Merge branch 'support-setting-lanes-via-ethtool'

Danielle Ratson says:

====================
Support setting lanes via ethtool

Some speeds can be achieved with different number of lanes. For example,
100Gbps can be achieved using two lanes of 50Gbps or four lanes of
25Gbps. This patchset adds a new selector that allows ethtool to
advertise link modes according to their number of lanes and also force a
specific number of lanes when autonegotiation is off.

Advertising all link modes with a speed of 100Gbps that use two lanes:

$ ethtool -s swp1 speed 100000 lanes 2 autoneg on

Forcing a speed of 100Gbps using four lanes:

$ ethtool -s swp1 speed 100000 lanes 4 autoneg off
====================

Link: https://lore.kernel.org/r/20210202180612.325099-1-danieller@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 249 insertions, 0 deletions

diff --git a/tools/testing/selftests/drivers/net/mlxsw/ethtool_lanes.sh b/tools/testing/selftests/drivers/net/mlxsw/ethtool_lanes.sh
new file mode 100755
index 000000000000..91891b9418d7
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/mlxsw/ethtool_lanes.sh
@@ -0,0 +1,187 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+lib_dir=$(dirname $0)/../../../net/forwarding
+
+ALL_TESTS="
+	autoneg
+	autoneg_force_mode
+"
+
+NUM_NETIFS=2
+: ${TIMEOUT:=30000} # ms
+source $lib_dir/lib.sh
+source $lib_dir/ethtool_lib.sh
+
+setup_prepare()
+{
+	swp1=${NETIFS[p1]}
+	swp2=${NETIFS[p2]}
+
+	ip link set dev $swp1 up
+	ip link set dev $swp2 up
+
+	busywait "$TIMEOUT" wait_for_port_up ethtool $swp2
+	check_err $? "ports did not come up"
+
+	local lanes_exist=$(ethtool $swp1 | grep 'Lanes:')
+	if [[ -z $lanes_exist ]]; then
+		log_test "SKIP: driver does not support lanes setting"
+		exit 1
+	fi
+
+	ip link set dev $swp2 down
+	ip link set dev $swp1 down
+}
+
+check_lanes()
+{
+	local dev=$1; shift
+	local lanes=$1; shift
+	local max_speed=$1; shift
+	local chosen_lanes
+
+	chosen_lanes=$(ethtool $dev | grep 'Lanes:')
+	chosen_lanes=${chosen_lanes#*"Lanes: "}
+
+	((chosen_lanes == lanes))
+	check_err $? "swp1 advertise $max_speed and $lanes, devs sync to $chosen_lanes"
+}
+
+check_unsupported_lanes()
+{
+	local dev=$1; shift
+	local max_speed=$1; shift
+	local max_lanes=$1; shift
+	local autoneg=$1; shift
+	local autoneg_str=""
+
+	local unsupported_lanes=$((max_lanes *= 2))
+
+	if [[ $autoneg -eq 0 ]]; then
+		autoneg_str="autoneg off"
+	fi
+
+	ethtool -s $swp1 speed $max_speed lanes $unsupported_lanes $autoneg_str &> /dev/null
+	check_fail $? "Unsuccessful $unsupported_lanes lanes setting was expected"
+}
+
+max_speed_and_lanes_get()
+{
+	local dev=$1; shift
+	local arr=("$@")
+	local max_lanes
+	local max_speed
+	local -a lanes_arr
+	local -a speeds_arr
+	local -a max_values
+
+	for ((i=0; i<${#arr[@]}; i+=2)); do
+		speeds_arr+=("${arr[$i]}")
+		lanes_arr+=("${arr[i+1]}")
+	done
+
+	max_values+=($(get_max "${speeds_arr[@]}"))
+	max_values+=($(get_max "${lanes_arr[@]}"))
+
+	echo ${max_values[@]}
+}
+
+search_linkmode()
+{
+	local speed=$1; shift
+	local lanes=$1; shift
+	local arr=("$@")
+
+	for ((i=0; i<${#arr[@]}; i+=2)); do
+		if [[ $speed -eq ${arr[$i]} && $lanes -eq ${arr[i+1]} ]]; then
+			return 1
+		fi
+	done
+	return 0
+}
+
+autoneg()
+{
+	RET=0
+
+	local lanes
+	local max_speed
+	local max_lanes
+
+	local -a linkmodes_params=($(dev_linkmodes_params_get $swp1 1))
+	local -a max_values=($(max_speed_and_lanes_get $swp1 "${linkmodes_params[@]}"))
+	max_speed=${max_values[0]}
+	max_lanes=${max_values[1]}
+
+	lanes=$max_lanes
+
+	while [[ $lanes -ge 1 ]]; do
+		search_linkmode $max_speed $lanes "${linkmodes_params[@]}"
+		if [[ $? -eq 1 ]]; then
+			ethtool_set $swp1 speed $max_speed lanes $lanes
+			ip link set dev $swp1 up
+			ip link set dev $swp2 up
+			busywait "$TIMEOUT" wait_for_port_up ethtool $swp2
+			check_err $? "ports did not come up"
+
+			check_lanes $swp1 $lanes $max_speed
+			log_test "$lanes lanes is autonegotiated"
+		fi
+		let $((lanes /= 2))
+	done
+
+	check_unsupported_lanes $swp1 $max_speed $max_lanes 1
+	log_test "Lanes number larger than max width is not set"
+
+	ip link set dev $swp2 down
+	ip link set dev $swp1 down
+}
+
+autoneg_force_mode()
+{
+	RET=0
+
+	local lanes
+	local max_speed
+	local max_lanes
+
+	local -a linkmodes_params=($(dev_linkmodes_params_get $swp1 1))
+	local -a max_values=($(max_speed_and_lanes_get $swp1 "${linkmodes_params[@]}"))
+	max_speed=${max_values[0]}
+	max_lanes=${max_values[1]}
+
+	lanes=$max_lanes
+
+	while [[ $lanes -ge 1 ]]; do
+		search_linkmode $max_speed $lanes "${linkmodes_params[@]}"
+		if [[ $? -eq 1 ]]; then
+			ethtool_set $swp1 speed $max_speed lanes $lanes autoneg off
+			ethtool_set $swp2 speed $max_speed lanes $lanes autoneg off
+			ip link set dev $swp1 up
+			ip link set dev $swp2 up
+			busywait "$TIMEOUT" wait_for_port_up ethtool $swp2
+			check_err $? "ports did not come up"
+
+			check_lanes $swp1 $lanes $max_speed
+			log_test "Autoneg off, $lanes lanes detected during force mode"
+		fi
+		let $((lanes /= 2))
+	done
+
+	check_unsupported_lanes $swp1 $max_speed $max_lanes 0
+	log_test "Lanes number larger than max width is not set"
+
+	ip link set dev $swp2 down
+	ip link set dev $swp1 down
+
+	ethtool -s $swp2 autoneg on
+	ethtool -s $swp1 autoneg on
+}
+
+check_ethtool_lanes_support
+setup_prepare
+
+tests_run
+
+exit $EXIT_STATUS
diff --git a/tools/testing/selftests/net/forwarding/ethtool_lib.sh b/tools/testing/selftests/net/forwarding/ethtool_lib.sh
index 9188e624dec0..b9bfb45085af 100644
--- a/tools/testing/selftests/net/forwarding/ethtool_lib.sh
+++ b/tools/testing/selftests/net/forwarding/ethtool_lib.sh
@@ -22,6 +22,40 @@ ethtool_set()
 	check_err $out "error in configuration. $cmd"
 }
 
