Re: [PATCH v4 2/9] remoteproc: Add new attach() remoteproc operation

From: Bjorn Andersson
Date: Mon Jun 22 2020 - 02:39:29 EST


On Mon 01 Jun 10:51 PDT 2020, Mathieu Poirier wrote:

> Add an new attach() operation in order to properly deal with
> scenarios where the remoteproc core needs to attach to a
> remote processor that has been booted by another entity.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
> drivers/remoteproc/remoteproc_internal.h | 8 ++++++++
> include/linux/remoteproc.h | 2 ++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> index 4ba7cb59d3e8..fc710866f8ce 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -79,6 +79,14 @@ static inline int rproc_unprepare_device(struct rproc *rproc)
> return 0;
> }
>
> +static inline int rproc_attach_device(struct rproc *rproc)
> +{
> + if (rproc->ops->attach)
> + return rproc->ops->attach(rproc);
> +
> + return 0;

Afaict we don't allow the registration of a remoteproc in DETACHED state
without an "attach" function specified and as such we shouldn't be able
to end up here.

On the other hand I think it would make sense to have a system where
"attach" simply just means bring up the communication with the remote
processor, so let's keep it as is and we can adjust it as necessary
later.

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Regards,
Bjorn

> +}
> +
> static inline
> int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw)
> {
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 21182ad2d059..bf6a310ba870 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -359,6 +359,7 @@ enum rsc_handling_status {
> * @unprepare: unprepare device after stop
> * @start: power on the device and boot it
> * @stop: power off the device
> + * @attach: attach to a device that his already powered up
> * @kick: kick a virtqueue (virtqueue id given as a parameter)
> * @da_to_va: optional platform hook to perform address translations
> * @parse_fw: parse firmware to extract information (e.g. resource table)
> @@ -379,6 +380,7 @@ struct rproc_ops {
> int (*unprepare)(struct rproc *rproc);
> int (*start)(struct rproc *rproc);
> int (*stop)(struct rproc *rproc);
> + int (*attach)(struct rproc *rproc);
> void (*kick)(struct rproc *rproc, int vqid);
> void * (*da_to_va)(struct rproc *rproc, u64 da, size_t len);
> int (*parse_fw)(struct rproc *rproc, const struct firmware *fw);
> --
> 2.20.1
>