简介

在网络硬件产品中，需要对网口链路状态（UP/DOWN）进行监测，能够及时感知到链路状态的变更；这里介绍下dpdk中的实现方式，详细信息可以参考示例examples/link_status_interrupt。

示例

使能lsc中断

在rte_eth_dev_configure()端口配置中，对lsc位进行置1。

C 复制代码

static struct rte_eth_conf port_conf = {
 	...
	.intr_conf = {
		.lsc = 1, /**< lsc interrupt feature enabled */
	},
};

注册回调函数

注册的事件类型为RTE_ETH_EVENT_INTR_LSC，在链路状态变更的情况下会触发中断，并执行回调函数。

c 复制代码

rte_eth_dev_callback_register(portid, RTE_ETH_EVENT_INTR_LSC, lsi_event_callback, NULL);

回调函数处理

调用rte_eth_link_get_nowait()获取链路状态信息，并通过rte_eth_link_to_str()转换成字符串。

c 复制代码

/**
 * It will be called as the callback for specified port after a LSI interrupt
 * has been fully handled. This callback needs to be implemented carefully as
 * it will be called in the interrupt host thread which is different from the
 * application main thread.
 *
 * @param port_id
 *  Port id.
 * @param type
 *  event type.
 * @param param
 *  Pointer to(address of) the parameters.
 *
 * @return
 *  int.
 */

/* lsi_event_callback 8< */
static int
lsi_event_callback(uint16_t port_id, enum rte_eth_event_type type, void *param,
		    void *ret_param)
{
	struct rte_eth_link link;
	int ret;
	char link_status_text[RTE_ETH_LINK_MAX_STR_LEN];

	RTE_SET_USED(param);
	RTE_SET_USED(ret_param);

	printf("\n\nIn registered callback...\n");
	printf("Event type: %s\n", type == RTE_ETH_EVENT_INTR_LSC ? "LSC interrupt" : "unknown event");
	ret = rte_eth_link_get_nowait(port_id, &link);
	if (ret < 0) {
		printf("Failed link get on port %d: %s\n",
		       port_id, rte_strerror(-ret));
		return ret;
	}
	rte_eth_link_to_str(link_status_text, sizeof(link_status_text), &link);
	printf("Port %d %s\n\n", port_id, link_status_text);

	return 0;
}
/* >8 End of registering one or more callbacks. */