Re: [PATCH 2/2] drm/vc4: replace obj lookup steps with drm_gem_objects_lookup

[André Almeida <andrealmeid@xxxxxxxxxx>]

Hi Maíra,

Thank you for your patch, it really simplifies the code.

I think it's OK as it is, so I'll give my

    Reviewed-by: André Almeida <andrealmeid@xxxxxxxxxx>

for this series. But I would also like to notice that VC4 had some extra 
DRM_ log functions that the DRM version hasn't, so I think they would be 
a good addition in a different patch.

On 1/2/23 09:45, Maíra Canal wrote:
> As vc4_cl_lookup_bos() performs the same steps as drm_gem_objects_lookup(),
> replace the open-coded implementation in vc4 to simply use the DRM function.
>
> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
> ---
>   drivers/gpu/drm/vc4/vc4_gem.c | 43 ++---------------------------------
>   1 file changed, 2 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
> index d6985d067e34..03648f954985 100644
> --- a/drivers/gpu/drm/vc4/vc4_gem.c
> +++ b/drivers/gpu/drm/vc4/vc4_gem.c
> @@ -746,7 +746,6 @@ vc4_cl_lookup_bos(struct drm_device *dev,
>   		  struct vc4_exec_info *exec)
>   {
>   	struct drm_vc4_submit_cl *args = exec->args;
> -	uint32_t *handles;
>   	int ret = 0;
>   	int i;
>   
> @@ -760,43 +759,8 @@ vc4_cl_lookup_bos(struct drm_device *dev,
>   		return -EINVAL;
>   	}
>   
> -	exec->bo = kvmalloc_array(exec->bo_count,
> -				    sizeof(struct drm_gem_dma_object *),
> -				    GFP_KERNEL | __GFP_ZERO);
> -	if (!exec->bo) {
> -		DRM_ERROR("Failed to allocate validated BO pointers\n");
> -		return -ENOMEM;
> -	}
> -
> -	handles = kvmalloc_array(exec->bo_count, sizeof(uint32_t), GFP_KERNEL);
> -	if (!handles) {
> -		ret = -ENOMEM;
> -		DRM_ERROR("Failed to allocate incoming GEM handles\n");
> -		goto fail;
> -	}
> -
> -	if (copy_from_user(handles, u64_to_user_ptr(args->bo_handles),
> -			   exec->bo_count * sizeof(uint32_t))) {
> -		ret = -EFAULT;
> -		DRM_ERROR("Failed to copy in GEM handles\n");
> -		goto fail;
> -	}
> -
> -	spin_lock(&file_priv->table_lock);
> -	for (i = 0; i < exec->bo_count; i++) {
> -		struct drm_gem_object *bo = idr_find(&file_priv->object_idr,
> -						     handles[i]);
> -		if (!bo) {
> -			DRM_DEBUG("Failed to look up GEM BO %d: %d\n",
> -				  i, handles[i]);
> -			ret = -EINVAL;
> -			break;
> -		}
> -
> -		drm_gem_object_get(bo);
> -		exec->bo[i] = bo;
> -	}
> -	spin_unlock(&file_priv->table_lock);
> +	ret = drm_gem_objects_lookup(file_priv, u64_to_user_ptr(args->bo_handles),
> +				     exec->bo_count, &exec->bo);
>   
>   	if (ret)
>   		goto fail_put_bo;
> @@ -807,7 +771,6 @@ vc4_cl_lookup_bos(struct drm_device *dev,
>   			goto fail_dec_usecnt;
>   	}
>   
> -	kvfree(handles);
>   	return 0;
>   
>   fail_dec_usecnt:
> @@ -827,8 +790,6 @@ vc4_cl_lookup_bos(struct drm_device *dev,
>   	for (i = 0; i < exec->bo_count && exec->bo[i]; i++)
>   		drm_gem_object_put(exec->bo[i]);
>   
> -fail:
> -	kvfree(handles);
>   	kvfree(exec->bo);
>   	exec->bo = NULL;
>   	return ret;