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roce分为软件实现的roce和硬件实现的roce，硬件roce就是在普通网卡中添加一个模块，其中pf和vf 都可以使用roce由于roce是网卡的一部分，因此roce在初始化的时候是包含在网卡初始化中的过程中，例如下面这个roce就会注册自己的初始化函数到网卡驱动中static const struct hnae3_client_ops hns_roce_hw_v2_ops = {	.init_instance = hns_roce_hw_v2_init_instance,	.uninit_instance = hns_roce_hw_v2_uninit_instance,};static struct hnae3_client hns_roce_hw_v2_client = {	.name = "hns_roce_hw_v2",	.type = HNAE3_CLIENT_ROCE,	.ops = &hns_roce_hw_v2_ops,};static int __init hns_roce_hw_v2_init(void){	return hnae3_register_client(&hns_roce_hw_v2_client);}执行hnae3_register_client 后，就把roce的初始化函数添加到网卡驱动中int hnae3_register_client(struct hnae3_client *client){	struct hnae3_client *client_tmp;	struct hnae3_ae_dev *ae_dev;	int ret = 0;	mutex_lock(&hnae3_common_lock);	/* one system should only have one client for every type */#检查一下roce是否已经加入到网口的初始化列表中，如果已经加入了，则不能重复加载，直接退出	list_for_each_entry(client_tmp, &hnae3_client_list, node) {		if (client_tmp->type == client->type)			goto exit;	}#把client加到入到网卡中	list_add_tail(&client->node, &hnae3_client_list);#为网卡的每个口都添加roce的client	/* initialize the client on every matched port */	list_for_each_entry(ae_dev, &hnae3_ae_dev_list, node) {		/* if the client could not be initialized on current port, for		 * any error reasons, move on to next available port		 */		ret = hnae3_match_n_instantiate(client, ae_dev, true);		if (ret)			dev_err(&ae_dev->pdev->dev,				"match }将roce添加到网卡驱动中后，就会调用ib_register_device来注册roce驱动这个函数第一个参数是要注册的device，一般在注册之前会将这个device 结构体的成员变量填充好。int ib_register_device(struct ib_device *device,		       int (*port_callback)(struct ib_device *,					    u8, struct kobject *)){	int ret;	struct ib_client *client;	struct ib_udata uhw = {.outlen = 0, .inlen = 0};	struct device *parent = device->dev.parent;	WARN_ON_ONCE(device->dma_device);#看这个设备是否提供dma操作的函数，这里dma操作分为一致性dma和流式dma	if (device->dev.dma_ops) {		/*		 * The caller provided custom DMA operations. Copy the		 * DMA-related fields that are used by e.g. dma_alloc_coherent()		 * into device->dev.		 */		device->dma_device = &device->dev;		if (!device->dev.dma_mask) {			if (parent)				device->dev.dma_mask = parent->dma_mask;			else				WARN_ON_ONCE(true);		}		mutex_lock(&device_mutex);#ib 设备申请name	if (strchr(device->name, '%')) {		ret = alloc_name(device->name);		if (ret)			goto out;	}#检查device是否提供基础的roce功能	if (ib_device_check_mandatory(device)) {		ret = -EINVAL;		goto out;	}#读取port和key	ret = read_port_immutable(device);	if (ret) {		pr_warn("Couldn't create per port immutable data %s\n",			device->name);		goto out;	}	ret = setup_port_pkey_list(device);	if (ret) {		pr_warn("Couldn't create per port_pkey_list\n");		goto out;	}#为ib设备建立cache	ret = ib_cache_setup_one(device);	if (ret) {		pr_warn("Couldn't set up InfiniBand P_Key/GID cache\n");		goto port_cleanup;	}#注册cgroup	ret = ib_device_register_rdmacg(device);	if (ret) {		pr_warn("Couldn't register device with rdma cgroup\n");		goto cache_cleanup;	}#查询设备的hw和attrs信息	memset(&device->attrs, 0, sizeof(device->attrs));	ret = device->query_device(device, &device->attrs, &uhw);	if (ret) {		pr_warn("Couldn't query the device attributes\n");		goto cg_cleanup;	}#注册sysfs信息	ret = ib_device_register_sysfs(device, port_callback);	if (ret) {		pr_warn("Couldn't register device %s with driver model\n",			device->name);		goto cg_cleanup;	}	device->reg_state = IB_DEV_REGISTERED;#增加context	list_for_each_entry(client, &client_list, list)		if (!add_client_context(device, client) && client->add)			client->add(device);	device->index = __dev_new_index();	down_write(&lists_rwsem);#所有的roce设备都放在&device_list 中	list_add_tail(&device->core_list, &device_list);	up_write(&lists_rwsem);	mutex_unlock(&device_mutex);	return 0;}

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