Currently, on my board with multiple sja1105 switches in disjoint trees
described in commit f66a6a69 ("net: dsa: permit cross-chip bridging
between all trees in the system"), rebooting the board triggers the
following benign warnings:

[   12.345566] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 1088 deletion: -ENOENT
[   12.353804] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 2112 deletion: -ENOENT
[   12.362019] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 1089 deletion: -ENOENT
[   12.370246] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 2113 deletion: -ENOENT
[   12.378466] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 1090 deletion: -ENOENT
[   12.386683] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 2114 deletion: -ENOENT

Basically switch 1 calls dsa_tag_8021q_unregister, and switch 1's TX and
RX VLANs cannot be found on switch 2's CPU port.

But why would switch 2 even attempt to delete switch 1's TX and RX
tag_8021q VLANs from its CPU port? Well, because we use dsa_broadcast,
and it is supposed that it had added those VLANs in the first place
(because in dsa_port_tag_8021q_vlan_match, all CPU ports match
regardless of their tree index or switch index).

The two trees probe asynchronously, and when switch 1 probed, it called
dsa_broadcast which did not notify the tree of switch 2, because that
didn't probe yet. But during unbind, switch 2's tree _is_ probed, so it
_is_ notified of the deletion.

Before jumping to introduce a synchronization mechanism between the
probing across disjoint switch trees, let's take a step back and see
whether we _need_ to do that in the first place.

The RX and TX VLANs of switch 1 would be needed on switch 2's CPU port
only if switch 1 and 2 were part of a cross-chip bridge. And
dsa_tag_8021q_bridge_join takes care precisely of that (but if probing
was synchronous, the bridge_join would just end up bumping the VLANs'
refcount, because they are already installed by the setup path).

Since by the time the ports are bridged, all DSA trees are already set
up, and we don't need the tag_8021q VLANs of one switch installed on the
other switches during probe time, the answer is that we don't need to
fix the synchronization issue.

So make the setup and teardown code paths call dsa_port_notify, which
notifies only the local tree, and the bridge code paths call
dsa_broadcast, which let the other trees know as well.
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>

All kernel devlink implementations call to devlink_alloc() during
initialization routine for specific device which is used later as
a parent device for devlink_register().

Such late device assignment causes to the situation which requires us to
call to device_register() before setting other parameters, but that call
opens devlink to the world and makes accessible for the netlink users.

Any attempt to move devlink_register() to be the last call generates the
following error due to access to the devlink->dev pointer.

[    8.758862]  devlink_nl_param_fill+0x2e8/0xe50
[    8.760305]  devlink_param_notify+0x6d/0x180
[    8.760435]  __devlink_params_register+0x2f1/0x670
[    8.760558]  devlink_params_register+0x1e/0x20

The simple change of API to set devlink device in the devlink_alloc()
instead of devlink_register() fixes all this above and ensures that
prior to call to devlink_register() everything already set.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Be there an "H" switch topology, where there are 2 switches connected as
follows:

         eth0                                                     eth1
          |                                                        |
       CPU port                                                CPU port
          |                        DSA link                        |
 sw0p0  sw0p1  sw0p2  sw0p3  sw0p4 -------- sw1p4  sw1p3  sw1p2  sw1p1  sw1p0
   |             |      |                            |      |             |
 user          user   user                         user   user          user
 port          port   port                         port   port          port

basically one where each switch has its own CPU port for termination,
but there is also a DSA link in case packets need to be forwarded in
hardware between one switch and another.

DSA insists to see this as a daisy chain topology, basically registering
all network interfaces as sw0p0@eth0, ... sw1p0@eth0 and disregarding
eth1 as a valid DSA master.

This is only half the story, since when asked using dsa_port_is_cpu(),
DSA will respond that sw1p1 is a CPU port, however one which has no
dp->cpu_dp pointing to it. So sw1p1 is enabled, but not used.

Furthermore, be there a driver for switches which support only one
upstream port. This driver iterates through its ports and checks using
dsa_is_upstream_port() whether the current port is an upstream one.
For switch 1, two ports pass the "is upstream port" checks:

- sw1p4 is an upstream port because it is a routing port towards the
  dedicated CPU port assigned using dsa_tree_setup_default_cpu()

- sw1p1 is also an upstream port because it is a CPU port, albeit one
  that is disabled. This is because dsa_upstream_port() returns:

	if (!cpu_dp)
		return port;

  which means that if @dp does not have a ->cpu_dp pointer (which is a
  characteristic of CPU ports themselves as well as unused ports), then
  @dp is its own upstream port.

So the driver for switch 1 rightfully says: I have two upstream ports,
but I don't support multiple upstream ports! So let me error out, I
don't know which one to choose and what to do with the other one.

