ixd: add devlink support

Enable initial support for the devlink interface with the ixd driver. The
ixd hardware is a single function PCIe device. So, the PCIe adapter gets
its own devlink instance to manage device-wide resources or configuration.

$ devlink dev show
pci/0000:83:00.6

$ devlink dev info pci/0000:83:00.6
pci/0000:83:00.6:
  driver ixd
  serial_number 00-a0-c9-ff-ff-23-45-67
  versions:
      fixed:
        device.type MEV
      running:
        fw.mgmt.api 2.0

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Tested-by: Bharath R <Bharath.r@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Documentation/networking/devlink/index.rst

@@ -87,6 +87,7 @@ parameters, info versions, and other features it supports.
    ice
    ionic
    iosm
+   ixd
    ixgbe
    kvaser_pciefd
    kvaser_usb

Documentation/networking/devlink/ixd.rst

@@ -0,0 +1,30 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================
+ixd devlink support
+===================
+
+This document describes the devlink features implemented by the ``ixd``
+device driver.
+
+Info versions
+=============
+
+The ``ixd`` driver reports the following versions
+
+.. list-table:: devlink info versions implemented
+    :widths: 5 5 5 90
+
+    * - Name
+      - Type
+      - Example
+      - Description
+    * - ``device.type``
+      - fixed
+      - MEV
+      - The hardware type for this device
+    * - ``fw.mgmt.api``
+      - running
+      - 2.0
+      - 2-digit version number (major.minor) of the communication channel
+        (virtchnl) used by the device.

drivers/net/ethernet/intel/ixd/Kconfig

@@ -6,6 +6,7 @@ config IXD
 	depends on PCI_MSI
 	select LIBIE_CP
 	select LIBIE_PCI
+	select NET_DEVLINK
 	help
 	  This driver supports Intel(R) Control Plane PCI Function
 	  of Intel E2100 and later IPUs and FNICs.

drivers/net/ethernet/intel/ixd/Makefile

@@ -8,5 +8,6 @@ obj-$(CONFIG_IXD) += ixd.o
 ixd-y := ixd_main.o
 ixd-y += ixd_ctlq.o
 ixd-y += ixd_dev.o
+ixd-y += ixd_devlink.o
 ixd-y += ixd_lib.o
 ixd-y += ixd_virtchnl.o

drivers/net/ethernet/intel/ixd/ixd.h

@@ -15,6 +15,7 @@
  * @init_task.init_work: Delayed initialization work
  * @init_task.reset_retries: How many times to check, whether reset is completed
  * @init_task.vc_retries: Number of retries to establish mailbox communication
+ * @init_task.success: init_work completion status
  * @mbx_task: Control queue Rx handling
  * @xnm: virtchnl transaction manager
  * @asq: Send control queue info
@@ -30,6 +31,7 @@ struct ixd_adapter {
 		struct delayed_work init_work;
 		u8 reset_retries;
 		u8 vc_retries;
+		bool success;
 	} init_task;
 	struct delayed_work mbx_task;
 	struct libie_ctlq_xn_manager *xnm;

drivers/net/ethernet/intel/ixd/ixd_devlink.c

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025, Intel Corporation. */
+
+#include "ixd.h"
+#include "ixd_devlink.h"
+
+#define IXD_DEVLINK_INFO_LEN	128
+
+/**
+ * ixd_fill_dsn - Get the serial number for the ixd device
+ * @adapter: adapter to query
+ * @buf: storage buffer for the info request
+ */
+static void ixd_fill_dsn(struct ixd_adapter *adapter, char *buf)
+{
+	u8 dsn[8];
+
+	/* Copy the DSN into an array in Big Endian format */
+	put_unaligned_be64(pci_get_dsn(adapter->cp_ctx.mmio_info.pdev), dsn);
+
+	snprintf(buf, IXD_DEVLINK_INFO_LEN, "%8phD", dsn);
+}
+
+/**
+ * ixd_fill_device_name - Get the name of the underlying hardware
+ * @adapter: adapter to query
+ * @buf: storage buffer for the info request
+ * @buf_size: size of the storage buffer
+ */
+static void ixd_fill_device_name(struct ixd_adapter *adapter, char *buf,
+				 size_t buf_size)
+{
+	if (adapter->caps.device_type == cpu_to_le32(VIRTCHNL2_MEV_DEVICE))
+		snprintf(buf, buf_size, "%s", "MEV");
+	else
+		snprintf(buf, buf_size, "%s", "UNKNOWN");
+}
+
+/**
+ * ixd_devlink_info_get - .info_get devlink handler
+ * @devlink: devlink instance structure
+ * @req: the devlink info request
+ * @extack: extended netdev ack structure
+ *
+ * Callback for the devlink .info_get operation. Reports information about the
+ * device.
+ *
+ * Return: zero on success or an error code on failure.
+ */
+static int ixd_devlink_info_get(struct devlink *devlink,
+				struct devlink_info_req *req,
+				struct netlink_ext_ack *extack)
+{
+	struct ixd_adapter *adapter = devlink_priv(devlink);
+	char buf[IXD_DEVLINK_INFO_LEN];
+	int err;
+
+	ixd_fill_dsn(adapter, buf);
+	err = devlink_info_serial_number_put(req, buf);
+	if (err)
+		return err;
+
+	ixd_fill_device_name(adapter, buf, IXD_DEVLINK_INFO_LEN);
+	err = devlink_info_version_fixed_put(req, "device.type", buf);
+	if (err)
+		return err;
+
+	snprintf(buf, sizeof(buf), "%u.%u",
+		 adapter->vc_ver.major, adapter->vc_ver.minor);
+
+	return devlink_info_version_running_put(req,
+						DEVLINK_INFO_VERSION_GENERIC_FW_MGMT_API,
+						buf);
+}
+
+static const struct devlink_ops ixd_devlink_ops = {
+	.info_get = ixd_devlink_info_get,
+};
+
+/**
+ * ixd_adapter_alloc - Allocate devlink and return adapter pointer
+ * @dev: the device to allocate for
+ *
+ * Allocate a devlink instance for this device and return the private area as
+ * the adapter structure.
+ *
+ * Return: adapter structure on success, NULL on failure
+ */
+struct ixd_adapter *ixd_adapter_alloc(struct device *dev)
+{
+	struct devlink *devlink;
+
+	devlink = devlink_alloc(&ixd_devlink_ops, sizeof(struct ixd_adapter),
+				dev);
+	if (!devlink)
+		return NULL;
+
+	return devlink_priv(devlink);
+}

