diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index 51fec6497164..b18e938312e1 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -847,6 +847,46 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	return 0;
 }
 
+static int config_rsvd_lut_win(struct switchtec_ntb *sndev,
+			       struct ntb_ctrl_regs __iomem *ctl,
+			       int lut_idx, int partition,
+			       dma_addr_t addr)
+{
+	int peer_bar = sndev->peer_direct_mw_to_bar[0];
+	u32 ctl_val;
+	int rc;
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
+				   NTB_CTRL_PART_STATUS_LOCKED);
+	if (rc)
+		return rc;
+
+	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
+	ctl_val &= 0xFF;
+	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
+	ctl_val |= ilog2(LUT_SIZE) << 8;
+	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
+	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);
+
+	iowrite64((NTB_CTRL_LUT_EN | (partition << 1) | addr),
+		  &ctl->lut_entry[lut_idx]);
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
+				   NTB_CTRL_PART_STATUS_NORMAL);
+	if (rc) {
+		u32 bar_error, lut_error;
+
+		bar_error = ioread32(&ctl->bar_error);
+		lut_error = ioread32(&ctl->lut_error);
+		dev_err(&sndev->stdev->dev,
+			"Error setting up reserved lut window: %08x / %08x\n",
+			bar_error, lut_error);
+		return rc;
+	}
+
+	return 0;
+}
+
 static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
 {
 	int i;
@@ -1004,10 +1044,7 @@ static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
 
 static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
 {
-	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
 	int self_bar = sndev->direct_mw_to_bar[0];
-	int peer_bar = sndev->peer_direct_mw_to_bar[0];
-	u32 ctl_val;
 	int rc;
 
 	sndev->nr_rsvd_luts++;
@@ -1023,35 +1060,12 @@ static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
 
 	switchtec_ntb_init_shared(sndev);
 
-	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
-				   NTB_CTRL_PART_STATUS_LOCKED);
+	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
+				 sndev->self_partition,
+				 sndev->self_shared_dma);
 	if (rc)
 		goto unalloc_and_exit;
 
-	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
-	ctl_val &= 0xFF;
-	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
-	ctl_val |= ilog2(LUT_SIZE) << 8;
-	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
-	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);
-
-	iowrite64((NTB_CTRL_LUT_EN | (sndev->self_partition << 1) |
-		   sndev->self_shared_dma),
-		  &ctl->lut_entry[0]);
-
-	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
-				   NTB_CTRL_PART_STATUS_NORMAL);
-	if (rc) {
-		u32 bar_error, lut_error;
-
-		bar_error = ioread32(&ctl->bar_error);
-		lut_error = ioread32(&ctl->lut_error);
-		dev_err(&sndev->stdev->dev,
-			"Error setting up shared MW: %08x / %08x\n",
-			bar_error, lut_error);
-		goto unalloc_and_exit;
-	}
-
 	sndev->peer_shared = pci_iomap(sndev->stdev->pdev, self_bar, LUT_SIZE);
 	if (!sndev->peer_shared) {
 		rc = -ENOMEM;