net: dsa: request drivers to perform FDB isolation
For DSA, to encourage drivers to perform FDB isolation simply means to track which bridge does each FDB and MDB entry belong to. It then becomes the driver responsibility to use something that makes the FDB entry from one bridge not match the FDB lookup of ports from other bridges. The top-level functions where the bridge is determined are: - dsa_port_fdb_{add,del} - dsa_port_host_fdb_{add,del} - dsa_port_mdb_{add,del} - dsa_port_host_mdb_{add,del} aka the pre-crosschip-notifier functions. Changing the API to pass a reference to a bridge is not superfluous, and looking at the passed bridge argument is not the same as having the driver look at dsa_to_port(ds, port)->bridge from the ->port_fdb_add() method. DSA installs FDB and MDB entries on shared (CPU and DSA) ports as well, and those do not have any dp->bridge information to retrieve, because they are not in any bridge - they are merely the pipes that serve the user ports that are in one or multiple bridges. The struct dsa_bridge associated with each FDB/MDB entry is encapsulated in a larger "struct dsa_db" database. Although only databases associated to bridges are notified for now, this API will be the starting point for implementing IFF_UNICAST_FLT in DSA. There, the idea is to install FDB entries on the CPU port which belong to the corresponding user port's port database. These are supposed to match only when the port is standalone. It is better to introduce the API in its expected final form than to introduce it for bridges first, then to have to change drivers which may have made one or more assumptions. Drivers can use the provided bridge.num, but they can also use a different numbering scheme that is more convenient. DSA must perform refcounting on the CPU and DSA ports by also taking into account the bridge number. So if two bridges request the same local address, DSA must notify the driver twice, once for each bridge. In fact, if the driver supports FDB isolation, DSA must perform refcounting per bridge, but if the driver doesn't, DSA must refcount host addresses across all bridges, otherwise it would be telling the driver to delete an FDB entry for a bridge and the driver would delete it for all bridges. So introduce a bool fdb_isolation in drivers which would make all bridge databases passed to the cross-chip notifier have the same number (0). This makes dsa_mac_addr_find() -> dsa_db_equal() say that all bridge databases are the same database - which is essentially the legacy behavior. Signed-off-by:Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
b6362bdf