Re: [PATCH v8 0/9] SCMI Notifications Core Support

[Sudeep Holla]

Hi Cristian,

On Wed, May 20, 2020 at 09:11:09AM +0100, Cristian Marussi wrote:
> Hi all,
>
> this series wants to introduce SCMI Notification Support, built on top of
> the standard Kernel notification chain subsystem.
>
> At initialization time each SCMI Protocol takes care to register with the
> new SCMI notification core the set of its own events which it intends to
> support.
>
> Using the API exposed via scmi_handle.notify_ops a Kernel user can register
> its own notifier_t callback (via a notifier_block as usual) against any
> registered event as identified by the tuple:
>
> 		(proto_id, event_id, src_id)
>
> where src_id represents a generic source identifier which is protocol
> dependent like domain_id, performance_id, sensor_id and so forth.
> (users can anyway do NOT provide any src_id, and subscribe instead to ALL
>  the existing (if any) src_id sources for that proto_id/evt_id combination)
>
> Each of the above tuple-specified eventis will be served on its own
> dedicated blocking notification chain, dynamically allocated on-demand when
> at least one user has shown interest on that event.
>
> Upon a notification delivery all the users' registered notifier_t callbacks
> will be in turn invoked and fed with the event_id as @action param and a
> generated custom per-event struct _report as @data param.
> (as in include/linux/scmi_protocol.h)
>
> The final step of notification delivery via users' callback invocation is
> instead delegated to a pool of deferred workers (Kernel cmwq): each
> SCMI protocol has its own dedicated worker and dedicated queue to push
> events from the rx ISR to the worker.
>
> Based on scmi-next/for-next/scmi 5.7 [1], on top of:
>
> commit f7199cf48902 ("firmware: arm_scmi: Fix return error code in
> 		     smc_send_message")
>
> This series has been tested on JUNO with an experimental firmware only
> supporting Perf Notifications.
>

Thanks for working on this. Looks mostly OK. I have few minor comments
or queries.

--
Regards,
Sudeep