Add the usual trampoline functionality from the generic DSA layer down
to the drivers for MST state changes.

When a state changes to disabled/blocking/listening, make sure to fast
age any dynamic entries in the affected VLANs (those controlled by the
MSTI in question).
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add the usual trampoline functionality from the generic DSA layer down
to the drivers for VLAN MSTI migrations.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Similar to the port-based default priority, IEEE 802.1Q-2018 allows the
Application Priority Table to define QoS classes (0 to 7) per IP DSCP
value (0 to 63).

In the absence of an app table entry for a packet with DSCP value X,
QoS classification for that packet falls back to other methods (VLAN PCP
or port-based default). The presence of an app table for DSCP value X
with priority Y makes the hardware classify the packet to QoS class Y.

As opposed to the default-prio where DSA exposes only a "set" in
dsa_switch_ops (because the port-based default is the fallback, it
always exists, either implicitly or explicitly), for DSCP priorities we
expose an "add" and a "del". The addition of a DSCP entry means trusting
that DSCP priority, the deletion means ignoring it.

Drivers that already trust (at least some) DSCP values can describe
their configuration in dsa_switch_ops :: port_get_dscp_prio(), which is
called for each DSCP value from 0 to 63.

Again, there can be more than one dcbnl app table entry for the same
DSCP value, DSA chooses the one with the largest configured priority.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The port-based default QoS class is assigned to packets that lack a
VLAN PCP (or the port is configured to not trust the VLAN PCP),
an IP DSCP (or the port is configured to not trust IP DSCP), and packets
on which no tc-skbedit action has matched.

Similar to other drivers, this can be exposed to user space using the
DCB Application Priority Table. IEEE 802.1Q-2018 specifies in Table
D-8 - Sel field values that when the Selector is 1, the Protocol ID
value of 0 denotes the "Default application priority. For use when
application priority is not otherwise specified."

The way in which the dcbnl integration in DSA has been designed has to
do with its requirements. Andrew Lunn explains that SOHO switches are
expected to come with some sort of pre-configured QoS profile, and that
it is desirable for this to come pre-loaded into the DSA slave interfaces'
DCB application priority table.

In the dcbnl design, this is possible because calls to dcb_ieee_setapp()
can be initiated by anyone including being self-initiated by this device
driver.

However, what makes this challenging to implement in DSA is that the DSA
core manages the net_devices (effectively hiding them from drivers),
while drivers manage the hardware. The DSA core has no knowledge of what
individual drivers' QoS policies are. DSA could export to drivers a
wrapper over dcb_ieee_setapp() and these could call that function to
pre-populate the app priority table, however drivers don't have a good
moment in time to do this. The dsa_switch_ops :: setup() method gets
called before the net_devices are created (dsa_slave_create), and so is
dsa_switch_ops :: port_setup(). What remains is dsa_switch_ops ::
port_enable(), but this gets called upon each ndo_open. If we add app
table entries on every open, we'd need to remove them on close, to avoid
duplicate entry errors. But if we delete app priority entries on close,
what we delete may not be the initial, driver pre-populated entries, but
rather user-added entries.

So it is clear that letting drivers choose the timing of the
dcb_ieee_setapp() call is inappropriate. The alternative which was
chosen is to introduce hardware-specific ops in dsa_switch_ops, and
effectively hide dcbnl details from drivers as well. For pre-populating
the application table, dsa_slave_dcbnl_init() will call
ds->ops->port_get_default_prio() which is supposed to read from
hardware. If the operation succeeds, DSA creates a default-prio app
table entry. The method is called as soon as the slave_dev is
registered, but before we release the rtnl_mutex. This is done such that
user space sees the app table entries as soon as it sees the interface
being registered.

The fact that we populate slave_dev->dcbnl_ops with a non-NULL pointer
changes behavior in dcb_doit() from net/dcb/dcbnl.c, which used to
return -EOPNOTSUPP for any dcbnl operation where netdev->dcbnl_ops is
NULL. Because there are still dcbnl-unaware DSA drivers even if they
have dcbnl_ops populated, the way to restore the behavior is to make all
dcbnl_ops return -EOPNOTSUPP on absence of the hardware-specific
dsa_switch_ops method.

The dcbnl framework absurdly allows there to be more than one app table
entry for the same selector and protocol (in other words, more than one
port-based default priority). In the iproute2 dcb program, there is a
"replace" syntactical sugar command which performs an "add" and a "del"
to hide this away. But we choose the largest configured priority when we
call ds->ops->port_set_default_prio(), using __fls(). When there is no
default-prio app table entry left, the port-default priority is restored
to 0.

Link: https://patchwork.kernel.org/project/netdevbpf/patch/20210113154139.1803705-2-olteanv@gmail.com/Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Felix driver declares FDB isolation but puts all standalone ports in
VID 0. This is mostly problem-free as discussed with Alvin here:
https://patchwork.kernel.org/project/netdevbpf/cover/20220302191417.1288145-1-vladimir.oltean@nxp.com/#24763870

however there is one catch. DSA still thinks that FDB entries are
installed on the CPU port as many times as there are user ports, and
this is problematic when multiple user ports share the same MAC address.

Consider the default case where all user ports inherit their MAC address
from the DSA master, and then the user runs:

ip link set swp0 address 00:01:02:03:04:05

The above will make dsa_slave_set_mac_address() call
dsa_port_standalone_host_fdb_add() for 00:01:02:03:04:05 in port 0's
standalone database, and dsa_port_standalone_host_fdb_del() for the old
address of swp0, again in swp0's standalone database.

Both the ->port_fdb_add() and ->port_fdb_del() will be propagated down
to the felix driver, which will end up deleting the old MAC address from
the CPU port. But this is still in use by other user ports, so we end up
breaking unicast termination for them.

There isn't a problem in the fact that DSA keeps track of host
standalone addresses in the individual database of each user port: some
drivers like sja1105 need this. There also isn't a problem in the fact
that some drivers choose the same VID/FID for all standalone ports.
It is just that the deletion of these host addresses must be delayed
until they are known to not be in use any longer, and only the driver
has this knowledge. Since DSA keeps these addresses in &cpu_dp->fdbs and
&cpu_db->mdbs, it is just a matter of walking over those lists and see
whether the same MAC address is present on the CPU port in the port db
of another user port.

I have considered reusing the generic dsa_port_walk_fdbs() and
dsa_port_walk_mdbs() schemes for this, but locking makes it difficult.
In the ->port_fdb_add() method and co, &dp->addr_lists_lock is held, but
dsa_port_walk_fdbs() also acquires that lock. Also, even assuming that
we introduce an unlocked variant of the address iterator, we'd still
need some relatively complex data structures, and a void *ctx in the
dsa_fdb_walk_cb_t which we don't currently pass, such that drivers are
able to figure out, after iterating, whether the same MAC address is or
isn't present in the port db of another port.

All the above, plus the fact that I expect other drivers to follow the
same model as felix where all standalone ports use the same FID, made me
conclude that a generic method provided by DSA is necessary:
dsa_fdb_present_in_other_db() and the mdb equivalent. Felix calls this
from the ->port_fdb_del() handler for the CPU port, when the database
was classified to either a port db, or a LAG db.

For symmetry, we also call this from ->port_fdb_add(), because if the
address was installed once, then installing it a second time serves no
purpose: it's already in hardware in VID 0 and it affects all standalone
ports.

This change moves dsa_db_equal() from switch.c to dsa.c, since it now
has one more caller.

