore, now that DSA has experimented with the bridge replay helpers
for a little bit, we can move the code to the bridge driver where it is
more readily available to all switchdev drivers.

To convert the switchdev object replay helpers from "pull mode" (where
the driver asks for them) to a "push mode" (where the bridge offers them
automatically), the biggest problem is that the bridge needs to be aware
when a switchdev port joins and leaves, even when the switchdev is only
indirectly a bridge port (for example when the bridge port is a LAG
upper of the switchdev).

Luckily, we already have a hook for that, in the form of the newly
introduced switchdev_bridge_port_offload() and
switchdev_bridge_port_unoffload() calls. These offer a natural place for
hooking the object addition and deletion replays.

Extend the above 2 functions with:
- pointers to the switchdev atomic notifier (for FDB replays) and the
  blocking notifier (for MDB and VLAN replays).
- the "const void *ctx" argument required for drivers to be able to
  disambiguate between which port is targeted, when multiple ports are
  lowers of the same LAG that is a bridge port. Most of the drivers pass
  NULL to this argument, except the ones that support LAG offload and have
  the proper context check already in place in the switchdev blocking
  notifier handler.

Also unexport the replay helpers, since nobody except the bridge calls
them directly now.

Note that:
(a) we abuse the terminology slightly, because FDB entries are not
    "switchdev objects", but we count them as objects nonetheless.
    With no direct way to prove it, I think they are not modeled as
    switchdev objects because those can only be installed by the bridge
    to the hardware (as opposed to FDB entries which can be propagated
    in the other direction too). This is merely an abuse of terms, FDB
    entries are replayed too, despite not being objects.
(b) the bridge does not attempt to sync port attributes to newly joined
    ports, just the countable stuff (the objects). The reason for this
    is simple: no universal and symmetric way to sync and unsync them is
    known. For example, VLAN filtering: what to do on unsync, disable or
    leave it enabled? Similarly, STP state, ageing timer, etc etc. What
    a switchdev port does when it becomes standalone again is not really
    up to the bridge's competence, and the driver should deal with it.
    On the other hand, replaying deletions of switchdev objects can be
    seen a matter of cleanup and therefore be treated by the bridge,
    hence this patch.

We make the replay helpers opt-in for drivers, because they might not
bring immediate benefits for them:

- nbp_vlan_init() is called _after_ netdev_master_upper_dev_link(),
  so br_vlan_replay() should not do anything for the new drivers on
  which we call it. The existing drivers where there was even a slight
  possibility for there to exist a VLAN on a bridge port before they
  join it are already guarded against this: mlxsw and prestera deny
  joining LAG interfaces that are members of a bridge.

- br_fdb_replay() should now notify of local FDB entries, but I patched
  all drivers except DSA to ignore these new entries in commit
  2c4eca3e ("net: bridge: switchdev: include local flag in FDB
  notifications"). Driver authors can lift this restriction as they
  wish, and when they do, they can also opt into the FDB replay
  functionality.

- br_mdb_replay() should fix a real issue which is described in commit
  4f2673b3 ("net: bridge: add helper to replay port and host-joined
  mdb entries"). However most drivers do not offload the
  SWITCHDEV_OBJ_ID_HOST_MDB to see this issue: only cpsw and am65_cpsw
  offload this switchdev object, and I don't completely understand the
  way in which they offload this switchdev object anyway. So I'll leave
  it up to these drivers' respective maintainers to opt into
  br_mdb_replay().

So most of the drivers pass NULL notifier blocks for the replay helpers,
except:
- dpaa2-switch which was already acked/regression-tested with the
  helpers enabled (and there isn't much of a downside in having them)
- ocelot which already had replay logic in "pull" mode
- DSA which already had replay logic in "pull" mode

An important observation is that the drivers which don't currently
request bridge event replays don't even have the
switchdev_bridge_port_{offload,unoffload} calls placed in proper places
right now. This was done to avoid unnecessary rework for drivers which
might never even add support for this. For driver writers who wish to
add replay support, this can be used as a tentative placement guide:
https://patchwork.kernel.org/project/netdevbpf/patch/20210720134655.892334-11-vladimir.oltean@nxp.com/

