On Tue, Aug 19, 2025 at 10:47:45PM +0530, Pavan Kondeti wrote:
> On Tue, Aug 19, 2025 at 10:24:36PM +0530, Mukesh Ojha wrote:
> > Currently, remoteproc and non-remoteproc subsystems use different
> > variants of the MDT loader helper API, primarily due to the handling of
> > the metadata context. Remoteproc subsystems retain this context until
> > authentication and reset, while non-remoteproc subsystems (e.g., video,
> > graphics) do not require it.
> >
> > Unify the metadata loading process for both remoteproc and
> > non-remoteproc subsystems by introducing a dedicated PAS context
> > initialization function.
> >
> > By introducing qcom_scm_pas_ctx_init(), we can standardize the API usage
> > across subsystems and reduce the number of parameters passed to MDT
> > loader functions, improving code clarity and maintainability.
> >
> > Signed-off-by: Mukesh Ojha <[email protected]>
> > ---
> > drivers/firmware/qcom/qcom_scm.c | 26 ++++++++++++++++++++++++++
> > include/linux/firmware/qcom/qcom_scm.h | 11 +++++++++++
> > 2 files changed, 37 insertions(+)
> >
> > diff --git a/drivers/firmware/qcom/qcom_scm.c
> > b/drivers/firmware/qcom/qcom_scm.c
> > index 96d5cf40a74c..33187d4f4aef 100644
> > --- a/drivers/firmware/qcom/qcom_scm.c
> > +++ b/drivers/firmware/qcom/qcom_scm.c
> > @@ -558,6 +558,32 @@ static void qcom_scm_set_download_mode(u32 dload_mode)
> > dev_err(__scm->dev, "failed to set download mode: %d\n", ret);
> > }
> >
> > +void *qcom_scm_pas_ctx_init(struct device *dev, u32 peripheral,
> > phys_addr_t mem_phys,
> > + size_t mem_size, bool save_mdt_ctx)
>
> Since we export this for other drivers/module, consider adding kerneldoc
> comments.
>
Sure.
> > +{
> > + struct qcom_scm_pas_ctx *ctx;
> > +
> > + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> > + if (!ctx)
> > + return NULL;
> > +
> > + ctx->dev = dev;
> > + ctx->peripheral = peripheral;
> > + ctx->mem_phys = mem_phys;
> > + ctx->mem_size = mem_size;
> > + ctx->save_mdt_ctx = save_mdt_ctx;
> > + ctx->metadata = NULL;
>
> This seems unnecessary.
Yes, it is redundant.
> > +
> > + if (save_mdt_ctx) {
> > + ctx->metadata = devm_kzalloc(dev, sizeof(*ctx->metadata),
> > GFP_KERNEL);
> > + if (!ctx->metadata)
> > + return NULL;
>
> Do we really need to pass this burden to the caller to pass save_mdt_ctx
> as true/false? What happens if we always keep metadata in qcom_scm_pas_ctx
> struct
> and let clients use it if needed.
>
Do not wanted to be aggressive like changing every driver which uses
qcom_mdt_load(), Hence, taken this safe approach of adapting the current
way.
Obviously, it is the one approach where I was looking to unify API's
across remoteproc or non-remoteproc subsystems and that's why I have
put comment in the 2/11 if we feel fine to do it for other drivers too.
> > + }
> > +
> > + return ctx;
> > +}
> > +EXPORT_SYMBOL_GPL(qcom_scm_pas_ctx_init);
>
> Is there an equivalant ctx_destroy() function? It would be confusing for
> drivers to call this in their probe and not doing anything upon error or
> in their bus::remove callbacks. I don't know if we really want to
> convert the whole function under devres or just provide a destroy
> callback.
>
I dont disagree., will wait for some more comments.
> > +
> > /**
> > * qcom_scm_pas_init_image() - Initialize peripheral authentication service
> > * state machine for a given peripheral, using the
> > diff --git a/include/linux/firmware/qcom/qcom_scm.h
> > b/include/linux/firmware/qcom/qcom_scm.h
> > index a55ca771286b..b7eb206561a9 100644
> > --- a/include/linux/firmware/qcom/qcom_scm.h
> > +++ b/include/linux/firmware/qcom/qcom_scm.h
> > @@ -72,6 +72,17 @@ struct qcom_scm_pas_metadata {
> > ssize_t size;
> > };
> >
> > +struct qcom_scm_pas_ctx {
> > + struct device *dev;
> > + u32 peripheral;
> > + phys_addr_t mem_phys;
> > + size_t mem_size;
> > + struct qcom_scm_pas_metadata *metadata;
> > + bool save_mdt_ctx;
>
> As mentioned above, can we just include qcom_scm_pas_metadata struct all
> the time?
>
> Thanks,
> Pavan
--
-Mukesh Ojha
