drm/debugfs: rework debugfs directory creation v5

Instead of the per minor directories only create a single debugfs
directory for the whole device directly when the device is initialized.

For DRM devices each minor gets a symlink to the per device directory
for now until we can be sure that this isn't useful any more in any way.

Accel devices create only the per device directory and also drops the mid
layer callback to create driver specific files.

v2: cleanup accel component as well
v3: fix typo when debugfs is disabled
v4: call drm_debugfs_dev_fini() during release as well,
    some kerneldoc typos fixed
v5: rebased and one more kerneldoc fix

Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230829110115.3442-4-christian.koenig@amd.com
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

1 files changed, 52 insertions, 24 deletions

diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 8a4c90fd9f02..5ec28c0e12d9 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -266,8 +266,46 @@ void drm_debugfs_create_files(const struct drm_info_list *files, int count,
 }
 EXPORT_SYMBOL(drm_debugfs_create_files);
 
-int drm_debugfs_init(struct drm_minor *minor, int minor_id,
-		     struct dentry *root)
+/**
+ * drm_debugfs_dev_init - create debugfs directory for the device
+ * @dev: the device which we want to create the directory for
+ * @root: the parent directory depending on the device type
+ *
+ * Creates the debugfs directory for the device under the given root directory.
+ */
+void drm_debugfs_dev_init(struct drm_device *dev, struct dentry *root)
+{
+	dev->debugfs_root = debugfs_create_dir(dev->unique, root);
+}
+
+/**
+ * drm_debugfs_dev_fini - cleanup debugfs directory
+ * @dev: the device to cleanup the debugfs stuff
+ *
+ * Remove the debugfs directory, might be called multiple times.
+ */
+void drm_debugfs_dev_fini(struct drm_device *dev)
+{
+	debugfs_remove_recursive(dev->debugfs_root);
+	dev->debugfs_root = NULL;
+}
+
+void drm_debugfs_dev_register(struct drm_device *dev)
+{
+	drm_debugfs_add_files(dev, drm_debugfs_list, DRM_DEBUGFS_ENTRIES);
+
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		drm_framebuffer_debugfs_init(dev);
+		drm_client_debugfs_init(dev);
+	}
+	if (drm_drv_uses_atomic_modeset(dev)) {
+		drm_atomic_debugfs_init(dev);
+		drm_bridge_debugfs_init(dev);
+	}
+}
+
+int drm_debugfs_register(struct drm_minor *minor, int minor_id,
+			 struct dentry *root)
 {
 	struct drm_device *dev = minor->dev;
 	struct drm_debugfs_entry *entry, *tmp;
@@ -276,20 +314,11 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 	INIT_LIST_HEAD(&minor->debugfs_list);
 	mutex_init(&minor->debugfs_lock);
 	sprintf(name, "%d", minor_id);
-	minor->debugfs_root = debugfs_create_dir(name, root);
-
-	drm_debugfs_add_files(minor->dev, drm_debugfs_list, DRM_DEBUGFS_ENTRIES);
+	minor->debugfs_symlink = debugfs_create_symlink(name, root,
+							dev->unique);
 
-	if (drm_drv_uses_atomic_modeset(dev)) {
-		drm_atomic_debugfs_init(minor);
-		drm_bridge_debugfs_init(minor);
-	}
-
-	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
-		drm_framebuffer_debugfs_init(minor);
-
-		drm_client_debugfs_init(minor);
-	}
+	/* TODO: Only for compatibility with drivers */
+	minor->debugfs_root = dev->debugfs_root;
 
 	if (dev->driver->debugfs_init && dev->render != minor)
 		dev->driver->debugfs_init(minor);
@@ -356,13 +385,12 @@ static void drm_debugfs_remove_all_files(struct drm_minor *minor)
 
 void drm_debugfs_cleanup(struct drm_minor *minor)
 {
-	if (!minor->debugfs_root)
+	if (!minor->debugfs_symlink)
 		return;
 
 	drm_debugfs_remove_all_files(minor);
-
-	debugfs_remove_recursive(minor->debugfs_root);
-	minor->debugfs_root = NULL;
+	debugfs_remove(minor->debugfs_symlink);
+	minor->debugfs_symlink = NULL;
 }
 
 /**
@@ -547,13 +575,13 @@ static const struct file_operations drm_connector_fops = {
 
 void drm_debugfs_connector_add(struct drm_connector *connector)
 {
-	struct drm_minor *minor = connector->dev->primary;
+	struct drm_device *dev = connector->dev;
 	struct dentry *root;
 
-	if (!minor->debugfs_root)
+	if (!dev->debugfs_root)
 		return;
 
-	root = debugfs_create_dir(connector->name, minor->debugfs_root);
+	root = debugfs_create_dir(connector->name, dev->debugfs_root);
 	connector->debugfs_entry = root;
 
 	/* force */
@@ -588,7 +616,7 @@ void drm_debugfs_connector_remove(struct drm_connector *connector)
 
 void drm_debugfs_crtc_add(struct drm_crtc *crtc)
 {
-	struct drm_minor *minor = crtc->dev->primary;
+	struct drm_device *dev = crtc->dev;
 	struct dentry *root;
 	char *name;
 
@@ -596,7 +624,7 @@ void drm_debugfs_crtc_add(struct drm_crtc *crtc)
 	if (!name)
 		return;
 
-	root = debugfs_create_dir(name, minor->debugfs_root);
+	root = debugfs_create_dir(name, dev->debugfs_root);
 	kfree(name);
 
 	crtc->debugfs_entry = root;