Cc: Vadym Kochan <vkochan@marvell.com>
Cc: Taras Chornyi <tchornyi@marvell.com>
Cc: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function skb_put() that is used by tail taggers to make room for the
DSA tag must only be called for linearized SKBS. However in case that the
slave device inherited features like NETIF_F_HW_SG or NETIF_F_FRAGLIST the
SKB passed to the slaves transmit function may not be linearized.
Avoid those SKBs by clearing the NETIF_F_HW_SG and NETIF_F_FRAGLIST flags
for tail taggers.
Furthermore since the tagging protocol can be changed at runtime move the
code for setting up the slaves features into dsa_slave_setup_tagger().
Suggested-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NLino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using the new fan-out helper for FDB entries installed on the software
bridge, we can install host addresses with the proper refcount on the
CPU port, such that this case:

ip link set swp0 master br0
ip link set swp1 master br0
ip link set swp2 master br0
ip link set swp3 master br0
ip link set br0 address 00:01:02:03:04:05
ip link set swp3 nomaster

works properly and the br0 address remains installed as a host entry
with refcount 3 instead of getting deleted.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is a bit difficult to understand what DSA checks when it tries to
avoid installing dynamically learned addresses on foreign interfaces as
local host addresses, so create a generic switchdev helper that can be
reused and is generally more readable.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When
(a) "dev" is a bridge port which the DSA switch tree offloads, but is
    otherwise not a dsa slave (such as a LAG netdev), or
(b) "dev" is the bridge net device itself

then strange things happen to the dev_hold/dev_put pair:
dsa_schedule_work() will still be called with a DSA port that offloads
that netdev, but dev_hold() will be called on the non-DSA netdev.
Then the "if" condition in dsa_slave_switchdev_event_work() does not
pass, because "dev" is not a DSA netdev, so dev_put() is not called.

This results in the simple fact that we have a reference counting
mismatch on the "dev" net device.

This can be seen when we add support for host addresses installed on the
bridge net device.

ip link add br1 type bridge
ip link set br1 address 00:01:02:03:04:05
ip link set swp0 master br1
ip link del br1
[  968.512278] unregister_netdevice: waiting for br1 to become free. Usage count = 5

It seems foolish to do penny pinching and not add the net_device pointer
in the dsa_switchdev_event_work structure, so let's finally do that.
As an added bonus, when we start offloading local entries pointing
towards the bridge, these will now properly appear as 'offloaded' in
'bridge fdb' (this was not possible before, because 'dev' was assumed to
only be a DSA net device):

00:01:02:03:04:05 dev br0 vlan 1 offload master br0 permanent
00:01:02:03:04:05 dev br0 offload master br0 permanent
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bridge supports a legacy way of adding local (non-forwarded) FDB
entries, which works on an individual port basis:

bridge fdb add dev swp0 00:01:02:03:04:05 master local

As well as a new way, added by Roopa Prabhu in commit 3741873b
("bridge: allow adding of fdb entries pointing to the bridge device"):

bridge fdb add dev br0 00:01:02:03:04:05 self local

The two commands are functionally equivalent, except that the first one
produces an entry with fdb->dst == swp0, and the other an entry with
fdb->dst == NULL. The confusing part, though, is that even if fdb->dst
is swp0 for the 'local on port' entry, that destination is not used.

Nonetheless, the idea is that the bridge has reference counting for
local entries, and local entries pointing towards the bridge are still
'as local' as local entries for a port.

The bridge adds the MAC addresses of the interfaces automatically as
FDB entries with is_local=1. For the MAC address of the ports, fdb->dst
will be equal to the port, and for the MAC address of the bridge,
fdb->dst will point towards the bridge (i.e. be NULL). Therefore, if the
MAC address of the bridge is not inherited from either of the physical
ports, then we must explicitly catch local FDB entries emitted towards
the br0, otherwise we'll miss the MAC address of the bridge (and, of
course, any entry with 'bridge add dev br0 ... self local').
Co-developed-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bridge automatically creates local (not forwarded) fdb entries
pointing towards physical ports with their interface MAC addresses.
For switchdev, the significance of these fdb entries is the exact
opposite of that of non-local entries: instead of sending these frame
outwards, we must send them inwards (towards the host).

