qed: iWARP - Use READ_ONCE and smp_store_release to access ep->state

Destroy QP waits for it's ep object state to be set to CLOSED
before proceeding. ep->state can be updated from a different
context. Add smp_store_release/READ_ONCE to synchronize.

Fixes: fc4c6065 ("qed: iWARP implement disconnect flows")
Signed-off-by: Ariel Elior <ariel.elior@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_iwarp.c

@@ -532,7 +532,8 @@ int qed_iwarp_destroy_qp(struct qed_hwfn *p_hwfn, struct qed_rdma_qp *qp)
 
 	/* Make sure ep is closed before returning and freeing memory. */
 	if (ep) {
-		while (ep->state != QED_IWARP_EP_CLOSED && wait_count++ < 200)
+		while (READ_ONCE(ep->state) != QED_IWARP_EP_CLOSED &&
+		       wait_count++ < 200)
 			msleep(100);
 
 		if (ep->state != QED_IWARP_EP_CLOSED)
@@ -1022,8 +1023,6 @@ qed_iwarp_mpa_complete(struct qed_hwfn *p_hwfn,
 
 	params.ep_context = ep;
 
-	ep->state = QED_IWARP_EP_CLOSED;
-
 	switch (fw_return_code) {
 	case RDMA_RETURN_OK:
 		ep->qp->max_rd_atomic_req = ep->cm_info.ord;
@@ -1083,6 +1082,10 @@ qed_iwarp_mpa_complete(struct qed_hwfn *p_hwfn,
 		break;
 	}
 
+	if (fw_return_code != RDMA_RETURN_OK)
+		/* paired with READ_ONCE in destroy_qp */
+		smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);
+
 	ep->event_cb(ep->cb_context, &params);
 
 	/* on passive side, if there is no associated QP (REJECT) we need to
@@ -2825,7 +2828,9 @@ static void qed_iwarp_qp_in_error(struct qed_hwfn *p_hwfn,
 	params.status = (fw_return_code == IWARP_QP_IN_ERROR_GOOD_CLOSE) ?
 			 0 : -ECONNRESET;
 
-	ep->state = QED_IWARP_EP_CLOSED;
+	/* paired with READ_ONCE in destroy_qp */
+	smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);
+
 	spin_lock_bh(&p_hwfn->p_rdma_info->iwarp.iw_lock);
 	list_del(&ep->list_entry);
 	spin_unlock_bh(&p_hwfn->p_rdma_info->iwarp.iw_lock);
@@ -2914,7 +2919,8 @@ qed_iwarp_tcp_connect_unsuccessful(struct qed_hwfn *p_hwfn,
 	params.event = QED_IWARP_EVENT_ACTIVE_COMPLETE;
 	params.ep_context = ep;
 	params.cm_info = &ep->cm_info;
-	ep->state = QED_IWARP_EP_CLOSED;
+	/* paired with READ_ONCE in destroy_qp */
+	smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);
 
 	switch (fw_return_code) {
 	case IWARP_CONN_ERROR_TCP_CONNECT_INVALID_PACKET: