+int ltt_channel_enable(struct ltt_channel *channel)
+{
+ int old;
+
+ if (channel == channel->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&channel->enabled, 1);
+ if (old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_channel_disable(struct ltt_channel *channel)
+{
+ int old;
+
+ if (channel == channel->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&channel->enabled, 0);
+ if (!old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_event_enable(struct ltt_event *event)
+{
+ int old;
+
+ if (event->chan == event->chan->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&event->enabled, 1);
+ if (old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_event_disable(struct ltt_event *event)
+{
+ int old;
+
+ if (event->chan == event->chan->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&event->enabled, 0);
+ if (!old)
+ return -EEXIST;
+ return 0;
+}
+