[PATCH v4 1/4] drm: move debugfs functionality from drm_drv.c to drm_debugfs.c

Christian König christian.koenig at amd.com
Wed Jun 18 14:08:00 UTC 2025


On 6/18/25 15:47, Sunil Khatri wrote:
> move the functions from drm_drv.c which uses the static
> drm_debugfs_root as parent node in the debugfs by drm.
> 
> move this root node to the debugfs for easily handling
> of future requirements to add more information in the
> root directory and one of which is planned to have
> directories for each client in the root directory
> which is dri.
> 
> Suggested-by: Christian König <christian.koenig at amd.com>
> Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>
> ---
>  drivers/gpu/drm/drm_debugfs.c  | 22 ++++++++++++++++++----
>  drivers/gpu/drm/drm_drv.c      | 11 ++++-------
>  drivers/gpu/drm/drm_internal.h |  6 ++----
>  include/drm/drm_drv.h          | 10 ++++++++++
>  4 files changed, 34 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
> index 2d43bda82887..5a33ec299c04 100644
> --- a/drivers/gpu/drm/drm_debugfs.c
> +++ b/drivers/gpu/drm/drm_debugfs.c
> @@ -44,6 +44,8 @@
>  #include "drm_crtc_internal.h"
>  #include "drm_internal.h"
>  
> +static struct dentry *drm_debugfs_root;
> +
>  /***************************************************
>   * Initialization, etc.
>   **************************************************/
> @@ -286,6 +288,16 @@ int drm_debugfs_remove_files(const struct drm_info_list *files, int count,
>  }
>  EXPORT_SYMBOL(drm_debugfs_remove_files);
>  
> +void drm_debugfs_create_dir(void)

I think we need a better name for this. drm_debugfs_init_root maybe? Ideas welcome.

> +{
> +	drm_debugfs_root = debugfs_create_dir("dri", NULL);
> +}
> +
> +void drm_debugfs_remove_dir(void)
> +{
> +	debugfs_remove(drm_debugfs_root);
> +}
> +
>  /**
>   * drm_debugfs_dev_init - create debugfs directory for the device
>   * @dev: the device which we want to create the directory for
> @@ -295,7 +307,10 @@ EXPORT_SYMBOL(drm_debugfs_remove_files);
>   */
>  void drm_debugfs_dev_init(struct drm_device *dev, struct dentry *root)
>  {
> -	dev->debugfs_root = debugfs_create_dir(dev->unique, root);
> +	if (!root)
> +		dev->debugfs_root = debugfs_create_dir(dev->unique, drm_debugfs_root);
> +	else
> +		dev->debugfs_root = debugfs_create_dir(dev->unique, root);

Ah! That is also used from the accel subsystem, isn't it?

Probably best to move accel_debugfs_root into this here as well and distinct based on drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL) where to create the debugfs directory.

We probably need the same distinction for other use cases as well, so probably best to create a helper function for that.

Apart from that looks really good to me.

Regards,
Christian.

>  }
>  
>  /**
> @@ -322,14 +337,13 @@ void drm_debugfs_dev_register(struct drm_device *dev)
>  		drm_atomic_debugfs_init(dev);
>  }
>  
> -int drm_debugfs_register(struct drm_minor *minor, int minor_id,
> -			 struct dentry *root)
> +int drm_debugfs_register(struct drm_minor *minor, int minor_id)
>  {
>  	struct drm_device *dev = minor->dev;
>  	char name[64];
>  
>  	sprintf(name, "%d", minor_id);
> -	minor->debugfs_symlink = debugfs_create_symlink(name, root,
> +	minor->debugfs_symlink = debugfs_create_symlink(name, drm_debugfs_root,
>  							dev->unique);
>  
>  	/* TODO: Only for compatibility with drivers */
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 17fc5dc708f4..8abc52eac8f3 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -69,8 +69,6 @@ DEFINE_XARRAY_ALLOC(drm_minors_xa);
>   */
>  static bool drm_core_init_complete;
>  
> -static struct dentry *drm_debugfs_root;
> -
>  DEFINE_STATIC_SRCU(drm_unplug_srcu);
>  
>  /*
> @@ -183,8 +181,7 @@ static int drm_minor_register(struct drm_device *dev, enum drm_minor_type type)
>  		return 0;
>  
>  	if (minor->type != DRM_MINOR_ACCEL) {
> -		ret = drm_debugfs_register(minor, minor->index,
> -					   drm_debugfs_root);
> +		ret = drm_debugfs_register(minor, minor->index);
>  		if (ret) {
>  			DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
>  			goto err_debugfs;
> @@ -754,7 +751,7 @@ static int drm_dev_init(struct drm_device *dev,
>  	if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL))
>  		accel_debugfs_init(dev);
>  	else
> -		drm_debugfs_dev_init(dev, drm_debugfs_root);
> +		drm_debugfs_dev_init(dev, NULL);
>  
>  	return 0;
>  
> @@ -1168,7 +1165,7 @@ static void drm_core_exit(void)
>  	drm_panic_exit();
>  	accel_core_exit();
>  	unregister_chrdev(DRM_MAJOR, "drm");
> -	debugfs_remove(drm_debugfs_root);
> +	drm_debugfs_remove_dir();
>  	drm_sysfs_destroy();
>  	WARN_ON(!xa_empty(&drm_minors_xa));
>  	drm_connector_ida_destroy();
> @@ -1187,7 +1184,7 @@ static int __init drm_core_init(void)
>  		goto error;
>  	}
>  
> -	drm_debugfs_root = debugfs_create_dir("dri", NULL);
> +	drm_debugfs_create_dir();
>  
>  	ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
>  	if (ret < 0)
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index b2b6a8e49dda..d2d8e72f32d9 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -186,8 +186,7 @@ void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map);
>  #if defined(CONFIG_DEBUG_FS)
>  void drm_debugfs_dev_fini(struct drm_device *dev);
>  void drm_debugfs_dev_register(struct drm_device *dev);
> -int drm_debugfs_register(struct drm_minor *minor, int minor_id,
> -			 struct dentry *root);
> +int drm_debugfs_register(struct drm_minor *minor, int minor_id);
>  void drm_debugfs_unregister(struct drm_minor *minor);
>  void drm_debugfs_connector_add(struct drm_connector *connector);
>  void drm_debugfs_connector_remove(struct drm_connector *connector);
> @@ -205,8 +204,7 @@ static inline void drm_debugfs_dev_register(struct drm_device *dev)
>  {
>  }
>  
> -static inline int drm_debugfs_register(struct drm_minor *minor, int minor_id,
> -				       struct dentry *root)
> +static inline int drm_debugfs_register(struct drm_minor *minor, int minor_id)
>  {
>  	return 0;
>  }
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index a43d707b5f36..4e77a0c4a7f9 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -567,10 +567,20 @@ static inline bool drm_firmware_drivers_only(void)
>  
>  #if defined(CONFIG_DEBUG_FS)
>  void drm_debugfs_dev_init(struct drm_device *dev, struct dentry *root);
> +void drm_debugfs_create_dir(void);
> +void drm_debugfs_remove_dir(void);
>  #else
>  static inline void drm_debugfs_dev_init(struct drm_device *dev, struct dentry *root)
>  {
>  }
> +
> +static inline void drm_debugfs_create_dir(void)
> +{
> +}
> +
> +static inline void drm_debugfs_remove_dir(void)
> +{
> +}
>  #endif
>  
>  #endif



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