[Intel-gfx] [PATCH v2 4/4] drm/vgem: use shmem helpers

Andi Shyti andi.shyti at intel.com
Thu Jun 3 18:42:00 UTC 2021


Hi Daniel,

> +/*
> + * This just sets wc mode for shmem helpers. vgem doesn't have any begin/end cpu
> + * access ioctls, there must use coherent memory or dma-buf sharing just wont
> + * work.
> + */
> +static struct drm_gem_object *vgem_gem_create_object(struct drm_device *dev, size_t size)
>  {
> -	struct drm_vgem_gem_object *obj;
> -	int npages;
> +	struct drm_gem_shmem_object *obj;
>  
> -	obj = __vgem_gem_create(dev, attach->dmabuf->size);
> -	if (IS_ERR(obj))
> -		return ERR_CAST(obj);
> -
> -	npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
> +	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> +	if (!obj)
> +		return NULL;
>  
> -	obj->table = sg;
> -	obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> -	if (!obj->pages) {
> -		__vgem_gem_destroy(obj);
> -		return ERR_PTR(-ENOMEM);
> -	}
> +	obj->base.funcs = &drm_gem_shmem_funcs;
> +	obj->map_wc = true;
>  
> -	obj->pages_pin_count++; /* perma-pinned */
> -	drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
>  	return &obj->base;

here you are allocating a bigger object than what you are
returning, in size. How does it get freed?

Andi


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