misc: life_mngr: add uart module

In the uart module, the following functions are implemented:
- init_uart_dev
Allocate UART device instance and initialize UART device
according to device name.
- deinit_uart_dev
Close UART devcie and free UART device instance.
- send_message_by_uart
Set handler to handle received message.
- receive_message_by_uart
Receive message and retry RETRY_RECV_TIMES time to
avoid miss message in some cases.
- get_uart_dev_fd
Get the file descriptor of a UART device
- get_uart_dev_path
Get the name of a UART device

v1-->v2:
	Update sync logic between uart in service VM and uart in
	user VM, lifecycle manager will not depend on VM boot order.
	Add code comments.
v2-->v3:
	This module only includes UART device operations, move other
	logic into uart channel module.
v3-->v4:
	Add parameters check for interface and refine some names.
v4-->v5:
	Refine interface parameter type, error value.
v5-->v6:
	Update condition check format of deinit_uart_dev.

Tracked-On: #6652

Signed-off-by: Xiangyang Wu <xiangyang.wu@intel.com>
Reviewed-by: fei1.li@intel.com

misc/services/life_mngr/uart.c

@@ -0,0 +1,161 @@
+/*
+ * Copyright (C)2021 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <sys/queue.h>
+#include <pthread.h>
+#include <limits.h>
+#include "uart.h"
+#include "uart_channel.h"
+#include "log.h"
+#include "config.h"
+
+/* it read from uart, and if end is '\0' or '\n' or len = buff-len it will return */
+static ssize_t try_receive_message_by_uart(int fd, void *buffer, size_t buf_len)
+{
+	ssize_t rc = 0U, count = 0U;
+	char *tmp;
+
+	do {
+		rc = read(fd, buffer + count, buf_len - count);
+		if (rc > 0) {
+			count += rc;
+			tmp = (char *)buffer;
+			if ((tmp[count - 1] == '\0') || (tmp[count - 1] == '\n')
+						|| (count == buf_len)) {
+				if (tmp[count - 1] == '\n')
+					tmp[count - 1] = '\0';
+				break;
+			}
+		}
+	} while (rc > 0U);
+
+	return count;
+}
+/**
+ * @brief Receive message and retry RETRY_RECV_TIMES time if
+ * message is missed in some cases.
+ */
+ssize_t receive_message_by_uart(struct uart_dev *dev, void *buf, size_t len)
+{
+	ssize_t count = 0;
+	unsigned int retry_times = RETRY_RECV_TIMES;
+
+	if ((dev == NULL) || (buf == NULL) || (len == 0))
+		return -EINVAL;
+	do {
+		usleep(WAIT_RECV);
+		count = try_receive_message_by_uart(dev->tty_fd, buf, len);
+		retry_times--;
+	} while ((count == 0) && (retry_times != 0U));
+	return count;
+}
+ssize_t send_message_by_uart(struct uart_dev *dev, const void *buf, size_t len)
+{
+	ssize_t ret = 0;
+
+	if ((dev == NULL) || (buf == NULL) || (len == 0))
+		return -EINVAL;
+	ret = write(dev->tty_fd, buf, len);
+
+	return ret;
+}
+static int set_tty_attr(int fd, int baudrate)
+{
+	struct termios tty;
+
+	if (tcgetattr(fd, &tty) < 0) {
+		LOG_PRINTF("Error from tcgetattr: %s\n", strerror(errno));
+		return errno;
+	}
+
+	cfsetospeed(&tty, (speed_t)baudrate);
+	cfsetispeed(&tty, (speed_t)baudrate);
+
+	/* set input-mode */
+	tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK |
+			ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+
+	/* set output-mode */
+	tty.c_oflag &= ~OPOST;
+
+	/* set control-mode */
+	tty.c_cflag |= (CLOCAL | CREAD | CS8);
+	tty.c_cflag &= ~(CSIZE | PARENB | CSTOPB | CRTSCTS);
+
+	/* set local-mode */
+	tty.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+
+	/* block until one char read, set next char's timeout */
+	tty.c_cc[VMIN] = 1;
+	tty.c_cc[VTIME] = 1;
+
+	tcflush(fd, TCIOFLUSH);
+
+	if (tcsetattr(fd, TCSANOW, &tty) != 0) {
+		LOG_PRINTF("Error from tcsetattr: %s\n", strerror(errno));
+		return errno;
+	}
+	return 0;
+}
+static int tty_listen_setup(const char *tty_path)
+{
+	int fd = -1;
+	int ret;
+
+	fd = open(tty_path, O_RDWR | O_NOCTTY | O_SYNC | O_NONBLOCK);
+	if (fd < 0) {
+		fprintf(stderr, "Can't open file %s\n", tty_path);
+		return errno;
+	}
+	ret = set_tty_attr(fd, B115200);
+	if (ret != 0) {
+		close(fd);
+		return ret;
+	}
+	LOG_PRINTF("Open tty device:%s, fd=%d\n", tty_path, fd);
+	return fd;
+}
+
+struct uart_dev *init_uart_dev(char *path)
+{
+	struct uart_dev *dev;
+
+	if (path == NULL)
+		return NULL;
+	LOG_PRINTF("UART device name:%s\n", path);
+	dev = calloc(1, sizeof(*dev));
+	if (!dev) {
+		LOG_PRINTF("Failed to alloc mem for uart device %s\n", path);
+		return NULL;
+	}
+	if (strlen(path) < TTY_PATH_MAX)
+		memcpy(dev->tty_path, path, strlen(path));
+
+	dev->tty_fd = tty_listen_setup(dev->tty_path);
+	if (dev->tty_fd < 0) {
+		LOG_PRINTF("Failed to setup uart device %s\n", path);
+		free(dev);
+		return NULL;
+	}
+	return dev;
+}
+void deinit_uart_dev(struct uart_dev *dev)
+{
+	if (dev != NULL) {
+		LOG_PRINTF("Close device: %s\n", dev->tty_path);
+		close(dev->tty_fd);
+		dev->tty_fd = -1;
+		free(dev);
+	}
+}
+

