smci: how do reboots work in scmi?

smci: how do reboots work in scmi?

[Dan Carpenter]

In scmi with pinctrl then we do a PINCTRL_REQUEST to claim the pins,
but then if we reboot without restarting the scmi server the the pins
are still claimed.  Is there some way to hook into VHOST_USER_NONE to
release all the pins?

regards,
dan carpenter

Re: smci: how do reboots work in scmi?

[Khaled Ali Ahmed]

Hello Dan,
the following message still has not been implemented yet:
- PINCTRL_REQUEST.
- PINCTRL_RELEASE.
- PINCTRL_SET_PERMISSIONS.
- NEGOTIATE_PROTOCOL_VERSION.

thank you so much for your attention and participation.

________________________________________
From: Dan Carpenter <dan.carpenter@linaro.org>
Sent: Saturday, February 1, 2025 1:57 PM
To: arm-scmi@vger.kernel.org <arm-scmi@vger.kernel.org>; Khaled Ali Ahmed <Khaled.AliAhmed@arm.com>; Girish Pathak <Girish.Pathak@arm.com>
Subject: smci: how do reboots work in scmi?

In scmi with pinctrl then we do a PINCTRL_REQUEST to claim the pins,
but then if we reboot without restarting the scmi server the the pins
are still claimed.  Is there some way to hook into VHOST_USER_NONE to
release all the pins?

regards,
dan carpenter
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Re: smci: how do reboots work in scmi?

[Dan Carpenter]

On Sun, Feb 02, 2025 at 10:12:17PM +0000, Khaled Ali Ahmed wrote:
> Hello Dan,
> the following message still has not been implemented yet:
> - PINCTRL_REQUEST.
> - PINCTRL_RELEASE.
> - PINCTRL_SET_PERMISSIONS.
> - NEGOTIATE_PROTOCOL_VERSION.
> 
> thank you so much for your attention and participation.
> 

Ah right, I was thinking of PINCTRL_SETTINGS_CONFIGURE.

When the system reboots, it would be nice to have a hook in SCP to just
reset everything.

regards,
dan carpenter

Re: smci: how do reboots work in scmi?

[Vincent Guittot]

On Mon, 3 Feb 2025 at 07:25, Dan Carpenter <dan.carpenter@linaro.org> wrote:
>
> On Sun, Feb 02, 2025 at 10:12:17PM +0000, Khaled Ali Ahmed wrote:
> > Hello Dan,
> > the following message still has not been implemented yet:
> > - PINCTRL_REQUEST.
> > - PINCTRL_RELEASE.
> > - PINCTRL_SET_PERMISSIONS.
> > - NEGOTIATE_PROTOCOL_VERSION.
> >
> > thank you so much for your attention and participation.
> >
>
> Ah right, I was thinking of PINCTRL_SETTINGS_CONFIGURE.
>
> When the system reboots, it would be nice to have a hook in SCP to just
> reset everything.

Maybe BASE_RESET_AGENT_CONFIGURATION :
" This command is used to reset platform resource settings that were
previously configured by an agent.
Platform resource settings refer to power domain, performance domain,
clock, sensors and other
settings associated with a device that the agent has access to. This
command can also be used to reset
agent-specific permission configurations to access devices and protocols."

>
> regards,
> dan carpenter
>
>
>

Re: smci: how do reboots work in scmi?

[Cristian Marussi]

On Mon, Feb 03, 2025 at 08:05:30AM +0100, Vincent Guittot wrote:
> On Mon, 3 Feb 2025 at 07:25, Dan Carpenter <dan.carpenter@linaro.org> wrote:
> >
> > On Sun, Feb 02, 2025 at 10:12:17PM +0000, Khaled Ali Ahmed wrote:
> > > Hello Dan,
> > > the following message still has not been implemented yet:
> > > - PINCTRL_REQUEST.
> > > - PINCTRL_RELEASE.
> > > - PINCTRL_SET_PERMISSIONS.
> > > - NEGOTIATE_PROTOCOL_VERSION.
> > >
> > > thank you so much for your attention and participation.
> > >
> >
> > Ah right, I was thinking of PINCTRL_SETTINGS_CONFIGURE.
> >
> > When the system reboots, it would be nice to have a hook in SCP to just
> > reset everything.
> 
> Maybe BASE_RESET_AGENT_CONFIGURATION :
> " This command is used to reset platform resource settings that were
> previously configured by an agent.
> Platform resource settings refer to power domain, performance domain,
> clock, sensors and other
> settings associated with a device that the agent has access to. This
> command can also be used to reset
> agent-specific permission configurations to access devices and protocols."

You mean Linux OSPM Agent invoking this commands for itself upon reboot ?
(and the platform acting accordignly..)

First I think we should clarify here what we mean with "system reboot".

- a single Agent rebooting by its own decision
    BASE_RESET_AGENT_CONFIGURATION(self) could be an option

- some Trusted agent causing other agents to shutdown/reboot
    in this case maybe there could be some interactions via SystemPower
    protocol, with the server asking upfront for a graceful shutdown
    which would trigger similarly a BASE_RESET_AGENT_CONFIGURATION(self).
    This would give the server a notion of an "agent resetting" which is
    something that currently is not present in SCMI because the server
    cannot know really if an agent is alive (and I am NOT saying that
    this would be a bad thing.. :P)

    ...BUT, on the other side, if a not-so-graceful shutdown is required
    the victim-agent wont have a chance for a clean reboot/shutdown so
    somehow the TrustedAgent could have to issue a BASE_RESET_AGENT_CONFIGURATION
    on behalf of that agent, OR maybe the server could just cleanup the
    config on its own for the disappearing agent...

- the whole system at the platform level, including the server itself:
  does it matter in this case to reset the agent configs ?
  ...IOW is there a scenario in which an SCMI server could reset, needing
  all its agents' states to be reset too, WHILE the platform that is running
  on somehow survives and retains some state ?

I think we never discussed these scenarios, especially in a virtualized
environement...

Thanks,
Cristian