[PATCH 3/7] firmware: ti_sci: Add support for Resoure Management at R5 SPL stage.

[Vignesh Raghavendra]

On 5/11/21 10:19 AM, Lokesh Vutla wrote:
> 
> 
> On 10/05/21 10:54 pm, Vignesh Raghavendra wrote:
>> On J721e and J7200, MCU R5 core (boot master) itself would run Device
>> Manager (DM) Firmware and interact with TI Foundational Security (TIFS)
>> firmware to enable DMA and such other Resource Management (RM) services.
>> So, during R5 SPL stage there is no such RM service available and ti_sci
>> driver will have to directly interact with TIFS using DM to DMSC
>> channels to request RM resources.
> 
> So, PM services are also not available at R5 and I do not see a new compatible
> for PM services. Can you help me understand why we cannot follow the same as
> being done in PM services.
> 

PM services can be handled entirely within R5 SPL. But RM service
requests need to forwarded to TIFS for openinng up channelized firewall
and ISC configuration (Message forwarding). These messages have to be
sent on a different secproxy channel than regular messages (DM to TIFS
channel) and the host ID used is R5's non secure host ID.
All these differences make RM service provider a different entity than
existing one.

> One of my worry is ti_sci driver already needs a heavy cleanup. Now adding more
> stuff to it will just keep increase the burden
> 

This patch adds new probe function (ti_sci_dm_probe()) which reassigns
RM GET_RANGE API to function that does static table look up instead of
API call to TIFS. I don't think its adding ady significant code to
existing driver and should not come in the way of any future cleanups.

Regards
Vignesh