diff --git a/drivers/net/ethernet/freescale/enetc/Kconfig b/drivers/net/ethernet/freescale/enetc/Kconfig
index ab92382c399a..d88f60c2bb82 100644
--- a/drivers/net/ethernet/freescale/enetc/Kconfig
+++ b/drivers/net/ethernet/freescale/enetc/Kconfig
@@ -2,6 +2,7 @@
 config FSL_ENETC
 	tristate "ENETC PF driver"
 	depends on PCI && PCI_MSI
+	depends on FSL_ENETC_IERB || FSL_ENETC_IERB=n
 	select FSL_ENETC_MDIO
 	select PHYLINK
 	select PCS_LYNX
@@ -25,6 +26,14 @@ config FSL_ENETC_VF
 
 	  If compiled as module (M), the module name is fsl-enetc-vf.
 
+config FSL_ENETC_IERB
+	tristate "ENETC IERB driver"
+	help
+	  This driver configures the Integrated Endpoint Register Block on NXP
+	  LS1028A.
+
+	  If compiled as module (M), the module name is fsl-enetc-ierb.
+
 config FSL_ENETC_MDIO
 	tristate "ENETC MDIO driver"
 	depends on PCI && MDIO_DEVRES && MDIO_BUS
diff --git a/drivers/net/ethernet/freescale/enetc/Makefile b/drivers/net/ethernet/freescale/enetc/Makefile
index 74f7ac253b8b..a139f2e9d59f 100644
--- a/drivers/net/ethernet/freescale/enetc/Makefile
+++ b/drivers/net/ethernet/freescale/enetc/Makefile
@@ -11,6 +11,9 @@ obj-$(CONFIG_FSL_ENETC_VF) += fsl-enetc-vf.o
 fsl-enetc-vf-y := enetc_vf.o $(common-objs)
 fsl-enetc-vf-$(CONFIG_FSL_ENETC_QOS) += enetc_qos.o
 
