Huawei BMA: Adding Huawei BMA driver: host_cdev_drv

driver inclusion
category: feature
bugzilla: 34535
CVE: NA

The BMA software is a system management software offered by Huawei. It supports
the status monitoring, performance monitoring, and event monitoring of various
components, including server CPUs, memory, hard disks, NICs, IB cards, PCIe
cards, RAID controller cards, and optical modules.

This host_cdev_drv driver is one of the communication driver used by BMA
software. It depends on the host_edma_drv driver. The host_cdev_drv driver will
create 4 char devices(hwbmc0, hwbmc1, hwbmc2, hwbmc3) once loaded. These char
devices offer interfaces, including open, close, read, write and poll, to upper
level applications. BMA uses them to send/receive ipmi commons to/from BMC.

Link: https://lkml.org/lkml/2020/6/22/752


Signed-off-by: Naixin Yu <yunaixin@huawei.com>
Reviewed-by: Wang Qindong <wangqindong@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>

drivers/net/ethernet/huawei/bma/Makefile

@@ -2,4 +2,5 @@
 # Makefile for BMA software driver
 #
 
-obj-$(CONFIG_BMA) += edma_drv/
\ No newline at end of file
+obj-$(CONFIG_BMA) += edma_drv/
+obj-$(CONFIG_BMA) += cdev_drv/
\ No newline at end of file

drivers/net/ethernet/huawei/bma/cdev_drv/Makefile

+obj-$(CONFIG_BMA) += host_cdev_drv.o
+host_cdev_drv-y := bma_cdev.o
\ No newline at end of file