Generally I am against enforcing any default policy in the kernel in
terms of user to CPU port assignment (like round robin or such) but this
case is different. To solve the conundrum, one would have to:

- Disable sw1p1 in the device tree or mark it as "not a CPU port" in
  order to comply with DSA's view of this topology as a daisy chain,
  where the termination traffic from switch 1 must pass through switch 0.
  This is counter-productive because it wastes 1Gbps of termination
  throughput in switch 1.
- Disable the DSA link between sw0p4 and sw1p4 and do software
  forwarding between switch 0 and 1, and basically treat the switches as
  part of disjoint switch trees. This is counter-productive because it
  wastes 1Gbps of autonomous forwarding throughput between switch 0 and 1.
- Treat sw0p4 and sw1p4 as user ports instead of DSA links. This could
  work, but it makes cross-chip bridging impossible. In this setup we
  would need to have 2 separate bridges, br0 spanning the ports of
  switch 0, and br1 spanning the ports of switch 1, and the "DSA links
  treated as user ports" sw0p4 (part of br0) and sw1p4 (part of br1) are
  the gateway ports between one bridge and another. This is hard to
  manage from a user's perspective, who wants to have a unified view of
  the switching fabric and the ability to transparently add ports to the
  same bridge. VLANs would also need to be explicitly managed by the
  user on these gateway ports.

So it seems that the only reasonable thing to do is to make DSA prefer
CPU ports that are local to the switch. Meaning that by default, the
user and DSA ports of switch 0 will get assigned to the CPU port from
switch 0 (sw0p1) and the user and DSA ports of switch 1 will get
assigned to the CPU port from switch 1.

The way this solves the problem is that sw1p4 is no longer an upstream
port as far as switch 1 is concerned (it no longer views sw0p1 as its
dedicated CPU port).

So here we are, the first multi-CPU port that DSA supports is also
perhaps the most uneventful one: the individual switches don't support
multiple CPUs, however the DSA switch tree as a whole does have multiple
CPU ports. No user space assignment of user ports to CPU ports is
desirable, necessary, or possible.

Ports that do not have a local CPU port (say there was an extra switch
hanging off of sw0p0) default to the standard implementation of getting
assigned to the first CPU port of the DSA switch tree. Is that good
enough? Probably not (if the downstream switch was hanging off of switch
1, we would most certainly prefer its CPU port to be sw1p1), but in
order to support that use case too, we would need to traverse the
dst->rtable in search of an optimum dedicated CPU port, one that has the
smallest number of hops between dp->ds and dp->cpu_dp->ds. At the
moment, the DSA routing table structure does not keep the number of hops
between dl->dp and dl->link_dp, and while it is probably deducible,
there is zero justification to write that code now. Let's hope DSA will
never have to support that use case.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is nothing specific to having a default CPU port to what
dsa_tree_teardown_default_cpu() does. Even with multiple CPU ports,
it would do the same thing: iterate through the ports of this switch
tree and reset the ->cpu_dp pointer to NULL. So rename it accordingly.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For a DSA switch, to offload the forwarding process of a bridge device
means to send the packets coming from the software bridge as data plane
packets. This is contrary to everything that DSA has done so far,
because the current taggers only know to send control packets (ones that
target a specific destination port), whereas data plane packets are
supposed to be forwarded according to the FDB lookup, much like packets
ingressing on any regular ingress port. If the FDB lookup process
returns multiple destination ports (flooding, multicast), then
replication is also handled by the switch hardware - the bridge only
sends a single packet and avoids the skb_clone().

DSA keeps for each bridge port a zero-based index (the number of the
bridge). Multiple ports performing TX forwarding offload to the same
bridge have the same dp->bridge_num value, and ports not offloading the
TX data plane of a bridge have dp->bridge_num = -1.

The tagger can check if the packet that is being transmitted on has
skb->offload_fwd_mark = true or not. If it does, it can be sure that the
packet belongs to the data plane of a bridge, further information about
which can be obtained based on dp->bridge_dev and dp->bridge_num.
It can then compose a DSA tag for injecting a data plane packet into
that bridge number.

For the switch driver side, we offer two new dsa_switch_ops methods,
called .port_bridge_fwd_offload_{add,del}, which are modeled after
.port_bridge_{join,leave}.
These methods are provided in case the driver needs to configure the
hardware to treat packets coming from that bridge software interface as
data plane packets. The switchdev <-> bridge interaction happens during
the netdev_master_upper_dev_link() call, so to switch drivers, the
effect is that the .port_bridge_fwd_offload_add() method is called
immediately after .port_bridge_join().

If the bridge number exceeds the number of bridges for which the switch
driver can offload the TX data plane (and this includes the case where
the driver can offload none), DSA falls back to simply returning
tx_fwd_offload = false in the switchdev_bridge_port_offload() call.
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 preparation of supporting data plane forwarding on behalf of a
software bridge, some drivers might need to view bridges as virtual
switches behind the CPU port in a cross-chip topology.

Give them some help and let them know how many physical switches there
are in the tree, so that they can count the virtual switches starting
from that number on.