Fixes: 54c31984 ("net: mscc: ocelot: enforce FDB isolation when VLAN-unaware")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Realtek switches supports the same tag both before ethertype or between
payload and the CRC.
Signed-off-by: NLuiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The "ocelot" and "ocelot-8021q" tagging protocols make use of different
hardware resources, and host FDB entries have different destination
ports in the switch analyzer module, practically speaking.

So when the user requests a tagging protocol change, the driver must
migrate all host FDB and MDB entries from the NPI port (in fact CPU port
module) towards the same physical port, but this time used as a regular
port.

It is pointless for the felix driver to keep a copy of the host
addresses, when we can create and export DSA helpers for walking through
the addresses that it already needs to keep on the CPU port, for
refcounting purposes.

felix_classify_db() is moved up to avoid a forward declaration.

We pass "bool change" because dp->fdbs and dp->mdbs are uninitialized
lists when felix_setup() first calls felix_set_tag_protocol(), so we
need to avoid calling dsa_port_walk_fdbs() during probe time.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As FDB isolation cannot be enforced between VLAN-aware bridges in lack
of hardware assistance like extra FID bits, it seems plausible that many
DSA switches cannot do it. Therefore, they need to reject configurations
with multiple VLAN-aware bridges from the two code paths that can
transition towards that state:

- joining a VLAN-aware bridge
- toggling VLAN awareness on an existing bridge

The .port_vlan_filtering method already propagates the netlink extack to
the driver, let's propagate it from .port_bridge_join too, to make sure
that the driver can use the same function for both.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For DSA, to encourage drivers to perform FDB isolation simply means to
track which bridge does each FDB and MDB entry belong to. It then
becomes the driver responsibility to use something that makes the FDB
entry from one bridge not match the FDB lookup of ports from other
bridges.

The top-level functions where the bridge is determined are:
- dsa_port_fdb_{add,del}
- dsa_port_host_fdb_{add,del}
- dsa_port_mdb_{add,del}
- dsa_port_host_mdb_{add,del}

aka the pre-crosschip-notifier functions.

Changing the API to pass a reference to a bridge is not superfluous, and
looking at the passed bridge argument is not the same as having the
driver look at dsa_to_port(ds, port)->bridge from the ->port_fdb_add()
method.

DSA installs FDB and MDB entries on shared (CPU and DSA) ports as well,
and those do not have any dp->bridge information to retrieve, because
they are not in any bridge - they are merely the pipes that serve the
user ports that are in one or multiple bridges.

The struct dsa_bridge associated with each FDB/MDB entry is encapsulated
in a larger "struct dsa_db" database. Although only databases associated
to bridges are notified for now, this API will be the starting point for
implementing IFF_UNICAST_FLT in DSA. There, the idea is to install FDB
entries on the CPU port which belong to the corresponding user port's
port database. These are supposed to match only when the port is
standalone.

It is better to introduce the API in its expected final form than to
introduce it for bridges first, then to have to change drivers which may
have made one or more assumptions.

Drivers can use the provided bridge.num, but they can also use a
different numbering scheme that is more convenient.

DSA must perform refcounting on the CPU and DSA ports by also taking
into account the bridge number. So if two bridges request the same local
address, DSA must notify the driver twice, once for each bridge.

In fact, if the driver supports FDB isolation, DSA must perform
refcounting per bridge, but if the driver doesn't, DSA must refcount
host addresses across all bridges, otherwise it would be telling the
driver to delete an FDB entry for a bridge and the driver would delete
it for all bridges. So introduce a bool fdb_isolation in drivers which
would make all bridge databases passed to the cross-chip notifier have
the same number (0). This makes dsa_mac_addr_find() -> dsa_db_equal()
say that all bridge databases are the same database - which is
essentially the legacy behavior.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change introduces support for installing static FDB entries towards
a bridge port that is a LAG of multiple DSA switch ports, as well as
support for filtering towards the CPU local FDB entries emitted for LAG
interfaces that are bridge ports.

Conceptually, host addresses on LAG ports are identical to what we do
for plain bridge ports. Whereas FDB entries _towards_ a LAG can't simply
be replicated towards all member ports like we do for multicast, or VLAN.
Instead we need new driver API. Hardware usually considers a LAG to be a
"logical port", and sets the entire LAG as the forwarding destination.
The physical egress port selection within the LAG is made by hashing
policy, as usual.

To represent the logical port corresponding to the LAG, we pass by value
a copy of the dsa_lag structure to all switches in the tree that have at
least one port in that LAG.

To illustrate why a refcounted list of FDB entries is needed in struct
dsa_lag, it is enough to say that:
- a LAG may be a bridge port and may therefore receive FDB events even
  while it isn't yet offloaded by any DSA interface
- DSA interfaces may be removed from a LAG while that is a bridge port;
  we don't want FDB entries lingering around, but we don't want to
  remove entries that are still in use, either

For all the cases below to work, the idea is to always keep an FDB entry
on a LAG with a reference count equal to the DSA member ports. So:
- if a port joins a LAG, it requests the bridge to replay the FDB, and
  the FDB entries get created, or their refcount gets bumped by one
- if a port leaves a LAG, the FDB replay deletes or decrements refcount
  by one
- if an FDB is installed towards a LAG with ports already present, that
  entry is created (if it doesn't exist) and its refcount is bumped by
  the amount of ports already present in the LAG

echo "Adding FDB entry to bond with existing ports"
ip link del bond0
ip link add bond0 type bond mode 802.3ad
ip link set swp1 down && ip link set swp1 master bond0 && ip link set swp1 up
ip link set swp2 down && ip link set swp2 master bond0 && ip link set swp2 up
ip link del br0
ip link add br0 type bridge
ip link set bond0 master br0
bridge fdb add dev bond0 00:01:02:03:04:05 master static

ip link del br0
ip link del bond0

echo "Adding FDB entry to empty bond"
ip link del bond0
ip link add bond0 type bond mode 802.3ad
ip link del br0
ip link add br0 type bridge
ip link set bond0 master br0
bridge fdb add dev bond0 00:01:02:03:04:05 master static
ip link set swp1 down && ip link set swp1 master bond0 && ip link set swp1 up
ip link set swp2 down && ip link set swp2 master bond0 && ip link set swp2 up

ip link del br0
ip link del bond0

echo "Adding FDB entry to empty bond, then removing ports one by one"
ip link del bond0
ip link add bond0 type bond mode 802.3ad
ip link del br0
ip link add br0 type bridge
ip link set bond0 master br0
bridge fdb add dev bond0 00:01:02:03:04:05 master static
ip link set swp1 down && ip link set swp1 master bond0 && ip link set swp1 up
ip link set swp2 down && ip link set swp2 master bond0 && ip link set swp2 up

ip link set swp1 nomaster
ip link set swp2 nomaster
ip link del br0
ip link del bond0
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The main purpose of this change is to create a data structure for a LAG
as seen by DSA. This is similar to what we have for bridging - we pass a
copy of this structure by value to ->port_lag_join and ->port_lag_leave.
For now we keep the lag_dev, id and a reference count in it. Future
patches will add a list of FDB entries for the LAG (these also need to
be refcounted to work properly).

The LAG structure is created using dsa_port_lag_create() and destroyed
using dsa_port_lag_destroy(), just like we have for bridging.

