Merge branch 'mlxsw-unified-bridge-conversion-part-4-6'

Merge branch 'mlxsw-unified-bridge-conversion-part-4-6'

Ido Schimmel says:

====================
mlxsw: Unified bridge conversion - part 4/6

This is the fourth part of the conversion of mlxsw to the unified bridge
model.

Unlike previous parts that prepared mlxsw for the conversion, this part
actually starts the conversion. It focuses on flooding configuration and
converts mlxsw to the more "raw" APIs of the unified bridge model.

The patches configure the different stages of the flooding pipeline in
Spectrum that looks as follows (at a high-level):

         +------------+                +----------+           +-------+
  {FID,  |            | {Packet type,  |          |           |       |  MID
   DMAC} | FDB lookup |  Bridge type}  |   SFGC   | MID base  |       | Index
+-------->   (miss)   +----------------> register +-----------> Adder +------->
         |            |                |          |           |       |
         |            |                |          |           |       |
         +------------+                +----+-----+           +---^---+
                                            |                     |
                                    Table   |                     |
                                     type   |                     | Offset
                                            |      +-------+      |
                                            |      |       |      |
                                            |      |       |      |
                                            +----->+  Mux  +------+
                                                   |       |
                                                   |       |
                                                   +-^---^-+
                                                     |   |
                                                  FID|   |FID
                                                     |   |offset
                                                     +   +

The multicast identifier (MID) index is used as an index to the port
group table (PGT) that contains a bitmap of ports via which a packet
needs to be replicated.

From the PGT table, the packet continues to the multicast port egress
(MPE) table that determines the packet's egress VLAN. This is a
two-dimensional table that is indexed by port and switch multicast port
to egress (SMPE) index. The latter can be thought of as a FID. Without
it, all the packets replicated via a certain port would get the same
VLAN, regardless of the bridge domain (FID).

Logically, these two steps look as follows:

                     PGT table                           MPE table
             +-----------------------+               +---------------+
             |                       | {Local port,  |               | Egress
  MID index  | Local ports bitmap #1 |  SMPE index}  |               |  VID
+------------>        ...            +--------------->               +-------->
             | Local ports bitmap #N |               |               |
             |                       |          SMPE |               |
             +-----------------------+               +---------------+
                                                        Local port

Patchset overview:

Patch #1 adds a variable to guard against mixed model configuration.
Will be removed in part 6 when mlxsw is fully converted to the unified
model.

Patches #2-#5 introduce two new FID attributes required for flooding
configuration in the new model:

1. 'flood_rsp': Instructs the firmware to handle flooding configuration
for this FID. Only set for router FIDs (rFIDs) which are used to connect
a {Port, VLAN} to the router block.

2. 'bridge_type': Allows the device to determine the flood table (i.e.,
base index to the PGT table) for the FID. The first type will be used
for FIDs in a VLAN-aware bridge and the second for FIDs representing
VLAN-unaware bridges.

Patch #6 configures the MPE table that determines the egress VLAN of a
packet that is forwarded according to L2 multicast / flood.

Patches #7-#11 add the PGT table and related APIs to allocate entries
and set / clear ports in them.

Patches #12-#13 convert the flooding configuration to use the new PGT
APIs.
====================

Link: https://lore.kernel.org/r/20220627070621.648499-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>