[PATCH v4 04/16] drm/vkms: Allow to configure the plane type via configfs

[Louis Chauvet]

Le 07/04/2025 à 10:14, José Expósito a écrit :
> From: Louis Chauvet <louis.chauvet at bootlin.com>
> 
> When a plane is created, add a `type` file to allow to set the type:
> 
>   - 0 overlay
>   - 1 primary
>   - 2 cursor

Reviewed-by: Louis Chauvet <louis.chauvet at bootlin.com>

> Signed-off-by: Louis Chauvet <louis.chauvet at bootlin.com>
> Co-developed-by: José Expósito <jose.exposito89 at gmail.com>
> Signed-off-by: José Expósito <jose.exposito89 at gmail.com>
> ---
>   Documentation/gpu/vkms.rst           |  5 +++
>   drivers/gpu/drm/vkms/vkms_configfs.c | 46 ++++++++++++++++++++++++++++
>   2 files changed, 51 insertions(+)
> 
> diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
> index bf23d0da33fe..a87e0925bebb 100644
> --- a/Documentation/gpu/vkms.rst
> +++ b/Documentation/gpu/vkms.rst
> @@ -84,6 +84,11 @@ Start by creating one or more planes::
>   
>     sudo mkdir /config/vkms/my-vkms/planes/plane0
>   
> +Planes have 1 configurable attribute:
> +
> +- type: Plane type: 0 overlay, 1 primary, 2 cursor (same values as those
> +  exposed by the "type" property of a plane)
> +
>   Once you are done configuring the VKMS instance, enable it::
>   
>     echo "1" | sudo tee /config/vkms/my-vkms/enabled
> diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
> index a7c705e00e4c..398755127759 100644
> --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> @@ -55,6 +55,51 @@ struct vkms_configfs_plane {
>   #define plane_item_to_vkms_configfs_plane(item) \
>   	container_of(to_config_group((item)), struct vkms_configfs_plane, group)
>   
> +static ssize_t plane_type_show(struct config_item *item, char *page)
> +{
> +	struct vkms_configfs_plane *plane;
> +	enum drm_plane_type type;
> +
> +	plane = plane_item_to_vkms_configfs_plane(item);
> +
> +	scoped_guard(mutex, &plane->dev->lock)
> +		type = vkms_config_plane_get_type(plane->config);
> +
> +	return sprintf(page, "%u", type);
> +}
> +
> +static ssize_t plane_type_store(struct config_item *item, const char *page,
> +				size_t count)
> +{
> +	struct vkms_configfs_plane *plane;
> +	enum drm_plane_type type;
> +
> +	plane = plane_item_to_vkms_configfs_plane(item);
> +
> +	if (kstrtouint(page, 10, &type))
> +		return -EINVAL;
> +
> +	if (type != DRM_PLANE_TYPE_OVERLAY && type != DRM_PLANE_TYPE_PRIMARY &&
> +	    type != DRM_PLANE_TYPE_CURSOR)
> +		return -EINVAL;
> +
> +	scoped_guard(mutex, &plane->dev->lock) {
> +		if (plane->dev->enabled)
> +			return -EBUSY;
> +
> +		vkms_config_plane_set_type(plane->config, type);
> +	}
> +
> +	return (ssize_t)count;
> +}
> +
> +CONFIGFS_ATTR(plane_, type);
> +
> +static struct configfs_attribute *plane_item_attrs[] = {
> +	&plane_attr_type,
> +	NULL,
> +};
> +
>   static void plane_release(struct config_item *item)
>   {
>   	struct vkms_configfs_plane *plane;
> @@ -74,6 +119,7 @@ static struct configfs_item_operations plane_item_operations = {
>   };
>   
>   static const struct config_item_type plane_item_type = {
> +	.ct_attrs	= plane_item_attrs,
>   	.ct_item_ops	= &plane_item_operations,
>   	.ct_owner	= THIS_MODULE,
>   };

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com