Because now, the dsa_lag itself is refcounted, we can simplify
dsa_lag_map() and dsa_lag_unmap(). These functions need to keep a LAG in
the dst->lags array only as long as at least one port uses it. The
refcounting logic inside those functions can be removed now - they are
called only when we should perform the operation.

dsa_lag_dev() is renamed to dsa_lag_by_id() and now returns the dsa_lag
structure instead of the lag_dev net_device.

dsa_lag_foreach_port() now takes the dsa_lag structure as argument.

dst->lags holds an array of dsa_lag structures.

dsa_lag_map() now also saves the dsa_lag->id value, so that linear
walking of dst->lags in drivers using dsa_lag_id() is no longer
necessary. They can just look at lag.id.

dsa_port_lag_id_get() is a helper, similar to dsa_port_bridge_num_get(),
which can be used by drivers to get the LAG ID assigned by DSA to a
given port.
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>

The DSA LAG API will be changed to become more similar with the bridge
data structures, where struct dsa_bridge holds an unsigned int num,
which is generated by DSA and is one-based. We have a similar thing
going with the DSA LAG, except that isn't stored anywhere, it is
calculated dynamically by dsa_lag_id() by iterating through dst->lags.

The idea of encoding an invalid (or not requested) LAG ID as zero for
the purpose of simplifying checks in drivers means that the LAG IDs
passed by DSA to drivers need to be one-based too. So back-and-forth
conversion is needed when indexing the dst->lags array, as well as in
drivers which assume a zero-based index.
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>

In preparation of converting struct net_device *dp->lag_dev into a
struct dsa_lag *dp->lag, we need to rename, for consistency purposes,
all occurrences of the "lag" variable in the DSA core to "lag_dev".
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>

With drivers converted over to using phylink PCS, there is no need for
the struct dsa_switch member "pcs_poll" to exist anymore - there is a
flag in the struct phylink_pcs which indicates whether this PCS needs
to be polled which supersedes this.
Signed-off-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add DSA support for the phylink mac_select_pcs() method so DSA drivers
can return provide phylink with the appropriate PCS for the PHY
interface mode.
Signed-off-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduced in commit cf963573 ("net: dsa: Allow providing PHY
statistics from CPU port"), it appears these were never used.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220216193726.2926320-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Currently, DSA programs VLANs on shared (DSA and CPU) ports each time it
does so on user ports. This is good for basic functionality but has
several limitations:

- the VLAN group which must reach the CPU may be radically different
  from the VLAN group that must be autonomously forwarded by the switch.
  In other words, the admin may want to isolate noisy stations and avoid
  traffic from them going to the control processor of the switch, where
  it would just waste useless cycles. The bridge already supports
  independent control of VLAN groups on bridge ports and on the bridge
  itself, and when VLAN-aware, it will drop packets in software anyway
  if their VID isn't added as a 'self' entry towards the bridge device.

- Replaying host FDB entries may depend, for some drivers like mv88e6xxx,
  on replaying the host VLANs as well. The 2 VLAN groups are
  approximately the same in most regular cases, but there are corner
  cases when timing matters, and DSA's approximation of replicating
  VLANs on shared ports simply does not work.

- If a user makes the bridge (implicitly the CPU port) join a VLAN by
  accident, there is no way for the CPU port to isolate itself from that
  noisy VLAN except by rebooting the system. This is because for each
  VLAN added on a user port, DSA will add it on shared ports too, but
  for each VLAN deletion on a user port, it will remain installed on
  shared ports, since DSA has no good indication of whether the VLAN is
  still in use or not.

Now that the bridge driver emits well-balanced SWITCHDEV_OBJ_ID_PORT_VLAN
addition and removal events, DSA has a simple and straightforward task
of separating the bridge port VLANs (these have an orig_dev which is a
DSA slave interface, or a LAG interface) from the host VLANs (these have
an orig_dev which is a bridge interface), and to keep a simple reference
count of each VID on each shared port.

Forwarding VLANs must be installed on the bridge ports and on all DSA
ports interconnecting them. We don't have a good view of the exact
topology, so we simply install forwarding VLANs on all DSA ports, which
is what has been done until now.

Host VLANs must be installed primarily on the dedicated CPU port of each
bridge port. More subtly, they must also be installed on upstream-facing
and downstream-facing DSA ports that are connecting the bridge ports and
the CPU. This ensures that the mv88e6xxx's problem (VID of host FDB
entry may be absent from VTU) is still addressed even if that switch is
in a cross-chip setup, and it has no local CPU port.

Therefore:
- user ports contain only bridge port (forwarding) VLANs, and no
  refcounting is necessary
- DSA ports contain both forwarding and host VLANs. Refcounting is
  necessary among these 2 types.
- CPU ports contain only host VLANs. Refcounting is also necessary.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mv88e6xxx is special among DSA drivers in that it requires the VTU to
contain the VID of the FDB entry it modifies in
mv88e6xxx_port_db_load_purge(), otherwise it will return -EOPNOTSUPP.

Sometimes due to races this is not always satisfied even if external
code does everything right (first deletes the FDB entries, then the
VLAN), because DSA commits to hardware FDB entries asynchronously since
commit c9eb3e0f ("net: dsa: Add support for learning FDB through
notification").

Therefore, the mv88e6xxx driver must close this race condition by
itself, by asking DSA to flush the switchdev workqueue of any FDB
deletions in progress, prior to exiting a VLAN.

Fixes: c9eb3e0f ("net: dsa: Add support for learning FDB through notification")
Reported-by: NRafael Richter <rafael.richter@gin.de>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NLuiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220208053210.14831-1-luizluca@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Given that standalone ports are now configured to bypass the ATU and
forward all frames towards the upstream port, extend the ATU bypass to
multichip systems.

Load VID 0 (standalone) into the VTU with the policy bit set. Since
VID 4095 (bridged) is already loaded, we now know that all VIDs in use
are always available in all VTUs. Therefore, we can safely enable
802.1Q on DSA ports.

Setting the DSA ports' VTU policy to TRAP means that all incoming
frames on VID 0 will be classified as MGMT - as a result, the ATU is
bypassed on all subsequent switches.

With this isolation in place, we are able to support configurations
that are simultaneously very quirky and very useful. Quirky because it
involves looping cables between local switchports like in this
example:

   CPU
    |     .------.
.---0---. | .----0----.
|  sw0  | | |   sw1   |
'-1-2-3-' | '-1-2-3-4-'
  $ @ '---'   $ @ % %

We have three physically looped pairs ($, @, and %).

This is very useful because it allows us to run the kernel's
kselftests for the bridge on mv88e6xxx hardware.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clear MapDA on standalone ports to bypass any ATU lookup that might
point the packet in the wrong direction. This means that all packets
are flooded using the PVT config. So make sure that standalone ports
are only allowed to communicate with the local upstream port.

Here is a scenario in which this is needed:

   CPU
    |     .----.
.---0---. | .--0--.
|  sw0  | | | sw1 |
'-1-2-3-' | '-1-2-'
      '---'

- sw0p1 and sw1p1 are bridged
- sw0p2 and sw1p2 are in standalone mode
- Learning must be enabled on sw0p3 in order for hardware forwarding
  to work properly between bridged ports

1. A packet with SA :aa comes in on sw1p2
   1a. Egresses sw1p0
   1b. Ingresses sw0p3, ATU adds an entry for :aa towards port 3
   1c. Egresses sw0p0

2. A packet with DA :aa comes in on sw0p2
   2a. If an ATU lookup is done at this point, the packet will be
       incorrectly forwarded towards sw0p3. With this change in place,
       the ATU is bypassed and the packet is forwarded in accordance
       with the PVT, which only contains the CPU port.
Signed-off-by: NTobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Certain drivers may need to send management traffic to the switch for
things like register access, FDB dump, etc, to accelerate what their
slow bus (SPI, I2C, MDIO) can already do.

Ethernet is faster (especially in bulk transactions) but is also more
unreliable, since the user may decide to bring the DSA master down (or
not bring it up), therefore severing the link between the host and the
attached switch.

