RDMA/hns: Add debugfs to hns RoCE

Add debugfs to hns RoCE. This patch only adds an empty directory
"hns_roce" to debugs root directory.

Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20231114123449.1106162-3-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hns/Makefile

@@ -7,7 +7,8 @@ ccflags-y :=  -I $(srctree)/drivers/net/ethernet/hisilicon/hns3
 
 hns-roce-objs := hns_roce_main.o hns_roce_cmd.o hns_roce_pd.o \
 	hns_roce_ah.o hns_roce_hem.o hns_roce_mr.o hns_roce_qp.o \
-	hns_roce_cq.o hns_roce_alloc.o hns_roce_db.o hns_roce_srq.o hns_roce_restrack.o
+	hns_roce_cq.o hns_roce_alloc.o hns_roce_db.o hns_roce_srq.o hns_roce_restrack.o \
+	hns_roce_debugfs.o
 
 ifdef CONFIG_INFINIBAND_HNS_HIP08
 hns-roce-hw-v2-objs := hns_roce_hw_v2.o $(hns-roce-objs)

drivers/infiniband/hw/hns/hns_roce_debugfs.c

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2023 Hisilicon Limited.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+
+#include "hns_roce_device.h"
+
+static struct dentry *hns_roce_dbgfs_root;
+
+static int hns_debugfs_seqfile_open(struct inode *inode, struct file *f)
+{
+	struct hns_debugfs_seqfile *seqfile = inode->i_private;
+
+	return single_open(f, seqfile->read, seqfile->data);
+}
+
+static const struct file_operations hns_debugfs_seqfile_fops = {
+	.owner = THIS_MODULE,
+	.open = hns_debugfs_seqfile_open,
+	.release = single_release,
+	.read = seq_read,
+	.llseek = seq_lseek
+};
+
+static void init_debugfs_seqfile(struct hns_debugfs_seqfile *seq,
+				 const char *name, struct dentry *parent,
+				 int (*read_fn)(struct seq_file *, void *),
+				 void *data)
+{
+	debugfs_create_file(name, 0400, parent, seq, &hns_debugfs_seqfile_fops);
+
+	seq->read = read_fn;
+	seq->data = data;
+}
+
+/* debugfs for device */
+void hns_roce_register_debugfs(struct hns_roce_dev *hr_dev)
+{
+	struct hns_roce_dev_debugfs *dbgfs = &hr_dev->dbgfs;
+
+	dbgfs->root = debugfs_create_dir(dev_name(&hr_dev->ib_dev.dev),
+					 hns_roce_dbgfs_root);
+}
+
+void hns_roce_unregister_debugfs(struct hns_roce_dev *hr_dev)
+{
+	debugfs_remove_recursive(hr_dev->dbgfs.root);
+}
+
+/* debugfs for hns module */
+void hns_roce_init_debugfs(void)
+{
+	hns_roce_dbgfs_root = debugfs_create_dir("hns_roce", NULL);
+}
+
+void hns_roce_cleanup_debugfs(void)
+{
+	debugfs_remove_recursive(hns_roce_dbgfs_root);
+	hns_roce_dbgfs_root = NULL;
+}

drivers/infiniband/hw/hns/hns_roce_debugfs.h

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2023 Hisilicon Limited.
+ */
+
+#ifndef __HNS_ROCE_DEBUGFS_H
+#define __HNS_ROCE_DEBUGFS_H
+
+/* debugfs seqfile */
+struct hns_debugfs_seqfile {
+	int (*read)(struct seq_file *seq, void *data);
+	void *data;
+};
+
+/* Debugfs for device */
+struct hns_roce_dev_debugfs {
+	struct dentry *root;
+};
+
+struct hns_roce_dev;
+
+void hns_roce_init_debugfs(void);
+void hns_roce_cleanup_debugfs(void);
+void hns_roce_register_debugfs(struct hns_roce_dev *hr_dev);
+void hns_roce_unregister_debugfs(struct hns_roce_dev *hr_dev);
+
+#endif

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -35,6 +35,7 @@
 
 #include <rdma/ib_verbs.h>
 #include <rdma/hns-abi.h>
+#include "hns_roce_debugfs.h"
 
 #define PCI_REVISION_ID_HIP08			0x21
 #define PCI_REVISION_ID_HIP09			0x30
@@ -979,6 +980,7 @@ struct hns_roce_dev {
 	u32 is_vf;
 	u32 cong_algo_tmpl_id;
 	u64 dwqe_page;
+	struct hns_roce_dev_debugfs dbgfs;
 };
 
 static inline struct hns_roce_dev *to_hr_dev(struct ib_device *ib_dev)

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -6958,12 +6958,14 @@ static struct hnae3_client hns_roce_hw_v2_client = {
 
 static int __init hns_roce_hw_v2_init(void)
 {
+	hns_roce_init_debugfs();
 	return hnae3_register_client(&hns_roce_hw_v2_client);
 }
 
 static void __exit hns_roce_hw_v2_exit(void)
 {
 	hnae3_unregister_client(&hns_roce_hw_v2_client);
+	hns_roce_cleanup_debugfs();
 }
 
 module_init(hns_roce_hw_v2_init);

drivers/infiniband/hw/hns/hns_roce_main.c

@@ -1079,6 +1079,8 @@ int hns_roce_init(struct hns_roce_dev *hr_dev)
 	if (ret)
 		goto error_failed_register_device;
 
+	hns_roce_register_debugfs(hr_dev);
+
 	return 0;
 
 error_failed_register_device:
@@ -1108,6 +1110,7 @@ int hns_roce_init(struct hns_roce_dev *hr_dev)
 
 void hns_roce_exit(struct hns_roce_dev *hr_dev)
 {
+	hns_roce_unregister_debugfs(hr_dev);
 	hns_roce_unregister_device(hr_dev);
 
 	if (hr_dev->hw->hw_exit)