// SPDX-License-Identifier: GPL-2.0+
/* Copyright (c) 2018-2019 Hisilicon Limited. */

#include <linux/debugfs.h>
#include <linux/device.h>

#include "hnae3.h"
#include "hns3_enet.h"

#define HNS3_DBG_READ_LEN 256

static struct dentry *hns3_dbgfs_root;

static void hns3_dbg_help(struct hnae3_handle *h)
{
	dev_info(&h->pdev->dev, "available commands\n");
	dev_info(&h->pdev->dev, "queue info [number]\n");
	dev_info(&h->pdev->dev, "dump fd tcam\n");
}

static ssize_t hns3_dbg_cmd_read(struct file *filp, char __user *buffer,
				 size_t count, loff_t *ppos)
{
	int uncopy_bytes;
	char *buf;
	int len;

	if (*ppos != 0)
		return 0;

	if (count < HNS3_DBG_READ_LEN)
		return -ENOSPC;

	buf = kzalloc(HNS3_DBG_READ_LEN, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	len = snprintf(buf, HNS3_DBG_READ_LEN, "%s\n",
		       "Please echo help to cmd to get help information");
	uncopy_bytes = copy_to_user(buffer, buf, len);

	kfree(buf);

	if (uncopy_bytes)
		return -EFAULT;

	return (*ppos = len);
}

static ssize_t hns3_dbg_cmd_write(struct file *filp, const char __user *buffer,
				  size_t count, loff_t *ppos)
{
	struct hnae3_handle *handle = filp->private_data;
	char *cmd_buf, *cmd_buf_tmp;
	int uncopied_bytes;
	int ret = 0;

	if (*ppos != 0)
		return 0;

	cmd_buf = kzalloc(count + 1, GFP_KERNEL);
	if (!cmd_buf)
		return count;

	uncopied_bytes = copy_from_user(cmd_buf, buffer, count);
	if (uncopied_bytes) {
		kfree(cmd_buf);
		return -EFAULT;
	}

	cmd_buf[count] = '\0';

	cmd_buf_tmp = strchr(cmd_buf, '\n');
	if (cmd_buf_tmp) {
		*cmd_buf_tmp = '\0';
		count = cmd_buf_tmp - cmd_buf + 1;
	}

	if (strncmp(cmd_buf, "help", 4) == 0)
		hns3_dbg_help(handle);

	if (ret)
		hns3_dbg_help(handle);

	kfree(cmd_buf);
	cmd_buf = NULL;

	return count;
}

static const struct file_operations hns3_dbg_cmd_fops = {
	.owner = THIS_MODULE,
	.open  = simple_open,
	.read  = hns3_dbg_cmd_read,
	.write = hns3_dbg_cmd_write,
};

void hns3_dbg_init(struct hnae3_handle *handle)
{
	const char *name = pci_name(handle->pdev);
	struct dentry *pfile;

	handle->hnae3_dbgfs = debugfs_create_dir(name, hns3_dbgfs_root);
	if (!handle->hnae3_dbgfs)
		return;

	pfile = debugfs_create_file("cmd", 0600, handle->hnae3_dbgfs, handle,
				    &hns3_dbg_cmd_fops);
	if (!pfile) {
		debugfs_remove_recursive(handle->hnae3_dbgfs);
		handle->hnae3_dbgfs = NULL;
		dev_warn(&handle->pdev->dev, "create file for %s fail\n",
			 name);
	}
}

void hns3_dbg_uninit(struct hnae3_handle *handle)
{
	debugfs_remove_recursive(handle->hnae3_dbgfs);
	handle->hnae3_dbgfs = NULL;
}

void hns3_dbg_register_debugfs(const char *debugfs_dir_name)
{
	hns3_dbgfs_root = debugfs_create_dir(debugfs_dir_name, NULL);
	if (!hns3_dbgfs_root) {
		pr_warn("Register debugfs for %s fail\n", debugfs_dir_name);
		return;
	}
}

void hns3_dbg_unregister_debugfs(void)
{
	debugfs_remove_recursive(hns3_dbgfs_root);
	hns3_dbgfs_root = NULL;
}