selftests: forwarding: generalize bail_on_lldpad from mlxsw

mlxsw selftests often invoke a bail_on_lldpad() helper to make sure LLDPAD
is not running, to prevent conflicts between the QoS configuration applied
through TC or DCB command line tool, and the DCB configuration that LLDPAD
might apply. This helper might be useful to others. Move the function to
lib.sh, and parameterize to make reusable in other contexts.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

selftests: mlxsw: Use shapers in QOS RED tests instead of forcing speed

QOS tests create congestion and verify the switch behavior. To create
congestion, they need to have more traffic than the port can handle, so
some of them force 1Gbps speed.

The tests assume that 1Gbps speed is supported, otherwise, they will fail.
Spectrum-4 ASIC will not support this speed in all ports, so to be able
to run the tests there, some adjustments are required. Use shapers to limit
the traffic instead of forcing speed. Note that for several ports, the
speed configuration is just for autoneg issues, so shaper is not needed
instead.

The tests already use ETS qdisc as a root and RED qdiscs as children. Add
a new TBF shaper to limit the rate of traffic, and use it as a root qdisc,
then save the previous hierarchy of qdiscs under the new TBF root.

In some ASICs, the shapers do not limit the traffic as accurately as
forcing speed. To make the tests stable, allow the backlog size to be up to
+-10% of the threshold. The aim of the tests is to make sure that with
backlog << threshold, there are no drops, and that packets are dropped
somewhere in vicinity of the configured threshold.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

selftests: mlxsw: bail_on_lldpad before installing the cleanup trap

A number of mlxsw-specific QoS tests use manual QoS DCB management. As
such, they need to make sure lldpad is not running, because it would
override the configuration the test has applied using other tools. To that
end, these selftests invoke the bail_on_lldpad() helper, which terminates
the selftest if th lldpad is running.

Some of these tests however first install the bash exit trap, which invokes
a cleanup() at the test exit. If bail_on_lldpad() has terminated the script
even before the setup part was run, the cleanup part will be very confused.

Therefore make sure bail_on_lldpad() is invoked before the cleanup is
registered.

While there are still edge cases where the user terminates the script
before the setup was fully done, this takes care of a common situation
where the cleanup would be invoked in an inconsistent state.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: RED: Test per-TC ECN counters

Add a variant of ECN test that uses qdisc marked counter (supported on
Spectrum-3 and above) instead of the aggregate ethtool ecn_marked counter.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

selftests: mlxsw: RED: Add selftests for the mark qevent

Add do_mark_test(), which is to do_ecn_test() like do_drop_test() is to
do_red_test(): meant to test that actions on the RED mark qevent block are
offloaded, and executed on ECN-marked packets.

The test splits install_qdisc() into its constituents, install_root_qdisc()
and install_qdisc_tcX(). This is in order to test that when mirroring is
enabled on one TC, the other TC does not mirror.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: sch_red_ets: Test proper counter cleaning in ETS

There was a bug introduced during the rework which cause non-zero backlog
being stuck at ETS. Introduce a selftest that would have caught the issue
earlier.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: RED: Test offload of trapping on RED qevents

Add a selftest for RED early_drop and mark qevents when a trap action is
attached at the associated block.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: RED: Test offload of mirror on RED early_drop qevent

Add a selftest for offloading a mirror action attached to the block
associated with RED early_drop qevent.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: RED: Test RED ECN nodrop offload

Extend RED testsuite to cover the new nodrop mode of RED-ECN. This test is
really similar to ECN test, diverging only in the last step, where UDP
traffic should go to backlog instead of being dropped. Thus extract a
common helper, ecn_test_common(), make do_ecn_test() into a relatively
simple wrapper, and add another one, do_ecn_nodrop_test().

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: mlxsw: Add a RED selftest

This tests that below the queue minimum length, there is no dropping /
marking, and above max, everything is dropped / marked.

The test is structured as a core file with topology and test code, and
three wrappers: one for RED used as a root Qdisc, and two for
testing (W)RED under PRIO and ETS.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>