Re: [PATCH v15 3/8] remoteproc: Introduce load_fw and release_fw optional operation

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Thu, Nov 28, 2024 at 09:42:10AM +0100, Arnaud Pouliquen wrote:
> This patch updates the rproc_ops structures to include two new optional
> operations.
> 
> - The load_fw() op is responsible for loading the remote processor
> non-ELF firmware image before starting the boot sequence. This ops will
> be used, for instance, to call OP-TEE to  authenticate an load the firmware
> image before accessing to its resources (a.e the resource table)
> 
> - The release_fw op is responsible for releasing the remote processor
> firmware image. For instance to clean memories.
> The ops is called in the following cases:
>  - An error occurs between the loading of the firmware image and the
>    start of the remote processor.
>  - after stopping the remote processor.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> ---
> Update vs version V13:
> - Rework the commit to introduce load_fw() op.
> - remove rproc_release_fw() call from  rproc_start() as called in
>   rproc_boot() and rproc_boot_recovery() in case of error.
> - create rproc_load_fw() and rproc_release_fw() internal functions.
> ---
>  drivers/remoteproc/remoteproc_core.c     | 16 +++++++++++++++-
>  drivers/remoteproc/remoteproc_internal.h | 14 ++++++++++++++
>  include/linux/remoteproc.h               |  6 ++++++
>  3 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index ace11ea17097..8df4b2c59bb6 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1488,6 +1488,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>  	kfree(rproc->cached_table);
>  	rproc->cached_table = NULL;
>  	rproc->table_ptr = NULL;
> +	rproc_release_fw(rproc);

This is not needed since rproc_release_fw() is called in rproc_boot().

>  unprepare_rproc:
>  	/* release HW resources if needed */
>  	rproc_unprepare_device(rproc);
> @@ -1855,8 +1856,14 @@ static int rproc_boot_recovery(struct rproc *rproc)
>  		return ret;
>  	}
>  
> +	ret = rproc_load_fw(rproc, firmware_p);
> +	if (ret)
> +		return ret;
> +
>  	/* boot the remote processor up again */
>  	ret = rproc_start(rproc, firmware_p);
> +	if (ret)
> +		rproc_release_fw(rproc);
>  
>  	release_firmware(firmware_p);
>  
> @@ -1997,7 +2004,13 @@ int rproc_boot(struct rproc *rproc)
>  			goto downref_rproc;
>  		}
>  
> +		ret = rproc_load_fw(rproc, firmware_p);
> +		if (ret)
> +			goto downref_rproc;

In case of error the firmware is not released.

> +
>  		ret = rproc_fw_boot(rproc, firmware_p);
> +		if (ret)
> +			rproc_release_fw(rproc);
>  
>  		release_firmware(firmware_p);
>  	}
> @@ -2071,6 +2084,7 @@ int rproc_shutdown(struct rproc *rproc)
>  	kfree(rproc->cached_table);
>  	rproc->cached_table = NULL;
>  	rproc->table_ptr = NULL;
> +	rproc_release_fw(rproc);

Please move this after rproc_disable_iommu().


>  out:
>  	mutex_unlock(&rproc->lock);
>  	return ret;
> @@ -2471,7 +2485,7 @@ static int rproc_alloc_ops(struct rproc *rproc, const struct rproc_ops *ops)
>  	if (!rproc->ops->coredump)
>  		rproc->ops->coredump = rproc_coredump;
>  
> -	if (rproc->ops->load)
> +	if (rproc->ops->load || rproc->ops->load_fw)
>  		return 0;
>  
>  	/* Default to ELF loader if no load function is specified */
> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> index 0cd09e67ac14..2104ca449178 100644
> --- a/drivers/remoteproc/remoteproc_internal.h
> +++ b/drivers/remoteproc/remoteproc_internal.h
> @@ -221,4 +221,18 @@ bool rproc_u64_fit_in_size_t(u64 val)
>  	return (val <= (size_t) -1);
>  }
>  
> +static inline void rproc_release_fw(struct rproc *rproc)
> +{
> +	if (rproc->ops->release_fw)
> +		rproc->ops->release_fw(rproc);
> +}
> +
> +static inline int rproc_load_fw(struct rproc *rproc, const struct firmware *fw)
> +{
> +	if (rproc->ops->load_fw)
> +		return rproc->ops->load_fw(rproc, fw);
> +
> +	return 0;
> +}
> +
>  #endif /* REMOTEPROC_INTERNAL_H */
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 2e0ddcb2d792..ba6fd560f7ba 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -381,6 +381,10 @@ enum rsc_handling_status {
>   * @panic:	optional callback to react to system panic, core will delay
>   *		panic at least the returned number of milliseconds
>   * @coredump:	  collect firmware dump after the subsystem is shutdown
> + * @load_fw:	optional function to load non-ELF firmware image to memory, where the remote

Round this down to 80 characters please.  Here having a longer line doesn't
improve readability.

> + *		processor expects to find it.
> + * @release_fw:	optional function to release the firmware image from memories.
> + *		This function is called after stopping the remote processor or in case of error

Same.

More comments tomorrow or later during the week.

Thanks,
Mathieu

>   */
>  struct rproc_ops {
>  	int (*prepare)(struct rproc *rproc);
> @@ -403,6 +407,8 @@ struct rproc_ops {
>  	u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
>  	unsigned long (*panic)(struct rproc *rproc);
>  	void (*coredump)(struct rproc *rproc);
> +	int (*load_fw)(struct rproc *rproc, const struct firmware *fw);
> +	void (*release_fw)(struct rproc *rproc);
>  };
>  
>  /**
> -- 
> 2.25.1
>