Drivers needing Ethernet-based register access already should have
fallback logic to the slow bus if the Ethernet method fails, but that
fallback may be based on a timeout, and the I/O to the switch may slow
down to a halt if the master is down, because every Ethernet packet will
have to time out. The driver also doesn't have the option to turn off
Ethernet-based I/O momentarily, because it wouldn't know when to turn it
back on.

Which is where this change comes in. By tracking NETDEV_CHANGE,
NETDEV_UP and NETDEV_GOING_DOWN events on the DSA master, we should know
the exact interval of time during which this interface is reliably
available for traffic. Provide this information to switches so they can
use it as they wish.

An helper is added dsa_port_master_is_operational() to check if a master
port is operational.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NAnsuel Smith <ansuelsmth@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As discussed during review here:
https://patchwork.kernel.org/project/netdevbpf/patch/20220105132141.2648876-3-vladimir.oltean@nxp.com/

we should inform developers about pitfalls of concurrent access to the
boolean properties of dsa_switch and dsa_port, now that they've been
converted to bit fields. No other measure than a comment needs to be
taken, since the code paths that update these bit fields are not
concurrent with each other.
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>

This is a cosmetic incremental fixup to commits
7787ff77 ("net: dsa: merge all bools of struct dsa_switch into a single u32")
bde82f38 ("net: dsa: merge all bools of struct dsa_port into a single u8")

The desire to make this change was enunciated after posting these
patches here:
https://patchwork.kernel.org/project/netdevbpf/cover/20220105132141.2648876-1-vladimir.oltean@nxp.com/

but due to a slight timing overlap (message posted at 2:28 p.m. UTC,
merge commit is at 2:46 p.m. UTC), that comment was missed and the
changes were applied as-is.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a 7 byte hole after dst->setup and a 4 byte hole after
dst->default_proto. Combining them, we have a single hole of just 3
bytes on 64 bit machines.

Before:

pahole -C dsa_switch_tree net/dsa/slave.o
struct dsa_switch_tree {
        struct list_head           list;                 /*     0    16 */
        struct list_head           ports;                /*    16    16 */
        struct raw_notifier_head   nh;                   /*    32     8 */
        unsigned int               index;                /*    40     4 */
        struct kref                refcount;             /*    44     4 */
        struct net_device * *      lags;                 /*    48     8 */
        bool                       setup;                /*    56     1 */

        /* XXX 7 bytes hole, try to pack */

        /* --- cacheline 1 boundary (64 bytes) --- */
        const struct dsa_device_ops  * tag_ops;          /*    64     8 */
        enum dsa_tag_protocol      default_proto;        /*    72     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_platform_data * pd;                   /*    80     8 */
        struct list_head           rtable;               /*    88    16 */
        unsigned int               lags_len;             /*   104     4 */
        unsigned int               last_switch;          /*   108     4 */

        /* size: 112, cachelines: 2, members: 13 */
        /* sum members: 101, holes: 2, sum holes: 11 */
        /* last cacheline: 48 bytes */
};

After:

pahole -C dsa_switch_tree net/dsa/slave.o
struct dsa_switch_tree {
        struct list_head           list;                 /*     0    16 */
        struct list_head           ports;                /*    16    16 */
        struct raw_notifier_head   nh;                   /*    32     8 */
        unsigned int               index;                /*    40     4 */
        struct kref                refcount;             /*    44     4 */
        struct net_device * *      lags;                 /*    48     8 */
        const struct dsa_device_ops  * tag_ops;          /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        enum dsa_tag_protocol      default_proto;        /*    64     4 */
        bool                       setup;                /*    68     1 */

        /* XXX 3 bytes hole, try to pack */

        struct dsa_platform_data * pd;                   /*    72     8 */
        struct list_head           rtable;               /*    80    16 */
        unsigned int               lags_len;             /*    96     4 */
        unsigned int               last_switch;          /*   100     4 */

        /* size: 104, cachelines: 2, members: 13 */
        /* sum members: 101, holes: 1, sum holes: 3 */
        /* last cacheline: 40 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dst->ports is accessed most notably by dsa_master_find_slave(), which is
invoked in the RX path.

dst->lags is accessed by dsa_lag_dev(), which is invoked in the RX path
of tag_dsa.c.

dst->tag_ops, dst->default_proto and dst->pd don't need to be in the
first cache line, so they are moved out by this change.

Before:

pahole -C dsa_switch_tree net/dsa/slave.o
struct dsa_switch_tree {
        struct list_head           list;                 /*     0    16 */
        struct raw_notifier_head   nh;                   /*    16     8 */
        unsigned int               index;                /*    24     4 */
        struct kref                refcount;             /*    28     4 */
        bool                       setup;                /*    32     1 */

        /* XXX 7 bytes hole, try to pack */

        const struct dsa_device_ops  * tag_ops;          /*    40     8 */
        enum dsa_tag_protocol      default_proto;        /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_platform_data * pd;                   /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct list_head           ports;                /*    64    16 */
        struct list_head           rtable;               /*    80    16 */
        struct net_device * *      lags;                 /*    96     8 */
        unsigned int               lags_len;             /*   104     4 */
        unsigned int               last_switch;          /*   108     4 */

        /* size: 112, cachelines: 2, members: 13 */
        /* sum members: 101, holes: 2, sum holes: 11 */
        /* last cacheline: 48 bytes */
};

After:

pahole -C dsa_switch_tree net/dsa/slave.o
struct dsa_switch_tree {
        struct list_head           list;                 /*     0    16 */
        struct list_head           ports;                /*    16    16 */
        struct raw_notifier_head   nh;                   /*    32     8 */
        unsigned int               index;                /*    40     4 */
        struct kref                refcount;             /*    44     4 */
        struct net_device * *      lags;                 /*    48     8 */
        bool                       setup;                /*    56     1 */

        /* XXX 7 bytes hole, try to pack */

        /* --- cacheline 1 boundary (64 bytes) --- */
        const struct dsa_device_ops  * tag_ops;          /*    64     8 */
        enum dsa_tag_protocol      default_proto;        /*    72     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_platform_data * pd;                   /*    80     8 */
        struct list_head           rtable;               /*    88    16 */
        unsigned int               lags_len;             /*   104     4 */
        unsigned int               last_switch;          /*   108     4 */

        /* size: 112, cachelines: 2, members: 13 */
        /* sum members: 101, holes: 2, sum holes: 11 */
        /* last cacheline: 48 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, num_ports is declared as size_t, which is defined as
__kernel_ulong_t, therefore it occupies 8 bytes of memory.

Even switches with port numbers in the range of tens are exotic, so
there is no need for this amount of storage.

Additionally, because the max_num_bridges member right above it is also
4 bytes, it means the compiler needs to add padding between the last 2
fields. By reducing the size, we don't need that padding and can reduce
the struct size.

