Re: [PATCH v8 07/11] drm/gem: Get rid of *_with_mnt helpers

[Boris Brezillon <boris.brezillon@collabora.com>]

On Thu, 13 Nov 2025 18:00:03 +0100
Loïc Molinari <loic.molinari@collabora.com> wrote:

> drm_gem_object_init_with_mnt() and drm_gem_shmem_create_with_mnt() can
> be removed now that the drivers use the new drm_gem_huge_mnt_create()
> and drm_gem_has_huge_mnt() helpers.
> 
> v5:
> - use drm_gem_has_huge_mnt() helper
> - compile out shmem_file_setup_with_mnt() call in builds with
>   CONFIG_TRANSPARENT_HUGEPAGE=n
> 
> Signed-off-by: Loïc Molinari <loic.molinari@collabora.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
>  drivers/gpu/drm/drm_gem.c              | 38 ++++++++------------------
>  drivers/gpu/drm/drm_gem_shmem_helper.c | 38 ++++++--------------------
>  drivers/gpu/drm/v3d/v3d_bo.c           |  5 ----
>  include/drm/drm_gem.h                  |  3 --
>  include/drm/drm_gem_shmem_helper.h     |  3 --
>  5 files changed, 20 insertions(+), 67 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index bbca2ab9e9a5..1b0b5813acef 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -171,31 +171,33 @@ drm_gem_init(struct drm_device *dev)
>  }
>  
>  /**
> - * drm_gem_object_init_with_mnt - initialize an allocated shmem-backed GEM
> - * object in a given shmfs mountpoint
> + * drm_gem_object_init - initialize an allocated shmem-backed GEM object
>   *
>   * @dev: drm_device the object should be initialized for
>   * @obj: drm_gem_object to initialize
>   * @size: object size
> - * @gemfs: tmpfs mount where the GEM object will be created. If NULL, use
> - * the usual tmpfs mountpoint (`shm_mnt`).
>   *
>   * Initialize an already allocated GEM object of the specified size with
> - * shmfs backing store.
> + * shmfs backing store. A huge mountpoint can be used by calling
> + * drm_gem_huge_mnt_create() beforehand.
>   */
> -int drm_gem_object_init_with_mnt(struct drm_device *dev,
> -				 struct drm_gem_object *obj, size_t size,
> -				 struct vfsmount *gemfs)
> +int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj,
> +			size_t size)
>  {
>  	struct file *filp;
>  
>  	drm_gem_private_object_init(dev, obj, size);
>  
> -	if (gemfs)
> -		filp = shmem_file_setup_with_mnt(gemfs, "drm mm object", size,
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> +	if (drm_gem_has_huge_mnt(dev))
> +		filp = shmem_file_setup_with_mnt(dev->huge_mnt,
> +						 "drm mm object", size,
>  						 VM_NORESERVE);
>  	else
>  		filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
> +#else
> +	filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
> +#endif

I keep thinking it'd be simpler with a drm_gem_get_huge_mnt() helper:

static inline struct vfsmount *
drm_gem_get_huge_mnt(struct drm_device *dev)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	return dev->huge_mnt;
#else
	return NULL;
#endif
}

so we can avoid those #ifdef CONFIG_TRANSPARENT_HUGEPAGE in a few other
places.

For this one that would give you something like:

	if (drm_gem_get_huge_mnt(dev))
		filp = shmem_file_setup_with_mnt(drm_gem_get_huge_mnt(dev),
						 "drm mm object", size,
						 VM_NORESERVE);
	else
		filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);