Note that the first dsa_switch_ops method where this information is
reliably available is .setup(). This is because of how DSA works:
in a tree with 3 switches, each calling dsa_register_switch(), the first
2 will advance until dsa_tree_setup() -> dsa_tree_setup_routing_table()
and exit with error code 0 because the topology is not complete. Since
probing is parallel at this point, one switch does not know about the
existence of the other. Then the third switch comes, and for it,
dsa_tree_setup_routing_table() returns complete = true. This switch goes
ahead and calls dsa_tree_setup_switches() for everybody else, calling
their .setup() methods too. This acts as the synchronization point.
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 same concerns expressed for host MDB entries are valid for host FDBs
just as well:

- in the case of multiple bridges spanning the same switch chip, deleting
  a host FDB entry that belongs to one bridge will result in breakage to
  the other bridge
- not deleting FDB entries across DSA links means that the switch's
  hardware tables will eventually run out, given enough wear&tear

So do the same thing and introduce reference counting for CPU ports and
DSA links using the same data structures as we have for MDB entries.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ever since the cross-chip notifiers were introduced, the design was
meant to be simplistic and just get the job done without worrying too
much about dangling resources left behind.

For example, somebody installs an MDB entry on sw0p0 in this daisy chain
topology. It gets installed using ds->ops->port_mdb_add() on sw0p0,
sw1p4 and sw2p4.

                                                    |
           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   ]

Then the same person deletes that MDB entry. The cross-chip notifier for
deletion only matches sw0p0:

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

Why?

Because the DSA links are 'trunk' ports, if we just go ahead and delete
the MDB from sw1p4 and sw2p4 directly, we might delete those multicast
entries when they are still needed. Just consider the fact that somebody
does:

- add a multicast MAC address towards sw0p0 [ via the cross-chip
  notifiers it gets installed on the DSA links too ]
- add the same multicast MAC address towards sw0p1 (another port of that
  same switch)
- delete the same multicast MAC address from sw0p0.

At this point, if we deleted the MAC address from the DSA links, it
would be flooded, even though there is still an entry on switch 0 which
needs it not to.

So that is why deletions only match the targeted source port and nothing
on DSA links. Of course, dangling resources means that the hardware
tables will eventually run out given enough additions/removals, but hey,
at least it's simple.

But there is a bigger concern which needs to be addressed, and that is
our support for SWITCHDEV_OBJ_ID_HOST_MDB. DSA simply translates such an
object into a dsa_port_host_mdb_add() which ends up as ds->ops->port_mdb_add()
on the upstream port, and a similar thing happens on deletion:
dsa_port_host_mdb_del() will trigger ds->ops->port_mdb_del() on the
upstream port.

When there are 2 VLAN-unaware bridges spanning the same switch (which is
a use case DSA proudly supports), each bridge will install its own
SWITCHDEV_OBJ_ID_HOST_MDB entries. But upon deletion, DSA goes ahead and
emits a DSA_NOTIFIER_MDB_DEL for dp->cpu_dp, which is shared between the
user ports enslaved to br0 and the user ports enslaved to br1. Not good.
The host-trapped multicast addresses installed by br1 will be deleted
when any state changes in br0 (IGMP timers expire, or ports leave, etc).

To avoid this, we could of course go the route of the zero-sum game and
delete the DSA_NOTIFIER_MDB_DEL call for dp->cpu_dp. But the better
design is to just admit that on shared ports like DSA links and CPU
ports, we should be reference counting calls, even if this consumes some
dynamic memory which DSA has traditionally avoided. On the flip side,
the hardware tables of switches are limited in size, so it would be good
if the OS managed them properly instead of having them eventually
overflow.

To address the memory usage concern, we only apply the refcounting of
MDB entries on ports that are really shared (CPU ports and DSA links)
and not on user ports. In a typical single-switch setup, this means only
the CPU port (and the host MDB entries are not that many, really).

The name of the newly introduced data structures (dsa_mac_addr) is
chosen in such a way that will be reusable for host FDB entries (next
patch).

With this change, we can finally have the same matching logic for the
MDB additions and deletions, as well as for their host-trapped variants.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The difference between dsa_is_user_port and dsa_port_is_user is that the
former needs to look up the list of ports of the DSA switch tree in
order to find the struct dsa_port, while the latter directly receives it
as an argument.

dsa_is_user_port is already in widespread use and has its place, so
there isn't any chance of converting all callers to a single form.
But being able to do:
	dsa_port_is_user(dp)
instead of
	dsa_is_user_port(dp->ds, dp->index)

is much more efficient too, especially when the "dp" comes from an
iterator over the DSA switch tree - this reduces the complexity from
quadratic to linear.

Move these helpers from dsa2.c to include/net/dsa.h so that others can
use them too.
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>

The cross-chip notifiers work by comparing each ds->index against the
info->sw_index value from the notifier. The ds->index is retrieved from
the device tree dsa,member property.

If a single tree cross-chip topology does not declare unique switch IDs,
this will result in hard-to-debug issues/voodoo effects such as the
cross-chip notifier for one switch port also matching the port with the
same number from another switch.

