RDMA/irdma: Flush iWARP QP if modified to ERR from RTR state

When connection establishment fails in iWARP mode, an app can drain the
QPs and hang because flush isn't issued when the QP is modified from RTR
state to error. Issue a flush in this case using function
irdma_cm_disconn().

Update irdma_cm_disconn() to do flush when cm_id is NULL, which is the
case when the QP is in RTR state and there is an error in the connection
establishment.

Fixes: b48c24c ("RDMA/irdma: Implement device supported verb APIs")
Link: https://lore.kernel.org/r/20220425181703.1634-2-shiraz.saleem@intel.com
Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/irdma/cm.c

@@ -3462,12 +3462,6 @@ static void irdma_cm_disconn_true(struct irdma_qp *iwqp)
 	}
 
 	cm_id = iwqp->cm_id;
-	/* make sure we havent already closed this connection */
-	if (!cm_id) {
-		spin_unlock_irqrestore(&iwqp->lock, flags);
-		return;
-	}
-
 	original_hw_tcp_state = iwqp->hw_tcp_state;
 	original_ibqp_state = iwqp->ibqp_state;
 	last_ae = iwqp->last_aeq;
@@ -3489,11 +3483,11 @@ static void irdma_cm_disconn_true(struct irdma_qp *iwqp)
 			disconn_status = -ECONNRESET;
 	}
 
-	if ((original_hw_tcp_state == IRDMA_TCP_STATE_CLOSED ||
-	     original_hw_tcp_state == IRDMA_TCP_STATE_TIME_WAIT ||
-	     last_ae == IRDMA_AE_RDMAP_ROE_BAD_LLP_CLOSE ||
-	     last_ae == IRDMA_AE_BAD_CLOSE ||
-	     last_ae == IRDMA_AE_LLP_CONNECTION_RESET || iwdev->rf->reset)) {
+	if (original_hw_tcp_state == IRDMA_TCP_STATE_CLOSED ||
+	    original_hw_tcp_state == IRDMA_TCP_STATE_TIME_WAIT ||
+	    last_ae == IRDMA_AE_RDMAP_ROE_BAD_LLP_CLOSE ||
+	    last_ae == IRDMA_AE_BAD_CLOSE ||
+	    last_ae == IRDMA_AE_LLP_CONNECTION_RESET || iwdev->rf->reset || !cm_id) {
 		issue_close = 1;
 		iwqp->cm_id = NULL;
 		qp->term_flags = 0;

drivers/infiniband/hw/irdma/verbs.c

@@ -1618,13 +1618,13 @@ int irdma_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask,
 
 	if (issue_modify_qp && iwqp->ibqp_state > IB_QPS_RTS) {
 		if (dont_wait) {
-			if (iwqp->cm_id && iwqp->hw_tcp_state) {
+			if (iwqp->hw_tcp_state) {
 				spin_lock_irqsave(&iwqp->lock, flags);
 				iwqp->hw_tcp_state = IRDMA_TCP_STATE_CLOSED;
 				iwqp->last_aeq = IRDMA_AE_RESET_SENT;
 				spin_unlock_irqrestore(&iwqp->lock, flags);
-				irdma_cm_disconn(iwqp);
 			}
+			irdma_cm_disconn(iwqp);
 		} else {
 			int close_timer_started;