NOTE: The bridge's own MAC address is also "local". If that address is
not shared with any port, the bridge's MAC is not be added by this
functionality - but the following commit takes care of that case.

NOTE 2: We mark these addresses as host-filtered regardless of the value
of ds->assisted_learning_on_cpu_port. This is because, as opposed to the
speculative logic done for dynamic address learning on foreign
interfaces, the local FDB entries are rather fixed, so there isn't any
risk of them migrating from one bridge port to another.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA is able to install FDB entries towards the CPU port for addresses
which were dynamically learnt by the software bridge on foreign
interfaces that are in the same bridge with a DSA switch interface.
Since this behavior is opportunistic, it is guarded by the
"assisted_learning_on_cpu_port" property which can be enabled by drivers
and is not done automatically (since certain switches may support
address learning of packets coming from the CPU port).

But if those FDB entries added on the foreign interfaces are static
(added by the user) instead of dynamically learnt, currently DSA does
not do anything (and arguably it should).

Because static FDB entries are not supposed to move on their own, there
is no downside in reusing the "assisted_learning_on_cpu_port" logic to
sync static FDB entries to the DSA CPU port unconditionally, even if
assisted_learning_on_cpu_port is not requested by the driver.

For example, this situation:

   br0
   / \
swp0 dummy0

$ bridge fdb add 02:00:de:ad:00:01 dev dummy0 vlan 1 master static

Results in DSA adding an entry in the hardware FDB, pointing this
address towards the CPU port.

The same is true for entries added to the bridge itself, e.g:

$ bridge fdb add 02:00:de:ad:00:01 dev br0 vlan 1 self local

(except that right now, DSA still ignores 'local' FDB entries, this will
be changed in a later patch)
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA treats some bridge FDB entries by trapping them to the CPU port.
Currently, the only class of such entries are FDB addresses learnt by
the software bridge on a foreign interface. However there are many more
to be added:

- FDB entries with the is_local flag (for termination) added by the
  bridge on the user ports (typically containing the MAC address of the
  bridge port)
- FDB entries pointing towards the bridge net device (for termination).
  Typically these contain the MAC address of the bridge net device.
- Static FDB entries installed on a foreign interface that is in the
  same bridge with a DSA user port.

The reason why a separate cross-chip notifier for host FDBs is justified
compared to normal FDBs is the same as in the case of host MDBs: the
cross-chip notifier matching function in switch.c should avoid
installing these entries on routing ports that route towards the
targeted switch, but not towards the CPU. This is required in order to
have proper support for H-like multi-chip topologies.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit abd49535 ("net: dsa: execute dsa_switch_mdb_add only for
routing port in cross-chip topologies") does a surprisingly good job
even for the SWITCHDEV_OBJ_ID_HOST_MDB use case, where DSA simply
translates a switchdev object received on dp into a cross-chip notifier
for dp->cpu_dp.

To visualize how that works, imagine the daisy chain topology below and
consider a SWITCHDEV_OBJ_ID_HOST_MDB object emitted on sw2p0. How does
the cross-chip notifier know to match on all the right ports (sw0p4, the
dedicated CPU port, sw1p4, an upstream DSA link, and sw2p4, another
upstream DSA link)?

                                                |
       sw0p0     sw0p1     sw0p2     sw0p3     sw0p4
    [  user ] [  user ] [  user ] [  dsa  ] [  cpu  ]
    [       ] [       ] [       ] [       ] [   x   ]
                                      |
                                      +---------+
                                                |
       sw1p0     sw1p1     sw1p2     sw1p3     sw1p4
    [  user ] [  user ] [  user ] [  dsa  ] [  dsa  ]
    [       ] [       ] [       ] [       ] [   x   ]
                                      |
                                      +---------+
                                                |
       sw2p0     sw2p1     sw2p2     sw2p3     sw2p4
    [  user ] [  user ] [  user ] [  user ] [  dsa  ]
    [       ] [       ] [       ] [       ] [   x   ]

The answer is simple: the dedicated CPU port of sw2p0 is sw0p4, and
dsa_routing_port returns the upstream port for all switches.