Check in dsa_switch_parse_member_of() whether the DSA switch tree
contains a DSA switch with the index we're preparing to add, before
actually adding it.
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>

Some combinations of tag protocols and Ethernet controllers are
incompatible, and it is hard for the driver to keep track of these.

Therefore, allow the device tree author (typically the board vendor)
to inform the driver of this fact by selecting an alternate protocol
that is known to work.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.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>

If PHY is not available on DSA port (described at devicetree but absent or
failed to detect) then kernel prints warning after 3700 secs:

[ 3707.948771] ------------[ cut here ]------------
[ 3707.948784] Type was not set for devlink port.
[ 3707.948894] WARNING: CPU: 1 PID: 17 at net/core/devlink.c:8097 0xc083f9d8

We should unregister the devlink port as a user port and
re-register it as an unused port before executing "continue" in case of
dsa_port_setup error.

Fixes: 86f8b1c0 ("net: dsa: Do not make user port errors fatal")
Signed-off-by: NMaxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a temporary variable to hold the return value from
dsa_tag_driver_get() instead of assigning it to dst->tag_ops. Leaving
an error value in dst->tag_ops can result in deferencing an invalid
pointer when a deferred switch configuration happens later.

Fixes: 357f203b ("net: dsa: keep a copy of the tagging protocol in the DSA switch tree")
Signed-off-by: NGeorge McCollister <george.mccollister@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since teardown is supposed to undo the effects of the setup method, it
should be called in the error path for dsa_switch_setup, not just in
dsa_switch_teardown.

Fixes: 5e3f847a ("net: dsa: Add teardown callback for drivers")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210204163351.2929670-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Currently DSA exposes the following sysfs:
$ cat /sys/class/net/eno2/dsa/tagging
ocelot

which is a read-only device attribute, introduced in the kernel as
commit 98cdb480 ("net: dsa: Expose tagging protocol to user-space"),
and used by libpcap since its commit 993db3800d7d ("Add support for DSA
link-layer types").

It would be nice if we could extend this device attribute by making it
writable:
$ echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging

This is useful with DSA switches that can make use of more than one
tagging protocol. It may be useful in dsa_loop in the future too, to
perform offline testing of various taggers, or for changing between dsa
and edsa on Marvell switches, if that is desirable.

In terms of implementation, drivers can support this feature by
implementing .change_tag_protocol, which should always leave the switch
in a consistent state: either with the new protocol if things went well,
or with the old one if something failed. Teardown of the old protocol,
if necessary, must be handled by the driver.

Some things remain as before:
- The .get_tag_protocol is currently only called at probe time, to load
  the initial tagging protocol driver. Nonetheless, new drivers should
  report the tagging protocol in current use now.
- The driver should manage by itself the initial setup of tagging
  protocol, no later than the .setup() method, as well as destroying
  resources used by the last tagger in use, no earlier than the
  .teardown() method.

For multi-switch DSA trees, error handling is a bit more complicated,
since e.g. the 5th out of 7 switches may fail to change the tag
protocol. When that happens, a revert to the original tag protocol is
attempted, but that may fail too, leaving the tree in an inconsistent
state despite each individual switch implementing .change_tag_protocol
transactionally. Since the intersection between drivers that implement
.change_tag_protocol and drivers that support D in DSA is currently the
empty set, the possibility for this error to happen is ignored for now.

Testing:

$ insmod mscc_felix.ko
[   79.549784] mscc_felix 0000:00:00.5: Adding to iommu group 14
[   79.565712] mscc_felix 0000:00:00.5: Failed to register DSA switch: -517
$ insmod tag_ocelot.ko
$ rmmod mscc_felix.ko
$ insmod mscc_felix.ko
[   97.261724] libphy: VSC9959 internal MDIO bus: probed
[   97.267363] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 0
[   97.274998] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 1
[   97.282561] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 2
[   97.289700] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 3
[   97.599163] mscc_felix 0000:00:00.5 swp0 (uninitialized): PHY [0000:00:00.3:10] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   97.862034] mscc_felix 0000:00:00.5 swp1 (uninitialized): PHY [0000:00:00.3:11] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   97.950731] mscc_felix 0000:00:00.5 swp0: configuring for inband/qsgmii link mode
[   97.964278] 8021q: adding VLAN 0 to HW filter on device swp0
[   98.146161] mscc_felix 0000:00:00.5 swp2 (uninitialized): PHY [0000:00:00.3:12] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   98.238649] mscc_felix 0000:00:00.5 swp1: configuring for inband/qsgmii link mode
[   98.251845] 8021q: adding VLAN 0 to HW filter on device swp1
[   98.433916] mscc_felix 0000:00:00.5 swp3 (uninitialized): PHY [0000:00:00.3:13] driver [Microsemi GE VSC8514 SyncE] (irq=POLL)
[   98.485542] mscc_felix 0000:00:00.5: configuring for fixed/internal link mode
[   98.503584] mscc_felix 0000:00:00.5: Link is Up - 2.5Gbps/Full - flow control rx/tx
[   98.527948] device eno2 entered promiscuous mode
[   98.544755] DSA: tree 0 setup

$ ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: seq=0 ttl=64 time=2.337 ms
64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.754 ms
^C
 -  10.0.0.1 ping statistics  -
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.754/1.545/2.337 ms

$ cat /sys/class/net/eno2/dsa/tagging
ocelot
$ cat ./test_ocelot_8021q.sh
        #!/bin/bash

        ip link set swp0 down
        ip link set swp1 down
        ip link set swp2 down
        ip link set swp3 down
        ip link set swp5 down
        ip link set eno2 down
        echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging
        ip link set eno2 up
        ip link set swp0 up
        ip link set swp1 up
        ip link set swp2 up
        ip link set swp3 up
        ip link set swp5 up
$ ./test_ocelot_8021q.sh
./test_ocelot_8021q.sh: line 9: echo: write error: Protocol not available
$ rmmod tag_ocelot.ko
rmmod: can't unload module 'tag_ocelot': Resource temporarily unavailable
$ insmod tag_ocelot_8021q.ko
$ ./test_ocelot_8021q.sh
$ cat /sys/class/net/eno2/dsa/tagging
ocelot-8021q
$ rmmod tag_ocelot.ko
$ rmmod tag_ocelot_8021q.ko
rmmod: can't unload module 'tag_ocelot_8021q': Resource temporarily unavailable
$ ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: seq=0 ttl=64 time=0.953 ms
64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.787 ms
64 bytes from 10.0.0.1: seq=2 ttl=64 time=0.771 ms
$ rmmod mscc_felix.ko
[  645.544426] mscc_felix 0000:00:00.5: Link is Down
[  645.838608] DSA: tree 0 torn down
$ rmmod tag_ocelot_8021q.ko
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Cascading DSA switches can be done multiple ways. There is the brute
force approach / tag stacking, where one upstream switch, located
between leaf switches and the host Ethernet controller, will just
happily transport the DSA header of those leaf switches as payload.
For this kind of setups, DSA works without any special kind of treatment
compared to a single switch - they just aren't aware of each other.
Then there's the approach where the upstream switch understands the tags
it transports from its leaves below, as it doesn't push a tag of its own,
but it routes based on the source port & switch id information present
in that tag (as opposed to DMAC & VID) and it strips the tag when
egressing a front-facing port. Currently only Marvell implements the
latter, and Marvell DSA trees contain only Marvell switches.

So it is safe to say that DSA trees already have a single tag protocol
shared by all switches, and in fact this is what makes the switches able
to understand each other. This fact is also implied by the fact that
currently, the tagging protocol is reported as part of a sysfs installed
on the DSA master and not per port, so it must be the same for all the
ports connected to that DSA master regardless of the switch that they
belong to.

It's time to make this official and enforce it (yes, this also means we
won't have any "switch understands tag to some extent but is not able to
speak it" hardware oddities that we'll support in the future).

This is needed due to the imminent introduction of the dsa_switch_ops::
change_tag_protocol driver API. When that is introduced, we'll have
to notify switches of the tagging protocol that they're configured to
use. Currently the tag_ops structure pointer is held only for CPU ports.
But there are switches which don't have CPU ports and nonetheless still
need to be configured. These would be Marvell leaf switches whose
upstream port is just a DSA link. How do we inform these of their
tagging protocol setup/deletion?

One answer to the above would be: iterate through the DSA switch tree's
ports once, list the CPU ports, get their tag_ops, then iterate again
now that we have it, and notify everybody of that tag_ops. But what to
do if conflicts appear between one cpu_dp->tag_ops and another? There's
no escaping the fact that conflict resolution needs to be done, so we
can be upfront about it.

Ease our work and just keep the master copy of the tag_ops inside the
struct dsa_switch_tree. Reference counting is now moved to be per-tree
too, instead of per-CPU port.

There are many places in the data path that access master->dsa_ptr->tag_ops
and we would introduce unnecessary performance penalty going through yet
another indirection, so keep those right where they are.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The existence of dsa_broadcast has generated some confusion in the past:
https://www.mail-archive.com/netdev@vger.kernel.org/msg365042.html

So let's document the existing dsa_port_notify and dsa_broadcast
functions and explain when each of them should be used.

Also, in fact, the in-between function has always been there but was
lacking a name, and is the main reason for this patch: dsa_tree_notify.
Refactor dsa_broadcast to use it.

This patch also moves dsa_broadcast (a top-level function) to dsa2.c,
where it really belonged in the first place, but had no companion so it
stood with dsa_port_notify.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Switches that care about QoS might have hardware support for reserving
buffer pools for individual ports or traffic classes, and configuring
their sizes and thresholds. Through devlink-sb (shared buffers), this is
all configurable, as well as their occupancy being viewable.

Add the plumbing in DSA for these operations.

