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Diffstat (limited to 'Documentation/networking/dsa')
| -rw-r--r-- | Documentation/networking/dsa/dsa.rst | 30 |
1 files changed, 30 insertions, 0 deletions
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 ==== |