Re: [PATCH v4 05/15] mei: pxp: add command streamer API to the PXP driver

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Sep 08, 2022 at 05:16:02PM -0700, Daniele Ceraolo Spurio wrote:
> +static ssize_t mei_pxp_gsc_command(struct device *dev, u8 client_id, u32 fence_id,
> +				   struct scatterlist *sg_in, size_t total_in_len,
> +				   struct scatterlist *sg_out)
> +{
> +	struct mei_cl_device *cldev;
> +
> +	if (!dev || !sg_in || !sg_out)
> +		return -EINVAL;

How can these ever be NULL?  Doesn't the core control this, so why would
that happen?

Don't check for things that can never happen.

> +
> +	cldev = to_mei_cl_device(dev);
> +
> +	return mei_cldev_send_gsc_command(cldev, client_id, fence_id, sg_in, total_in_len, sg_out);
> +}
> +
>  static const struct i915_pxp_component_ops mei_pxp_ops = {
>  	.owner = THIS_MODULE,
>  	.send = mei_pxp_send_message,
>  	.recv = mei_pxp_receive_message,
> +	.gsc_command = mei_pxp_gsc_command,
>  };
>  
>  static int mei_component_master_bind(struct device *dev)
> diff --git a/include/drm/i915_pxp_tee_interface.h b/include/drm/i915_pxp_tee_interface.h
> index af593ec64469..a702b6ec17f7 100644
> --- a/include/drm/i915_pxp_tee_interface.h
> +++ b/include/drm/i915_pxp_tee_interface.h
> @@ -8,6 +8,7 @@
>  
>  #include <linux/mutex.h>
>  #include <linux/device.h>
> +struct scatterlist;
>  
>  /**
>   * struct i915_pxp_component_ops - ops for PXP services.
> @@ -23,6 +24,10 @@ struct i915_pxp_component_ops {
>  
>  	int (*send)(struct device *dev, const void *message, size_t size);
>  	int (*recv)(struct device *dev, void *buffer, size_t size);
> +	ssize_t (*gsc_command)(struct device *dev, u8 client_id, u32 fence_id,
> +			       struct scatterlist *sg_in, size_t total_in_len,
> +			       struct scatterlist *sg_out);

No documentation for this new callback?

The build should give you are warning :(