bng_en: Add devlink interface

Allocate a base device and devlink interface with minimal
devlink ops.
Add dsn and board related information.
Map PCIe BAR (bar0), which helps to communicate with the
firmware.

Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Reviewed-by: Rajashekar Hudumula <rajashekar.hudumula@broadcom.com>
Link: https://patch.msgid.link/20250701143511.280702-3-vikas.gupta@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/Kconfig

@@ -256,6 +256,7 @@ config BNXT_HWMON
 config BNGE
 	tristate "Broadcom Ethernet device support"
 	depends on PCI
+	select NET_DEVLINK
 	help
 	  This driver supports Broadcom 50/100/200/400/800 gigabit Ethernet cards.
 	  The module will be called bng_en. To compile this driver as a module,

drivers/net/ethernet/broadcom/bnge/Makefile

@@ -2,4 +2,5 @@
 
 obj-$(CONFIG_BNGE) += bng_en.o
 
-bng_en-y := bnge_core.o
+bng_en-y := bnge_core.o \
+	    bnge_devlink.o

drivers/net/ethernet/broadcom/bnge/bnge.h

@@ -13,4 +13,15 @@ enum board_idx {
 	BCM57708,
 };
 
+struct bnge_dev {
+	struct device	*dev;
+	struct pci_dev	*pdev;
+	u64	dsn;
+#define BNGE_VPD_FLD_LEN	32
+	char		board_partno[BNGE_VPD_FLD_LEN];
+	char		board_serialno[BNGE_VPD_FLD_LEN];
+
+	void __iomem	*bar0;
+};
+
 #endif /* _BNGE_H_ */

drivers/net/ethernet/broadcom/bnge/bnge_core.c

@@ -7,6 +7,7 @@
 #include <linux/pci.h>
 
 #include "bnge.h"
+#include "bnge_devlink.h"
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION(DRV_SUMMARY);
@@ -77,8 +78,19 @@ err_pci_disable:
 	return rc;
 }
 
+static void bnge_unmap_bars(struct pci_dev *pdev)
+{
+	struct bnge_dev *bd = pci_get_drvdata(pdev);
+
+	if (bd->bar0) {
+		pci_iounmap(pdev, bd->bar0);
+		bd->bar0 = NULL;
+	}
+}
+
 static int bnge_probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
+	struct bnge_dev *bd;
 	int rc;
 
 	if (pci_is_bridge(pdev))
@@ -100,13 +112,40 @@ static int bnge_probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	bnge_print_device_info(pdev, ent->driver_data);
 
+	bd = bnge_devlink_alloc(pdev);
+	if (!bd) {
+		dev_err(&pdev->dev, "Devlink allocation failed\n");
+		rc = -ENOMEM;
+		goto err_pci_disable;
+	}
+
+	bd->bar0 = pci_ioremap_bar(pdev, 0);
+	if (!bd->bar0) {
+		dev_err(&pdev->dev, "Failed mapping BAR-0, aborting\n");
+		rc = -ENOMEM;
+		goto err_devl_free;
+	}
+
 	pci_save_state(pdev);
 
 	return 0;
+
+err_devl_free:
+	bnge_devlink_free(bd);
+
+err_pci_disable:
+	bnge_pci_disable(pdev);
+	return rc;
 }
 
 static void bnge_remove_one(struct pci_dev *pdev)
 {
+	struct bnge_dev *bd = pci_get_drvdata(pdev);
+
+	bnge_unmap_bars(pdev);
+
+	bnge_devlink_free(bd);
+
 	bnge_pci_disable(pdev);
 }
 

