scsi: qla2xxx: Fix exchange oversubscription for management commands

Add resource checking for management (non-I/O) commands.

Fixes: 89c72f4245 ("scsi: qla2xxx: Add IOCB resource tracking")
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_dfs.c

@@ -235,7 +235,7 @@ qla_dfs_fw_resource_cnt_show(struct seq_file *s, void *unused)
 	uint16_t mb[MAX_IOCB_MB_REG];
 	int rc;
 	struct qla_hw_data *ha = vha->hw;
-	u16 iocbs_used, i;
+	u16 iocbs_used, i, exch_used;
 
 	rc = qla24xx_res_count_wait(vha, mb, SIZEOF_IOCB_MB_REG);
 	if (rc != QLA_SUCCESS) {
@@ -263,13 +263,19 @@ qla_dfs_fw_resource_cnt_show(struct seq_file *s, void *unused)
 	if (ql2xenforce_iocb_limit) {
 		/* lock is not require. It's an estimate. */
 		iocbs_used = ha->base_qpair->fwres.iocbs_used;
+		exch_used = ha->base_qpair->fwres.exch_used;
 		for (i = 0; i < ha->max_qpairs; i++) {
-			if (ha->queue_pair_map[i])
+			if (ha->queue_pair_map[i]) {
 				iocbs_used += ha->queue_pair_map[i]->fwres.iocbs_used;
+				exch_used += ha->queue_pair_map[i]->fwres.exch_used;
+			}
 		}
 
 		seq_printf(s, "Driver: estimate iocb used [%d] high water limit [%d]\n",
 			   iocbs_used, ha->base_qpair->fwres.iocbs_limit);
+
+		seq_printf(s, "estimate exchange used[%d] high water limit [%d] n",
+			   exch_used, ha->base_qpair->fwres.exch_limit);
 	}
 
 	return 0;

drivers/scsi/qla2xxx/qla_inline.h

@@ -380,7 +380,7 @@ qla2xxx_get_fc4_priority(struct scsi_qla_host *vha)
 
 enum {
 	RESOURCE_NONE,
-	RESOURCE_IOCB  = BIT_0,
+	RESOURCE_IOCB = BIT_0,
 	RESOURCE_EXCH = BIT_1,  /* exchange */
 	RESOURCE_FORCE = BIT_2,
 };
@@ -396,6 +396,8 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
 		iores->res_type = RESOURCE_NONE;
 		return 0;
 	}
+	if (iores->res_type & RESOURCE_FORCE)
+		goto force;
 
 	if ((iores->iocb_cnt + qp->fwres.iocbs_used) >= qp->fwres.iocbs_qp_limit) {
 		/* no need to acquire qpair lock. It's just rough calculation */
@@ -423,6 +425,7 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
 			return -ENOSPC;
 		}
 	}
+force:
 	qp->fwres.iocbs_used += iores->iocb_cnt;
 	qp->fwres.exch_used += iores->exch_cnt;
 	return 0;

drivers/scsi/qla2xxx/qla_iocb.c

@@ -3817,6 +3817,65 @@ qla24xx_prlo_iocb(srb_t *sp, struct logio_entry_24xx *logio)
 	logio->vp_index = sp->fcport->vha->vp_idx;
 }
 
+int qla_get_iocbs_resource(struct srb *sp)
+{
+	bool get_exch;
+	bool push_it_through = false;
+
+	if (!ql2xenforce_iocb_limit) {
+		sp->iores.res_type = RESOURCE_NONE;
+		return 0;
+	}
+	sp->iores.res_type = RESOURCE_NONE;
+
+	switch (sp->type) {
+	case SRB_TM_CMD:
+	case SRB_PRLI_CMD:
+	case SRB_ADISC_CMD:
+		push_it_through = true;
+		fallthrough;
+	case SRB_LOGIN_CMD:
+	case SRB_ELS_CMD_RPT:
+	case SRB_ELS_CMD_HST:
+	case SRB_ELS_CMD_HST_NOLOGIN:
+	case SRB_CT_CMD:
+	case SRB_NVME_LS:
+	case SRB_ELS_DCMD:
+		get_exch = true;
+		break;
+
+	case SRB_FXIOCB_DCMD:
+	case SRB_FXIOCB_BCMD:
+		sp->iores.res_type = RESOURCE_NONE;
+		return 0;
+
+	case SRB_SA_UPDATE:
+	case SRB_SA_REPLACE:
+	case SRB_MB_IOCB:
+	case SRB_ABT_CMD:
+	case SRB_NACK_PLOGI:
+	case SRB_NACK_PRLI:
+	case SRB_NACK_LOGO:
+	case SRB_LOGOUT_CMD:
+	case SRB_CTRL_VP:
+		push_it_through = true;
+		fallthrough;
+	default:
+		get_exch = false;
+	}
+
+	sp->iores.res_type |= RESOURCE_IOCB;
+	sp->iores.iocb_cnt = 1;
+	if (get_exch) {
+		sp->iores.res_type |= RESOURCE_EXCH;
+		sp->iores.exch_cnt = 1;
+	}
+	if (push_it_through)
+		sp->iores.res_type |= RESOURCE_FORCE;
+
+	return qla_get_fw_resources(sp->qpair, &sp->iores);
+}
+
 int
 qla2x00_start_sp(srb_t *sp)
 {
@@ -3831,6 +3890,12 @@ qla2x00_start_sp(srb_t *sp)
 		return -EIO;
 
 	spin_lock_irqsave(qp->qp_lock_ptr, flags);
+	rval = qla_get_iocbs_resource(sp);
+	if (rval) {
+		spin_unlock_irqrestore(qp->qp_lock_ptr, flags);
+		return -EAGAIN;
+	}
+
 	pkt = __qla2x00_alloc_iocbs(sp->qpair, sp);
 	if (!pkt) {
 		rval = EAGAIN;
@@ -3931,6 +3996,8 @@ qla2x00_start_sp(srb_t *sp)
 	wmb();
 	qla2x00_start_iocbs(vha, qp->req);
 done:
+	if (rval)
+		qla_put_fw_resources(sp->qpair, &sp->iores);
 	spin_unlock_irqrestore(qp->qp_lock_ptr, flags);
 	return rval;
 }

drivers/scsi/qla2xxx/qla_isr.c

@@ -3112,6 +3112,7 @@ qla25xx_process_bidir_status_iocb(scsi_qla_host_t *vha, void *pkt,
 	}
 	bsg_reply->reply_payload_rcv_len = 0;
 
+	qla_put_fw_resources(sp->qpair, &sp->iores);
 done:
 	/* Return the vendor specific reply to API */
 	bsg_reply->reply_data.vendor_reply.vendor_rsp[0] = rval;