selftests: forwarding: ethtool_mm: fall back to aggregate if device does not report pMAC stats

Some devices do not support individual 'pmac' and 'emac' stats.
For such devices, resort to 'aggregate' stats.

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -25,6 +25,10 @@ traffic_test()
 	local after=
 	local delta=
 
+	if [ ${has_pmac_stats[$if]} = false ]; then
+		src="aggregate"
+	fi
+
 	before=$(ethtool_std_stats_get $if "eth-mac" "FramesTransmittedOK" $src)
 
 	$MZ $if -q -c $num_pkts -p 64 -b bcast -t ip -R $PREEMPTIBLE_PRIO
@@ -317,6 +321,13 @@ for netif in ${NETIFS[@]}; do
 		echo "SKIP: $netif does not support MAC Merge"
 		exit $ksft_skip
 	fi
+
+	if check_ethtool_pmac_std_stats_support $netif eth-mac; then
+		has_pmac_stats[$netif]=true
+	else
+		has_pmac_stats[$netif]=false
+		echo "$netif does not report pMAC statistics, falling back to aggregate"
+	fi
 done
 
 trap cleanup EXIT

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

@@ -155,6 +155,15 @@ check_ethtool_counter_group_support()
 	fi
 }
 
+check_ethtool_pmac_std_stats_support()
+{
+	local dev=$1; shift
+	local grp=$1; shift
+
+	[ 0 -ne $(ethtool --json -S $dev --all-groups --src pmac 2>/dev/null \
+		| jq ".[].\"$grp\" | length") ]
+}
+
 check_locked_port_support()
 {
 	if ! bridge -d link show | grep -q " locked"; then