drivers/net/ethernet/intel/ixd/ixd_devlink.h

@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2025, Intel Corporation. */
+
+#ifndef _IXD_DEVLINK_H_
+#define _IXD_DEVLINK_H_
+
+#include <net/devlink.h>
+
+#include "ixd.h"
+
+struct ixd_adapter *ixd_adapter_alloc(struct device *dev);
+
+/**
+ * ixd_devlink_free - teardown the devlink
+ * @adapter: the adapter structure to free
+ *
+ */
+static inline void ixd_devlink_free(struct ixd_adapter *adapter)
+{
+	struct devlink *devlink = priv_to_devlink(adapter);
+
+	devlink_free(devlink);
+}
+
+/**
+ * ixd_devlink_unregister - Unregister devlink for this adapter.
+ * @adapter: the adapter structure to cleanup
+ *
+ * Init task must be completed or cancelled beforehand.
+ */
+static inline void ixd_devlink_unregister(struct ixd_adapter *adapter)
+{
+	if (!adapter->init_task.success)
+		return;
+
+	devlink_unregister(priv_to_devlink(adapter));
+}
+
+/**
+ * ixd_devlink_register - Register devlink interface for this adapter
+ * @adapter: pointer to ixd adapter structure to be associated with devlink
+ *
+ * Register the devlink instance associated with this adapter
+ */
+static inline void ixd_devlink_register(struct ixd_adapter *adapter)
+{
+	devlink_register(priv_to_devlink(adapter));
+}
+
+#endif /* _IXD_DEVLINK_H_ */

drivers/net/ethernet/intel/ixd/ixd_lib.c

@@ -3,6 +3,7 @@
 
 #include "ixd.h"
 #include "ixd_ctlq.h"
+#include "ixd_devlink.h"
 #include "ixd_virtchnl.h"
 
 #define IXD_DFLT_MBX_Q_LEN 64
@@ -151,6 +152,8 @@ void ixd_init_task(struct work_struct *work)
 	err = ixd_vc_dev_init(adapter);
 	if (!err) {
 		adapter->init_task.vc_retries = 0;
+		adapter->init_task.success = true;
+		ixd_devlink_register(adapter);
 		return;
 	}
 

drivers/net/ethernet/intel/ixd/ixd_main.c

@@ -4,6 +4,7 @@
 #include "ixd.h"
 #include "ixd_ctlq.h"
 #include "ixd_lan_regs.h"
+#include "ixd_devlink.h"
 
 MODULE_DESCRIPTION("Intel(R) Control Plane Function Device Driver");
 MODULE_IMPORT_NS("LIBIE_CP");
@@ -21,6 +22,8 @@ static void ixd_remove(struct pci_dev *pdev)
 	/* Do not mix removal with (re)initialization */
 	cancel_delayed_work_sync(&adapter->init_task.init_work);
 
+	ixd_devlink_unregister(adapter);
+
 	/* Leave the device clean on exit */
 	if (adapter->xnm)
 		libie_ctlq_xn_shutdown(adapter->xnm);
@@ -28,6 +31,7 @@ static void ixd_remove(struct pci_dev *pdev)
 	ixd_deinit_dflt_mbx(adapter);
 
 	libie_pci_unmap_all_mmio_regions(&adapter->cp_ctx.mmio_info);
+	ixd_devlink_free(adapter);
 }
 
 /**
@@ -92,7 +96,7 @@ static int ixd_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ixd_adapter *adapter;
 	int err;
 
-	adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
+	adapter = ixd_adapter_alloc(&pdev->dev);
 	if (!adapter)
 		return -ENOMEM;
 
@@ -101,13 +105,13 @@ static int ixd_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	err = libie_pci_init_dev(pdev);
 	if (err)
-		return err;
+		goto free_adapter;
 
 	pci_set_drvdata(pdev, adapter);
 
 	err = ixd_iomap_regions(adapter);
 	if (err)
-		return err;
+		goto free_adapter;
 
 	INIT_DELAYED_WORK(&adapter->init_task.init_work,
 			  ixd_init_task);
@@ -118,6 +122,10 @@ static int ixd_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			   IXD_INIT_TASK_DELAY_JIFFIES);
 
 	return 0;
+
+free_adapter:
+	ixd_devlink_free(adapter);
+	return err;
 }
 
 static const struct pci_device_id ixd_pci_tbl[] = {