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 30b22b71630e..7ca17bb024eb 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);
@@ -1115,6 +1116,30 @@ 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)
{
@@ -1125,6 +1150,14 @@ 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");