Before:

pahole -C dsa_switch net/dsa/slave.o
struct dsa_switch {
        struct device *            dev;                  /*     0     8 */
        struct dsa_switch_tree *   dst;                  /*     8     8 */
        unsigned int               index;                /*    16     4 */
        u32                        setup:1;              /*    20: 0  4 */
        u32                        vlan_filtering_is_global:1; /*    20: 1  4 */
        u32                        needs_standalone_vlan_filtering:1; /*    20: 2  4 */
        u32                        configure_vlan_while_not_filtering:1; /*    20: 3  4 */
        u32                        untag_bridge_pvid:1;  /*    20: 4  4 */
        u32                        assisted_learning_on_cpu_port:1; /*    20: 5  4 */
        u32                        vlan_filtering:1;     /*    20: 6  4 */
        u32                        pcs_poll:1;           /*    20: 7  4 */
        u32                        mtu_enforcement_ingress:1; /*    20: 8  4 */

        /* XXX 23 bits hole, try to pack */

        struct notifier_block      nb;                   /*    24    24 */

        /* XXX last struct has 4 bytes of padding */

        void *                     priv;                 /*    48     8 */
        void *                     tagger_data;          /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_chip_data *     cd;                   /*    64     8 */
        const struct dsa_switch_ops  * ops;              /*    72     8 */
        u32                        phys_mii_mask;        /*    80     4 */

        /* XXX 4 bytes hole, try to pack */

        struct mii_bus *           slave_mii_bus;        /*    88     8 */
        unsigned int               ageing_time_min;      /*    96     4 */
        unsigned int               ageing_time_max;      /*   100     4 */
        struct dsa_8021q_context * tag_8021q_ctx;        /*   104     8 */
        struct devlink *           devlink;              /*   112     8 */
        unsigned int               num_tx_queues;        /*   120     4 */
        unsigned int               num_lag_ids;          /*   124     4 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        unsigned int               max_num_bridges;      /*   128     4 */

        /* XXX 4 bytes hole, try to pack */

        size_t                     num_ports;            /*   136     8 */

        /* size: 144, cachelines: 3, members: 27 */
        /* sum members: 132, holes: 2, sum holes: 8 */
        /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 23 bits */
        /* paddings: 1, sum paddings: 4 */
        /* last cacheline: 16 bytes */
};

After:

pahole -C dsa_switch net/dsa/slave.o
struct dsa_switch {
        struct device *            dev;                  /*     0     8 */
        struct dsa_switch_tree *   dst;                  /*     8     8 */
        unsigned int               index;                /*    16     4 */
        u32                        setup:1;              /*    20: 0  4 */
        u32                        vlan_filtering_is_global:1; /*    20: 1  4 */
        u32                        needs_standalone_vlan_filtering:1; /*    20: 2  4 */
        u32                        configure_vlan_while_not_filtering:1; /*    20: 3  4 */
        u32                        untag_bridge_pvid:1;  /*    20: 4  4 */
        u32                        assisted_learning_on_cpu_port:1; /*    20: 5  4 */
        u32                        vlan_filtering:1;     /*    20: 6  4 */
        u32                        pcs_poll:1;           /*    20: 7  4 */
        u32                        mtu_enforcement_ingress:1; /*    20: 8  4 */

        /* XXX 23 bits hole, try to pack */

        struct notifier_block      nb;                   /*    24    24 */

        /* XXX last struct has 4 bytes of padding */

        void *                     priv;                 /*    48     8 */
        void *                     tagger_data;          /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_chip_data *     cd;                   /*    64     8 */
        const struct dsa_switch_ops  * ops;              /*    72     8 */
        u32                        phys_mii_mask;        /*    80     4 */

        /* XXX 4 bytes hole, try to pack */

        struct mii_bus *           slave_mii_bus;        /*    88     8 */
        unsigned int               ageing_time_min;      /*    96     4 */
        unsigned int               ageing_time_max;      /*   100     4 */
        struct dsa_8021q_context * tag_8021q_ctx;        /*   104     8 */
        struct devlink *           devlink;              /*   112     8 */
        unsigned int               num_tx_queues;        /*   120     4 */
        unsigned int               num_lag_ids;          /*   124     4 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        unsigned int               max_num_bridges;      /*   128     4 */
        unsigned int               num_ports;            /*   132     4 */

        /* size: 136, cachelines: 3, members: 27 */
        /* sum members: 128, holes: 1, sum holes: 4 */
        /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 23 bits */
        /* paddings: 1, sum paddings: 4 */
        /* last cacheline: 8 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct dsa_switch has 9 boolean properties, many of which are in fact
set by drivers for custom behavior (vlan_filtering_is_global,
needs_standalone_vlan_filtering, etc etc). The binary layout of the
structure could be improved. For example, the "bool setup" at the
beginning introduces a gratuitous 7 byte hole in the first cache line.

The change merges all boolean properties into bitfields of an u32, and
places that u32 in the first cache line of the structure, since many
bools are accessed from the data path (untag_bridge_pvid, vlan_filtering,
vlan_filtering_is_global).

We place this u32 after the existing ds->index, which is also 4 bytes in
size. As a positive side effect, ds->tagger_data now fits into the first
cache line too, because 4 bytes are saved.

Before:

pahole -C dsa_switch net/dsa/slave.o
struct dsa_switch {
        bool                       setup;                /*     0     1 */

        /* XXX 7 bytes hole, try to pack */

        struct device *            dev;                  /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        unsigned int               index;                /*    24     4 */

        /* XXX 4 bytes hole, try to pack */

        struct notifier_block      nb;                   /*    32    24 */

        /* XXX last struct has 4 bytes of padding */

        void *                     priv;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        void *                     tagger_data;          /*    64     8 */
        struct dsa_chip_data *     cd;                   /*    72     8 */
        const struct dsa_switch_ops  * ops;              /*    80     8 */
        u32                        phys_mii_mask;        /*    88     4 */

        /* XXX 4 bytes hole, try to pack */

        struct mii_bus *           slave_mii_bus;        /*    96     8 */
        unsigned int               ageing_time_min;      /*   104     4 */
        unsigned int               ageing_time_max;      /*   108     4 */
        struct dsa_8021q_context * tag_8021q_ctx;        /*   112     8 */
        struct devlink *           devlink;              /*   120     8 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        unsigned int               num_tx_queues;        /*   128     4 */
        bool                       vlan_filtering_is_global; /*   132     1 */
        bool                       needs_standalone_vlan_filtering; /*   133     1 */
        bool                       configure_vlan_while_not_filtering; /*   134     1 */
        bool                       untag_bridge_pvid;    /*   135     1 */
        bool                       assisted_learning_on_cpu_port; /*   136     1 */
        bool                       vlan_filtering;       /*   137     1 */
        bool                       pcs_poll;             /*   138     1 */
        bool                       mtu_enforcement_ingress; /*   139     1 */
        unsigned int               num_lag_ids;          /*   140     4 */
        unsigned int               max_num_bridges;      /*   144     4 */

        /* XXX 4 bytes hole, try to pack */

        size_t                     num_ports;            /*   152     8 */

        /* size: 160, cachelines: 3, members: 27 */
        /* sum members: 141, holes: 4, sum holes: 19 */
        /* paddings: 1, sum paddings: 4 */
        /* last cacheline: 32 bytes */
};

After:

pahole -C dsa_switch net/dsa/slave.o
struct dsa_switch {
        struct device *            dev;                  /*     0     8 */
        struct dsa_switch_tree *   dst;                  /*     8     8 */
        unsigned int               index;                /*    16     4 */
        u32                        setup:1;              /*    20: 0  4 */
        u32                        vlan_filtering_is_global:1; /*    20: 1  4 */
        u32                        needs_standalone_vlan_filtering:1; /*    20: 2  4 */
        u32                        configure_vlan_while_not_filtering:1; /*    20: 3  4 */
        u32                        untag_bridge_pvid:1;  /*    20: 4  4 */
        u32                        assisted_learning_on_cpu_port:1; /*    20: 5  4 */
        u32                        vlan_filtering:1;     /*    20: 6  4 */
        u32                        pcs_poll:1;           /*    20: 7  4 */
        u32                        mtu_enforcement_ingress:1; /*    20: 8  4 */

