Subject: Re: [net-next] net: mvpp2: Add reserved port private flag configuration

From: Russell King - ARM Linux admin <[email-masked]>
Date: Wed, 10 Mar 2021 19:00:18 +0000

On Wed, Mar 10, 2021 at 11:42:09AM +0200, [email-masked] wrote:
> From: Stefan Chulski <[email-masked]>
> 
> According to Armada SoC architecture and design, all the PPv2 ports
> which are populated on the same communication processor silicon die
> (CP11x) share the same Classifier and Parser engines.
> 
> Armada is an embedded platform and therefore there is a need to reserve
> some of the PPv2 ports for different use cases.
> 
> For example, a port can be reserved for a CM3 CPU running FreeRTOS for
> management purposes or by user-space data plane application.
> 
> During port reservation all common configurations are preserved and
> only RXQ, TXQ, and interrupt vectors are disabled.

If a port is reserved for use by the CM3, what are the implications
for Linux running on the AP? Should Linux have knowledge of the port?
What configurations of the port should be permitted?

I think describing how a port reserved for use by the CM3 CPU should
appear to Linux is particularly important for the commit commentry
to cover.

-- 
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