misc/services/life_mngr/uart.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C)2021 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef _UART_H_
+#define _UART_H_
+#include <sys/types.h>
+#include <stdint.h>
+#include <sys/queue.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <sys/un.h>
+
+#define TTY_PATH_MAX 32U
+
+#define SCECOND_TO_US 1000000
+#define WAIT_RECV (SCECOND_TO_US>>2)
+#define RETRY_RECV_TIMES 20U
+
+struct uart_dev {
+	char tty_path[TTY_PATH_MAX]; /**< UART device name */
+	int tty_fd; /**< the FD of opened UART device */
+};
+/**
+ * @brief Allocate UART device instance and initialize UART
+ * device according to device name
+ *
+ * @param path UART device name
+ * @return struct uart_dev* Ponit to UART device instance
+ */
+struct uart_dev *init_uart_dev(char *path);
+/**
+ * @brief Close UART devcie and free UART device instance
+ *
+ * @param dev Poin to UART device instance
+ */
+void deinit_uart_dev(struct uart_dev *dev);
+/**
+ * @brief Set handler to handle received message
+ */
+ssize_t send_message_by_uart(struct uart_dev *dev, const void *buf, size_t len);
+/**
+ * @brief Receive message and retry RETRY_RECV_TIMES time to
+ * avoid miss message in some cases.
+ */
+ssize_t receive_message_by_uart(struct uart_dev *dev, void *buf, size_t len);
+/**
+ * @brief Get the file descriptor of a UART device
+ */
+static inline int get_uart_dev_fd(struct uart_dev *dev)
+{
+	return dev->tty_fd;
+}
+/**
+ * @brief Get the name of a UART device
+ */
+static inline char *get_uart_dev_path(struct uart_dev *dev)
+{
+	return dev->tty_path;
+}
+#endif
+