RDMA/bng_re: Add basic debugfs infrastructure

Add basic debugfs infrastructure for Broadcom next generation
controller.

Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
Link: https://patch.msgid.link/20251117171136.128193-8-siva.kallam@broadcom.com
Reviewed-by: Usman Ansari <usman.ansari@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/bng_re/Makefile

@@ -4,4 +4,5 @@ ccflags-y := -I $(srctree)/drivers/net/ethernet/broadcom/bnge -I $(srctree)/driv
 obj-$(CONFIG_INFINIBAND_BNG_RE) += bng_re.o
 
 bng_re-y := bng_dev.o bng_fw.o \
-	    bng_res.o bng_sp.o
+	    bng_res.o bng_sp.o \
+	    bng_debugfs.o

drivers/infiniband/hw/bng_re/bng_debugfs.c

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2025 Broadcom.
+#include <linux/debugfs.h>
+#include <linux/pci.h>
+
+#include <rdma/ib_verbs.h>
+
+#include "bng_res.h"
+#include "bng_fw.h"
+#include "bnge.h"
+#include "bnge_auxr.h"
+#include "bng_re.h"
+#include "bng_debugfs.h"
+
+static struct dentry *bng_re_debugfs_root;
+
+void bng_re_debugfs_add_pdev(struct bng_re_dev *rdev)
+{
+	struct pci_dev *pdev = rdev->aux_dev->pdev;
+
+	rdev->dbg_root =
+		debugfs_create_dir(dev_name(&pdev->dev), bng_re_debugfs_root);
+}
+
+void bng_re_debugfs_rem_pdev(struct bng_re_dev *rdev)
+{
+	debugfs_remove_recursive(rdev->dbg_root);
+	rdev->dbg_root = NULL;
+}
+
+void bng_re_register_debugfs(void)
+{
+	bng_re_debugfs_root = debugfs_create_dir("bng_re", NULL);
+}
+
+void bng_re_unregister_debugfs(void)
+{
+	debugfs_remove(bng_re_debugfs_root);
+}

drivers/infiniband/hw/bng_re/bng_debugfs.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2025 Broadcom.
+
+#ifndef __BNG_RE_DEBUGFS__
+#define __BNG_RE_DEBUGFS__
+
+void bng_re_debugfs_add_pdev(struct bng_re_dev *rdev);
+void bng_re_debugfs_rem_pdev(struct bng_re_dev *rdev);
+
+void bng_re_register_debugfs(void);
+void bng_re_unregister_debugfs(void);
+#endif

drivers/infiniband/hw/bng_re/bng_dev.c

@@ -14,6 +14,7 @@
 #include "bnge_auxr.h"
 #include "bng_re.h"
 #include "bnge_hwrm.h"
+#include "bng_debugfs.h"
 
 MODULE_AUTHOR("Siva Reddy Kallam <siva.kallam@broadcom.com>");
 MODULE_DESCRIPTION(BNG_RE_DESC);
@@ -215,6 +216,7 @@ static void bng_re_query_hwrm_version(struct bng_re_dev *rdev)
 
 static void bng_re_dev_uninit(struct bng_re_dev *rdev)
 {
+	bng_re_debugfs_rem_pdev(rdev);
 	bng_re_disable_rcfw_channel(&rdev->rcfw);
 	bng_re_net_ring_free(rdev, rdev->rcfw.creq.ring_id,
 			     RING_ALLOC_REQ_RING_TYPE_NQ);
@@ -314,6 +316,9 @@ static int bng_re_dev_init(struct bng_re_dev *rdev)
 	rc = bng_re_get_dev_attr(&rdev->rcfw);
 	if (rc)
 		goto disable_rcfw;
+
+	bng_re_debugfs_add_pdev(rdev);
+
 	return 0;
 disable_rcfw:
 	bng_re_disable_rcfw_channel(&rdev->rcfw);
@@ -419,17 +424,24 @@ static int __init bng_re_mod_init(void)
 	int rc;
 
 
+	bng_re_register_debugfs();
+
 	rc = auxiliary_driver_register(&bng_re_driver);
 	if (rc) {
 		pr_err("%s: Failed to register auxiliary driver\n",
 		       KBUILD_MODNAME);
+		goto unreg_debugfs;
 	}
+	return 0;
+unreg_debugfs:
+	bng_re_unregister_debugfs();
 	return rc;
 }
 
 static void __exit bng_re_mod_exit(void)
 {
 	auxiliary_driver_unregister(&bng_re_driver);
+	bng_re_unregister_debugfs();
 }
 
 module_init(bng_re_mod_init);

drivers/infiniband/hw/bng_re/bng_re.h

@@ -75,6 +75,7 @@ struct bng_re_dev {
 	struct bng_re_nq_record		*nqr;
 	/* Device Resources */
 	struct bng_re_dev_attr		*dev_attr;
+	struct dentry			*dbg_root;
 };
 
 #endif