        /* XXX 23 bits hole, try to pack */

        struct notifier_block      nb;                   /*    24    24 */

        /* XXX last struct has 4 bytes of padding */

        void *                     priv;                 /*    48     8 */
        void *                     tagger_data;          /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_chip_data *     cd;                   /*    64     8 */
        const struct dsa_switch_ops  * ops;              /*    72     8 */
        u32                        phys_mii_mask;        /*    80     4 */

        /* XXX 4 bytes hole, try to pack */

        struct mii_bus *           slave_mii_bus;        /*    88     8 */
        unsigned int               ageing_time_min;      /*    96     4 */
        unsigned int               ageing_time_max;      /*   100     4 */
        struct dsa_8021q_context * tag_8021q_ctx;        /*   104     8 */
        struct devlink *           devlink;              /*   112     8 */
        unsigned int               num_tx_queues;        /*   120     4 */
        unsigned int               num_lag_ids;          /*   124     4 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        unsigned int               max_num_bridges;      /*   128     4 */

        /* XXX 4 bytes hole, try to pack */

        size_t                     num_ports;            /*   136     8 */

        /* size: 144, cachelines: 3, members: 27 */
        /* sum members: 132, holes: 2, sum holes: 8 */
        /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 23 bits */
        /* paddings: 1, sum paddings: 4 */
        /* last cacheline: 16 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both dsa_port :: type and dsa_port :: index introduce a 4 octet hole
after them, so we can group them together and the holes would be
eliminated, turning 16 octets of storage into just 8. This makes the
cpu_dp pointer fit in the first cache line, which is good, because
dsa_slave_to_master(), called by dsa_enqueue_skb(), uses it.

Before:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    32     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_switch *        ds;                   /*    40     8 */
        unsigned int               index;                /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        const char  *              name;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_port *          cpu_dp;               /*    64     8 */
        u8                         mac[6];               /*    72     6 */
        u8                         stp_state;            /*    78     1 */
        u8                         vlan_filtering:1;     /*    79: 0  1 */
        u8                         learning:1;           /*    79: 1  1 */
        u8                         lag_tx_enabled:1;     /*    79: 2  1 */
        u8                         devlink_port_setup:1; /*    79: 3  1 */
        u8                         setup:1;              /*    79: 4  1 */

        /* XXX 3 bits hole, try to pack */

        struct device_node *       dn;                   /*    80     8 */
        unsigned int               ageing_time;          /*    88     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_bridge *        bridge;               /*    96     8 */
        struct devlink_port        devlink_port;         /*   104   288 */
        /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */
        struct phylink *           pl;                   /*   392     8 */
        struct phylink_config      pl_config;            /*   400    40 */
        struct net_device *        lag_dev;              /*   440     8 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct net_device *        hsr_dev;              /*   448     8 */
        struct list_head           list;                 /*   456    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   472     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   480     8 */
        struct mutex               addr_lists_lock;      /*   488    32 */
        /* --- cacheline 8 boundary (512 bytes) was 8 bytes ago --- */
        struct list_head           fdbs;                 /*   520    16 */
        struct list_head           mdbs;                 /*   536    16 */

        /* size: 552, cachelines: 9, members: 30 */
        /* sum members: 539, holes: 3, sum holes: 12 */
        /* sum bitfield members: 5 bits, bit holes: 1, sum bit holes: 3 bits */
        /* last cacheline: 40 bytes */
};

After:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        struct dsa_switch *        ds;                   /*    32     8 */
        unsigned int               index;                /*    40     4 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    44     4 */
        const char  *              name;                 /*    48     8 */
        struct dsa_port *          cpu_dp;               /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        u8                         mac[6];               /*    64     6 */
        u8                         stp_state;            /*    70     1 */
        u8                         vlan_filtering:1;     /*    71: 0  1 */
        u8                         learning:1;           /*    71: 1  1 */
        u8                         lag_tx_enabled:1;     /*    71: 2  1 */
        u8                         devlink_port_setup:1; /*    71: 3  1 */
        u8                         setup:1;              /*    71: 4  1 */

        /* XXX 3 bits hole, try to pack */

        struct device_node *       dn;                   /*    72     8 */
        unsigned int               ageing_time;          /*    80     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_bridge *        bridge;               /*    88     8 */
        struct devlink_port        devlink_port;         /*    96   288 */
        /* --- cacheline 6 boundary (384 bytes) --- */
        struct phylink *           pl;                   /*   384     8 */
        struct phylink_config      pl_config;            /*   392    40 */
        struct net_device *        lag_dev;              /*   432     8 */
        struct net_device *        hsr_dev;              /*   440     8 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct list_head           list;                 /*   448    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   464     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   472     8 */
        struct mutex               addr_lists_lock;      /*   480    32 */
        /* --- cacheline 8 boundary (512 bytes) --- */
        struct list_head           fdbs;                 /*   512    16 */
        struct list_head           mdbs;                 /*   528    16 */

        /* size: 544, cachelines: 9, members: 30 */
        /* sum members: 539, holes: 1, sum holes: 4 */
        /* sum bitfield members: 5 bits, bit holes: 1, sum bit holes: 3 bits */
        /* last cacheline: 32 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct dsa_port has 5 bool members which create quite a number of 7 byte
holes in the structure layout. By merging them all into bitfields of an
u8, and placing that u8 in the 1-byte hole after dp->mac and dp->stp_state,
we can reduce the structure size from 576 bytes to 552 bytes on arm64.

Before:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    32     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_switch *        ds;                   /*    40     8 */
        unsigned int               index;                /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        const char  *              name;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_port *          cpu_dp;               /*    64     8 */
        u8                         mac[6];               /*    72     6 */
        u8                         stp_state;            /*    78     1 */

        /* XXX 1 byte hole, try to pack */

        struct device_node *       dn;                   /*    80     8 */
        unsigned int               ageing_time;          /*    88     4 */
        bool                       vlan_filtering;       /*    92     1 */
        bool                       learning;             /*    93     1 */

        /* XXX 2 bytes hole, try to pack */

        struct dsa_bridge *        bridge;               /*    96     8 */
        struct devlink_port        devlink_port;         /*   104   288 */
        /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */
        bool                       devlink_port_setup;   /*   392     1 */

        /* XXX 7 bytes hole, try to pack */

        struct phylink *           pl;                   /*   400     8 */
        struct phylink_config      pl_config;            /*   408    40 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct net_device *        lag_dev;              /*   448     8 */
        bool                       lag_tx_enabled;       /*   456     1 */

        /* XXX 7 bytes hole, try to pack */

        struct net_device *        hsr_dev;              /*   464     8 */
        struct list_head           list;                 /*   472    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   488     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   496     8 */
        struct mutex               addr_lists_lock;      /*   504    32 */
        /* --- cacheline 8 boundary (512 bytes) was 24 bytes ago --- */
        struct list_head           fdbs;                 /*   536    16 */
        struct list_head           mdbs;                 /*   552    16 */
        bool                       setup;                /*   568     1 */

        /* size: 576, cachelines: 9, members: 30 */
        /* sum members: 544, holes: 6, sum holes: 25 */
        /* padding: 7 */
};

After:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    32     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_switch *        ds;                   /*    40     8 */
        unsigned int               index;                /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        const char  *              name;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_port *          cpu_dp;               /*    64     8 */
        u8                         mac[6];               /*    72     6 */
        u8                         stp_state;            /*    78     1 */
        u8                         vlan_filtering:1;     /*    79: 0  1 */
        u8                         learning:1;           /*    79: 1  1 */
        u8                         lag_tx_enabled:1;     /*    79: 2  1 */
        u8                         devlink_port_setup:1; /*    79: 3  1 */
        u8                         setup:1;              /*    79: 4  1 */

