linux.git/net/dsa/switch.c, branch v6.4

net: dsa: add trace points for VLAN operations

2023-04-12T07:36:07+00:00

These are not as critical as the FDB/MDB trace points (I'm not aware of
outstanding VLAN related bugs), but maybe they are useful to somebody,
either debugging something or simply trying to learn more.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: dsa: add trace points for FDB/MDB operations

2023-04-12T07:36:07+00:00

DSA performs non-trivial housekeeping of unicast and multicast addresses
on shared (CPU and DSA) ports, and puts a bit of pressure on higher
layers, requiring them to behave correctly (remove these addresses
exactly as many times as they were added). Otherwise, either addresses
linger around forever, or DSA returns -ENOENT complaining that entries
that were already deleted must be deleted again.

To aid debugging, introduce some trace points specifically for FDB and
MDB - that's where some of the bugs still are right now.

Some bugs I have seen were also due to race conditions, see:
- 630fd4822af2 ("net: dsa: flush switchdev workqueue on bridge join error path")
- a2614140dc0f ("net: dsa: mv88e6xxx: flush switchdev FDB workqueue before removing VLAN")

so it would be good to not disturb the timing too much, hence the choice
to use trace points vs regular dev_dbg().

I've had these for some time on my computer in a less polished form, and
they've proven useful. What I found most useful was to enable
CONFIG_BOOTTIME_TRACING, add "trace_event=dsa" to the kernel cmdline,
and run "cat /sys/kernel/debug/tracing/trace". This is to debug more
complex environments with network managers started by the init system,
things like that.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: dsa: kill off dsa_priv.h

2022-11-23T04:41:54+00:00

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

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

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

net: dsa: move tag_8021q headers to their proper place

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

tag_8021q definitions are all over the place. Some are exported to
linux/dsa/8021q.h (visible by DSA core, taggers, switch drivers and
everyone else), and some are in dsa_priv.h.

Move the structures that don't need external visibility into tag_8021q.c,
and the ones which don't need the world or switch drivers to see them
into tag_8021q.h.

We also have the tag_8021q.h inclusion from switch.c, which is basically
the entire reason why tag_8021q.c was built into DSA in commit
8b6e638b4be2 ("net: dsa: build tag_8021q.c as part of DSA core").
I still don't know how to better deal with that, so leave it alone.

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

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 dsa_tree_notify() and dsa_broadcast() to switch.c

2022-11-23T04:41:51+00:00

There isn't an intuitive place for these 2 cross-chip notifier functions
according to the function-to-file classification based on names
(dsa_switch_*() goes to switch.c), but I consider these to be part of
the cross-chip notifier handling, therefore part of switch.c. Move them
there to reduce bloat in dsa2.c (the place where all code with no better
place to go goes).

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

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

2022-11-23T04:41:51+00:00

Reduce code bloat in dsa_priv.h by moving the prototypes exported by
switch.h into their own header file.

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

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

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

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

This is just approximate to get the code structure right. There are some
interdependencies with static inline code left in dsa_priv.h, so leave
slave.h included from there for now.

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: 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