can: kvaser_pciefd: Add devlink support

Add devlink support at device level.

Example output:
  $ devlink dev
  pci/0000:07:00.0
  pci/0000:08:00.0
  pci/0000:09:00.0

  $ devlink dev info
  pci/0000:07:00.0:
    driver kvaser_pciefd
  pci/0000:08:00.0:
    driver kvaser_pciefd
  pci/0000:09:00.0:
    driver kvaser_pciefd

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://patch.msgid.link/20250725123230.8-8-extja@kvaser.com
[mkl: kvaser_pciefd_remove(): fix use-after-free]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: Jimmy Assarsson

drivers/net/can/Kconfig

@@ -154,6 +154,7 @@ config CAN_JANZ_ICAN3
 config CAN_KVASER_PCIEFD
 	depends on PCI
 	tristate "Kvaser PCIe FD cards"
+	select NET_DEVLINK
 	help
 	  This is a driver for the Kvaser PCI Express CAN FD family.
 

drivers/net/can/kvaser_pciefd/Makefile

@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_CAN_KVASER_PCIEFD) += kvaser_pciefd.o
-kvaser_pciefd-y = kvaser_pciefd_core.o
+kvaser_pciefd-y = kvaser_pciefd_core.o kvaser_pciefd_devlink.o

drivers/net/can/kvaser_pciefd/kvaser_pciefd.h

@@ -13,6 +13,7 @@
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 #include <linux/types.h>
+#include <net/devlink.h>
 
 #define KVASER_PCIEFD_MAX_CAN_CHANNELS 8UL
 #define KVASER_PCIEFD_DMA_COUNT 2U
@@ -87,4 +88,5 @@ struct kvaser_pciefd {
 	struct kvaser_pciefd_fw_version fw_version;
 };
 
+extern const struct devlink_ops kvaser_pciefd_devlink_ops;
 #endif /* _KVASER_PCIEFD_H */

drivers/net/can/kvaser_pciefd/kvaser_pciefd_core.c

@@ -1751,22 +1751,24 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev,
 			       const struct pci_device_id *id)
 {
 	int ret;
+	struct devlink *devlink;
 	struct device *dev = &pdev->dev;
 	struct kvaser_pciefd *pcie;
 	const struct kvaser_pciefd_irq_mask *irq_mask;
 
-	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
-	if (!pcie)
+	devlink = devlink_alloc(&kvaser_pciefd_devlink_ops, sizeof(*pcie), dev);
+	if (!devlink)
 		return -ENOMEM;
 
+	pcie = devlink_priv(devlink);
 	pci_set_drvdata(pdev, pcie);
 	pcie->pci = pdev;
 	pcie->driver_data = (const struct kvaser_pciefd_driver_data *)id->driver_data;
 	irq_mask = pcie->driver_data->irq_mask;
 
 	ret = pci_enable_device(pdev);
 	if (ret)
-		return ret;
+		goto err_free_devlink;
 
 	ret = pci_request_regions(pdev, KVASER_PCIEFD_DRV_NAME);
 	if (ret)
@@ -1830,6 +1832,8 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev,
 	if (ret)
 		goto err_free_irq;
 
+	devlink_register(devlink);
+
 	return 0;
 
 err_free_irq:
@@ -1853,6 +1857,9 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev,
 err_disable_pci:
 	pci_disable_device(pdev);
 
+err_free_devlink:
+	devlink_free(devlink);
+
 	return ret;
 }
 
@@ -1876,9 +1883,11 @@ static void kvaser_pciefd_remove(struct pci_dev *pdev)
 	for (i = 0; i < pcie->nr_channels; ++i)
 		free_candev(pcie->can[i]->can.dev);
 
+	devlink_unregister(priv_to_devlink(pcie));
 	pci_iounmap(pdev, pcie->reg_base);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
+	devlink_free(priv_to_devlink(pcie));
 }
 
 static struct pci_driver kvaser_pciefd = {

drivers/net/can/kvaser_pciefd/kvaser_pciefd_devlink.c

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+/* kvaser_pciefd devlink functions
+ *
+ * Copyright (C) 2025 KVASER AB, Sweden. All rights reserved.
+ */
+#include "kvaser_pciefd.h"
+
+#include <net/devlink.h>
+
+const struct devlink_ops kvaser_pciefd_devlink_ops = {
+};