linux-stable.git/net/dsa/master.c, branch linux-6.2.y

net: dsa: rename dsa2.c back into dsa.c and create its header

2022-11-23T04:41:53+00:00

The previous change moved the code into the larger file (dsa2.c) to
minimize the delta. Rename that now to dsa.c, and create dsa.h, where
all related definitions from dsa_priv.h go.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: Jakub Kicinski

net: dsa: move tagging protocol code to tag.{c,h}

2022-11-23T04:41:50+00:00

It would be nice if tagging protocol drivers could include just the
header they need, since they are (mostly) data path and isolated from
most of the other DSA core code does.

Create a tag.c and a tag.h file which are meant to support tagging
protocol drivers.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: Jakub Kicinski

net: dsa: move headers exported by master.c to master.h

2022-11-23T04:41:49+00:00

Minimize the use of the bloated dsa_priv.h by moving the prototypes
exported by master.c to their own header file.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: Jakub Kicinski

net: dsa: move headers exported by port.c to port.h

2022-11-23T04:41:48+00:00

Minimize the use of the bloated dsa_priv.h by moving the prototypes
exported by port.c to their own header file.

Signed-off-by: Vladimir Oltean 
Reviewed-by: Florian Fainelli 
Signed-off-by: Jakub Kicinski

net: dsa: autoload tag driver module on tagging protocol change

2022-11-18T05:16:42+00:00

Issue a request_module() call when an attempt to change the tagging
protocol is made, either by sysfs or by device tree. In the case of
ocelot (the only driver for which the default and the alternative
tagging protocol are compiled as different modules), the user is now no
longer required to insert tag_ocelot_8021q.ko manually.

In the particular case of ocelot, this solves a problem where
tag_ocelot_8021q.ko is built as module, and this is present in the
device tree:

&mscc_felix_port4 {
	dsa-tag-protocol = "ocelot-8021q";
};

&mscc_felix_port5 {
	dsa-tag-protocol = "ocelot-8021q";
};

Because no one attempts to load the module into the kernel at boot time,
the switch driver will fail to probe (actually forever defer) until
someone manually inserts tag_ocelot_8021q.ko. This is now no longer
necessary and happens automatically.

Rename dsa_find_tagger_by_name() to denote the change in functionality:
there is now feature parity with dsa_tag_driver_get_by_id(), i.o.w. we
also load the module if it's missing.

Link: https://lore.kernel.org/lkml/20221027113248.420216-1-michael@walle.cc/
Suggested-by: Michael Walle 
Signed-off-by: Vladimir Oltean 
Tested-by: Michael Walle  # on kontron-sl28 w/ ocelot_8021q
Tested-by: Michael Walle 
Signed-off-by: Jakub Kicinski

net: dsa: strip sysfs "tagging" string of trailing newline

2022-11-18T05:16:42+00:00

Currently, dsa_find_tagger_by_name() uses sysfs_streq() which works both
with strings that contain \n at the end (echo ocelot > .../dsa/tagging)
and with strings that don't (printf ocelot > .../dsa/tagging).

There will be a problem once we'll want to construct the modalias string
based on which we auto-load the protocol kernel module. If the sysfs
buffer ends in a newline, we need to strip it first. This is a
preparatory patch specifically for that.

Signed-off-by: Vladimir Oltean 
Tested-by: Michael Walle 
Signed-off-by: Jakub Kicinski

net: dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims

2022-11-14T11:30:49+00:00

There are multi-generational drivers like mv88e6xxx which have code like
this:

int mv88e6xxx_port_hwtstamp_get(struct dsa_switch *ds, int port,
				struct ifreq *ifr)
{
	if (!chip->info->ptp_support)
		return -EOPNOTSUPP;

	...
}

DSA wants to deny PTP timestamping on the master if the switch supports
timestamping too. However it currently relies on the presence of the
port_hwtstamp_get() callback to determine PTP capability, and this
clearly does not work in that case (method is present but returns
-EOPNOTSUPP).

We should not deny PTP on the DSA master for those switches which truly
do not support hardware timestamping.

Create a dsa_port_supports_hwtstamp() method which actually probes for
support by calling port_hwtstamp_get() and seeing whether that returned
-EOPNOTSUPP or not.

Fixes: f685e609a301 ("net: dsa: Deny PTP on master if switch supports it")
Link: https://patchwork.kernel.org/project/netdevbpf/patch/20221110124345.3901389-1-festevam@gmail.com/
Reported-by: Fabio Estevam 
Reported-by: Steffen Bätz 
Signed-off-by: Vladimir Oltean 
Tested-by: Fabio Estevam 
Signed-off-by: David S. Miller

net: dsa: allow masters to join a LAG

2022-09-20T08:32:36+00:00

There are 2 ways in which a DSA user port may become handled by 2 CPU
ports in a LAG:

(1) its current DSA master joins a LAG

 ip link del bond0 && ip link add bond0 type bond mode 802.3ad
 ip link set eno2 master bond0

When this happens, all user ports with "eno2" as DSA master get
automatically migrated to "bond0" as DSA master.

(2) it is explicitly configured as such by the user

 # Before, the DSA master was eno3
 ip link set swp0 type dsa master bond0

The design of this configuration is that the LAG device dynamically
becomes a DSA master through dsa_master_setup() when the first physical
DSA master becomes a LAG slave, and stops being so through
dsa_master_teardown() when the last physical DSA master leaves.

A LAG interface is considered as a valid DSA master only if it contains
existing DSA masters, and no other lower interfaces. Therefore, we
mainly rely on method (1) to enter this configuration.

Each physical DSA master (LAG slave) retains its dev->dsa_ptr for when
it becomes a standalone DSA master again. But the LAG master also has a
dev->dsa_ptr, and this is actually duplicated from one of the physical
LAG slaves, and therefore needs to be balanced when LAG slaves come and
go.

To the switch driver, putting DSA masters in a LAG is seen as putting
their associated CPU ports in a LAG.

We need to prepare cross-chip host FDB notifiers for CPU ports in a LAG,
by calling the driver's ->lag_fdb_add method rather than ->port_fdb_add.

Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni

net: dsa: suppress device links to LAG DSA masters

2022-09-20T08:32:36+00:00

These don't work (print a harmless error about the operation failing)
and make little sense to have anyway, because when a LAG DSA master goes
away, we will introduce logic to move our CPU port back to the first
physical DSA master. So suppress these device links in preparation for
adding support for LAG DSA masters.

Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni

net: dsa: suppress appending ethtool stats to LAG DSA masters

2022-09-20T08:32:36+00:00

Similar to the discussion about tracking the admin/oper state of LAG DSA
masters, we have the problem here that struct dsa_port *cpu_dp caches a
single pair of orig_ethtool_ops and netdev_ops pointers.

So if we call dsa_master_setup(bond0, cpu_dp) where cpu_dp is also the
dev->dsa_ptr of one of the physical DSA masters, we'd effectively
overwrite what we cached from that physical netdev with what replaced
from the bonding interface.

We don't need DSA ethtool stats on the bonding interface when used as
DSA master, it's good enough to have them just on the physical DSA
masters, so suppress this logic.

Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni