Commit d41c7983 authored by Boris Brezillon's avatar Boris Brezillon Committed by Steven Price
Browse files

drm/panfrost: Display list of device JM contexts over debugfs 



For DebugFS builds, create a filesystem knob that, for every single open
file of the Panfrost DRM device, shows its command name information and
PID (when applicable), and all of its existing JM contexts.

For every context, show the DRM scheduler priority value of all of its
scheduling entities.

Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: default avatarAdrián Larumbe <adrian.larumbe@collabora.com>
Signed-off-by: default avatarSteven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250917191859.500279-5-adrian.larumbe@collabora.com
parent a017f7b8

drivers/gpu/drm/panfrost/panfrost_drv.c

+96 −0
Original line number Diff line number Diff line
@@ -716,6 +716,47 @@ static int panthor_gems_show(struct seq_file *m, void *data) 
	return 0;

}



static void show_panfrost_jm_ctx(struct panfrost_jm_ctx *jm_ctx, u32 handle,

				 struct seq_file *m)

{

	struct drm_device *ddev = ((struct drm_info_node *)m->private)->minor->dev;

	const char *prio = "UNKNOWN";



	static const char * const prios[] = {

		[DRM_SCHED_PRIORITY_HIGH] = "HIGH",

		[DRM_SCHED_PRIORITY_NORMAL] = "NORMAL",

		[DRM_SCHED_PRIORITY_LOW] = "LOW",

	};



	if (jm_ctx->slot_entity[0].priority !=

	    jm_ctx->slot_entity[1].priority)

		drm_warn(ddev, "Slot priorities should be the same in a single context");



	if (jm_ctx->slot_entity[0].priority < ARRAY_SIZE(prios))

		prio = prios[jm_ctx->slot_entity[0].priority];



	seq_printf(m, " JM context %u: priority %s\n", handle, prio);

}



static int show_file_jm_ctxs(struct panfrost_file_priv *pfile,

			     struct seq_file *m)

{

	struct panfrost_jm_ctx *jm_ctx;

	unsigned long i;



	xa_lock(&pfile->jm_ctxs);

	xa_for_each(&pfile->jm_ctxs, i, jm_ctx) {

		jm_ctx = panfrost_jm_ctx_get(jm_ctx);

		xa_unlock(&pfile->jm_ctxs);

		show_panfrost_jm_ctx(jm_ctx, i, m);

		panfrost_jm_ctx_put(jm_ctx);

		xa_lock(&pfile->jm_ctxs);

	}

	xa_unlock(&pfile->jm_ctxs);



	return 0;

}



static struct drm_info_list panthor_debugfs_list[] = {

	{"gems", panthor_gems_show, 0, NULL},

};
@@ -729,9 +770,64 @@ static int panthor_gems_debugfs_init(struct drm_minor *minor) 
	return 0;

}



static int show_each_file(struct seq_file *m, void *arg)

{

	struct drm_info_node *node = (struct drm_info_node *)m->private;

	struct drm_device *ddev = node->minor->dev;

	int (*show)(struct panfrost_file_priv *, struct seq_file *) =

		node->info_ent->data;

	struct drm_file *file;

	int ret;



	ret = mutex_lock_interruptible(&ddev->filelist_mutex);

	if (ret)

		return ret;



	list_for_each_entry(file, &ddev->filelist, lhead) {

		struct task_struct *task;

		struct panfrost_file_priv *pfile = file->driver_priv;

		struct pid *pid;



		/*

		 * Although we have a valid reference on file->pid, that does

		 * not guarantee that the task_struct who called get_pid() is

		 * still alive (e.g. get_pid(current) => fork() => exit()).

		 * Therefore, we need to protect this ->comm access using RCU.

		 */

		rcu_read_lock();

		pid = rcu_dereference(file->pid);

		task = pid_task(pid, PIDTYPE_TGID);

		seq_printf(m, "client_id %8llu pid %8d command %s:\n",

			   file->client_id, pid_nr(pid),

			   task ? task->comm : "<unknown>");

		rcu_read_unlock();



		ret = show(pfile, m);

		if (ret < 0)

			break;



		seq_puts(m, "\n");

	}



	mutex_unlock(&ddev->filelist_mutex);

	return ret;

}



static struct drm_info_list panfrost_sched_debugfs_list[] = {

	{ "sched_ctxs", show_each_file, 0, show_file_jm_ctxs },

};



static void panfrost_sched_debugfs_init(struct drm_minor *minor)

{

	drm_debugfs_create_files(panfrost_sched_debugfs_list,

				 ARRAY_SIZE(panfrost_sched_debugfs_list),

				 minor->debugfs_root, minor);

}



static void panfrost_debugfs_init(struct drm_minor *minor)

{

	panthor_gems_debugfs_init(minor);

	panfrost_sched_debugfs_init(minor);

}

#endif