drivers/net/ethernet/huawei/bma/cdev_drv/bma_cdev.c

+// SPDX-License-Identifier: GPL-2.0
+/* Huawei iBMA driver.
+ * Copyright (c) 2017, Huawei Technologies Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/miscdevice.h>
+#include <linux/netdevice.h>
+#include "../edma_drv/bma_include.h"
+#include "../include/bma_ker_intf.h"
+
+#define CDEV_NAME_PREFIX	"hwibmc"
+
+#ifdef DRV_VERSION
+#define CDEV_VERSION		MICRO_TO_STR(DRV_VERSION)
+#else
+#define CDEV_VERSION		"0.3.4"
+#endif
+
+#define CDEV_DEFAULT_NUM	4
+#define CDEV_MAX_NUM		8
+
+#define CDEV_NAME_MAX_LEN	32
+#define CDEV_INVALID_ID		(0xffffffff)
+
+struct cdev_statistics_s {
+	unsigned int recv_bytes;
+	unsigned int send_bytes;
+	unsigned int send_pkgs;
+	unsigned int recv_pkgs;
+	unsigned int send_failed_count;
+	unsigned int recv_failed_count;
+	unsigned int open_status;
+};
+
+struct cdev_dev {
+	struct miscdevice dev_struct;
+	struct cdev_statistics_s s;
+	char dev_name[CDEV_NAME_MAX_LEN];
+	dev_t dev_id;
+	void *dev_data;
+	atomic_t open;
+	int type;
+};
+
+struct cdev_dev_set {
+	struct cdev_dev dev_list[CDEV_MAX_NUM];
+	int dev_num;
+	unsigned int init_time;
+};
+
+int dev_num = CDEV_DEFAULT_NUM;	/* the dev num want to create */
+int debug = DLOG_ERROR;                  /* debug switch */
+module_param(dev_num, int, 0640);
+MODULE_PARM_DESC(dev_num, "cdev num you want");
+MODULE_PARM_DESC(debug, "Debug switch (0=close debug, 1=open debug)");
+
+#define CDEV_LOG(level, fmt, args...) do {\
+	if (debug >= (level)) {\
+		netdev_info(0, "edma_cdev: %s, %d, " fmt "\n", \
+		__func__, __LINE__, ## args);\
+	} \
+} while (0)
+
+static int cdev_open(struct inode *inode, struct file *filp);
+static int cdev_release(struct inode *inode, struct file *filp);
+static unsigned int cdev_poll(struct file *file, poll_table *wait);
+static ssize_t cdev_read(struct file *filp, char __user  *data, size_t count,
+			 loff_t *ppos);
+static ssize_t cdev_write(struct file *filp, const char __user *data,
+			  size_t count, loff_t *ppos);
+
+struct cdev_dev_set g_cdev_set;
+
+#define GET_PRIVATE_DATA(f) (((struct cdev_dev *)((f)->private_data))->dev_data)
+
+module_param_call(debug, &edma_param_set_debug, &param_get_int, &debug, 0644);
+
+static int cdev_param_get_statics(char *buf, const struct kernel_param *kp)
+{
+	int len = 0;
+	int i = 0;
+	__kernel_time_t running_time = 0;
+
+	if (!buf)
+		return 0;
+
+	GET_SYS_SECONDS(running_time);
+	running_time -= g_cdev_set.init_time;
+	len += sprintf(buf + len,
+		       "============================CDEV_DRIVER_INFO=======================\n");
+	len += sprintf(buf + len, "version      :%s\n", CDEV_VERSION);
+
+	len += sprintf(buf + len, "running_time :%luD %02lu:%02lu:%02lu\n",
+		       running_time / (SECONDS_PER_DAY),
+		       running_time % (SECONDS_PER_DAY) / SECONDS_PER_HOUR,
+		       running_time % SECONDS_PER_HOUR / SECONDS_PER_MINUTE,
+		       running_time % SECONDS_PER_MINUTE);
+
+	for (i = 0; i < g_cdev_set.dev_num; i++) {
+		len += sprintf(buf + len,
+			       "===================================================\n");
+		len += sprintf(buf + len, "name      :%s\n",
+			       g_cdev_set.dev_list[i].dev_name);
+		len +=
+		    sprintf(buf + len, "dev_id    :%08x\n",
+			    g_cdev_set.dev_list[i].dev_id);
+		len += sprintf(buf + len, "type      :%u\n",
+			       g_cdev_set.dev_list[i].type);
+		len += sprintf(buf + len, "status    :%s\n",
+			       g_cdev_set.dev_list[i].s.open_status ==
+			       1 ? "open" : "close");
+		len += sprintf(buf + len, "send_pkgs :%u\n",
+			       g_cdev_set.dev_list[i].s.send_pkgs);
+		len +=
+		    sprintf(buf + len, "send_bytes:%u\n",
+			    g_cdev_set.dev_list[i].s.send_bytes);
+		len += sprintf(buf + len, "send_failed_count:%u\n",
+			       g_cdev_set.dev_list[i].s.send_failed_count);
+		len += sprintf(buf + len, "recv_pkgs :%u\n",
+			       g_cdev_set.dev_list[i].s.recv_pkgs);
+		len += sprintf(buf + len, "recv_bytes:%u\n",
+			       g_cdev_set.dev_list[i].s.recv_bytes);
+		len += sprintf(buf + len, "recv_failed_count:%u\n",
+			       g_cdev_set.dev_list[i].s.recv_failed_count);
+	}
+
+	return len;
+}
+module_param_call(statistics, NULL, cdev_param_get_statics, &debug, 0444);
+MODULE_PARM_DESC(statistics, "Statistics info of cdev driver,readonly");
+
+const struct file_operations g_bma_cdev_fops = {
+	.owner = THIS_MODULE,
+	.open = cdev_open,
+	.release = cdev_release,
+	.poll = cdev_poll,
+	.read = cdev_read,
+	.write = cdev_write,
+};
+
+static int __init bma_cdev_init(void)
+{
+	int i = 0;
+
+	int ret = 0;
+	int err_count = 0;
+
+	if (!bma_intf_check_edma_supported())
+		return -ENXIO;
+
+	if (dev_num <= 0 || dev_num > CDEV_MAX_NUM)
+		return -EINVAL;
+
