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
Patchset overview:
Patch #1-#2 allows user space to configure the desired number of lanes.
Patch #3-#4 adjusts ethtool to dump to user space the number of lanes
currently in use.
Patches #5-#7 add support for lanes configuration in mlxsw.
Patch #8 adds a selftest.
v4:
* Add patch #1 for validating parameters before rtnl_lock().
v3:
* Patch #1: Change ethtool_ops.capabilities to be a bitfield,
and set min and max for the lanes policy.
* Patch #2: Remove LINK_MODE_UNKNOWN and move the speed, duplex
and lanes derivation to the wrapper
__ethtool_get_link_ksettings().
* Patch #5: Set the bitfield of supporting lanes in the driver
* to 'true'.
* Patch #7: Move the test to drivers/net/mlxsw.
v2:
* Patch #1: Remove ETHTOOL_LANES defines and simply use a number
instead.
* Patches #2,#6: Pass link mode from driver to ethtool instead
* of the parameters themselves.
* Patch #5: Add an actual width field for spectrum-2 link modes
in order to set the suitable link mode when lanes parameter is
passed.
* Patch #6: Changed lanes to be unsigned in
'struct link_mode_info'.
* Patch #7: Remove the test for recieving max_width when lanes
is not set by user. When not setting lanes, we don't promise
anything regarding what number of lanes will be chosen.
Danielle Ratson (8):
ethtool: Validate master slave configuration before rtnl_lock()
ethtool: Extend link modes settings uAPI with lanes
ethtool: Get link mode in use instead of speed and duplex parameters
ethtool: Expose the number of lanes in use
mlxsw: ethtool: Remove max lanes filtering
mlxsw: ethtool: Add support for setting lanes when autoneg is off
mlxsw: ethtool: Pass link mode in use to ethtool
net: selftests: Add lanes setting test
Documentation/networking/ethtool-netlink.rst | 11 +-
.../net/ethernet/mellanox/mlxsw/spectrum.h | 13 +-
.../mellanox/mlxsw/spectrum_ethtool.c | 196 ++++++++++-------
include/linux/ethtool.h | 5 +
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/common.c | 147 +++++++++++++
net/ethtool/common.h | 7 +
net/ethtool/ioctl.c | 18 +-
net/ethtool/linkmodes.c | 208 ++++++------------
net/ethtool/netlink.h | 2 +-
.../drivers/net/mlxsw/ethtool_lanes.sh | 187 ++++++++++++++++
.../selftests/net/forwarding/ethtool_lib.sh | 34 +++
tools/testing/selftests/net/forwarding/lib.sh | 28 +++
13 files changed, 626 insertions(+), 231 deletions(-)
create mode 100755 tools/testing/selftests/drivers/net/mlxsw/ethtool_lanes.sh
--
2.26.2
