Le 07/04/2025 à 10:14, José Expósito a écrit :
From: Louis Chauvet <[email protected]>
Create a default subgroup at /config/vkms/planes/plane/possible_crtcs
that will contain symbolic links to the possible CRTCs for the plane.
Reviewed-by: Louis Chauvet <[email protected]>
Signed-off-by: Louis Chauvet <[email protected]>
Co-developed-by: José Expósito <[email protected]>
Signed-off-by: José Expósito <[email protected]>
---
Documentation/gpu/vkms.rst | 9 +++++
drivers/gpu/drm/vkms/vkms_configfs.c | 58 ++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index abe7a0f5a4ab..13b96837a266 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -98,6 +98,14 @@ CRTCs have 1 configurable attribute:
- writeback: Enable or disable writeback connector support by writing 1 or 0
+To finish the configuration, link the different pipeline items::
+
+ sudo ln -s /config/vkms/my-vkms/crtcs/crtc0
/config/vkms/my-vkms/planes/plane0/possible_crtcs
+
+Since at least one primary plane is required, make sure to set the right type::
+
+ echo "1" | sudo tee /config/vkms/my-vkms/planes/plane0/type
+
Once you are done configuring the VKMS instance, enable it::
echo "1" | sudo tee /config/vkms/my-vkms/enabled
@@ -108,6 +116,7 @@ Finally, you can remove the VKMS instance disabling it::
And removing the top level directory and its subdirectories::
+ sudo rm /config/vkms/my-vkms/planes/*/possible_crtcs/*
sudo rmdir /config/vkms/my-vkms/planes/*
sudo rmdir /config/vkms/my-vkms/crtcs/*
sudo rmdir /config/vkms/my-vkms
diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c
b/drivers/gpu/drm/vkms/vkms_configfs.c
index e9f445043268..2cf97c2b6203 100644
--- a/drivers/gpu/drm/vkms/vkms_configfs.c
+++ b/drivers/gpu/drm/vkms/vkms_configfs.c
@@ -38,11 +38,13 @@ struct vkms_configfs_device {
*
* @group: Top level configuration group that represents a plane.
* Initialized when a new directory is created under "/config/vkms/planes"
+ * @possible_crtcs_group: Default subgroup of @group at "plane/possible_crtcs"
* @dev: The vkms_configfs_device this plane belongs to
* @config: Configuration of the VKMS plane
*/
struct vkms_configfs_plane {
struct config_group group;
+ struct config_group possible_crtcs_group;
struct vkms_configfs_device *dev;
struct vkms_config_plane *config;
};
@@ -71,6 +73,10 @@ struct vkms_configfs_crtc {
#define plane_item_to_vkms_configfs_plane(item) \
container_of(to_config_group((item)), struct vkms_configfs_plane, group)
+#define plane_possible_crtcs_item_to_vkms_configfs_plane(item) \
+ container_of(to_config_group((item)), struct vkms_configfs_plane, \
+ possible_crtcs_group)
+
#define crtc_item_to_vkms_configfs_crtc(item) \
container_of(to_config_group((item)), struct vkms_configfs_crtc, group)
@@ -178,6 +184,52 @@ static const struct config_item_type crtc_group_type = {
.ct_owner = THIS_MODULE,
};
+static int plane_possible_crtcs_allow_link(struct config_item *src,
+ struct config_item *target)
+{
+ struct vkms_configfs_plane *plane;
+ struct vkms_configfs_crtc *crtc;
+ int ret;
+
+ if (target->ci_type != &crtc_item_type)
+ return -EINVAL;
+
+ plane = plane_possible_crtcs_item_to_vkms_configfs_plane(src);
+ crtc = crtc_item_to_vkms_configfs_crtc(target);
+
+ scoped_guard(mutex, &plane->dev->lock) {
+ if (plane->dev->enabled)
+ return -EBUSY;
+
+ ret = vkms_config_plane_attach_crtc(plane->config,
crtc->config);
+ }
+
+ return ret;
+}
+
+static void plane_possible_crtcs_drop_link(struct config_item *src,
+ struct config_item *target)
+{
+ struct vkms_configfs_plane *plane;
+ struct vkms_configfs_crtc *crtc;
+
+ plane = plane_possible_crtcs_item_to_vkms_configfs_plane(src);
+ crtc = crtc_item_to_vkms_configfs_crtc(target);
+
+ scoped_guard(mutex, &plane->dev->lock)
+ vkms_config_plane_detach_crtc(plane->config, crtc->config);
+}
+
+static struct configfs_item_operations plane_possible_crtcs_item_operations = {
+ .allow_link = plane_possible_crtcs_allow_link,
+ .drop_link = plane_possible_crtcs_drop_link,
+};
+
+static const struct config_item_type plane_possible_crtcs_group_type = {
+ .ct_item_ops = &plane_possible_crtcs_item_operations,
+ .ct_owner = THIS_MODULE,
+};
+
static ssize_t plane_type_show(struct config_item *item, char *page)
{
struct vkms_configfs_plane *plane;
@@ -272,6 +324,12 @@ static struct config_group *make_plane_group(struct
config_group *group,
}
config_group_init_type_name(&plane->group, name, &plane_item_type);
+
+ config_group_init_type_name(&plane->possible_crtcs_group,
+ "possible_crtcs",
+ &plane_possible_crtcs_group_type);
+ configfs_add_default_group(&plane->possible_crtcs_group,
+ &plane->group);
}
return &plane->group;
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
