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: Add helpers for skipping selftests

A number of mlxsw-specific selftests currently detect whether they are run
on a compatible machine, and bail out silently when not. These tests are
however done in a somewhat impenetrable manner by directly comparing PCI
IDs against a blacklist or a whitelist, and bailing out silently if the
machine is not compatible.

Instead, add a helper, mlxsw_only_on_spectrum(), which allows specifying
the supported machines in a human-readable manner. If the current machine
is incompatible, the helper emits a SKIP message and returns an error code,
based on which the caller can gracefully bail out in a suitable way. This
allows a more readable conditions such as:

mlxsw_only_on_spectrum 2+ || return

Convert all existing open-coded guards to the new helper. Also add two new
guards to do_mark_test() and do_drop_test(), which are supported only on
Spectrum-2+, but the corresponding check was not there.

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_core: Drop two unused variables

These variables are cut'n'pasted from other functions in the file and not
actually used.

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: Increase the tolerance of backlog buildup

The intention behind this test is to make sure that qdisc limit is
correctly projected to the HW. However, first, due to rounding in the
qdisc, and then in the driver, the number cannot actually be accurate. And
second, the approach to testing this is to oversubscribe the port with
traffic generated on the same switch. The actual backlog size therefore
fluctuates.

In practice, this test proved to be noisier than the rest, and spuriously
fails every now and then. Increase the tolerance to 10 % to avoid these
issues.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: forwarding: devlink_lib: Split devlink_..._set() into save & set

Changing pool type from static to dynamic causes reinterpretation of
threshold values. They therefore need to be saved before pool type is
changed, then the pool type can be changed, and then the new values need
to be set up.

For that reason, set cannot subsume save, because it would be saving the
wrong thing, with possibly a nonsensical value, and restore would then fail
to restore the nonsensical value.

Thus extract a _save() from each of the relevant _set()'s. This way it is
possible to save everything up front, then to tweak it, and then restore in
the required order.

Signed-off-by: Petr Machata <petrm@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: forwarding: Convert until_counter_is() to take expression

until_counter_is() currently takes as an argument a number and the
condition holds when the current counter value is >= that number. Make the
function more generic by taking a partial expression instead of just the
number.

Convert the two existing users.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Amit Cohen <amitc@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>