On Tue, Jan 11, 2022 at 11:33:27AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
>
> 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@xxxxxxx>
> ---
> 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);
The problem of how to handle crash recoveries for processors that have been
attached to is difficult. Finding a solution for that should be on a patchset
of its own so that people can provide input.
>
> 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
>