drivers/net/ethernet/broadcom/bnge/bnge_devlink.c

@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2025 Broadcom.
+
+#include <linux/unaligned.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <net/devlink.h>
+
+#include "bnge.h"
+#include "bnge_devlink.h"
+
+static int bnge_dl_info_put(struct bnge_dev *bd, struct devlink_info_req *req,
+			    enum bnge_dl_version_type type, const char *key,
+			    char *buf)
+{
+	if (!strlen(buf))
+		return 0;
+
+	switch (type) {
+	case BNGE_VERSION_FIXED:
+		return devlink_info_version_fixed_put(req, key, buf);
+	case BNGE_VERSION_RUNNING:
+		return devlink_info_version_running_put(req, key, buf);
+	case BNGE_VERSION_STORED:
+		return devlink_info_version_stored_put(req, key, buf);
+	}
+
+	return 0;
+}
+
+static void bnge_vpd_read_info(struct bnge_dev *bd)
+{
+	struct pci_dev *pdev = bd->pdev;
+	unsigned int vpd_size, kw_len;
+	int pos, size;
+	u8 *vpd_data;
+
+	vpd_data = pci_vpd_alloc(pdev, &vpd_size);
+	if (IS_ERR(vpd_data)) {
+		pci_warn(pdev, "Unable to read VPD\n");
+		return;
+	}
+
+	pos = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
+					   PCI_VPD_RO_KEYWORD_PARTNO, &kw_len);
+	if (pos < 0)
+		goto read_sn;
+
+	size = min_t(int, kw_len, BNGE_VPD_FLD_LEN - 1);
+	memcpy(bd->board_partno, &vpd_data[pos], size);
+
+read_sn:
+	pos = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
+					   PCI_VPD_RO_KEYWORD_SERIALNO,
+					   &kw_len);
+	if (pos < 0)
+		goto exit;
+
+	size = min_t(int, kw_len, BNGE_VPD_FLD_LEN - 1);
+	memcpy(bd->board_serialno, &vpd_data[pos], size);
+
+exit:
+	kfree(vpd_data);
+}
+
+static int bnge_devlink_info_get(struct devlink *devlink,
+				 struct devlink_info_req *req,
+				 struct netlink_ext_ack *extack)
+{
+	struct bnge_dev *bd = devlink_priv(devlink);
+	int rc;
+
+	if (bd->dsn) {
+		char buf[32];
+		u8 dsn[8];
+		int rc;
+
+		put_unaligned_le64(bd->dsn, dsn);
+		sprintf(buf, "%02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X",
+			dsn[7], dsn[6], dsn[5], dsn[4],
+			dsn[3], dsn[2], dsn[1], dsn[0]);
+		rc = devlink_info_serial_number_put(req, buf);
+		if (rc) {
+			NL_SET_ERR_MSG_MOD(extack, "Failed to set dsn");
+			return rc;
+		}
+	}
+
+	if (strlen(bd->board_serialno)) {
+		rc = devlink_info_board_serial_number_put(req,
+							  bd->board_serialno);
+		if (rc) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to set board serial number");
+			return rc;
+		}
+	}
+
+	rc = bnge_dl_info_put(bd, req, BNGE_VERSION_FIXED,
+			      DEVLINK_INFO_VERSION_GENERIC_BOARD_ID,
+			      bd->board_partno);
+	if (rc) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to set board part number");
+		return rc;
+	}
+
+	return rc;
+}
+
+static const struct devlink_ops bnge_devlink_ops = {
+	.info_get = bnge_devlink_info_get,
+};
+
+void bnge_devlink_free(struct bnge_dev *bd)
+{
+	struct devlink *devlink = priv_to_devlink(bd);
+
+	devlink_free(devlink);
+}
+
+struct bnge_dev *bnge_devlink_alloc(struct pci_dev *pdev)
+{
+	struct devlink *devlink;
+	struct bnge_dev *bd;
+
+	devlink = devlink_alloc(&bnge_devlink_ops, sizeof(*bd), &pdev->dev);
+	if (!devlink)
+		return NULL;
+
+	bd = devlink_priv(devlink);
+	pci_set_drvdata(pdev, bd);
+	bd->dev = &pdev->dev;
+	bd->pdev = pdev;
+
+	bd->dsn = pci_get_dsn(pdev);
+	if (!bd->dsn)
+		pci_warn(pdev, "Failed to get DSN\n");
+
+	bnge_vpd_read_info(bd);
+
+	return bd;
+}

drivers/net/ethernet/broadcom/bnge/bnge_devlink.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2025 Broadcom */
+
+#ifndef _BNGE_DEVLINK_H_
+#define _BNGE_DEVLINK_H_
+
+enum bnge_dl_version_type {
+	BNGE_VERSION_FIXED,
+	BNGE_VERSION_RUNNING,
+	BNGE_VERSION_STORED,
+};
+
+void bnge_devlink_free(struct bnge_dev *bd);
+struct bnge_dev *bnge_devlink_alloc(struct pci_dev *pdev);
+
+#endif /* _BNGE_DEVLINK_H_ */