selftests: mlxsw: Add PCI reset test

Test that PCI reset works correctly by verifying that only the expected
reset methods are supported and that after issuing the reset the ifindex
of the port changes.

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

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

@@ -0,0 +1,58 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test that PCI reset works correctly by verifying that only the expected reset
+# methods are supported and that after issuing the reset the ifindex of the
+# port changes.
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="
+	pci_reset_test
+"
+NUM_NETIFS=1
+source $lib_dir/lib.sh
+source $lib_dir/devlink_lib.sh
+
+pci_reset_test()
+{
+	RET=0
+
+	local bus=$(echo $DEVLINK_DEV | cut -d '/' -f 1)
+	local bdf=$(echo $DEVLINK_DEV | cut -d '/' -f 2)
+
+	if [ $bus != "pci" ]; then
+		check_err 1 "devlink device is not a PCI device"
+		log_test "pci reset"
+		return
+	fi
+
+	if [ ! -f /sys/bus/pci/devices/$bdf/reset_method ]; then
+		check_err 1 "reset is not supported"
+		log_test "pci reset"
+		return
+	fi
+
+	[[ $(cat /sys/bus/pci/devices/$bdf/reset_method) == "bus" ]]
+	check_err $? "only \"bus\" reset method should be supported"
+
+	local ifindex_pre=$(ip -j link show dev $swp1 | jq '.[]["ifindex"]')
+
+	echo 1 > /sys/bus/pci/devices/$bdf/reset
+	check_err $? "reset failed"
+
+	# Wait for udev to rename newly created netdev.
+	udevadm settle
+
+	local ifindex_post=$(ip -j link show dev $swp1 | jq '.[]["ifindex"]')
+
+	[[ $ifindex_pre != $ifindex_post ]]
+	check_err $? "reset not performed"
+
+	log_test "pci reset"
+}
+
+swp1=${NETIFS[p1]}
+tests_run
+
+exit $EXIT_STATUS