Re: [PATCH v6 05/16] remoteproc: Add new get_loaded_rsc_table() to rproc_ops

[Mathieu Poirier]

On Fri, Feb 26, 2021 at 05:14:36PM +0100, Arnaud POULIQUEN wrote:
> Hi Mathieu,
> 

Good morning,

> On 2/24/21 12:35 AM, Mathieu Poirier wrote:
> > Add a 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>
> > ---
> > New for V6:
> > - Don't return an error if a resource table doesn't exist.
> > ---
> > 
> >  drivers/remoteproc/remoteproc_core.c     | 32 ++++++++++++++++++++++++
> >  drivers/remoteproc/remoteproc_internal.h | 10 ++++++++
> >  include/linux/remoteproc.h               |  6 ++++-
> >  3 files changed, 47 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index 8c7e9f1d50d7..0012b7bdce24 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1537,6 +1537,32 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> >  	return ret;
> >  }
> >  
> > +static int rproc_set_loaded_rsc_table(struct rproc *rproc)
> > +{
> > +	struct resource_table *table_ptr;
> > +	struct device *dev = &rproc->dev;
> > +	size_t table_sz;
> > +	int ret;
> > +
> > +	table_ptr = rproc_get_loaded_rsc_table(rproc, &table_sz);
> > +	if (!table_ptr) {
> > +		/* Not having a resource table is acceptable */
> > +		return 0;
> 
> Would it be an over protection to set rproc->table_ptr to NULL here?
> 

I thought about that too but since memory for @rproc is allocated with kzalloc()
it wouldn't provide anything more. 

> else
> 
> Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
> 
> Thanks,
> Arnaud
> 
> > +	}
> > +
> > +	if (IS_ERR(table_ptr)) {
> > +		ret = PTR_ERR(table_ptr);
> > +		dev_err(dev, "can't load resource table: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	rproc->cached_table = NULL;
> > +	rproc->table_ptr = table_ptr;
> > +	rproc->table_sz = table_sz;
> > +
> > +	return 0;
> > +}
> > +
> >  /*
> >   * Attach to remote processor - similar to rproc_fw_boot() but without
> >   * the steps that deal with the firmware image.
> > @@ -1556,6 +1582,12 @@ static int rproc_attach(struct rproc *rproc)
> >  		return ret;
> >  	}
> >  
> > +	ret = rproc_set_loaded_rsc_table(rproc);
> > +	if (ret) {
> > +		dev_err(dev, "can't load resource table: %d\n", ret);
> > +		goto disable_iommu;
> > +	}
> > +
> >  	/* reset max_notifyid */
> >  	rproc->max_notifyid = -1;
> >  
> > diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> > index c34002888d2c..4f73aac7e60d 100644
> > --- a/drivers/remoteproc/remoteproc_internal.h
> > +++ b/drivers/remoteproc/remoteproc_internal.h
> > @@ -177,6 +177,16 @@ struct resource_table *rproc_find_loaded_rsc_table(struct rproc *rproc,
> >  	return NULL;
> >  }
> >  
> > +static inline
> > +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);
> > +
> > +	return NULL;
> > +}
> > +
> >  static inline
> >  bool rproc_u64_fit_in_size_t(u64 val)
> >  {
> > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > index 6b0a0ed30a03..51538a7d120d 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
> > @@ -390,6 +392,8 @@ struct rproc_ops {
> >  			  int offset, int avail);
> >  	struct resource_table *(*find_loaded_rsc_table)(
> >  				struct rproc *rproc, const struct firmware *fw);
> > +	struct resource_table *(*get_loaded_rsc_table)(
> > +				struct rproc *rproc, size_t *size);
> >  	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);
> >