[PATCH 2/6] drm: add drm_gem_object_is_shared_for_memory_stats() helper

[Hamza Mahfooz]

On 1/30/24 11:12, Alex Deucher wrote:
> Add a helper so that drm drivers can consistently report
> shared status via the fdinfo shared memory stats interface.
> 
> In addition to handle count, show buffers as shared if they
> are shared via dma-buf as well (e.g., shared with v4l or some
> other subsystem).
> 
> Link: https://lore.kernel.org/all/20231207180225.439482-1-alexander.deucher@amd.com/
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/drm_gem.c | 16 ++++++++++++++++
>   include/drm/drm_gem.h     |  1 +
>   2 files changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 44a948b80ee1..71b5f628d828 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -1506,3 +1506,19 @@ int drm_gem_evict(struct drm_gem_object *obj)
>   	return 0;
>   }
>   EXPORT_SYMBOL(drm_gem_evict);
> +
> +/**
> + * drm_gem_object_is_shared_for_memory_stats - helper for shared memory stats
> + *
> + * This helper should only be used for fdinfo shared memory stats to determine
> + * if a GEM object is shared.
> + *
> + * @obj: obj in question
> + */
> +bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj)
> +{
> +	if ((obj->handle_count > 1) || obj->dma_buf)
> +		return true;
> +	return false;

nit: you can simplify this to:
	return (obj->handle_count > 1) || obj->dma_buf;

(It maybe worth just inlining this to drm_gem.h).

> +}
> +EXPORT_SYMBOL(drm_gem_object_is_shared_for_memory_stats);
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 369505447acd..86a9c696f038 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -552,6 +552,7 @@ unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
>   			       bool (*shrink)(struct drm_gem_object *obj));
>   
>   int drm_gem_evict(struct drm_gem_object *obj);
> +bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj);
>   
>   #ifdef CONFIG_LOCKDEP
>   /**
-- 
Hamza