selftests: mlxsw: Test policers' occupancy

Test that policers shared by different tc filters are correctly
reference counted by observing policers' occupancy via devlink-resource.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/drivers/net/mlxsw/tc_police_occ.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test that policers shared by different tc filters are correctly reference
+# counted by observing policers' occupancy via devlink-resource.
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="
+	tc_police_occ_test
+"
+NUM_NETIFS=2
+source $lib_dir/lib.sh
+source $lib_dir/devlink_lib.sh
+
+h1_create()
+{
+	simple_if_init $h1
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1
+}
+
+switch_create()
+{
+	simple_if_init $swp1
+	tc qdisc add dev $swp1 clsact
+}
+
+switch_destroy()
+{
+	tc qdisc del dev $swp1 clsact
+	simple_if_fini $swp1
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	vrf_prepare
+
+	h1_create
+	switch_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	switch_destroy
+	h1_destroy
+
+	vrf_cleanup
+}
+
+tc_police_occ_get()
+{
+	devlink_resource_occ_get global_policers single_rate_policers
+}
+
+tc_police_occ_test()
+{
+	RET=0
+
+	local occ=$(tc_police_occ_get)
+
+	tc filter add dev $swp1 ingress pref 1 handle 101 proto ip \
+		flower skip_sw \
+		action police rate 100mbit burst 100k conform-exceed drop/ok
+	(( occ + 1 == $(tc_police_occ_get) ))
+	check_err $? "Got occupancy $(tc_police_occ_get), expected $((occ + 1))"
+
+	tc filter del dev $swp1 ingress pref 1 handle 101 flower
+	(( occ == $(tc_police_occ_get) ))
+	check_err $? "Got occupancy $(tc_police_occ_get), expected $occ"
+
+	tc filter add dev $swp1 ingress pref 1 handle 101 proto ip \
+		flower skip_sw \
+		action police rate 100mbit burst 100k conform-exceed drop/ok \
+		index 10
+	tc filter add dev $swp1 ingress pref 2 handle 102 proto ip \
+		flower skip_sw action police index 10
+
+	(( occ + 1 == $(tc_police_occ_get) ))
+	check_err $? "Got occupancy $(tc_police_occ_get), expected $((occ + 1))"
+
+	tc filter del dev $swp1 ingress pref 2 handle 102 flower
+	(( occ + 1 == $(tc_police_occ_get) ))
+	check_err $? "Got occupancy $(tc_police_occ_get), expected $((occ + 1))"
+
+	tc filter del dev $swp1 ingress pref 1 handle 101 flower
+	(( occ == $(tc_police_occ_get) ))
+	check_err $? "Got occupancy $(tc_police_occ_get), expected $occ"
+
+	log_test "tc police occupancy"
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS

tools/testing/selftests/net/forwarding/devlink_lib.sh

@@ -98,6 +98,11 @@ devlink_resource_size_set()
 	check_err $? "Failed setting path $path to size $size"
 }
 
+devlink_resource_occ_get()
+{
+	devlink_resource_get "$@" | jq '.["occ"]'
+}
+
 devlink_reload()
 {
 	local still_pending