From: David S. Miller <davem@davemloft.net>
Date: Fri, 26 May 2017 19:18:50 +0000 (-0400)
Subject: Merge branch 'mlxsw-Improve-extensibility'
X-Git-Tag: v4.13-rc1~157^2~357
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0ca3737526576d41e6a9e599428c7d44896f1c95;p=karo-tx-linux.git

Merge branch 'mlxsw-Improve-extensibility'

Jiri Pirko says:

====================
mlxsw: Improve extensibility

Ido says:

Since the initial introduction of the bridge offload in commit
56ade8fe3fe1 ("mlxsw: spectrum: Add initial support for Spectrum ASIC")
the per-port struct was used to store both physical properties of the
port as well as logical bridge properties such as learning and active
VLANs in the VLAN-aware bridge.

The above resulted in a bloated struct and code that is getting
increasingly difficult to extend when stacked devices are taken into
account as well as more advanced use cases such as IGMP snooping.

Due to the incremental development nature of this driver as well as the
complexity of the underlying hardware, subsequent design decisions failed
to generalize the FID and RIF resources, which could've benefited from
a more generic design, resulting in consolidated code paths and better
extensibility with regards to future ASICs and use cases.

This patchset tries to solve both of these design problems, as they're
tightly coupled. To ease the code review, the changes are done in a
bottom-up manner, in which the port struct is the first to be patched,
then the FIDs the ports are mapped to and finally the RIFs configured on
top.

The first half of the patchset gradually moves away from the previous
design to a design that is more in sync with the underlying hardware and
which clearly separates between hardware-specific structs and logical
ones such as a bridge port.

All the bridge-specific information is removed from the port struct, as
well as the list of VLAN devices ("vPorts") configured on top of it.
Instead, a linked list of VLANs is introduced, which allows each VLAN
to hold a state, such as mapping to a particular FID and membership in
a bridge. The data structures are depicted in the following figure:

                                  mlxsw_sp_bridge_device
                                       +----------+
                                       |          |
                                  +----+          |
                                  |    |          |
                                  |    +----------+
                                  |
             mlxsw_sp_bridge_port |
                 +----------+     |
                 |          |     |
              +-->          +-----+--> ..
              |  |          |
              |  +----+-----+
              |       |
              |       v
              | mlxsw_sp_bridge_vlan
              |  +----------+
              |  | vid X    |
              |  |          +--> ..
              |  |          |
              |  +----+-----+
              |       |
              +--+----v-----+
                 | vid X    |
              +--+          +--> ..
              |  |          |
mlxsw_sp_port |  +----------+
+----------+  | mlxsw_sp_port_vlan
|          |  |
|          +--+
|          |
+----------+

This model allows us to consolidate many of the code paths relating to
VLAN-aware and VLAN-unaware bridges, as the latter is simply represented
using a bridge port with a VLAN list size of one. Another advantage of
the model is that it's easy to extend it with future per-VLAN
attributes - such as mrouter indication - by merely pushing these down
from the bridge port struct to the bridge VLAN one.

The second half of the patchset builds on top of previous work and
prepares the driver for the common FID and RIF cores, which are finally
implemented in the last two patches. These exploit the fact that despite
the different kinds of FIDs and RIFs, they do share a common object on
which the core operations can operate on.

By hiding both objects from the rest of the driver and modeling their
operations using a VFT, it'll be easier to extend the driver for future
use cases such as VXLAN.

Tested using following LNST recipes:
https://github.com/jpirko/lnst/tree/master/recipes/switchdev
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
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0ca3737526576d41e6a9e599428c7d44896f1c95