That is fine, but there are other topologies where this does not work as
well. There are trees with "H" topologies in the wild, where there are 2
or more switches with DSA links between them, but every switch has its
dedicated CPU port. For these topologies, it seems stupid for the neighbor
switches to install an MDB entry on the routing port, since these
multicast addresses are fundamentally different than the usual ones we
support (and that is the justification for this patch, to introduce the
concept of a termination plane multicast MAC address, as opposed to a
forwarding plane multicast MAC address).

For example, when a SWITCHDEV_OBJ_ID_HOST_MDB would get added to sw0p0,
without this patch, it would get treated as a regular port MDB on sw0p2
and it would match on the ports below (including the sw1p3 routing port).

                         |                                  |
    sw0p0     sw0p1     sw0p2     sw0p3          sw1p3     sw1p2     sw1p1     sw1p0
 [  user ] [  user ] [  cpu  ] [  dsa  ]      [  dsa  ] [  cpu  ] [  user ] [  user ]
 [       ] [       ] [   x   ] [       ] ---- [   x   ] [       ] [       ] [       ]

With the patch, the host MDB notifier on sw0p0 matches only on the local
switch, which is what we want for a termination plane address.

                         |                                  |
    sw0p0     sw0p1     sw0p2     sw0p3          sw1p3     sw1p2     sw1p1     sw1p0
 [  user ] [  user ] [  cpu  ] [  dsa  ]      [  dsa  ] [  cpu  ] [  user ] [  user ]
 [       ] [       ] [   x   ] [       ] ---- [       ] [       ] [       ] [       ]

Name this new matching function "dsa_switch_host_address_match" since we
will be reusing it soon for host FDB entries as well.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We want to add reference counting for FDB entries in cross-chip
topologies, and in order for that to have any chance of working and not
be unbalanced (leading to entries which are never deleted), we need to
ensure that higher layers are sane, because if they aren't, it's garbage
in, garbage out.

For example, if we add a bridge FDB entry twice, the bridge properly
errors out:

$ bridge fdb add dev swp0 00:01:02:03:04:07 master static
$ bridge fdb add dev swp0 00:01:02:03:04:07 master static
RTNETLINK answers: File exists

However, the same thing cannot be said about the bridge bypass
operations:

$ bridge fdb add dev swp0 00:01:02:03:04:07
$ bridge fdb add dev swp0 00:01:02:03:04:07
$ bridge fdb add dev swp0 00:01:02:03:04:07
$ bridge fdb add dev swp0 00:01:02:03:04:07
$ echo $?
0

But one 'bridge fdb del' is enough to remove the entry, no matter how
many times it was added.

The bridge bypass operations are impossible to maintain in these
circumstances and lack of support for reference counting the cross-chip
notifiers is holding us back from making further progress, so just drop
support for them. The only way left for users to install static bridge
FDB entries is the proper one, using the "master static" flags.

With this change, rtnl_fdb_add() falls back to calling
ndo_dflt_fdb_add() which uses the duplicate-exclusive variant of
dev_uc_add(): dev_uc_add_excl(). Because DSA does not (yet) declare
IFF_UNICAST_FLT, this results in us going to promiscuous mode:

$ bridge fdb add dev swp0 00:01:02:03:04:05
[   28.206743] device swp0 entered promiscuous mode
$ bridge fdb add dev swp0 00:01:02:03:04:05
RTNETLINK answers: File exists

So even if it does not completely fail, there is at least some indication
that it is behaving differently from before, and closer to user space
expectations, I would argue (the lack of a "local|static" specifier
defaults to "local", or "host-only", so dev_uc_add() is a reasonable
default implementation). If the generic implementation of .ndo_fdb_add
provided by Vlad Yasevich is a proof of anything, it only proves that
the implementation provided by DSA was always wrong, by not looking at
"ndm->ndm_state & NUD_NOARP" (the "static" flag which means that the FDB
entry points outwards) and "ndm->ndm_state & NUD_PERMANENT" (the "local"
flag which means that the FDB entry points towards the host). It all
used to mean the same thing to DSA.

Update the documentation so that the users are not confused about what's
going on.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a DSA switch port leaves a bonding interface that is under a
bridge, there might be dangling switchdev objects on that port left
behind, because the bridge is not aware that its lower interface (the
bond) changed state in any way.

Call the bridge replay helpers with adding=false before changing
dp->bridge_dev to NULL, because we need to simulate to
dsa_slave_port_obj_del() that these notifications were emitted by the
bridge.

We add this hook to the NETDEV_PRECHANGEUPPER event handler, because
we are calling into switchdev (and the __switchdev_handle_port_obj_del
fanout helpers expect the upper/lower adjacency lists to still be valid)
and PRECHANGEUPPER is the last moment in time when they still are.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to add more logic to the DSA NETDEV_PRECHANGEUPPER event
handler, more exactly we need to request an unsync of switchdev objects.
In order to fit more code, refactor the existing logic into a helper.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a slight inconvenience in the switchdev replay helpers added
recently, and this is when:

ip link add br0 type bridge
ip link add bond0 type bond
ip link set bond0 master br0
bridge vlan add dev bond0 vid 100
ip link set swp0 master bond0
ip link set swp1 master bond0

Since the underlying driver (currently only DSA) asks for a replay of
VLANs when swp0 and swp1 join the LAG because it is bridged, what will
happen is that DSA will try to react twice on the VLAN event for swp0.
This is not really a huge problem right now, because most drivers accept
duplicates since the bridge itself does, but it will become a problem
when we add support for replaying switchdev object deletions.

Let's fix this by adding a blank void *ctx in the replay helpers, which
will be passed on by the bridge in the switchdev notifications. If the
context is NULL, everything is the same as before. But if the context is
populated with a valid pointer, the underlying switchdev driver
(currently DSA) can use the pointer to 'see through' the bridge port
(which in the example above is bond0) and 'know' that the event is only
for a particular physical port offloading that bridge port, and not for
all of them.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the case where the driver asks for a replay of a certain type of
event (port object or attribute) for a bridge port that is a LAG, it may
do so because this port has just joined the LAG.

But there might already be other switchdev ports in that LAG, and it is
preferable that those preexisting switchdev ports do not act upon the
replayed event.

The solution is to add a context to switchdev events, which is NULL most
of the time (when the bridge layer initiates the call) but which can be
set to a value controlled by the switchdev driver when a replay is
requested. The driver can then check the context to figure out if all
ports within the LAG should act upon the switchdev event, or just the
ones that match the context.

We have to modify all switchdev_handle_* helper functions as well as the
prototypes in the drivers that use these helpers too, because these
helpers hide the underlying struct switchdev_notifier_info from us and
there is no way to retrieve the context otherwise.

The context structure will be populated and used in later patches.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dsa_slave_change_mtu() calls dsa_port_mtu_change() twice:
- it sends a cross-chip notifier with the MTU of the CPU port which is
  used to update the DSA links.
- it sends one targeted MTU notifier which is supposed to only match the
  user port on which we are changing the MTU. The "propagate_upstream"
  variable is used here to bypass the cross-chip notifier system from
  switch.c

But due to a mistake, the second, targeted notifier matches not only on
the user port, but also on the DSA link which is a member of the same
switch, if that exists.

And because the DSA links of the entire dst were programmed in a
previous round to the largest_mtu via a "propagate_upstream == true"
notification, then the dsa_port_mtu_change(propagate_upstream == false)
call that is immediately upcoming will break the MTU on the one DSA link
which is chip-wise local to the dp whose MTU is changing right now.