+	memset(&g_cdev_set, 0, sizeof(struct cdev_dev_set));
+	g_cdev_set.dev_num = dev_num;
+
+	for (i = 0; i < dev_num; i++) {
+		struct cdev_dev *pdev = &g_cdev_set.dev_list[i];
+
+		sprintf(pdev->dev_name, "%s%d", CDEV_NAME_PREFIX, i);
+		pdev->dev_struct.name = pdev->dev_name;
+		pdev->dev_struct.minor = MISC_DYNAMIC_MINOR;
+		pdev->dev_struct.fops = &g_bma_cdev_fops;
+
+		pdev->dev_id = CDEV_INVALID_ID;
+
+		ret = misc_register(&pdev->dev_struct);
+
+		if (ret) {
+			CDEV_LOG(DLOG_DEBUG, "misc_register failed %d", i);
+			err_count++;
+			continue;
+		}
+
+		pdev->dev_id = MKDEV(MISC_MAJOR, pdev->dev_struct.minor);
+
+		ret = bma_intf_register_type(TYPE_CDEV + i, 0, INTR_DISABLE,
+					     &pdev->dev_data);
+
+		if (ret) {
+			CDEV_LOG(DLOG_ERROR,
+				 "cdev %d open failed ,result = %d",
+				 i, ret);
+			misc_deregister(&pdev->dev_struct);
+			pdev->dev_id = CDEV_INVALID_ID;
+			err_count++;
+			continue;
+		} else {
+			pdev->type = TYPE_CDEV + i;
+			atomic_set(&pdev->open, 1);
+		}
+
+		CDEV_LOG(DLOG_DEBUG, "%s id is %08x", pdev->dev_struct.name,
+			 pdev->dev_id);
+	}
+
+	if (err_count == dev_num) {
+		CDEV_LOG(DLOG_ERROR, "init cdev failed!");
+		return -EFAULT;
+	}
+	GET_SYS_SECONDS(g_cdev_set.init_time);
+	return 0;
+}
+
+static void __exit bma_cdev_exit(void)
+{
+	while (dev_num--) {
+		struct cdev_dev *pdev = &g_cdev_set.dev_list[dev_num];
+
+		if (pdev->dev_id != CDEV_INVALID_ID) {
+			if (pdev->dev_data && pdev->type != 0)
+				(void)bma_intf_unregister_type(&pdev->dev_data);
+
+			(void)misc_deregister
+				(&g_cdev_set.dev_list[dev_num].dev_struct);
+		}
+	}
+}
+
+int cdev_open(struct inode *inode_prt, struct file *filp)
+{
+	int i = 0;
+	struct cdev_dev *pdev = NULL;
+
+	if (!inode_prt)
+		return -EFAULT;
+	if (!filp)
+		return -EFAULT;
+
+	if (dev_num <= 0) {
+		CDEV_LOG(DLOG_ERROR, "dev_num error");
+		return -EFAULT;
+	}
+
+	for (i = 0; i < dev_num; i++) {
+		pdev = &g_cdev_set.dev_list[i];
+
+		if (pdev->dev_id == inode_prt->i_rdev)
+			break;
+	}
+
+	if (i == dev_num) {
+		CDEV_LOG(DLOG_ERROR, "can not find dev id %08x",
+			 inode_prt->i_rdev);
+		return -ENODEV;
+	}
+	/*each device can be opened only onece */
+	if (atomic_dec_and_test(&pdev->open) == 0) {
+		CDEV_LOG(DLOG_ERROR, "%s is already opened",
+			 pdev->dev_name);
+			atomic_inc(&pdev->open);
+			return -EBUSY;	/* already opened */
+	}
+
+	filp->private_data = &g_cdev_set.dev_list[i];
+	bma_intf_set_open_status(pdev->dev_data, DEV_OPEN);
+	((struct cdev_dev *)filp->private_data)->s.open_status++;
+
+	return 0;
+}
+
+int cdev_release(struct inode *inode_prt, struct file *filp)
+{
+	struct cdev_dev *pdev = NULL;
+
+	if (!filp)
+		return 0;
+
+	pdev = (struct cdev_dev *)filp->private_data;
+	if (pdev) {
+		((struct cdev_dev *)filp->private_data)->s.open_status--;
+		bma_intf_set_open_status(pdev->dev_data, DEV_CLOSE);
+		atomic_inc(&pdev->open);
+		filp->private_data = NULL;
+	}
+
+	return 0;
+}
+
+unsigned int cdev_poll(struct file *filp, poll_table *wait)
+{
+	unsigned int mask = 0;
+	wait_queue_head_t *queue_head = NULL;
+
+	if (!filp)
+		return 0;
+	queue_head = (wait_queue_head_t *)
+	    bma_cdev_get_wait_queue(GET_PRIVATE_DATA(filp));
+
+	if (!queue_head)
+		return 0;
+
+	poll_wait(filp, queue_head, wait);
+
+	if (bma_cdev_check_recv(GET_PRIVATE_DATA(filp)))
+		mask |= (POLLIN | POLLRDNORM);
+
+	CDEV_LOG(DLOG_DEBUG, "poll return %08x", mask);
+
+	return mask;
+}
+
+ssize_t cdev_read(struct file *filp, char __user *data, size_t count,
+		  loff_t *ppos)
+{
+	int ret = 0;
+
+	CDEV_LOG(DLOG_DEBUG, "data is %p,count is %u", data,
+		 (unsigned int)count);
+
+	if (!data || count <= 0)
+		return -EFAULT;
+
+	ret = bma_cdev_recv_msg(GET_PRIVATE_DATA(filp), data, count);
+
+	if (ret > 0) {
+		((struct cdev_dev *)filp->private_data)->s.recv_bytes += ret;
+		((struct cdev_dev *)filp->private_data)->s.recv_pkgs++;
+	} else {
+		((struct cdev_dev *)filp->private_data)->s.recv_failed_count++;
+	}
+
+	return ret;
+}
+
+ssize_t cdev_write(struct file *filp, const char __user *data, size_t count,
+		   loff_t *ppos)
+{
+	int ret = 0;
+
+	if (!data || count <= 0)
+		return -EFAULT;
+
+	CDEV_LOG(DLOG_DEBUG, "data is %p,count is %u", data,
+		 (unsigned int)count);
+	ret = bma_cdev_add_msg(GET_PRIVATE_DATA(filp), data, count);
+
+	if (ret > 0) {
+		((struct cdev_dev *)filp->private_data)->s.send_bytes += ret;
+		((struct cdev_dev *)filp->private_data)->s.send_pkgs++;
+	} else {
+		((struct cdev_dev *)filp->private_data)->s.send_failed_count++;
+	}
+
+	return ret;
+}
+
+MODULE_AUTHOR("HUAWEI TECHNOLOGIES CO., LTD.");
+MODULE_DESCRIPTION("HUAWEI CDEV DRIVER");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(CDEV_VERSION);
+
+module_init(bma_cdev_init);
+module_exit(bma_cdev_exit);