Individual drivers still need to call devlink_sb_register() with the
shared buffers they want to expose. A helper was not created in DSA for
this purpose (unlike, say, dsa_devlink_params_register), since in my
opinion it does not bring any benefit over plainly calling
devlink_sb_register() directly.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

As explained in commit 54a0ed0d ("net: dsa: provide an option for
drivers to always receive bridge VLANs"), DSA has historically been
skipping VLAN switchdev operations when the bridge wasn't in
vlan_filtering mode, but the reason why it was doing that has never been
clear. So the configure_vlan_while_not_filtering option is there merely
to preserve functionality for existing drivers. It isn't some behavior
that drivers should opt into. Ideally, when all drivers leave this flag
set, we can delete the dsa_port_skip_vlan_configuration() function.

New drivers always seem to omit setting this flag, for some reason. So
let's reverse the logic: the DSA core sets it by default to true before
the .setup() callback, and legacy drivers can turn it off. This way, new
drivers get the new behavior by default, unless they explicitly set the
flag to false, which is more obvious during review.

Remove the assignment from drivers which were setting it to true, and
add the assignment to false for the drivers that didn't previously have
it. This way, it should be easier to see how many we have left.

The following drivers: lan9303, mv88e6060 were skipped from setting this
flag to false, because they didn't have any VLAN offload ops in the
first place.

The Broadcom Starfighter 2 driver calls the common b53_switch_alloc and
therefore also inherits the configure_vlan_while_not_filtering=true
behavior.

Also, print a message through netlink extack every time a VLAN has been
skipped. This is mildly annoying on purpose, so that (a) it is at least
clear that VLANs are being skipped - the legacy behavior in itself is
confusing, and the extack should be much more difficult to miss, unlike
kernel logs - and (b) people have one more incentive to convert to the
new behavior.

No behavior change except for the added prints is intended at this time.

$ ip link add br0 type bridge vlan_filtering 0
$ ip link set sw0p2 master br0
[   60.315148] br0: port 1(sw0p2) entered blocking state
[   60.320350] br0: port 1(sw0p2) entered disabled state
[   60.327839] device sw0p2 entered promiscuous mode
[   60.334905] br0: port 1(sw0p2) entered blocking state
[   60.340142] br0: port 1(sw0p2) entered forwarding state
Warning: dsa_core: skipping configuration of VLAN. # This was the pvid
$ bridge vlan add dev sw0p2 vid 100
Warning: dsa_core: skipping configuration of VLAN.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210115231919.43834-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Monitor the following events and notify the driver when:

- A DSA port joins/leaves a LAG.
- A LAG, made up of DSA ports, joins/leaves a bridge.
- A DSA port in a LAG is enabled/disabled (enabled meaning
  "distributing" in 802.3ad LACP terms).

When a LAG joins a bridge, the DSA subsystem will treat that as each
individual port joining the bridge. The driver may look at the port's
LAG device pointer to see if it is associated with any LAG, if that is
required. This is analogue to how switchdev events are replicated out
to all lower devices when reaching e.g. a LAG.

Drivers can optionally request that DSA maintain a linear mapping from
a LAG ID to the corresponding netdev by setting ds->num_lag_ids to the
desired size.

In the event that the hardware is not capable of offloading a
particular LAG for any reason (the typical case being use of exotic
modes like broadcast), DSA will take a hands-off approach, allowing
the LAG to be formed as a pure software construct. This is reported
back through the extended ACK, but is otherwise transparent to the
user.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Tested-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Florian reported a use-after-free bug in devlink_nl_port_fill found with
KASAN:

(devlink_nl_port_fill)
(devlink_port_notify)
(devlink_port_unregister)
(dsa_switch_teardown.part.3)
(dsa_tree_teardown_switches)
(dsa_unregister_switch)
(bcm_sf2_sw_remove)
(platform_remove)
(device_release_driver_internal)
(device_links_unbind_consumers)
(device_release_driver_internal)
(device_driver_detach)
(unbind_store)

Allocated by task 31:
 alloc_netdev_mqs+0x5c/0x50c
 dsa_slave_create+0x110/0x9c8
 dsa_register_switch+0xdb0/0x13a4
 b53_switch_register+0x47c/0x6dc
 bcm_sf2_sw_probe+0xaa4/0xc98
 platform_probe+0x90/0xf4
 really_probe+0x184/0x728
 driver_probe_device+0xa4/0x278
 __device_attach_driver+0xe8/0x148
 bus_for_each_drv+0x108/0x158

Freed by task 249:
 free_netdev+0x170/0x194
 dsa_slave_destroy+0xac/0xb0
 dsa_port_teardown.part.2+0xa0/0xb4
 dsa_tree_teardown_switches+0x50/0xc4
 dsa_unregister_switch+0x124/0x250
 bcm_sf2_sw_remove+0x98/0x13c
 platform_remove+0x44/0x5c
 device_release_driver_internal+0x150/0x254
 device_links_unbind_consumers+0xf8/0x12c
 device_release_driver_internal+0x84/0x254
 device_driver_detach+0x30/0x34
 unbind_store+0x90/0x134

What happens is that devlink_port_unregister emits a netlink
DEVLINK_CMD_PORT_DEL message which associates the devlink port that is
getting unregistered with the ifindex of its corresponding net_device.
Only trouble is, the net_device has already been unregistered.