Example given this daisy chain topology:

   sw0p0     sw0p1     sw0p2     sw0p3     sw0p4
[  cpu  ] [  user ] [  user ] [  dsa  ] [  user ]
[   x   ] [       ] [       ] [   x   ] [       ]
                                  |
                                  +---------+
                                            |
   sw1p0     sw1p1     sw1p2     sw1p3     sw1p4
[  user ] [  user ] [  user ] [  dsa  ] [  dsa  ]
[       ] [       ] [       ] [       ] [   x   ]

ip link set sw0p1 mtu 9000
ip link set sw1p1 mtu 9000 # at this stage, sw0p1 and sw1p1 can talk
                           # to one another using jumbo frames
ip link set sw0p2 mtu 1500 # this programs the sw0p3 DSA link first to
                           # the largest_mtu of 9000, then reprograms it to
                           # 1500 with the "propagate_upstream == false"
                           # notifier, breaking communication between
                           # sw0p1 and sw1p1

To escape from this situation, make the targeted match really match on a
single port - the user port, and rename the "propagate_upstream"
variable to "targeted_match" to clarify the intention and avoid future
issues.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we have a cross-chip topology like this:

   sw0p0     sw0p1     sw0p2     sw0p3     sw0p4
[  cpu  ] [  user ] [  user ] [  dsa  ] [  user ]
                                  |
                                  +---------+
                                            |
   sw1p0     sw1p1     sw1p2     sw1p3     sw1p4
[  user ] [  user ] [  user ] [  dsa  ] [  dsa  ]

and we issue the following commands:

1. ip link set sw0p1 mtu 1700
2. ip link set sw1p1 mtu 1600

we notice the following happening:

Command 1. emits a non-targeted MTU notifier for the CPU port (sw0p0)
with the largest_mtu calculated across switch 0, of 1700. This matches
sw0p0, sw0p3 and sw1p4 (all CPU ports and DSA links).
Then, it emits a targeted MTU notifier for the user port (sw0p1), again
with MTU 1700 (this doesn't matter).

Command 2. emits a non-targeted MTU notifier for the CPU port (sw0p0)
with the largest_mtu calculated across switch 1, of 1600. This matches
the same group of ports as above, and decreases the MTU for the CPU port
and the DSA links from 1700 to 1600.

As a result, the sw0p1 user port can no longer communicate with its CPU
port at MTU 1700.

To address this, we should calculate the largest_mtu across all switches
that may share a CPU port, and only emit MTU notifiers with that value.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current get_phy_flags() is only processed when we connect to a PHY
via a designed phy-handle property via phylink_of_phy_connect(), but if
we fallback on the internal MDIO bus created by a switch and take the
dsa_slave_phy_connect() path then we would not be processing that flag
and using it at PHY connection time.
Suggested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some really really weird switches just couldn't decide whether to use a
normal or a tail tagger, so they just did both.

This creates problems for DSA, because we only have the concept of an
'overhead' which can be applied to the headroom or to the tailroom of
the skb (like for example during the central TX reallocation procedure),
depending on the value of bool tail_tag, but not to both.

We need to generalize DSA to cater for these odd switches by
transforming the 'overhead / tail_tag' pair into 'needed_headroom /
needed_tailroom'.

The DSA master's MTU is increased to account for both.

The flow dissector code is modified such that it only calls the DSA
adjustment callback if the tagger has a non-zero header length.

Taggers are trivially modified to declare either needed_headroom or
needed_tailroom, based on the tail_tag value that they currently
declare.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA implements a bunch of 'standardized' ethtool statistics counters,
namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
hardware driver returns in .get_sset_count(), we need to add 4 to that.

That is ok, except that .get_sset_count() can return a negative error
code, for example:

b53_get_sset_count
-> phy_ethtool_get_sset_count
   -> return -EIO

-EIO is -5, and with 4 added to it, it becomes -1, aka -EPERM. One can
imagine that certain error codes may even become positive, although
based on code inspection I did not see instances of that.

Check the error code first, if it is negative return it as-is.

Based on a similar patch for dsa_master_get_strings from Dan Carpenter:
https://patchwork.kernel.org/project/netdevbpf/patch/YJaSe3RPgn7gKxZv@mwanda/

Fixes: 91da11f8 ("net: Distributed Switch Architecture protocol support")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Free skb->cb usage in core driver and let device drivers decide to
use or not. The reason having a DSA_SKB_CB(skb)->clone was because
dsa_skb_tx_timestamp() which may set the clone pointer was called
before p->xmit() which would use the clone if any, and the device
driver has no way to initialize the clone pointer.

