drm/debugfs: Add internal client debugfs file

Print the names of the internal clients currently attached.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703160354.59955-6-noralf@tronnes.org

drivers/gpu/drm/drm_client.c

@@ -385,3 +385,31 @@ void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
 	drm_client_buffer_delete(buffer);
 }
 EXPORT_SYMBOL(drm_client_framebuffer_delete);
+
+#ifdef CONFIG_DEBUG_FS
+static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_printer p = drm_seq_file_printer(m);
+	struct drm_client_dev *client;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list)
+		drm_printf(&p, "%s\n", client->name);
+	mutex_unlock(&dev->clientlist_mutex);
+
+	return 0;
+}
+
+static const struct drm_info_list drm_client_debugfs_list[] = {
+	{ "internal_clients", drm_client_debugfs_internal_clients, 0 },
+};
+
+int drm_client_debugfs_init(struct drm_minor *minor)
+{
+	return drm_debugfs_create_files(drm_client_debugfs_list,
+					ARRAY_SIZE(drm_client_debugfs_list),
+					minor->debugfs_root, minor);
+}
+#endif

drivers/gpu/drm/drm_debugfs.c

@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/export.h>
 
+#include <drm/drm_client.h>
 #include <drm/drm_debugfs.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_atomic.h>
@@ -164,6 +165,12 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 			DRM_ERROR("Failed to create framebuffer debugfs file\n");
 			return ret;
 		}
+
+		ret = drm_client_debugfs_init(minor);
+		if (ret) {
+			DRM_ERROR("Failed to create client debugfs file\n");
+			return ret;
+		}
 	}
 
 	if (dev->driver->debugfs_init) {

include/drm/drm_client.h

@@ -10,6 +10,7 @@ struct drm_device;
 struct drm_file;
 struct drm_framebuffer;
 struct drm_gem_object;
+struct drm_minor;
 struct module;
 
 /**
@@ -133,4 +134,6 @@ struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
 
+int drm_client_debugfs_init(struct drm_minor *minor);
+
 #endif