>  
>  	if (IS_ERR(filp))
>  		return PTR_ERR(filp);
> @@ -204,22 +206,6 @@ int drm_gem_object_init_with_mnt(struct drm_device *dev,
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL(drm_gem_object_init_with_mnt);
> -
> -/**
> - * drm_gem_object_init - initialize an allocated shmem-backed GEM object
> - * @dev: drm_device the object should be initialized for
> - * @obj: drm_gem_object to initialize
> - * @size: object size
> - *
> - * Initialize an already allocated GEM object of the specified size with
> - * shmfs backing store.
> - */
> -int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj,
> -			size_t size)
> -{
> -	return drm_gem_object_init_with_mnt(dev, obj, size, NULL);
> -}
>  EXPORT_SYMBOL(drm_gem_object_init);
>  
>  /**
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 81f4ac7cb8f6..43a80f3fcfd9 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -50,7 +50,7 @@ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {
>  };
>  
>  static int __drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_object *shmem,
> -				size_t size, bool private, struct vfsmount *gemfs)
> +				size_t size, bool private)
>  {
>  	struct drm_gem_object *obj = &shmem->base;
>  	int ret = 0;
> @@ -62,7 +62,7 @@ static int __drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_obj
>  		drm_gem_private_object_init(dev, obj, size);
>  		shmem->map_wc = false; /* dma-buf mappings use always writecombine */
>  	} else {
> -		ret = drm_gem_object_init_with_mnt(dev, obj, size, gemfs);
> +		ret = drm_gem_object_init(dev, obj, size);
>  	}
>  	if (ret) {
>  		drm_gem_private_object_fini(obj);
> @@ -103,13 +103,12 @@ static int __drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_obj
>   */
>  int drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_object *shmem, size_t size)
>  {
> -	return __drm_gem_shmem_init(dev, shmem, size, false, NULL);
> +	return __drm_gem_shmem_init(dev, shmem, size, false);
>  }
>  EXPORT_SYMBOL_GPL(drm_gem_shmem_init);
>  
>  static struct drm_gem_shmem_object *
> -__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private,
> -		       struct vfsmount *gemfs)
> +__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
>  {
>  	struct drm_gem_shmem_object *shmem;
>  	struct drm_gem_object *obj;
> @@ -129,7 +128,7 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private,
>  		obj = &shmem->base;
>  	}
>  
> -	ret = __drm_gem_shmem_init(dev, shmem, size, private, gemfs);
> +	ret = __drm_gem_shmem_init(dev, shmem, size, private);
>  	if (ret) {
>  		kfree(obj);
>  		return ERR_PTR(ret);
> @@ -150,31 +149,10 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private,
>   */
>  struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)
>  {
> -	return __drm_gem_shmem_create(dev, size, false, NULL);
> +	return __drm_gem_shmem_create(dev, size, false);
>  }
>  EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
>  
> -/**
> - * drm_gem_shmem_create_with_mnt - Allocate an object with the given size in a
> - * given mountpoint
> - * @dev: DRM device
> - * @size: Size of the object to allocate
> - * @gemfs: tmpfs mount where the GEM object will be created
> - *
> - * This function creates a shmem GEM object in a given tmpfs mountpoint.
> - *
> - * Returns:
> - * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
> - * error code on failure.
> - */
> -struct drm_gem_shmem_object *drm_gem_shmem_create_with_mnt(struct drm_device *dev,
> -							   size_t size,
> -							   struct vfsmount *gemfs)
> -{
> -	return __drm_gem_shmem_create(dev, size, false, gemfs);
> -}
> -EXPORT_SYMBOL_GPL(drm_gem_shmem_create_with_mnt);
> -
>  /**
>   * drm_gem_shmem_release - Release resources associated with a shmem GEM object.
>   * @shmem: shmem GEM object
> @@ -861,7 +839,7 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
>  	size_t size = PAGE_ALIGN(attach->dmabuf->size);
>  	struct drm_gem_shmem_object *shmem;
>  
> -	shmem = __drm_gem_shmem_create(dev, size, true, NULL);
> +	shmem = __drm_gem_shmem_create(dev, size, true);
>  	if (IS_ERR(shmem))
>  		return ERR_CAST(shmem);
>  
> @@ -909,7 +887,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
>  
>  	size = PAGE_ALIGN(attach->dmabuf->size);
>  
> -	shmem = __drm_gem_shmem_create(dev, size, true, NULL);
> +	shmem = __drm_gem_shmem_create(dev, size, true);
>  	if (IS_ERR(shmem)) {
>  		ret = PTR_ERR(shmem);
>  		goto fail_detach;
> diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c
> index 3bc714ea6392..d3b68ee05dbb 100644
> --- a/drivers/gpu/drm/v3d/v3d_bo.c
> +++ b/drivers/gpu/drm/v3d/v3d_bo.c
> @@ -153,12 +153,7 @@ struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
>  	struct v3d_bo *bo;
>  	int ret;
>  
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -	shmem_obj = drm_gem_shmem_create_with_mnt(dev, unaligned_size,
> -						  dev->huge_mnt);
> -#else
>  	shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
> -#endif
>  	if (IS_ERR(shmem_obj))
>  		return ERR_CAST(shmem_obj);
>  	bo = to_v3d_bo(&shmem_obj->base);
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 58fa1e6b9773..75276a12208e 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -529,9 +529,6 @@ void drm_gem_object_release(struct drm_gem_object *obj);
>  void drm_gem_object_free(struct kref *kref);
>  int drm_gem_object_init(struct drm_device *dev,
>  			struct drm_gem_object *obj, size_t size);
> -int drm_gem_object_init_with_mnt(struct drm_device *dev,
> -				 struct drm_gem_object *obj, size_t size,
> -				 struct vfsmount *gemfs);
>  void drm_gem_private_object_init(struct drm_device *dev,
>  				 struct drm_gem_object *obj, size_t size);
>  void drm_gem_private_object_fini(struct drm_gem_object *obj);
> diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
> index 589f7bfe7506..6b6478f5ca24 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -109,9 +109,6 @@ struct drm_gem_shmem_object {
>  
>  int drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_object *shmem, size_t size);
>  struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
> -struct drm_gem_shmem_object *drm_gem_shmem_create_with_mnt(struct drm_device *dev,
> -							   size_t size,
> -							   struct vfsmount *gemfs);
>  void drm_gem_shmem_release(struct drm_gem_shmem_object *shmem);
>  void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem);
>