Re: [PATCH v4 05/17] remoteproc: Add new get_loaded_rsc_table() remoteproc operation

[Mathieu Poirier]

On Wed, Jan 27, 2021 at 09:44:28AM +0100, Arnaud POULIQUEN wrote:
> Hi Mathieu,
> 
> Come back on you series...
> 
> On 12/18/20 6:32 PM, Mathieu Poirier wrote:
> > Add an new get_loaded_rsc_table() operation in order to support
> > scenarios where the remoteproc core has booted a remote processor
> > and detaches from it.  When re-attaching to the remote processor,
> > the core needs to know where the resource table has been placed
> > in memory.
> > 
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > ---
> >  drivers/remoteproc/remoteproc_core.c     | 6 ++++++
> >  drivers/remoteproc/remoteproc_internal.h | 8 ++++++++
> >  include/linux/remoteproc.h               | 5 ++++-
> >  3 files changed, 18 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index d0f6b39b56f9..3d87c910aca7 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1556,6 +1556,12 @@ static int rproc_attach(struct rproc *rproc)
> >  		return ret;
> >  	}
> >  
> > +	ret = rproc_get_loaded_rsc_table(rproc);
> > +	if (ret) {
> > +		dev_err(dev, "can't load resource table: %d\n", ret);
> > +		goto disable_iommu;
> > +	}
> > +
> 
> This function is rather ambiguous. Without the example of stm32, it is not
> obvious what the platform driver has to do in this ops. And the update of rproc
> in the in the core instead of in platform driver seems to me more reliable.
> 
> Here is a suggestion considering that ->cached_table is always NULL:
> 
> 
> struct resource_table *rproc_get_loaded_rsc_table(struct rproc *rproc,
>                                                   size_t* size)
> {
> 
> 	if (rproc->ops->get_loaded_rsc_table) {
> 		return rproc->ops->get_loaded_rsc_table(rproc, size);
> 
> 	*size = 0;
> 	return NULL;
> }
> 
> then in rproc_attach:
> 
> 	table_ptr = rproc_get_loaded_rsc_table(rproc, &tab_size);
> 	if (PTR_ERR(table_ptr) {
> 		dev_err(dev, "can't load resource table: %d\n", ret);
> 		goto disable_iommu;
> 	}
>  	rproc->cached_table = NULL;
>  	rproc->table_ptr = table_ptr;
>  	rproc->table_sz = table_sz;
>

Much better yes, thanks for the suggestion.
 
> 
> Thanks,
> Arnaud
> 
> >  	/* reset max_notifyid */
> >  	rproc->max_notifyid = -1;
> >  
> > diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> > index c34002888d2c..c48b301d6ad1 100644
> > --- a/drivers/remoteproc/remoteproc_internal.h
> > +++ b/drivers/remoteproc/remoteproc_internal.h
> > @@ -177,6 +177,14 @@ struct resource_table *rproc_find_loaded_rsc_table(struct rproc *rproc,
> >  	return NULL;
> >  }
> >  
> > +static inline int rproc_get_loaded_rsc_table(struct rproc *rproc)
> > +{
> > +	if (rproc->ops->get_loaded_rsc_table)
> > +		return rproc->ops->get_loaded_rsc_table(rproc);
> > +
> > +	return 0;
> > +}
> > +
> >  static inline
> >  bool rproc_u64_fit_in_size_t(u64 val)
> >  {
> > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > index 3fa3ba6498e8..571615e77e6f 100644
> > --- a/include/linux/remoteproc.h
> > +++ b/include/linux/remoteproc.h
> > @@ -368,7 +368,9 @@ enum rsc_handling_status {
> >   * RSC_HANDLED if resource was handled, RSC_IGNORED if not handled and a
> >   * negative value on error
> >   * @load_rsc_table:	load resource table from firmware image
> > - * @find_loaded_rsc_table: find the loaded resouce table
> > + * @find_loaded_rsc_table: find the loaded resource table from firmware image
> > + * @get_loaded_rsc_table: get resource table installed in memory
> > + *			  by external entity
> >   * @load:		load firmware to memory, where the remote processor
> >   *			expects to find it
> >   * @sanity_check:	sanity check the fw image
> > @@ -389,6 +391,7 @@ struct rproc_ops {
> >  			  int offset, int avail);
> >  	struct resource_table *(*find_loaded_rsc_table)(
> >  				struct rproc *rproc, const struct firmware *fw);
> > +	int (*get_loaded_rsc_table)(struct rproc *rproc);
> >  	int (*load)(struct rproc *rproc, const struct firmware *fw);
> >  	int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
> >  	u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> >