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>

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

@@ -11,3 +11,53 @@ if [[ ! -v MLXSW_CHIP ]]; then
 		exit 1
 	fi
 fi
+
+MLXSW_SPECTRUM_REV=$(case $MLXSW_CHIP in
+			     mlxsw_spectrum)
+				     echo 1 ;;
+			     mlxsw_spectrum*)
+				     echo ${MLXSW_CHIP#mlxsw_spectrum} ;;
+			     *)
+				     echo "Couldn't determine Spectrum chip revision." \
+					  > /dev/stderr ;;
+		     esac)
+
+mlxsw_on_spectrum()
+{
+	local rev=$1; shift
+	local op="=="
+	local rev2=${rev%+}
+
+	if [[ $rev2 != $rev ]]; then
+		op=">="
+	fi
+
+	((MLXSW_SPECTRUM_REV $op rev2))
+}
+
+__mlxsw_only_on_spectrum()
+{
+	local rev=$1; shift
+	local caller=$1; shift
+	local src=$1; shift
+
+	if ! mlxsw_on_spectrum "$rev"; then
+		log_test_skip $src:$caller "(Spectrum-$rev only)"
+		return 1
+	fi
+}
+
+mlxsw_only_on_spectrum()
+{
+	local caller=${FUNCNAME[1]}
+	local src=${BASH_SOURCE[1]}
+	local rev
+
+	for rev in "$@"; do
+		if __mlxsw_only_on_spectrum "$rev" "$caller" "$src"; then
+			return 0
+		fi
+	done
+
+	return 1
+}