TMDS64EVM: Exposed mode vs. Private mode for rings in RingAccelerator

Boshra

Part Number: TMDS64EVM

Hi,

I would like to know in more detail what are the differences between the Exposed mode and Private mode for Rings in RingAccelerator.

What is the use case for each of them?

I read that the Private mode needs to be used only with Secure Proxy. On the other hand, I saw in the code that Secure Proxy is used for Sending messages to DMSC (core M3). Does it mean that the Private mode is used for messaging to DMSC? Does it have any other use case?

To me, it seems that the Drivers for DMASS are using exposed mode. How should we use it in Private mode?

Can I use firewalls with both modes?

Thanks,
Boshra

over 2 years ago

0 Kallikuppa Sreenivasa over 2 years ago

TI__Guru**** 197129 points

Hello Boshra,

Thank you for the query.

I did a quick search and see information related to the above query covered in the below section.

11.1 Data Movement Architecture Overview

I will review your queries and comeback.

Regards,

Sreenivasa

0 Pekka Varis over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Mastermind 27050 points

The TRM section is again an overview of the architecture, AM64x implements a subset.

For talking to the DMSS please use the interface documented at Introduction — TISCI User Guide maybe specifically good to look at AM64X Ring Accelerator Device Descriptions — TISCI User Guide for rings. There is a separate ring accelerator for DMSS, it is part of a subsystem (IPCSS), which is not documented in the TRM that well, we only support interfacing to device management/sysfw/DMSS using the TISCI interface. This ring accelerator uses message mode.

For the DMA rings only exposed mode is supported (QMODE is read only 1).

Pekka

0 Boshra over 2 years ago in reply to Pekka Varis

Intellectual 418 points

Thanks for your reply.

Pekka Varis said:
DMSS

I'm just a little confused. Here you are talking about the DMSC(M3 in our case), not DMSS, right?

But still, my other question is that when we are queueing the Descriptor to the Ring, is it used by only hardware, or there is software that takes care of it and does the scheduling between the channels, etc.. Is this software located on M3 as well?

Thanks,
Boshra

+1 Pekka Varis over 2 years ago in reply to Boshra

TI__Mastermind 27050 points

Sorry DMSC (not DMSS) the device management, use TISCI to talk to it.

It is HW on the other side of the ring. So doing a DMA transfer and placing something on a ring, HW picks it up. As you can see from the QMODE registers related to DMA channels, the mode is not configurable, it is read only as 1 in the TRM. There are no cores of any kind involved in DMA, it is all HW state machines.

0 Boshra over 2 years ago in reply to Pekka Varis

Intellectual 418 points

Thanks. It answered my question.

0 Kallikuppa Sreenivasa over 2 years ago in reply to Boshra

TI__Guru**** 197129 points

Hello Boshra,

Thank you for the note.

Regards,

Sreenivasa

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TMDS64EVM: Exposed mode vs. Private mode for rings in RingAccelerator