It looks like we can stub out the search for a corresponding net_device
if we clear the devlink_port's type. This looks like a bit of a hack,
but also seems to be the reason why the devlink_port_type_clear function
exists in the first place.

Fixes: 3122433e ("net: dsa: Register devlink ports before calling DSA driver setup()")
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>
Reported-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210112004831.3778323-1-olteanv@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Looking for an -EINVAL all over the dsa code could take hours for
inexperienced DSA users.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210106090915.21439-1-zajec5@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

DSA drivers want to create regions on devlink ports as well as the
devlink device instance, in order to export registers and other tables
per port. To keep all this code together in the drivers, have the
devlink ports registered early, so the setup() method can setup both
device and port devlink regions.

v3:
Remove dp->setup
Move common code out of switch statement.
Fix wrong goto
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Tested-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a port is unused, still create a devlink port for it, but set the
flavour to unused. This allows us to attach devlink regions to the
port, etc.
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Tested-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow the DSA drivers to implement the devlink call to get info info,
e.g. driver name, firmware version, ASIC ID, etc.

v2:
Combine declaration and the assignment on a single line.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to unified Ethernet Switch Device Tree Bindings allow for ethernet-ports as
encapsulating node as well.
Signed-off-by: NKurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, devlink_port_attrs_set accepts a long list of parameters,
that most of them are devlink port's attributes.

Use the devlink_port_attrs struct to replace the relevant parameters.
Signed-off-by: NDanielle Ratson <danieller@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Somewhat similar to dsa_tree_find, dsa_switch_find returns a dsa_switch
structure pointer by searching for its tree index and switch index (the
parameters from dsa,member). To be used, for example, by drivers who
implement .crosschip_bridge_join and need a reference to the other
switch indicated to by the tree_index and sw_index arguments.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Prior to 1d27732f ("net: dsa: setup and teardown ports"), we would
not treat failures to set-up an user port as fatal, but after this
commit we would, which is a regression for some systems where interfaces
may be declared in the Device Tree, but the underlying hardware may not
be present (pluggable daughter cards for instance).

Fixes: 1d27732f ("net: dsa: setup and teardown ports")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many switches don't have an explicit knob for configuring the MTU
(maximum transmission unit per interface).  Instead, they do the
length-based packet admission checks on the ingress interface, for
reasons that are easy to understand (why would you accept a packet in
the queuing subsystem if you know you're going to drop it anyway).

So it is actually the MRU that these switches permit configuring.

In Linux there only exists the IFLA_MTU netlink attribute and the
associated dev_set_mtu function. The comments like to play blind and say
that it's changing the "maximum transfer unit", which is to say that
there isn't any directionality in the meaning of the MTU word. So that
is the interpretation that this patch is giving to things: MTU == MRU.

When 2 interfaces having different MTUs are bridged, the bridge driver
MTU auto-adjustment logic kicks in: what br_mtu_auto_adjust() does is it
adjusts the MTU of the bridge net device itself (and not that of the
slave net devices) to the minimum value of all slave interfaces, in
order for forwarded packets to not exceed the MTU regardless of the
interface they are received and send on.

The idea behind this behavior, and why the slave MTUs are not adjusted,
is that normal termination from Linux over the L2 forwarding domain
should happen over the bridge net device, which _is_ properly limited by
the minimum MTU. And termination over individual slave devices is
possible even if those are bridged. But that is not "forwarding", so
there's no reason to do normalization there, since only a single
interface sees that packet.

The problem with those switches that can only control the MRU is with
the offloaded data path, where a packet received on an interface with
MRU 9000 would still be forwarded to an interface with MRU 1500. And the
br_mtu_auto_adjust() function does not really help, since the MTU
configured on the bridge net device is ignored.

In order to enforce the de-facto MTU == MRU rule for these switches, we
need to do MTU normalization, which means: in order for no packet larger
than the MTU configured on this port to be sent, then we need to limit
the MRU on all ports that this packet could possibly come from. AKA
since we are configuring the MRU via MTU, it means that all ports within
a bridge forwarding domain should have the same MTU.

And that is exactly what this patch is trying to do.

>From an implementation perspective, we try to follow the intent of the
user, otherwise there is a risk that we might livelock them (they try to
change the MTU on an already-bridged interface, but we just keep
changing it back in an attempt to keep the MTU normalized). So the MTU
that the bridge is normalized to is either:

 - The most recently changed one:

   ip link set dev swp0 master br0
   ip link set dev swp1 master br0
   ip link set dev swp0 mtu 1400

   This sequence will make swp1 inherit MTU 1400 from swp0.

