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

[Sunil Khatri]

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)
+{
+}
 #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;
 };
 
 /**
-- 
2.34.1