[SCSI] bfa: Added support to collect and reset fcport stats

- Added support to collect and reset fcport stats.
- Modified design to allow multiple requests for fcport stats.
  - fcport will remember the stats request in its stats_pending
    queue and service each of the queued requests after receiving
    a firmware response for the prior request.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/bfa/bfa_core.c b/drivers/scsi/bfa/bfa_core.c
index 0c23696..4613bdd 100644
--- a/drivers/scsi/bfa/bfa_core.c
+++ b/drivers/scsi/bfa/bfa_core.c
@@ -1533,10 +1533,17 @@
 	struct list_head		*qe;
 	struct list_head		*qen;
 	struct bfa_cb_qe_s	*hcb_qe;
+	bfa_cb_cbfn_status_t	cbfn;
 
 	list_for_each_safe(qe, qen, comp_q) {
 		hcb_qe = (struct bfa_cb_qe_s *) qe;
-		hcb_qe->cbfn(hcb_qe->cbarg, BFA_TRUE);
+		if (hcb_qe->pre_rmv) {
+			/* qe is invalid after return, dequeue before cbfn() */
+			list_del(qe);
+			cbfn = (bfa_cb_cbfn_status_t)(hcb_qe->cbfn);
+			cbfn(hcb_qe->cbarg, hcb_qe->fw_status);
+		} else
+			hcb_qe->cbfn(hcb_qe->cbarg, BFA_TRUE);
 	}
 }
 
@@ -1549,6 +1556,7 @@
 	while (!list_empty(comp_q)) {
 		bfa_q_deq(comp_q, &qe);
 		hcb_qe = (struct bfa_cb_qe_s *) qe;
+		WARN_ON(hcb_qe->pre_rmv);
 		hcb_qe->cbfn(hcb_qe->cbarg, BFA_FALSE);
 	}
 }