 - The one of the most recently added interface to the bridge:

   ip link set dev swp0 master br0
   ip link set dev swp1 mtu 1400
   ip link set dev swp1 master br0

   The above sequence will make swp0 inherit MTU 1400 as well.
Suggested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA sets up a switch tree little by little. Every switch of the N
members of the tree calls dsa_register_switch, and (N - 1) will just
touch the dst->ports list with their ports and quickly exit. Only the
last switch that calls dsa_register_switch will find all DSA links
complete in dsa_tree_setup_routing_table, and not return zero as a
result but instead go ahead and set up the entire DSA switch tree
(practically on behalf of the other switches too).

The trouble is that the (N - 1) switches don't clean up after themselves
after they get an error such as EPROBE_DEFER. Their footprint left in
dst->ports by dsa_switch_touch_ports is still there. And switch N, the
one responsible with actually setting up the tree, is going to work with
those stale dp, dp->ds and dp->ds->dev pointers. In particular ds and
ds->dev might get freed by the device driver.

Be there a 2-switch tree and the following calling order:
- Switch 1 calls dsa_register_switch
  - Calls dsa_switch_touch_ports, populates dst->ports
  - Calls dsa_port_parse_cpu, gets -EPROBE_DEFER, exits.
- Switch 2 calls dsa_register_switch
  - Calls dsa_switch_touch_ports, populates dst->ports
  - Probe doesn't get deferred, so it goes ahead.
  - Calls dsa_tree_setup_routing_table, which returns "complete == true"
    due to Switch 1 having called dsa_switch_touch_ports before.
  - Because the DSA links are complete, it calls dsa_tree_setup_switches
    now.
  - dsa_tree_setup_switches iterates through dst->ports, initializing
    the Switch 1 ds structure (invalid) and the Switch 2 ds structure
    (valid).
  - Undefined behavior (use after free, sometimes NULL pointers, etc).

Real example below (debugging prints added by me, as well as guards
against NULL pointers):

[    5.477947] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.313002] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.319932] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.329693] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.339458] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.349226] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.358991] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.368758] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.378524] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.388291] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.398057] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803df0b980 (dev ffffff803f775c00)
[    6.407912] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.417682] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.427446] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.437212] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.446979] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.456744] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.466512] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.476277] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.486043] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.495810] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.505577] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803da02f80 (dev 0000000000000000)
[    6.515433] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.354120] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.361045] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.370805] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.380571] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.390337] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.400104] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.409872] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.419637] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.429403] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803db15b80 (dev ffffff803d8e4800)
[    7.439169] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803db15b80 (dev ffffff803d8e4800)

The solution is to recognize that the functions that call
dsa_switch_touch_ports (dsa_switch_parse_of, dsa_switch_parse) have side
effects, and therefore one should clean up their side effects on error
path. The cleanup of dst->ports was taken from dsa_switch_remove and
moved into a dedicated dsa_switch_release_ports function, which should
really be per-switch (free only the members of dst->ports that are also
members of ds, instead of all switch ports).
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is possible to stack multiple DSA switches in a way that they are not
part of the tree (disjoint) but the DSA master of a switch is a DSA
slave of another. When that happens switch drivers may have to know this
is the case so as to determine whether their tagging protocol has a
remove chance of working.

This is useful for specific switch drivers such as b53 where devices
have been known to be stacked in the wild without the Broadcom tag
protocol supporting that feature. This allows b53 to continue supporting
those devices by forcing the disabling of Broadcom tags on the outermost
switches if necessary.

The get_tag_protocol() function is therefore updated to gain an
additional enum dsa_tag_protocol argument which denotes the current
tagging protocol used by the DSA master we are attached to, else
DSA_TAG_PROTO_NONE for the top of the dsa_switch_tree.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dsa_link_touch() is not exported, or defined outside of the
file it is in so make it static to avoid the following warning:

net/dsa/dsa2.c:127:17: warning: symbol 'dsa_link_touch' was not declared. Should it be static?
Signed-off-by: NBen Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The order in which the ports are deleted from the list and freed and the
call to dsa_switch_remove() is done is reversed, which leads to an
use after free condition. Reverse the two: first tear down the ports and
switch from the fabric, then free the ports associated with that switch
fabric.

Fixes: 05f294a8 ("net: dsa: allocate ports on touch")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because there is no static array describing the links between switches
anymore, we have no reason to force a limitation of the index value
set by the device tree.
Signed-off-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The DSA fabric setup code has been simplified a lot so get rid of
the dsa_tree_remove_switch, dsa_tree_add_switch and dsa_switch_add
helpers, and keep the code simple with only the dsa_switch_probe and
dsa_switch_remove functions.
Signed-off-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that the DSA ports are listed in the switch fabric, there is
no need to store the dsa_switch structures from the drivers in the
fabric anymore. So get rid of the dst->ds static array.
Signed-off-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The dsa_switch structure has no routing table specific data to setup,
so the switch fabric can directly walk its ports and initialize its
routing table from them.

This allows us to remove the dsa_switch_setup_routing_table function.
Signed-off-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drivers do not use the ds->rtable static arrays anymore, get rid of it.
Signed-off-by: NVivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>