[PATCH 3/5] drm/udl: Add GEM object functions for free(), vmap(), and vunmap()

[Daniel Vetter]

On Thu, Oct 24, 2019 at 04:42:35PM +0200, Thomas Zimmermann wrote:
> Implementing vmap() and vunmap() of struct drm_gem_object_funcs is
> required by generic fbdev emulation. Supporting free() is easy as
> well. More udl-specific interfaces can probably be replaced by GEM
> object functions in later patches.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  drivers/gpu/drm/udl/udl_gem.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
> index 3ea0cd9ae2d6..6ca097c270d6 100644
> --- a/drivers/gpu/drm/udl/udl_gem.c
> +++ b/drivers/gpu/drm/udl/udl_gem.c
> @@ -11,6 +11,8 @@
>  
>  #include "udl_drv.h"
>  
> +static const struct drm_gem_object_funcs udl_gem_object_funcs;
> +
>  struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
>  					    size_t size)
>  {
> @@ -25,6 +27,7 @@ struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
>  		return NULL;
>  	}
>  
> +	obj->base.funcs = &udl_gem_object_funcs;
>  	obj->flags = UDL_BO_CACHEABLE;
>  	return obj;
>  }
> @@ -230,3 +233,34 @@ int udl_gem_mmap(struct drm_file *file, struct drm_device *dev,
>  	mutex_unlock(&udl->gem_lock);
>  	return ret;
>  }
> +
> +/*
> + * Helpers for struct drm_gem_object_funcs
> + */
> +
> +static void udl_gem_object_free(struct drm_gem_object *obj)
> +{
> +	udl_gem_free_object(obj);
> +}
> +
> +static void *udl_gem_object_vmap(struct drm_gem_object *obj)
> +{
> +	struct udl_gem_object *uobj = to_udl_bo(obj);
> +	int ret;
> +
> +	ret = udl_gem_vmap(uobj);
> +	if (ret)
> +		return ERR_PTR(ret);
> +	return uobj->vmapping;
> +}
> +
> +static void udl_gem_object_vunmap(struct drm_gem_object *obj, void *vaddr)
> +{
> +	return udl_gem_vunmap(to_udl_bo(obj));
> +}
> +
> +static const struct drm_gem_object_funcs udl_gem_object_funcs = {
> +	.free	= udl_gem_object_free,
> +	.vmap	= udl_gem_object_vmap,
> +	.vunmap	= udl_gem_object_vunmap,

Yeah this doesn't work, you need to refcount the vmap here I think. I'd
say simpler to first cut over to shmem helpers.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch