linux-kernel - RE: [PATCH V2] remoteproc: support self recovery after rproc crash

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Date:   Mon, 7 Feb 2022 01:31:07 +0000
From:   Peng Fan <peng.fan@....com>
To:     "Peng Fan (OSS)" <peng.fan@....nxp.com>,
        "bjorn.andersson@...aro.org" <bjorn.andersson@...aro.org>,
        "mathieu.poirier@...aro.org" <mathieu.poirier@...aro.org>,
        "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH V2] remoteproc: support self recovery after rproc crash

> Subject: [PATCH V2] remoteproc: support self recovery after rproc crash

Any comments?

Thanks,
Peng.

> 
> From: Peng Fan <peng.fan@....com>
> 
> Current logic only support main processor to stop/start the remote processor
> after rproc crash. However to SoC, such as i.MX8QM/QXP, the remote
> processor could do self recovery after crash and trigger watchdog reboot. It
> does not need main processor to load image, stop/start M4 core.
> 
> This patch add a new flag to indicate whether the SoC has self recovery
> capability. And introduce two functions: rproc_self_recovery,
> rproc_assisted_recovery for the two cases. Assisted recovery is as before, let
> main processor to help recovery, while self recovery is recover itself withou
> help. To self recovery, we only do detach and attach.
> 
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
> 
> V2:
>  Nothing change in V2.
>  Only move this patch out from
>  https://patchwork.kernel.org/project/linux-remoteproc/list/?series=604364
> 
>  drivers/remoteproc/remoteproc_core.c | 66 ++++++++++++++++++++--------
>  include/linux/remoteproc.h           |  2 +
>  2 files changed, 49 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> index 69f51acf235e..4bd5544dab8f 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1887,6 +1887,49 @@ static int __rproc_detach(struct rproc *rproc)
>  	return 0;
>  }
> 
> +static int rproc_self_recovery(struct rproc *rproc) {
> +	int ret;
> +
> +	mutex_unlock(&rproc->lock);
> +	ret = rproc_detach(rproc);
> +	mutex_lock(&rproc->lock);
> +	if (ret)
> +		return ret;
> +
> +	if (atomic_inc_return(&rproc->power) > 1)
> +		return 0;
> +	return rproc_attach(rproc);
> +}
> +
> +static int rproc_assisted_recovery(struct rproc *rproc) {
> +	const struct firmware *firmware_p;
> +	struct device *dev = &rproc->dev;
> +	int ret;
> +
> +	ret = rproc_stop(rproc, true);
> +	if (ret)
> +		return ret;
> +
> +	/* generate coredump */
> +	rproc->ops->coredump(rproc);
> +
> +	/* load firmware */
> +	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> +	if (ret < 0) {
> +		dev_err(dev, "request_firmware failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* boot the remote processor up again */
> +	ret = rproc_start(rproc, firmware_p);
> +
> +	release_firmware(firmware_p);
> +
> +	return ret;
> +}
> +
>  /**
>   * rproc_trigger_recovery() - recover a remoteproc
>   * @rproc: the remote processor
> @@ -1901,7 +1944,6 @@ static int __rproc_detach(struct rproc *rproc)
>   */
>  int rproc_trigger_recovery(struct rproc *rproc)  {
> -	const struct firmware *firmware_p;
>  	struct device *dev = &rproc->dev;
>  	int ret;
> 
> @@ -1915,24 +1957,10 @@ int rproc_trigger_recovery(struct rproc *rproc)
> 
>  	dev_err(dev, "recovering %s\n", rproc->name);
> 
> -	ret = rproc_stop(rproc, true);
> -	if (ret)
> -		goto unlock_mutex;
> -
> -	/* generate coredump */
> -	rproc->ops->coredump(rproc);
> -
> -	/* load firmware */
> -	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> -	if (ret < 0) {
> -		dev_err(dev, "request_firmware failed: %d\n", ret);
> -		goto unlock_mutex;
> -	}
> -
> -	/* boot the remote processor up again */
> -	ret = rproc_start(rproc, firmware_p);
> -
> -	release_firmware(firmware_p);
> +	if (rproc->self_recovery)
> +		ret = rproc_self_recovery(rproc);
> +	else
> +		ret = rproc_assisted_recovery(rproc);
> 
>  unlock_mutex:
>  	mutex_unlock(&rproc->lock);
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index
> e0600e1e5c17..b32ef46f8aa4 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -529,6 +529,7 @@ struct rproc_dump_segment {
>   * @elf_machine: firmware ELF machine
>   * @cdev: character device of the rproc
>   * @cdev_put_on_release: flag to indicate if remoteproc should be
> shutdown on @char_dev release
> + * @self_recovery: flag to indicate if remoteproc support self recovery
>   */
>  struct rproc {
>  	struct list_head node;
> @@ -568,6 +569,7 @@ struct rproc {
>  	u16 elf_machine;
>  	struct cdev cdev;
>  	bool cdev_put_on_release;
> +	bool self_recovery;
>  };
> 
>  /**
> --
> 2.25.1