IB/hfi1: Handle wakeup of orphaned QPs for pio

Once a send context is taken down due to a link failure, any QPs waiting
for pio credits will stay on the waitlist indefinitely.

Fix by wakeing up all QPs linked to piowait list.

Fixes: 7724105686 ("IB/hfi1: add driver files")
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/pio.c

@@ -952,6 +952,22 @@ void sc_disable(struct send_context *sc)
 		}
 	}
 	spin_unlock(&sc->release_lock);
+
+	write_seqlock(&sc->waitlock);
+	while (!list_empty(&sc->piowait)) {
+		struct iowait *wait;
+		struct rvt_qp *qp;
+		struct hfi1_qp_priv *priv;
+
+		wait = list_first_entry(&sc->piowait, struct iowait, list);
+		qp = iowait_to_qp(wait);
+		priv = qp->priv;
+		list_del_init(&priv->s_iowait.list);
+		priv->s_iowait.lock = NULL;
+		hfi1_qp_wakeup(qp, RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
+	}
+	write_sequnlock(&sc->waitlock);
+
 	spin_unlock_irq(&sc->alloc_lock);
 }