net: dsa: sja1105: save/restore VLANs using a delta commit method
Managing the VLAN table that is present in hardware will become very difficult once we add a third operating state (best_effort_vlan_filtering). That is because correct cleanup (not too little, not too much) becomes virtually impossible, when VLANs can be added from the bridge layer, from dsa_8021q for basic tagging, for cross-chip bridging, as well as retagging rules for sub-VLANs and cross-chip sub-VLANs. So we need to rethink VLAN interaction with the switch in a more scalable way. In preparation for that, use the priv->expect_dsa_8021q boolean to classify any VLAN request received through .port_vlan_add or .port_vlan_del towards either one of 2 internal lists: bridge VLANs and dsa_8021q VLANs. Then, implement a central sja1105_build_vlan_table method that creates a VLAN configuration from scratch based on the 2 lists of VLANs kept by the driver, and based on the VLAN awareness state. Currently, if we are VLAN-unaware, install the dsa_8021q VLANs, otherwise the bridge VLANs. Then, implement a delta commit procedure that identifies which VLANs from this new configuration are actually different from the config previously committed to hardware. We apply the delta through the dynamic configuration interface (we don't reset the switch). The result is that the hardware should see the exact sequence of operations as before this patch. This also helps remove the "br" argument passed to dsa_8021q_crosschip_bridge_join, which it was only using to figure out whether it should commit the configuration back to us or not, based on the VLAN awareness state of the bridge. We can simplify that, by always allowing those VLANs inside of our dsa_8021q_vlans list, and committing those to hardware when necessary. Signed-off-by:Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: