drm/vkms: Allow to configure multiple planes via configfs

Create a default subgroup at /config/vkms/planes to allow to create as
many planes as required.

Tested-by: Mark Yacoub <markyacoub@google.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Co-developed-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20251016175618.10051-4-jose.exposito89@gmail.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
This commit is contained in:
Louis Chauvet
2025-10-16 19:56:05 +02:00
committed by Luca Ceresoli
parent 13fc9b9745
commit 2f1734ba27
2 changed files with 103 additions and 1 deletions

View File

@@ -71,6 +71,19 @@ By default, the instance is disabled::
cat /config/vkms/my-vkms/enabled
0
And directories are created for each configurable item of the display pipeline::
tree /config/vkms/my-vkms
├── enabled
└── planes
To add items to the display pipeline, create one or more directories under the
available paths.
Start by creating one or more planes::
sudo mkdir /config/vkms/my-vkms/planes/plane0
Once you are done configuring the VKMS instance, enable it::
echo "1" | sudo tee /config/vkms/my-vkms/enabled
@@ -79,8 +92,9 @@ Finally, you can remove the VKMS instance disabling it::
echo "0" | sudo tee /config/vkms/my-vkms/enabled
And removing the top level directory::
And removing the top level directory and its subdirectories::
sudo rmdir /config/vkms/my-vkms/planes/*
sudo rmdir /config/vkms/my-vkms
Testing With IGT

View File

@@ -16,6 +16,7 @@ static bool is_configfs_registered;
*
* @group: Top level configuration group that represents a VKMS device.
* Initialized when a new directory is created under "/config/vkms/"
* @planes_group: Default subgroup of @group at "/config/vkms/planes"
* @lock: Lock used to project concurrent access to the configuration attributes
* @config: Protected by @lock. Configuration of the VKMS device
* @enabled: Protected by @lock. The device is created or destroyed when this
@@ -23,16 +24,99 @@ static bool is_configfs_registered;
*/
struct vkms_configfs_device {
struct config_group group;
struct config_group planes_group;
struct mutex lock;
struct vkms_config *config;
bool enabled;
};
/**
* struct vkms_configfs_plane - Configfs representation of a plane
*
* @group: Top level configuration group that represents a plane.
* Initialized when a new directory is created under "/config/vkms/planes"
* @dev: The vkms_configfs_device this plane belongs to
* @config: Configuration of the VKMS plane
*/
struct vkms_configfs_plane {
struct config_group group;
struct vkms_configfs_device *dev;
struct vkms_config_plane *config;
};
#define device_item_to_vkms_configfs_device(item) \
container_of(to_config_group((item)), struct vkms_configfs_device, \
group)
#define child_group_to_vkms_configfs_device(group) \
device_item_to_vkms_configfs_device((&(group)->cg_item)->ci_parent)
#define plane_item_to_vkms_configfs_plane(item) \
container_of(to_config_group((item)), struct vkms_configfs_plane, group)
static void plane_release(struct config_item *item)
{
struct vkms_configfs_plane *plane;
struct mutex *lock;
plane = plane_item_to_vkms_configfs_plane(item);
lock = &plane->dev->lock;
scoped_guard(mutex, lock) {
vkms_config_destroy_plane(plane->config);
kfree(plane);
}
}
static struct configfs_item_operations plane_item_operations = {
.release = &plane_release,
};
static const struct config_item_type plane_item_type = {
.ct_item_ops = &plane_item_operations,
.ct_owner = THIS_MODULE,
};
static struct config_group *make_plane_group(struct config_group *group,
const char *name)
{
struct vkms_configfs_device *dev;
struct vkms_configfs_plane *plane;
dev = child_group_to_vkms_configfs_device(group);
scoped_guard(mutex, &dev->lock) {
if (dev->enabled)
return ERR_PTR(-EBUSY);
plane = kzalloc(sizeof(*plane), GFP_KERNEL);
if (!plane)
return ERR_PTR(-ENOMEM);
plane->dev = dev;
plane->config = vkms_config_create_plane(dev->config);
if (IS_ERR(plane->config)) {
kfree(plane);
return ERR_CAST(plane->config);
}
config_group_init_type_name(&plane->group, name, &plane_item_type);
}
return &plane->group;
}
static struct configfs_group_operations planes_group_operations = {
.make_group = &make_plane_group,
};
static const struct config_item_type plane_group_type = {
.ct_group_ops = &planes_group_operations,
.ct_owner = THIS_MODULE,
};
static ssize_t device_enabled_show(struct config_item *item, char *page)
{
struct vkms_configfs_device *dev;
@@ -128,6 +212,10 @@ static struct config_group *make_device_group(struct config_group *group,
config_group_init_type_name(&dev->group, name, &device_item_type);
mutex_init(&dev->lock);
config_group_init_type_name(&dev->planes_group, "planes",
&plane_group_type);
configfs_add_default_group(&dev->planes_group, &dev->group);
return &dev->group;
}