+obj-$(CONFIG_FSL_ENETC_IERB) += fsl-enetc-ierb.o
+fsl-enetc-ierb-y := enetc_ierb.o
+
 obj-$(CONFIG_FSL_ENETC_MDIO) += fsl-enetc-mdio.o
 fsl-enetc-mdio-y := enetc_pci_mdio.o enetc_mdio.o
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ierb.c b/drivers/net/ethernet/freescale/enetc/enetc_ierb.c
new file mode 100644
index 000000000000..8b356c485507
--- /dev/null
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ierb.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Copyright 2021 NXP Semiconductors
+ *
+ * The Integrated Endpoint Register Block (IERB) is configured by pre-boot
+ * software and is supposed to be to ENETC what a NVRAM is to a 'real' PCIe
+ * card. Upon FLR, values from the IERB are transferred to the ENETC PFs, and
+ * are read-only in the PF memory space.
+ *
+ * This driver fixes up the power-on reset values for the ENETC shared FIFO,
+ * such that the TX and RX allocations are sufficient for jumbo frames, and
+ * that intelligent FIFO dropping is enabled before the internal data
+ * structures are corrupted.
+ *
+ * Even though not all ports might be used on a given board, we are not
+ * concerned with partitioning the FIFO, because the default values configure
+ * no strict reservations, so the entire FIFO can be used by the RX of a single
+ * port, or the TX of a single port.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include "enetc.h"
+#include "enetc_ierb.h"
+
+/* IERB registers */
+#define ENETC_IERB_TXMBAR(port)			(((port) * 0x100) + 0x8080)
+#define ENETC_IERB_RXMBER(port)			(((port) * 0x100) + 0x8090)
+#define ENETC_IERB_RXMBLR(port)			(((port) * 0x100) + 0x8094)
+#define ENETC_IERB_RXBCR(port)			(((port) * 0x100) + 0x80a0)
+#define ENETC_IERB_TXBCR(port)			(((port) * 0x100) + 0x80a8)
+#define ENETC_IERB_FMBDTR			0xa000
+
+#define ENETC_RESERVED_FOR_ICM			1024
+
+struct enetc_ierb {
+	void __iomem *regs;
+};
+
+static void enetc_ierb_write(struct enetc_ierb *ierb, u32 offset, u32 val)
+{
+	iowrite32(val, ierb->regs + offset);
+}
+
+int enetc_ierb_register_pf(struct platform_device *pdev,
+			   struct pci_dev *pf_pdev)
+{
+	struct enetc_ierb *ierb = platform_get_drvdata(pdev);
+	int port = enetc_pf_to_port(pf_pdev);
+	u16 tx_credit, rx_credit, tx_alloc;
+
+	if (port < 0)
+		return -ENODEV;
+
+	if (!ierb)
+		return -EPROBE_DEFER;
+
+	/* By default, it is recommended to set the Host Transfer Agent
+	 * per port transmit byte credit to "1000 + max_frame_size/2".
+	 * The power-on reset value (1800 bytes) is rounded up to the nearest
+	 * 100 assuming a maximum frame size of 1536 bytes.
+	 */
+	tx_credit = roundup(1000 + ENETC_MAC_MAXFRM_SIZE / 2, 100);
+
+	/* Internal memory allocated for transmit buffering is guaranteed but
+	 * not reserved; i.e. if the total transmit allocation is not used,
+	 * then the unused portion is not left idle, it can be used for receive
+	 * buffering but it will be reclaimed, if required, from receive by
+	 * intelligently dropping already stored receive frames in the internal
+	 * memory to ensure that the transmit allocation is respected.
+	 *
+	 * PaTXMBAR must be set to a value larger than
+	 *     PaTXBCR + 2 * max_frame_size + 32
+	 * if frame preemption is not enabled, or to
+	 *     2 * PaTXBCR + 2 * p_max_frame_size (pMAC maximum frame size) +
+	 *     2 * np_max_frame_size (eMAC maximum frame size) + 64
+	 * if frame preemption is enabled.
+	 */
+	tx_alloc = roundup(2 * tx_credit + 4 * ENETC_MAC_MAXFRM_SIZE + 64, 16);
+
+	/* Initial credits, in units of 8 bytes, to the Ingress Congestion
+	 * Manager for the maximum amount of bytes the port is allocated for
+	 * pending traffic.
+	 * It is recommended to set the initial credits to 2 times the maximum
+	 * frame size (2 frames of maximum size).
+	 */
+	rx_credit = DIV_ROUND_UP(ENETC_MAC_MAXFRM_SIZE * 2, 8);
+
+	enetc_ierb_write(ierb, ENETC_IERB_TXBCR(port), tx_credit);
+	enetc_ierb_write(ierb, ENETC_IERB_TXMBAR(port), tx_alloc);
+	enetc_ierb_write(ierb, ENETC_IERB_RXBCR(port), rx_credit);
+
+	return 0;
+}
+EXPORT_SYMBOL(enetc_ierb_register_pf);
+
+static int enetc_ierb_probe(struct platform_device *pdev)
+{
+	struct enetc_ierb *ierb;
+	struct resource *res;
+	void __iomem *regs;
+
+	ierb = devm_kzalloc(&pdev->dev, sizeof(*ierb), GFP_KERNEL);
+	if (!ierb)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	ierb->regs = regs;
+
+	/* Free buffer depletion threshold in bytes.
+	 * This sets the minimum amount of free buffer memory that should be
+	 * maintained in the datapath sub system, and when the amount of free
+	 * buffer memory falls below this threshold, a depletion indication is
+	 * asserted, which may trigger "intelligent drop" frame releases from
+	 * the ingress queues in the ICM.
+	 * It is recommended to set the free buffer depletion threshold to 1024
+	 * bytes, since the ICM needs some FIFO memory for its own use.
+	 */
+	enetc_ierb_write(ierb, ENETC_IERB_FMBDTR, ENETC_RESERVED_FOR_ICM);
+
+	platform_set_drvdata(pdev, ierb);
+
+	return 0;
+}
+
+static int enetc_ierb_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static const struct of_device_id enetc_ierb_match[] = {
+	{ .compatible = "fsl,ls1028a-enetc-ierb", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, enetc_ierb_match);
+
+static struct platform_driver enetc_ierb_driver = {
+	.driver = {
+		.name = "fsl-enetc-ierb",
+		.of_match_table = enetc_ierb_match,
+	},
+	.probe = enetc_ierb_probe,
+	.remove = enetc_ierb_remove,
+};
+
+module_platform_driver(enetc_ierb_driver);
+
+MODULE_DESCRIPTION("NXP ENETC IERB");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ierb.h b/drivers/net/ethernet/freescale/enetc/enetc_ierb.h
new file mode 100644
index 000000000000..b3b774e0998a
--- /dev/null
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ierb.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Copyright 2021 NXP Semiconductors */
+
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#if IS_ENABLED(CONFIG_FSL_ENETC_IERB)
+
+int enetc_ierb_register_pf(struct platform_device *pdev,
+			   struct pci_dev *pf_pdev);
+
+#else
+
+static inline int enetc_ierb_register_pf(struct platform_device *pdev,
+					 struct pci_dev *pf_pdev)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index be3dde0618e7..1ae2473cbc16 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -4,8 +4,10 @@
 #include <linux/mdio.h>
 #include <linux/module.h>
 #include <linux/fsl/enetc_mdio.h>
+#include <linux/of_platform.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
+#include "enetc_ierb.h"
 #include "enetc_pf.h"
 
