cndm: Add support for devlink

Signed-off-by: Alex Forencich <alex@alexforencich.com>

src/cndm/modules/cndm/Makefile

@@ -5,6 +5,7 @@ ifneq ($(KERNELRELEASE),)
 
 obj-m += cndm.o
 cndm-y += cndm_main.o
+cndm-y += cndm_devlink.o
 cndm-y += cndm_netdev.o
 cndm-y += cndm_tx.o
 cndm-y += cndm_rx.o

src/cndm/modules/cndm/cndm.h

@@ -16,6 +16,7 @@ Authors:
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/ptp_clock_kernel.h>
+#include <net/devlink.h>
 
 #define DRIVER_NAME "cndm"
 #define DRIVER_VERSION "0.1"
@@ -122,14 +123,21 @@ struct cndm_cpl {
 	__u8 phase;
 };
 
+// cndm_devlink.c
+struct devlink *cndm_devlink_alloc(struct device *dev);
+void cndm_devlink_free(struct devlink *devlink);
+
+// cndm_netdev.c
 irqreturn_t cndm_irq(int irqn, void *data);
 struct net_device *cndm_create_netdev(struct cndm_dev *cdev, int port, void __iomem *hw_addr);
 void cndm_destroy_netdev(struct net_device *ndev);
 
+// cndm_tx.c
 int cndm_free_tx_buf(struct cndm_priv *priv);
 int cndm_poll_tx_cq(struct napi_struct *napi, int budget);
 int cndm_start_xmit(struct sk_buff *skb, struct net_device *ndev);
 
+// cndm_rx.c
 int cndm_free_rx_buf(struct cndm_priv *priv);
 int cndm_refill_rx_buffers(struct cndm_priv *priv);
 int cndm_poll_rx_cq(struct napi_struct *napi, int budget);

src/cndm/modules/cndm/cndm_devlink.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL
+/*
+
+Copyright (c) 2025 FPGA Ninja, LLC
+
+Authors:
+- Alex Forencich
+
+*/
+
+#include "cndm.h"
+
+#include <linux/version.h>
+
+static int cndm_devlink_info_get(struct devlink *devlink,
+	struct devlink_info_req *req, struct netlink_ext_ack *extack)
+{
+	struct cndm_dev *cdev = devlink_priv(devlink);
+	char str[32];
+	int ret = 0;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 2, 0)
+	ret = devlink_info_driver_name_put(req, KBUILD_MODNAME);
+	if (ret)
+		return ret;
+#endif
+
+	snprintf(str, sizeof(str), "%08x", 0); // TODO
+
+	ret = devlink_info_version_fixed_put(req, "fpga.id", str);
+	if (ret)
+		return ret;
+
+	snprintf(str, sizeof(str), "%08x", 0); // TODO
+
+	ret = devlink_info_version_fixed_put(req, DEVLINK_INFO_VERSION_GENERIC_BOARD_ID, str);
+	if (ret)
+		return ret;
+
+	snprintf(str, sizeof(str), "%08x", 0); // TODO
+
+	ret = devlink_info_version_fixed_put(req, DEVLINK_INFO_VERSION_GENERIC_BOARD_REV, str);
+	if (ret)
+		return ret;
+
+	snprintf(str, sizeof(str), "%08x", 0); // TODO
+
+	ret = devlink_info_version_running_put(req, "fw.id", str);
+	if (ret)
+		return ret;
+
+	snprintf(str, sizeof(str), "%08x", 0); // TODO
+
+	ret = devlink_info_version_running_put(req, DEVLINK_INFO_VERSION_GENERIC_FW, str);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+static const struct devlink_ops cndm_devlink_ops = {
+	.info_get = cndm_devlink_info_get,
+};
+
+struct devlink *cndm_devlink_alloc(struct device *dev)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
+	return devlink_alloc(&cndm_devlink_ops, sizeof(struct cndm_dev), dev);
+#else
+	return devlink_alloc(&cndm_devlink_ops, sizeof(struct cndm_dev));
+#endif
+}
+
+void cndm_devlink_free(struct devlink *devlink) {
+	devlink_free(devlink);
+}

src/cndm/modules/cndm/cndm_main.c

@@ -11,6 +11,7 @@ Authors:
 #include "cndm.h"
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/version.h>
 
 MODULE_DESCRIPTION("Corundum device driver");
 MODULE_AUTHOR("FPGA Ninja");
@@ -20,6 +21,7 @@ MODULE_VERSION(DRIVER_VERSION);
 static int cndm_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	struct device *dev = &pdev->dev;
+	struct devlink *devlink;
 	struct cndm_dev *cdev;
 	int ret = 0;
 	int k;
@@ -32,10 +34,11 @@ static int cndm_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pcie_print_link_status(pdev);
 
-	cdev = devm_kzalloc(dev, sizeof(struct cndm_dev), GFP_KERNEL);
+	devlink = cndm_devlink_alloc(dev);
-	if (!cdev)
+	if (!devlink)
 		return -ENOMEM;
 
+	cdev = devlink_priv(devlink);
 	cdev->pdev = pdev;
 	cdev->dev = dev;
 	pci_set_drvdata(pdev, cdev);
@@ -76,6 +79,12 @@ static int cndm_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto fail_map_bars;
 	}
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
+	devlink_register(devlink);
+#else
+	devlink_register(devlink, dev);
+#endif
+
 	cdev->port_count = ioread32(cdev->bar + 0x0100);
 	cdev->port_offset = ioread32(cdev->bar + 0x0104);
 	cdev->port_stride = ioread32(cdev->bar + 0x0108);
@@ -113,6 +122,7 @@ fail_netdev:
 			cdev->ndev[k] = NULL;
 		}
 	}
+	devlink_unregister(devlink);
 	pci_free_irq_vectors(pdev);
 fail_map_bars:
 	if (cdev->bar)
@@ -122,6 +132,7 @@ fail_regions:
 	pci_clear_master(pdev);
 	pci_disable_device(pdev);
 fail_enable_device:
+	cndm_devlink_free(devlink);
 	return ret;
 }
 
@@ -129,6 +140,7 @@ static void cndm_pci_remove(struct pci_dev *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cndm_dev *cdev = pci_get_drvdata(pdev);
+	struct devlink *devlink = priv_to_devlink(cdev);
 	int k;
 
 	dev_info(dev, DRIVER_NAME " PCI remove");
@@ -140,12 +152,14 @@ static void cndm_pci_remove(struct pci_dev *pdev)
 			cdev->ndev[k] = NULL;
 		}
 	}
+	devlink_unregister(devlink);
 	pci_free_irq_vectors(pdev);
 	if (cdev->bar)
 		pci_iounmap(pdev, cdev->bar);
 	pci_release_regions(pdev);
 	pci_clear_master(pdev);
 	pci_disable_device(pdev);
+	cndm_devlink_free(devlink);
 }
 
 static const struct pci_device_id cndm_pci_id_table[] = {