[PATCH v5 3/5] drm: add debugfs support on per client-id basis

[Tvrtko Ursulin]

On 24/06/2025 12:34, Sunil Khatri wrote:
> add support to add a directory for each client-id
> with root at the dri level. Since the clients are
> unique and not just related to one single drm device,
> so it makes more sense to add all the client based
> nodes with root as dri.
> 
> Also create a symlink back to the parent drm device
> from each client.
> 
> Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>
> ---
>   drivers/gpu/drm/drm_debugfs.c | 26 ++++++++++++++++++++++++++
>   drivers/gpu/drm/drm_file.c    |  6 ++++++
>   include/drm/drm_debugfs.h     | 11 +++++++++++
>   include/drm/drm_file.h        |  7 +++++++
>   4 files changed, 50 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
> index a227903c29c4..ebdf60665b86 100644
> --- a/drivers/gpu/drm/drm_debugfs.c
> +++ b/drivers/gpu/drm/drm_debugfs.c
> @@ -309,6 +309,32 @@ void drm_debugfs_remove_accel_root(void)
>   	debugfs_remove(accel_debugfs_root);
>   }
>   
> +void drm_debugfs_clients_add(struct drm_file *file)
> +{
> +	char *client;
> +
> +	client = kasprintf(GFP_KERNEL, "client-%llu", file->client_id);
> +	if (!client)
> +		return;
> +
> +	/* Create a debugfs directory for the client in root on drm debugfs */
> +	file->debugfs_client = debugfs_create_dir(client, drm_debugfs_root);
> +	kfree(client);
> +
> +	client = kasprintf(GFP_KERNEL, "../%s", file->minor->dev->unique);
> +	if (!client)
> +		return;
> +
> +	/* Create a link from client_id to the drm device this client id belongs to */
> +	debugfs_create_symlink("device", file->debugfs_client, client);
> +	kfree(client);
> +}
> +
> +void drm_debugfs_clients_remove(struct drm_file *file)
> +{
> +	debugfs_remove_recursive(file->debugfs_client);
> +	file->debugfs_client = NULL;
> +}
>   
>   /**
>    * drm_debugfs_dev_init - create debugfs directory for the device
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index 06ba6dcbf5ae..17b803ab119e 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -45,6 +45,7 @@
>   #include <drm/drm_file.h>
>   #include <drm/drm_gem.h>
>   #include <drm/drm_print.h>
> +#include <drm/drm_debugfs.h>
>   
>   #include "drm_crtc_internal.h"
>   #include "drm_internal.h"
> @@ -167,6 +168,8 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor)
>   
>   	drm_prime_init_file_private(&file->prime);
>   
> +	drm_debugfs_clients_add(file);
> +
>   	if (dev->driver->open) {
>   		ret = dev->driver->open(dev, file);
>   		if (ret < 0)
> @@ -181,6 +184,8 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor)
>   		drm_syncobj_release(file);
>   	if (drm_core_check_feature(dev, DRIVER_GEM))
>   		drm_gem_release(dev, file);
> +
> +	drm_debugfs_clients_remove(file);
>   	put_pid(rcu_access_pointer(file->pid));
>   	kfree(file);
>   
> @@ -236,6 +241,7 @@ void drm_file_free(struct drm_file *file)
>   		     atomic_read(&dev->open_count));
>   
>   	drm_events_release(file);
> +	drm_debugfs_clients_remove(file);
>   
>   	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
>   		drm_fb_release(file);
> diff --git a/include/drm/drm_debugfs.h b/include/drm/drm_debugfs.h
> index cf06cee4343f..2b3767ad8f5d 100644
> --- a/include/drm/drm_debugfs.h
> +++ b/include/drm/drm_debugfs.h
> @@ -153,6 +153,9 @@ void drm_debugfs_add_files(struct drm_device *dev,
>   
>   int drm_debugfs_gpuva_info(struct seq_file *m,
>   			   struct drm_gpuvm *gpuvm);
> +
> +void drm_debugfs_clients_add(struct drm_file *file);
> +void drm_debugfs_clients_remove(struct drm_file *file);
>   #else
>   static inline void drm_debugfs_create_files(const struct drm_info_list *files,
>   					    int count, struct dentry *root,
> @@ -181,6 +184,14 @@ static inline int drm_debugfs_gpuva_info(struct seq_file *m,
>   {
>   	return 0;
>   }
> +
> +static void drm_debugfs_clients_add(struct drm_file *file)
> +{
> +}
> +
> +static void drm_debugfs_clients_remove(struct drm_file *file)
> +{
> +}

You forgot static inline for these two.

Regards,

Tvrtko

>   #endif
>   
>   #endif /* _DRM_DEBUGFS_H_ */
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 5c3b2aa3e69d..eab7546aad79 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -400,6 +400,13 @@ struct drm_file {
>   	 * @client_name_lock: Protects @client_name.
>   	 */
>   	struct mutex client_name_lock;
> +
> +	/**
> +	 * @debugfs_client:
> +	 *
> +	 * debugfs directory for each client under a drm node.
> +	 */
> +	struct dentry *debugfs_client;
>   };
>   
>   /**