drm/xe: Don't restart parallel queues multiple times on GT reset

In case of parallel submissions multiple GuC id will point to the
same exec queue and on GT reset such exec queues will get restarted
multiple times which is not desirable.

v2: don't use exec_queue_enabled() which could race,
do the same for xe_guc_submit_stop (Matt B)

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2295
Cc: Jonathan Cavitt <[e-mail]>
Cc: Himal Prasad Ghimiray <[e-mail]>
Cc: Matthew Auld <[e-mail]>
Cc: Matthew Brost <[e-mail]>
Cc: Tejas Upadhyay <[e-mail]>
Reviewed-by: Matthew Brost <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Nirmoy Das <[e-mail]>

drivers/gpu/drm/xe/xe_guc_submit.c

···
 
 	mutex_lock(&guc->submission_state.lock);
 
-	xa_for_each(&guc->submission_state.exec_queue_lookup, index, q)
+	xa_for_each(&guc->submission_state.exec_queue_lookup, index, q) {
+		/* Prevent redundant attempts to stop parallel queues */
+		if (q->guc->id != index)
+			continue;
+
 		guc_exec_queue_stop(guc, q);
+	}
 
 	mutex_unlock(&guc->submission_state.lock);
 
···
 
 	mutex_lock(&guc->submission_state.lock);
 	atomic_dec(&guc->submission_state.stopped);
-	xa_for_each(&guc->submission_state.exec_queue_lookup, index, q)
+	xa_for_each(&guc->submission_state.exec_queue_lookup, index, q) {
+		/* Prevent redundant attempts to start parallel queues */
+		if (q->guc->id != index)
+			continue;
+
 		guc_exec_queue_start(q);
+	}
 	mutex_unlock(&guc->submission_state.lock);
 
 	wake_up_all(&guc->ct.wq);