Re: [PATCH v3 2/2] remoteproc: qcom: Add notification types to SSR

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Tue 28 Apr 15:16 PDT 2020, Rishabh Bhatnagar wrote:

> From: Siddharth Gupta <sidgup@codeaurora.org>
> 
> The SSR subdevice only adds callback for the unprepare event. Add callbacks
> for unprepare, start and prepare events. The client driver for a particular
> remoteproc might be interested in knowing the status of the remoteproc
> while undergoing SSR, not just when the remoteproc has finished shutting
> down.
> 
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
> ---
>  drivers/remoteproc/qcom_common.c      | 46 +++++++++++++++++++++++++++++++++--
>  include/linux/remoteproc/qcom_rproc.h | 14 +++++++++++
>  2 files changed, 58 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
> index 7cd17be..0d91cf3 100644
> --- a/drivers/remoteproc/qcom_common.c
> +++ b/drivers/remoteproc/qcom_common.c
> @@ -197,7 +197,7 @@ struct rproc_notif_info *find_notif_info(const char *name)
>   *
>   * This registers the @nb notifier block as part the notifier chain for a
>   * remoteproc associated with @name. The notifier block's callback
> - * will be invoked when the particular remote processor is stopped.
> + * will be invoked when the particular remote processor is started/stopped.
>   */
>  void *qcom_register_ssr_notifier(const char *name, struct notifier_block *nb)
>  {
> @@ -239,6 +239,44 @@ int qcom_unregister_ssr_notifier(void *notify, struct notifier_block *nb)
>  }
>  EXPORT_SYMBOL_GPL(qcom_unregister_ssr_notifier);
>  
> +static int ssr_notify_prepare(struct rproc_subdev *subdev)
> +{
> +	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> +	struct rproc_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = false,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 RPROC_BEFORE_POWERUP, &data);
> +	return 0;
> +}
> +
> +static int ssr_notify_start(struct rproc_subdev *subdev)
> +{
> +	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> +	struct rproc_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = false,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 RPROC_AFTER_POWERUP, &data);
> +	return 0;
> +}
> +
> +static void ssr_notify_stop(struct rproc_subdev *subdev, bool crashed)
> +{
> +	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> +	struct rproc_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = crashed,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 RPROC_BEFORE_SHUTDOWN, &data);
> +}
> +
>  static void ssr_notify_unprepare(struct rproc_subdev *subdev)
>  {
>  	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> @@ -247,7 +285,8 @@ static void ssr_notify_unprepare(struct rproc_subdev *subdev)
>  		.crashed = false,
>  	};
>  
> -	srcu_notifier_call_chain(&ssr->info->notifier_list, 0, &data);
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 RPROC_AFTER_SHUTDOWN, &data);
>  }
>  
>  
> @@ -282,6 +321,9 @@ void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
>  	}
>  	mutex_unlock(&rproc_notif_lock);
>  	ssr->info = info;
> +	ssr->subdev.prepare = ssr_notify_prepare;
> +	ssr->subdev.start = ssr_notify_start;
> +	ssr->subdev.stop = ssr_notify_stop;
>  	ssr->subdev.unprepare = ssr_notify_unprepare;
>  
>  	rproc_add_subdev(rproc, &ssr->subdev);
> diff --git a/include/linux/remoteproc/qcom_rproc.h b/include/linux/remoteproc/qcom_rproc.h
> index 3dc65c0..567c1f9 100644
> --- a/include/linux/remoteproc/qcom_rproc.h
> +++ b/include/linux/remoteproc/qcom_rproc.h
> @@ -5,6 +5,20 @@
>  
>  #if IS_ENABLED(CONFIG_QCOM_RPROC_COMMON)
>  
> +/**
> + * enum rproc_notif_type - Different stages of remoteproc notifications
> + * @RPROC_BEFORE_SHUTDOWN:	unprepare stage of  remoteproc
> + * @RPROC_AFTER_SHUTDOWN:	stop stage of  remoteproc
> + * @RPROC_BEFORE_POWERUP:	prepare stage of  remoteproc
> + * @RPROC_AFTER_POWERUP:	start stage of  remoteproc
> + */
> +enum rproc_notif_type {
> +	RPROC_BEFORE_SHUTDOWN,
> +	RPROC_AFTER_SHUTDOWN,
> +	RPROC_BEFORE_POWERUP,
> +	RPROC_AFTER_POWERUP,

Given that these are not generic remoteproc things I would like a qcom
prefix on them.

How about QCOM_SSR_BEFORE_SHUTDOWN ... 

Apart from that, this looks good.

Thanks,
Bjorn

> +};
> +
>  struct rproc_notif_data {
>  	const char *name;
>  	bool crashed;
> -- 
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