Re: [PATCHv2 0/5] Support for Marvell switches with integrated CPUs

[Chris Packham]

On 05/01/17 17:07, Florian Fainelli wrote:
> Le 01/04/17 à 19:36, Chris Packham a écrit :
>> The 98DX3236, 98DX3336 and 98DX4251 are a set of switch ASICs with
>> integrated CPUs. They CPU block is common within these product lines and
>> (as far as I can tell/have been told) is based on the Armada XP. There
>> are a few differences due to the fact they have to squeeze the CPU into
>> the same package as the switch.
>
> It's really great to see these changes, do you have a plan to also add
> support for the integrated switch using a DSA/switchdev driver?

I'd love to see a switchdev driver but it's a huge task (and no I'm not 
committing to writing it). As it stands Marvell ship a switch SDK 
largely executes in userspace with a small kernel module providing some 
linkage to the underlying hardware.

We (a few of us here at Allied Telesis NZ) have discussed switchdev and 
how we get from using Marvell's SDK in our products to using switchdev 
proper.

The first step would probably be some kind of trampoline driver which 
communicates with a userspace helper to do the actual work. 
Alternatively there is some support in Marvell's SDK for compilation as 
a binary blob so a proprietary kernel module is another option. Neither 
of these are particularly nice in a free software world.

A full "free" implementation would be a large undertaking. Ideally I'd 
like to see Marvell involved with producing one but so far they've not 
been interested whenever I've brought it up.