[SCSI] bfa: FC credit recovery and misc bug fixes.

- Introduce FC credit recovery.
- Added module parameter to enable/disable credit recovery.

Bug Fixes:
- Removed check for ignoring plogi from initiator in switched fabric mode.
- The ABTS for PLOGI is going out few millisecs earlier due to FW
  timer calibration (around 300 miilisecs earlier). So there is a
  window if an accept comes during this time HBA would have initiated
  an ABORT.
- Added 1 to FC_ELS_TOV for compensating for FW timer.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 54 insertions, 6 deletions

diff --git a/drivers/scsi/bfa/bfa_fcs.c b/drivers/scsi/bfa/bfa_fcs.c
index eb42e74ed423..6c8a27e78974 100644
--- a/drivers/scsi/bfa/bfa_fcs.c
+++ b/drivers/scsi/bfa/bfa_fcs.c
@@ -196,6 +196,9 @@ static void bfa_fcs_fabric_flogiacc_comp(void *fcsarg,
 					 u32 rsp_len,
 					 u32 resid_len,
 					 struct fchs_s *rspfchs);
+static u8 bfa_fcs_fabric_oper_bbscn(struct bfa_fcs_fabric_s *fabric);
+static bfa_boolean_t bfa_fcs_fabric_is_bbscn_enabled(
+				struct bfa_fcs_fabric_s *fabric);
 
 static void	bfa_fcs_fabric_sm_uninit(struct bfa_fcs_fabric_s *fabric,
 					 enum bfa_fcs_fabric_event event);
@@ -322,7 +325,8 @@ bfa_fcs_fabric_sm_flogi(struct bfa_fcs_fabric_s *fabric,
 	case BFA_FCS_FABRIC_SM_CONT_OP:
 
 		bfa_fcport_set_tx_bbcredit(fabric->fcs->bfa,
-					   fabric->bb_credit);
+					   fabric->bb_credit,
+					   bfa_fcs_fabric_oper_bbscn(fabric));
 		fabric->fab_type = BFA_FCS_FABRIC_SWITCHED;
 
 		if (fabric->auth_reqd && fabric->is_auth) {
@@ -350,7 +354,8 @@ bfa_fcs_fabric_sm_flogi(struct bfa_fcs_fabric_s *fabric,
 	case BFA_FCS_FABRIC_SM_NO_FABRIC:
 		fabric->fab_type = BFA_FCS_FABRIC_N2N;
 		bfa_fcport_set_tx_bbcredit(fabric->fcs->bfa,
-					   fabric->bb_credit);
+					   fabric->bb_credit,
+					   bfa_fcs_fabric_oper_bbscn(fabric));
 		bfa_fcs_fabric_notify_online(fabric);
 		bfa_sm_set_state(fabric, bfa_fcs_fabric_sm_nofabric);
 		break;
@@ -518,7 +523,8 @@ bfa_fcs_fabric_sm_nofabric(struct bfa_fcs_fabric_s *fabric,
 	case BFA_FCS_FABRIC_SM_NO_FABRIC:
 		bfa_trc(fabric->fcs, fabric->bb_credit);
 		bfa_fcport_set_tx_bbcredit(fabric->fcs->bfa,
-					   fabric->bb_credit);
+					   fabric->bb_credit,
+					   bfa_fcs_fabric_oper_bbscn(fabric));
 		break;
 
 	default:
@@ -764,6 +770,10 @@ bfa_cb_lps_flogi_comp(void *bfad, void *uarg, bfa_status_t status)
 
 	case BFA_STATUS_FABRIC_RJT:
 		fabric->stats.flogi_rejects++;
+		if (fabric->lps->lsrjt_rsn == FC_LS_RJT_RSN_LOGICAL_ERROR &&
+		    fabric->lps->lsrjt_expl == FC_LS_RJT_EXP_NO_ADDL_INFO)
+			fabric->fcs->bbscn_flogi_rjt = BFA_TRUE;
+
 		bfa_sm_send_event(fabric, BFA_FCS_FABRIC_SM_RETRY_OP);
 		return;
 
@@ -808,13 +818,17 @@ bfa_fcs_fabric_login(struct bfa_fcs_fabric_s *fabric)
 {
 	struct bfa_s		*bfa = fabric->fcs->bfa;
 	struct bfa_lport_cfg_s	*pcfg = &fabric->bport.port_cfg;
-	u8			alpa = 0;
+	u8			alpa = 0, bb_scn = 0;
 
 	if (bfa_fcport_get_topology(bfa) == BFA_PORT_TOPOLOGY_LOOP)
 		alpa = bfa_fcport_get_myalpa(bfa);
 
+	if (bfa_fcs_fabric_is_bbscn_enabled(fabric) &&
+	    (!fabric->fcs->bbscn_flogi_rjt))
+		bb_scn = BFA_FCS_PORT_DEF_BB_SCN;
+
 	bfa_lps_flogi(fabric->lps, fabric, alpa, bfa_fcport_get_maxfrsize(bfa),
-		      pcfg->pwwn, pcfg->nwwn, fabric->auth_reqd);
+		      pcfg->pwwn, pcfg->nwwn, fabric->auth_reqd, bb_scn);
 
 	fabric->stats.flogi_sent++;
 }
@@ -873,6 +887,37 @@ bfa_fcs_fabric_delay(void *cbarg)
 }
 
 /*
+ * Computes operating BB_SCN value
+ */
+static u8
+bfa_fcs_fabric_oper_bbscn(struct bfa_fcs_fabric_s *fabric)
+{
+	u8	pr_bbscn = fabric->lps->pr_bbscn;
+
+	if (!(fabric->fcs->bbscn_enabled && pr_bbscn))
+		return 0;
+
+	/* return max of local/remote bb_scn values */
+	return ((pr_bbscn > BFA_FCS_PORT_DEF_BB_SCN) ?
+		pr_bbscn : BFA_FCS_PORT_DEF_BB_SCN);
+}
+
+/*
+ * Check if BB_SCN can be enabled.
+ */
+static bfa_boolean_t
+bfa_fcs_fabric_is_bbscn_enabled(struct bfa_fcs_fabric_s *fabric)
+{
+	if (bfa_ioc_get_fcmode(&fabric->fcs->bfa->ioc) &&
+			fabric->fcs->bbscn_enabled &&
+			!bfa_fcport_is_qos_enabled(fabric->fcs->bfa) &&
+			!bfa_fcport_is_trunk_enabled(fabric->fcs->bfa))
+		return BFA_TRUE;
+	else
+		return BFA_FALSE;
+}
+
+/*
  * Delete all vports and wait for vport delete completions.
  */
 static void
@@ -989,6 +1034,7 @@ void
 bfa_fcs_fabric_link_down(struct bfa_fcs_fabric_s *fabric)
 {
 	bfa_trc(fabric->fcs, fabric->bport.port_cfg.pwwn);
+	fabric->fcs->bbscn_flogi_rjt = BFA_FALSE;
 	bfa_sm_send_event(fabric, BFA_FCS_FABRIC_SM_LINK_DOWN);
 }
 
@@ -1192,6 +1238,7 @@ bfa_fcs_fabric_process_flogi(struct bfa_fcs_fabric_s *fabric,
 	}
 
 	fabric->bb_credit = be16_to_cpu(flogi->csp.bbcred);
+	fabric->lps->pr_bbscn = (be16_to_cpu(flogi->csp.rxsz) >> 12);
 	bport->port_topo.pn2n.rem_port_wwn = flogi->port_name;
 	bport->port_topo.pn2n.reply_oxid = fchs->ox_id;
 
@@ -1224,7 +1271,8 @@ bfa_fcs_fabric_send_flogi_acc(struct bfa_fcs_fabric_s *fabric)
 				    n2n_port->reply_oxid, pcfg->pwwn,
 				    pcfg->nwwn,
 				    bfa_fcport_get_maxfrsize(bfa),
-				    bfa_fcport_get_rx_bbcredit(bfa));
+				    bfa_fcport_get_rx_bbcredit(bfa),
+				    bfa_fcs_fabric_oper_bbscn(fabric));
 
 	bfa_fcxp_send(fcxp, NULL, fabric->vf_id, fabric->lps->lp_tag,
 		      BFA_FALSE, FC_CLASS_3,