 #define ENETC_DRV_NAME_STR "ENETC PF driver"
@@ -518,7 +520,6 @@ static void enetc_configure_port_mac(struct enetc_hw *hw)
 		      ENETC_SET_MAXFRM(ENETC_RX_MAXFRM_SIZE));
 
 	enetc_port_wr(hw, ENETC_PTCMSDUR(0), ENETC_MAC_MAXFRM_SIZE);
-	enetc_port_wr(hw, ENETC_PTXMBAR, 2 * ENETC_MAC_MAXFRM_SIZE);
 
 	enetc_port_wr(hw, ENETC_PM0_CMD_CFG, ENETC_PM0_CMD_PHY_TX_EN |
 		      ENETC_PM0_CMD_TXP	| ENETC_PM0_PROMISC);
@@ -1116,6 +1117,30 @@ static int enetc_init_port_rss_memory(struct enetc_si *si)
 	return err;
 }
 
+static int enetc_pf_register_with_ierb(struct pci_dev *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct platform_device *ierb_pdev;
+	struct device_node *ierb_node;
+
+	/* Don't register with the IERB if the PF itself is disabled */
+	if (!node || !of_device_is_available(node))
+		return 0;
+
+	ierb_node = of_find_compatible_node(NULL, NULL,
+					    "fsl,ls1028a-enetc-ierb");
+	if (!ierb_node || !of_device_is_available(ierb_node))
+		return -ENODEV;
+
+	ierb_pdev = of_find_device_by_node(ierb_node);
+	of_node_put(ierb_node);
+
+	if (!ierb_pdev)
+		return -EPROBE_DEFER;
+
+	return enetc_ierb_register_pf(ierb_pdev, pdev);
+}
+
 static int enetc_pf_probe(struct pci_dev *pdev,
 			  const struct pci_device_id *ent)
 {
@@ -1126,6 +1151,14 @@ static int enetc_pf_probe(struct pci_dev *pdev,
 	struct enetc_pf *pf;
 	int err;
 
+	err = enetc_pf_register_with_ierb(pdev);
+	if (err == -EPROBE_DEFER)
+		return err;
+	if (err)
+		dev_warn(&pdev->dev,
+			 "Could not register with IERB driver: %pe, please update the device tree\n",
+			 ERR_PTR(err));
+
 	err = enetc_pci_probe(pdev, KBUILD_MODNAME, sizeof(*pf));
 	if (err) {
 		dev_err(&pdev->dev, "PCI probing failed\n");
