Re: [PATCH v5 2/2] remoteproc: qcom: Add notification types to SSR

[Alex Elder <elder@ieee.org>]

On 6/22/20 8:04 PM, Rishabh Bhatnagar wrote:
> The SSR subdevice only adds callback for the unprepare event. Add callbacks
> for prepare, 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>

This looks good to me.

Reviewed-by: Alex Elder <elder@linaro.org>

> ---
>   drivers/remoteproc/qcom_common.c      | 44 ++++++++++++++++++++++++++++++++++-
>   include/linux/remoteproc/qcom_rproc.h | 16 +++++++++++++
>   2 files changed, 59 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
> index 658f2ca..0848bf1 100644
> --- a/drivers/remoteproc/qcom_common.c
> +++ b/drivers/remoteproc/qcom_common.c
> @@ -262,6 +262,44 @@ 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 qcom_ssr_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = false,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 QCOM_SSR_BEFORE_POWERUP, &data);
> +	return 0;
> +}
> +
> +static int ssr_notify_start(struct rproc_subdev *subdev)
> +{
> +	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> +	struct qcom_ssr_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = false,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 QCOM_SSR_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 qcom_ssr_notif_data data = {
> +		.name = ssr->info->name,
> +		.crashed = crashed,
> +	};
> +
> +	srcu_notifier_call_chain(&ssr->info->notifier_list,
> +				 QCOM_SSR_BEFORE_SHUTDOWN, &data);
> +}
> +
>   static void ssr_notify_unprepare(struct rproc_subdev *subdev)
>   {
>   	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
> @@ -270,7 +308,8 @@ 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,
> +				 QCOM_SSR_AFTER_SHUTDOWN, &data);
>   }
>   
>   /**
> @@ -294,6 +333,9 @@ void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
>   	}
>   
>   	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 58422b1..83ac8e8 100644
> --- a/include/linux/remoteproc/qcom_rproc.h
> +++ b/include/linux/remoteproc/qcom_rproc.h
> @@ -5,6 +5,22 @@ struct notifier_block;
>   
>   #if IS_ENABLED(CONFIG_QCOM_RPROC_COMMON)
>   
> +/**
> + * enum qcom_ssr_notif_type - Startup/Shutdown events related to a remoteproc
> + * processor.
> + *
> + * @QCOM_SSR_BEFORE_POWERUP:	Remoteproc about to start (prepare stage)
> + * @QCOM_SSR_AFTER_POWERUP:	Remoteproc is running (start stage)
> + * @QCOM_SSR_BEFORE_SHUTDOWN:	Remoteproc crashed or shutting down (stop stage)
> + * @QCOM_SSR_AFTER_SHUTDOWN:	Remoteproc is down (unprepare stage)
> + */
> +enum qcom_ssr_notif_type {
> +	QCOM_SSR_BEFORE_POWERUP,
> +	QCOM_SSR_AFTER_POWERUP,
> +	QCOM_SSR_BEFORE_SHUTDOWN,
> +	QCOM_SSR_AFTER_SHUTDOWN,
> +};
> +
>   struct qcom_ssr_notif_data {
>   	const char *name;
>   	bool crashed;
>