Re: [PATCH 2/2] drm/xe/dma-buf: Use drm helper to detect dma-buf self-import

[Matthew Brost <matthew.brost@intel.com>]

On Mon, Oct 12, 2026 at 11:05:43AM -0700, Niranjana Vishwanathapura wrote:
> From: Farah Kassabri <farah.kassabri@intel.com>
> 
> Instead of driver-specific code, use the new drm helper
> drm_gem_prime_self_import() to detect self-import of a dma-buf in Xe.
> 
> Expose the helper within Xe as xe_dma_buf_to_gem() for future use.
> 
> Signed-off-by: Farah Kassabri <farah.kassabri@intel.com>
> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_dma_buf.c | 23 +++++++++++++----------
>  drivers/gpu/drm/xe/xe_dma_buf.h |  2 ++
>  2 files changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_dma_buf.c b/drivers/gpu/drm/xe/xe_dma_buf.c
> index 6a85b292dee7..4e1b447f4235 100644
> --- a/drivers/gpu/drm/xe/xe_dma_buf.c
> +++ b/drivers/gpu/drm/xe/xe_dma_buf.c
> @@ -239,6 +239,12 @@ static const struct dma_buf_ops xe_dmabuf_ops = {
>  	.vunmap = drm_gem_dmabuf_vunmap,
>  };
>  
> +struct drm_gem_object *xe_dma_buf_to_gem(struct drm_device *dev,
> +					 struct dma_buf *dma_buf)
> +{
> +	return drm_gem_prime_self_import(dev, dma_buf, &xe_dmabuf_ops);
> +}
> +
>  struct dma_buf *xe_gem_prime_export(struct drm_gem_object *obj, int flags)
>  {
>  	struct xe_bo *bo = gem_to_xe_bo(obj);
> @@ -372,17 +378,14 @@ struct drm_gem_object *xe_gem_prime_import(struct drm_device *dev,
>  	struct dma_buf_attachment *attach;
>  	struct drm_gem_object *obj;
>  
> -	if (dma_buf->ops == &xe_dmabuf_ops) {
> -		obj = dma_buf->priv;
> -		if (obj->dev == dev &&
> -		    !XE_TEST_ONLY(test && test->force_different_devices)) {
> -			/*
> -			 * Importing dmabuf exported from out own gem increases
> -			 * refcount on gem itself instead of f_count of dmabuf.
> -			 */
> -			drm_gem_object_get(obj);
> +	obj = xe_dma_buf_to_gem(dev, dma_buf);
> +	if (obj) {
> +		if (!XE_TEST_ONLY(test && test->force_different_devices))
>  			return obj;
> -		}
> +
> +		/* Test only: force different devices */
> +		drm_gem_object_put(obj);
> +		obj = NULL;
>  	}
>  
>  	/*
> diff --git a/drivers/gpu/drm/xe/xe_dma_buf.h b/drivers/gpu/drm/xe/xe_dma_buf.h
> index 861dd28a862c..d0c7893a5a6f 100644
> --- a/drivers/gpu/drm/xe/xe_dma_buf.h
> +++ b/drivers/gpu/drm/xe/xe_dma_buf.h
> @@ -8,6 +8,8 @@
>  
>  #include <drm/drm_gem.h>
>  
> +struct drm_gem_object *xe_dma_buf_to_gem(struct drm_device *dev,
> +					 struct dma_buf *dma_buf);
>  struct dma_buf *xe_gem_prime_export(struct drm_gem_object *obj, int flags);
>  struct drm_gem_object *xe_gem_prime_import(struct drm_device *dev,
>  					   struct dma_buf *dma_buf);
> -- 
> 2.43.0
>