        /* XXX 3 bits hole, try to pack */

        struct device_node *       dn;                   /*    80     8 */
        unsigned int               ageing_time;          /*    88     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_bridge *        bridge;               /*    96     8 */
        struct devlink_port        devlink_port;         /*   104   288 */
        /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */
        struct phylink *           pl;                   /*   392     8 */
        struct phylink_config      pl_config;            /*   400    40 */
        struct net_device *        lag_dev;              /*   440     8 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct net_device *        hsr_dev;              /*   448     8 */
        struct list_head           list;                 /*   456    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   472     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   480     8 */
        struct mutex               addr_lists_lock;      /*   488    32 */
        /* --- cacheline 8 boundary (512 bytes) was 8 bytes ago --- */
        struct list_head           fdbs;                 /*   520    16 */
        struct list_head           mdbs;                 /*   536    16 */

        /* size: 552, cachelines: 9, members: 30 */
        /* sum members: 539, holes: 3, sum holes: 12 */
        /* sum bitfield members: 5 bits, bit holes: 1, sum bit holes: 3 bits */
        /* last cacheline: 40 bytes */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The MAC address of a port is 6 octets in size, and this creates a 2
octet hole after it. There are some other u8 members of struct dsa_port
that we can put in that hole. One such member is the stp_state.

Before:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    32     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_switch *        ds;                   /*    40     8 */
        unsigned int               index;                /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        const char  *              name;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_port *          cpu_dp;               /*    64     8 */
        u8                         mac[6];               /*    72     6 */

        /* XXX 2 bytes hole, try to pack */

        struct device_node *       dn;                   /*    80     8 */
        unsigned int               ageing_time;          /*    88     4 */
        bool                       vlan_filtering;       /*    92     1 */
        bool                       learning;             /*    93     1 */
        u8                         stp_state;            /*    94     1 */

        /* XXX 1 byte hole, try to pack */

        struct dsa_bridge *        bridge;               /*    96     8 */
        struct devlink_port        devlink_port;         /*   104   288 */
        /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */
        bool                       devlink_port_setup;   /*   392     1 */

        /* XXX 7 bytes hole, try to pack */

        struct phylink *           pl;                   /*   400     8 */
        struct phylink_config      pl_config;            /*   408    40 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct net_device *        lag_dev;              /*   448     8 */
        bool                       lag_tx_enabled;       /*   456     1 */

        /* XXX 7 bytes hole, try to pack */

        struct net_device *        hsr_dev;              /*   464     8 */
        struct list_head           list;                 /*   472    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   488     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   496     8 */
        struct mutex               addr_lists_lock;      /*   504    32 */
        /* --- cacheline 8 boundary (512 bytes) was 24 bytes ago --- */
        struct list_head           fdbs;                 /*   536    16 */
        struct list_head           mdbs;                 /*   552    16 */
        bool                       setup;                /*   568     1 */

        /* size: 576, cachelines: 9, members: 30 */
        /* sum members: 544, holes: 6, sum holes: 25 */
        /* padding: 7 */
};

After:

pahole -C dsa_port net/dsa/slave.o
struct dsa_port {
        union {
                struct net_device * master;              /*     0     8 */
                struct net_device * slave;               /*     0     8 */
        };                                               /*     0     8 */
        const struct dsa_device_ops  * tag_ops;          /*     8     8 */
        struct dsa_switch_tree *   dst;                  /*    16     8 */
        struct sk_buff *           (*rcv)(struct sk_buff *, struct net_device *); /*    24     8 */
        enum {
                DSA_PORT_TYPE_UNUSED = 0,
                DSA_PORT_TYPE_CPU    = 1,
                DSA_PORT_TYPE_DSA    = 2,
                DSA_PORT_TYPE_USER   = 3,
        } type;                                          /*    32     4 */

        /* XXX 4 bytes hole, try to pack */

        struct dsa_switch *        ds;                   /*    40     8 */
        unsigned int               index;                /*    48     4 */

        /* XXX 4 bytes hole, try to pack */

        const char  *              name;                 /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct dsa_port *          cpu_dp;               /*    64     8 */
        u8                         mac[6];               /*    72     6 */
        u8                         stp_state;            /*    78     1 */

        /* XXX 1 byte hole, try to pack */

        struct device_node *       dn;                   /*    80     8 */
        unsigned int               ageing_time;          /*    88     4 */
        bool                       vlan_filtering;       /*    92     1 */
        bool                       learning;             /*    93     1 */

        /* XXX 2 bytes hole, try to pack */

        struct dsa_bridge *        bridge;               /*    96     8 */
        struct devlink_port        devlink_port;         /*   104   288 */
        /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */
        bool                       devlink_port_setup;   /*   392     1 */

        /* XXX 7 bytes hole, try to pack */

        struct phylink *           pl;                   /*   400     8 */
        struct phylink_config      pl_config;            /*   408    40 */
        /* --- cacheline 7 boundary (448 bytes) --- */
        struct net_device *        lag_dev;              /*   448     8 */
        bool                       lag_tx_enabled;       /*   456     1 */

        /* XXX 7 bytes hole, try to pack */

        struct net_device *        hsr_dev;              /*   464     8 */
        struct list_head           list;                 /*   472    16 */
        const struct ethtool_ops  * orig_ethtool_ops;    /*   488     8 */
        const struct dsa_netdevice_ops  * netdev_ops;    /*   496     8 */
        struct mutex               addr_lists_lock;      /*   504    32 */
        /* --- cacheline 8 boundary (512 bytes) was 24 bytes ago --- */
        struct list_head           fdbs;                 /*   536    16 */
        struct list_head           mdbs;                 /*   552    16 */
        bool                       setup;                /*   568     1 */

        /* size: 576, cachelines: 9, members: 30 */
        /* sum members: 544, holes: 6, sum holes: 25 */
        /* padding: 7 */
};
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On the NXP Bluebox 3 board which uses a multi-switch setup with sja1105,
the mechanism through which the tagger connects to the switch tree is
broken, due to improper DSA code design. At the time when tag_ops->connect()
is called in dsa_port_parse_cpu(), DSA hasn't finished "touching" all
the ports, so it doesn't know how large the tree is and how many ports
it has. It has just seen the first CPU port by this time. As a result,
this function will call the tagger's ->connect method too early, and the
tagger will connect only to the first switch from the tree.

This could be perhaps addressed a bit more simply by just moving the
tag_ops->connect(dst) call a bit later (for example in dsa_tree_setup),
but there is already a design inconsistency at present: on the switch
side, the notification is on a per-switch basis, but on the tagger side,
it is on a per-tree basis. Furthermore, the persistent storage itself is
per switch (ds->tagger_data). And the tagger connect and disconnect
procedures (at least the ones that exist currently) could see a fair bit
of simplification if they didn't have to iterate through the switches of
a tree.

To fix the issue, this change transforms tag_ops->connect(dst) into
tag_ops->connect(ds) and moves it somewhere where we already iterate
over all switches of a tree. That is in dsa_switch_setup_tag_protocol(),
which is a good placement because we already have there the connection
call to the switch side of things.