+dev_linkmodes_params_get()
+{
+	local dev=$1; shift
+	local adver=$1; shift
+	local -a linkmodes_params
+	local param_count
+	local arr
+
+	if (($adver)); then
+		mode="Advertised link modes"
+	else
+		mode="Supported link modes"
+	fi
+
+	local -a dev_linkmodes=($(dev_speeds_get $dev 1 $adver))
+	for ((i=0; i<${#dev_linkmodes[@]}; i++)); do
+		linkmodes_params[$i]=$(echo -e "${dev_linkmodes[$i]}" | \
+			# Replaces all non numbers with spaces
+			sed -e 's/[^0-9]/ /g' | \
+			# Squeeze spaces in sequence to 1 space
+			tr -s ' ')
+		# Count how many numbers were found in the linkmode
+		param_count=$(echo "${linkmodes_params[$i]}" | wc -w)
+		if [[ $param_count -eq 1 ]]; then
+			linkmodes_params[$i]="${linkmodes_params[$i]} 1"
+		elif [[ $param_count -ge 3 ]]; then
+			arr=(${linkmodes_params[$i]})
+			# Take only first two params
+			linkmodes_params[$i]=$(echo "${arr[@]:0:2}")
+		fi
+	done
+	echo ${linkmodes_params[@]}
+}
+
 dev_speeds_get()
 {
 	local dev=$1; shift
diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
index 98ea37d26c44..40b3a86a62cf 100644
--- a/tools/testing/selftests/net/forwarding/lib.sh
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -69,6 +69,15 @@ check_tc_action_hw_stats_support()
 	fi
 }
 
+check_ethtool_lanes_support()
+{
+	ethtool --help 2>&1| grep lanes &> /dev/null
+	if [[ $? -ne 0 ]]; then
+		echo "SKIP: ethtool too old; it is missing lanes support"
+		exit 1
+	fi
+}
+
 if [[ "$(id -u)" -ne 0 ]]; then
 	echo "SKIP: need root privileges"
 	exit 0
@@ -263,6 +272,20 @@ not()
 	[[ $? != 0 ]]
 }
 
+get_max()
+{
+	local arr=("$@")
+
+	max=${arr[0]}
+	for cur in ${arr[@]}; do
+		if [[ $cur -gt $max ]]; then
+			max=$cur
+		fi
+	done
+
+	echo $max
+}
+
 grep_bridge_fdb()
 {
 	local addr=$1; shift
@@ -279,6 +302,11 @@ grep_bridge_fdb()
 	$@ | grep $addr | grep $flag "$word"
 }
 
+wait_for_port_up()
+{
+	"$@" | grep -q "Link detected: yes"
+}
+
 wait_for_offload()
 {
 	"$@" | grep -q offload