This patch just put memset(skb->cb, 0, sizeof(skb->cb)) at beginning
of dsa_slave_xmit(). Some new features in the future, like one-step
timestamp may need more bytes of skb->cb to use in
dsa_skb_tx_timestamp(), and p->xmit().
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It was a waste to clone skb directly in dsa_skb_tx_timestamp().
For one-step timestamping, a clone was not needed. For any failure of
port_txtstamp (this may usually happen), the skb clone had to be freed.

So this patch moves skb cloning for tx timestamp out of dsa core, and
let drivers clone skb in port_txtstamp if they really need.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Tested-by: NKurt Kanzenbach <kurt@linutronix.de>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move ptp_classify_raw out of dsa core driver for handling tx
timestamp request. Let device drivers do this if they want.
Not all drivers want to limit tx timestamping for only PTP
packet.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Tested-by: NKurt Kanzenbach <kurt@linutronix.de>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Check tx timestamp request in core driver at very beginning of
dsa_skb_tx_timestamp(), so that most skbs not requiring tx
timestamp just return. And drop such checking in device drivers.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Tested-by: NKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most of generic selftest should be able to work with probably all ethernet
controllers. The DSA switches are not exception, so enable it by default at
least for DSA.

This patch was tested with SJA1105 and AR9331.
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As explained in bugfix commit 6ab4c311 ("net: bridge: don't notify
switchdev for local FDB addresses") as well as in this discussion:
https://lore.kernel.org/netdev/20210117193009.io3nungdwuzmo5f7@skbuf/

the switchdev notifiers for FDB entries managed to have a zero-day bug,
which was that drivers would not know what to do with local FDB entries,
because they were not told that they are local. The bug fix was to
simply not notify them of those addresses.

Let us now add the 'is_local' bit to bridge FDB entries, and make all
drivers ignore these entries by their own choice.
Co-developed-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_get_mac_address() returns a "const void*" pointer to a MAC address.
Lately, support to fetch the MAC address by an NVMEM provider was added.
But this will only work with platform devices. It will not work with
PCI devices (e.g. of an integrated root complex) and esp. not with DSA
ports.

There is an of_* variant of the nvmem binding which works without
devices. The returned data of a nvmem_cell_read() has to be freed after
use. On the other hand the return of_get_mac_address() points to some
static data without a lifetime. The trick for now, was to allocate a
device resource managed buffer which is then returned. This will only
work if we have an actual device.

Change it, so that the caller of of_get_mac_address() has to supply a
buffer where the MAC address is written to. Unfortunately, this will
touch all drivers which use the of_get_mac_address().

Usually the code looks like:

  const char *addr;
  addr = of_get_mac_address(np);
  if (!IS_ERR(addr))
    ether_addr_copy(ndev->dev_addr, addr);

This can then be simply rewritten as:

  of_get_mac_address(np, ndev->dev_addr);

Sometimes is_valid_ether_addr() is used to test the MAC address.
of_get_mac_address() already makes sure, it just returns a valid MAC
address. Thus we can just test its return code. But we have to be
careful if there are still other sources for the MAC address before the
of_get_mac_address(). In this case we have to keep the
is_valid_ether_addr() call.

The following coccinelle patch was used to convert common cases to the
new style. Afterwards, I've manually gone over the drivers and fixed the
return code variable: either used a new one or if one was already
available use that. Mansour Moufid, thanks for that coccinelle patch!

<spml>
@a@
identifier x;
expression y, z;
@@
- x = of_get_mac_address(y);
+ x = of_get_mac_address(y, z);
  <...
- ether_addr_copy(z, x);
  ...>

@@
identifier a.x;
@@
- if (<+... x ...+>) {}

@@
identifier a.x;
@@
  if (<+... x ...+>) {
      ...
  }
- else {}

@@
identifier a.x;
expression e;
@@
- if (<+... x ...+>@e)
-     {}
- else
+ if (!(e))
      {...}

@@
expression x, y, z;
@@
- x = of_get_mac_address(y, z);
+ of_get_mac_address(y, z);
  ... when != x
</spml>

All drivers, except drivers/net/ethernet/aeroflex/greth.c, were
compile-time tested.
Suggested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NMichael Walle <michael@walle.cc>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>