As for the dsa_tree_bind_tag_proto() method (called from the code path
that changes the tag protocol), things are a bit more complicated
because we receive the tree as argument, yet when we unwind on errors,
it would be nice to not call tag_ops->disconnect(ds) where we didn't
previously call tag_ops->connect(ds). We didn't have this problem before
because the tag_ops connection operations passed the entire dst before,
and this is more fine grained now. To solve the error rewind case using
the new API, we have to create yet one more cross-chip notifier for
disconnection, and stay connected with the old tag protocol to all the
switches in the tree until we've succeeded to connect with the new one
as well. So if something fails half way, the whole tree is still
connected to the old tagger. But there may still be leaks if the tagger
fails to connect to the 2nd out of 3 switches in a tree: somebody needs
to tell the tagger to disconnect from the first switch. Nothing comes
for free, and this was previously handled privately by the tagging
protocol driver before, but now we need to emit a disconnect cross-chip
notifier for that, because DSA has to take care of the unwind path. We
assume that the tagging protocol has connected to a switch if it has set
ds->tagger_data to something, otherwise we avoid calling its
disconnection method in the error rewind path.

The rest of the changes are in the tagging protocol drivers, and have to
do with the replacement of dst with ds. The iteration is removed and the
error unwind path is simplified, as mentioned above.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All current in-tree uses of dp->priv have been replaced with
ds->tagger_data, which provides for a safer API especially when the
connection isn't the regular 1:1 link between one switch driver and one
tagging protocol driver, but could be either one switch to many taggers,
or many switches to one tagger.

Therefore, we can remove this unused pointer.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ansuel is working on register access over Ethernet for the qca8k switch
family. This requires the qca8k tagging protocol driver to receive
frames which aren't intended for the network stack, but instead for the
qca8k switch driver itself.

The dp->priv is currently the prevailing method for passing data back
and forth between the tagging protocol driver and the switch driver.
However, this method is riddled with caveats.

The DSA design allows in principle for any switch driver to return any
protocol it desires in ->get_tag_protocol(). The dsa_loop driver can be
modified to do just that. But in the current design, the memory behind
dp->priv has to be allocated by the switch driver, so if the tagging
protocol is paired to an unexpected switch driver, we may end up in NULL
pointer dereferences inside the kernel, or worse (a switch driver may
allocate dp->priv according to the expectations of a different tagger).

The latter possibility is even more plausible considering that DSA
switches can dynamically change tagging protocols in certain cases
(dsa <-> edsa, ocelot <-> ocelot-8021q), and the current design lends
itself to mistakes that are all too easy to make.

This patch proposes that the tagging protocol driver should manage its
own memory, instead of relying on the switch driver to do so.
After analyzing the different in-tree needs, it can be observed that the
required tagger storage is per switch, therefore a ds->tagger_data
pointer is introduced. In principle, per-port storage could also be
introduced, although there is no need for it at the moment. Future
changes will replace the current usage of dp->priv with ds->tagger_data.

We define a "binding" event between the DSA switch tree and the tagging
protocol. During this binding event, the tagging protocol's ->connect()
method is called first, and this may allocate some memory for each
switch of the tree. Then a cross-chip notifier is emitted for the
switches within that tree, and they are given the opportunity to fix up
the tagger's memory (for example, they might set up some function
pointers that represent virtual methods for consuming packets).
Because the memory is owned by the tagger, there exists a ->disconnect()
method for the tagger (which is the place to free the resources), but
there doesn't exist a ->disconnect() method for the switch driver.
This is part of the design. The switch driver should make minimal use of
the public part of the tagger data, and only after type-checking it
using the supplied "proto" argument.

In the code there are in fact two binding events, one is the initial
event in dsa_switch_setup_tag_protocol(). At this stage, the cross chip
notifier chains aren't initialized, so we call each switch's connect()
method by hand. Then there is dsa_tree_bind_tag_proto() during
dsa_tree_change_tag_proto(), and here we have an old protocol and a new
one. We first connect to the new one before disconnecting from the old
one, to simplify error handling a bit and to ensure we remain in a valid
state at all times.
Co-developed-by: NAnsuel Smith <ansuelsmth@gmail.com>
Signed-off-by: NAnsuel Smith <ansuelsmth@gmail.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't really need new switch API for these, and with new switches
which intend to add support for this feature, it will become cumbersome
to maintain.

The change consists in restructuring the two drivers that implement this
offload (sja1105 and mv88e6xxx) such that the offload is enabled and
disabled from the ->port_bridge_{join,leave} methods instead of the old
->port_bridge_tx_fwd_{,un}offload.

The only non-trivial change is that mv88e6xxx_map_virtual_bridge_to_pvt()
has been moved to avoid a forward declaration, and the
mv88e6xxx_reg_lock() calls from inside it have been removed, since
locking is now done from mv88e6xxx_port_bridge_{join,leave}.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

This is a preparation patch for the removal of the DSA switch methods
->port_bridge_tx_fwd_offload() and ->port_bridge_tx_fwd_unoffload().
The plan is for the switch to report whether it offloads TX forwarding
directly as a response to the ->port_bridge_join() method.

This change deals with the noisy portion of converting all existing
function prototypes to take this new boolean pointer argument.
The bool is placed in the cross-chip notifier structure for bridge join,
and a reference to it is provided to drivers. In the next change, DSA
will then actually look at this value instead of calling
->port_bridge_tx_fwd_offload().
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The main desire behind this is to provide coherent bridge information to
the fast path without locking.

For example, right now we set dp->bridge_dev and dp->bridge_num from
separate code paths, it is theoretically possible for a packet
transmission to read these two port properties consecutively and find a
bridge number which does not correspond with the bridge device.

Another desire is to start passing more complex bridge information to
dsa_switch_ops functions. For example, with FDB isolation, it is
expected that drivers will need to be passed the bridge which requested
an FDB/MDB entry to be offloaded, and along with that bridge_dev, the
associated bridge_num should be passed too, in case the driver might
want to implement an isolation scheme based on that number.

We already pass the {bridge_dev, bridge_num} pair to the TX forwarding
offload switch API, however we'd like to remove that and squash it into
the basic bridge join/leave API. So that means we need to pass this
pair to the bridge join/leave API.

During dsa_port_bridge_leave, first we unset dp->bridge_dev, then we
call the driver's .port_bridge_leave with what used to be our
dp->bridge_dev, but provided as an argument.

When bridge_dev and bridge_num get folded into a single structure, we
need to preserve this behavior in dsa_port_bridge_leave: we need a copy
of what used to be in dp->bridge.

Switch drivers check bridge membership by comparing dp->bridge_dev with
the provided bridge_dev, but now, if we provide the struct dsa_bridge as
a pointer, they cannot keep comparing dp->bridge to the provided
pointer, since this only points to an on-stack copy. To make this
obvious and prevent driver writers from forgetting and doing stupid
things, in this new API, the struct dsa_bridge is provided as a full
structure (not very large, contains an int and a pointer) instead of a
pointer. An explicit comparison function needs to be used to determine
bridge membership: dsa_port_offloads_bridge().
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Move the static inline helpers from net/dsa/dsa_priv.h to
include/net/dsa.h, so that drivers can call functions such as
dsa_port_offloads_bridge_dev(), which will be necessary after the
transition to a more complex bridge structure.

More functions than are needed right now are being moved, but this is
done for uniformity.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The location of the bridge device pointer and number is going to change.
It is not going to be kept individually per port, but in a common
structure allocated dynamically and which will have lockdep validation.

Create helpers to access these elements so that we have a migration path
to the new organization.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The service where DSA assigns a unique bridge number for each forwarding
domain is useful even for drivers which do not implement the TX
forwarding offload feature.

For example, drivers might use the dp->bridge_num for FDB isolation.

So rename ds->num_fwd_offloading_bridges to ds->max_num_bridges, and
calculate a unique bridge_num for all drivers that set this value.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NAlvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>