The 03/16/2021 13:24, Vladimir Oltean wrote: > > From: Vladimir Oltean <vladimir.olt...@nxp.com> > > Add a short summary of the methods that a driver writer must implement > for getting an MRP instance to work on top of a DSA switch. > > Cc: Horatiu Vultur <horatiu.vul...@microchip.com> > Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com> > --- > Documentation/networking/dsa/dsa.rst | 30 ++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/Documentation/networking/dsa/dsa.rst > b/Documentation/networking/dsa/dsa.rst > index e8576e81735c..0daafa2fb9eb 100644 > --- a/Documentation/networking/dsa/dsa.rst > +++ b/Documentation/networking/dsa/dsa.rst > @@ -757,6 +757,36 @@ can optionally populate ``ds->num_lag_ids`` from the > ``dsa_switch_ops::setup`` > method. The LAG ID associated with a bonding/team interface can then be > retrieved by a DSA switch driver using the ``dsa_lag_id`` function. > > +IEC 62439-2 (MRP) > +----------------- > + > +The Media Redundancy Protocol is a topology management protocol optimized for > +fast fault recovery time for ring networks, which has some components > +implemented as a function of the bridge driver. MRP uses management PDUs > +(Test, Topology, LinkDown/Up, Option) sent at a multicast destination MAC > +address range of 01:15:4e:00:00:0x and with an EtherType of 0x88e3. > +Depending on the node's role in the ring (MRM: Media Redundancy Manager, > +MRC: Media Redundancy Client, MRA: Media Redundancy Automanager), certain MRP > +PDUs might need to be terminated locally and others might need to be > forwarded. > +An MRM might also benefit from offloading to hardware the creation and > +transmission of certain MRP PDUs (Test). > + > +Normally an MRP instance can be created on top of any network interface, > +however in the case of a device with an offloaded data path such as DSA, it > is > +necessary for the hardware, even if it is not MRP-aware, to be able to > extract > +the MRP PDUs from the fabric before the driver can proceed with the software > +implementation. DSA today has no driver which is MRP-aware, therefore it only > +listens for the bare minimum switchdev objects required for the software > assist > +to work properly. The operations are detailed below. > + > +- ``port_mrp_add`` and ``port_mrp_del``: notifies driver when an MRP instance > + with a certain ring ID, priority, primary port and secondary port is > + created/deleted. > +- ``port_mrp_add_ring_role`` and ``port_mrp_del_ring_role``: function invoked > + when an MRP instance changes ring roles between MRM or MRC. This affects > + which MRP PDUs should be trapped to software and which should be > autonomously > + forwarded. > + > TODO > ==== > > -- > 2.25.1 >
Reviewed-by: Horatiu Vultur <horatiu.vul...@microchip.com> -- /Horatiu
