网络设备之分配net_device结构

 ?1 /** ?2 ?* alloc_netdev_mqs - allocate network device ?3 ?* @sizeof_priv: size of private data to allocate space for ?4 ?* @name: device name format string ?5 ?* @name_assign_type: origin of device name ?6 ?* @setup: callback to initialize device ?7 ?* @txqs: the number of TX subqueues to allocate ?8 ?* @rxqs: the number of RX subqueues to allocate ?9 ?* 10 ?* Allocates a struct net_device with private data area for driver use 11 ?* and performs basic initialization. ?Also allocates subqueue structs 12 ?* for each queue on the device. 13 ?*/ 14 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, 15 ????????unsigned char name_assign_type, 16 ????????void (*setup)(struct net_device *), 17 ????????unsigned int txqs, unsigned int rxqs) 18 { 19 ????struct net_device *dev; 20 ????size_t alloc_size; 21 ????struct net_device *p; 22 ?23 ????BUG_ON(strlen(name) >= sizeof(dev->name)); 24 ?25 ????/* 检查发送队列数 */ 26 ????if (txqs < 1) { 27 ????????pr_err("alloc_netdev: Unable to allocate device with zero queues\n"); 28 ????????return NULL; 29 ????} 30 ?31 ????/* 检查接收队列数 */ 32 #ifdef CONFIG_SYSFS 33 ????if (rxqs < 1) { 34 ????????pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n"); 35 ????????return NULL; 36 ????} 37 #endif 38 ?39 ????/* 计算net_device结构大小 */ 40 ????alloc_size = sizeof(struct net_device); 41 ????/* 加上私有数据大小 */ 42 ????if (sizeof_priv) { 43 ????????/* ensure 32-byte alignment of private area */ 44 ????????alloc_size = ALIGN(alloc_size, NETDEV_ALIGN); 45 ????????alloc_size += sizeof_priv; 46 ????} 47 ????/* ensure 32-byte alignment of whole construct */ 48 ????/* 整个空间做对齐后的大小 */ 49 ????alloc_size += NETDEV_ALIGN - 1; 50 ?51 ????/* 分配内存 */ 52 ????p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_REPEAT); 53 ????if (!p) 54 ????????return NULL; 55 ?56 ????/* 内存对齐 */ 57 ????dev = PTR_ALIGN(p, NETDEV_ALIGN); 58 ?59 ????/* 计算对齐的填充 */ 60 ????dev->padded = (char *)dev - (char *)p; 61 ?62 ????/* 分配设备引用 */ 63 ????dev->pcpu_refcnt = alloc_percpu(int); 64 ????if (!dev->pcpu_refcnt) 65 ????????goto free_dev; 66 ?67 ????/* 地址列表初始化 */ 68 ????if (dev_addr_init(dev)) 69 ????????goto free_pcpu; 70 ?71 ????/* 组播列表初始化 */ 72 ????dev_mc_init(dev); 73 ?74 ????/* 单播列表初始化 */ 75 ????dev_uc_init(dev); 76 ?77 ????/* 设置net */ 78 ????dev_net_set(dev, &init_net); 79 ?80 ????/* GSO设置 */ 81 ????dev->gso_max_size = GSO_MAX_SIZE; 82 ????dev->gso_max_segs = GSO_MAX_SEGS; 83 ?84 ????/* 初始化各种链表 */ 85 ????INIT_LIST_HEAD(&dev->napi_list); 86 ????INIT_LIST_HEAD(&dev->unreg_list); 87 ????INIT_LIST_HEAD(&dev->close_list); 88 ????INIT_LIST_HEAD(&dev->link_watch_list); 89 ????INIT_LIST_HEAD(&dev->adj_list.upper); 90 ????INIT_LIST_HEAD(&dev->adj_list.lower); 91 ????INIT_LIST_HEAD(&dev->ptype_all); 92 ????INIT_LIST_HEAD(&dev->ptype_specific); 93 #ifdef CONFIG_NET_SCHED 94 ????hash_init(dev->qdisc_hash); 95 #endif 96 ????dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM; 97 ?98 ????/* 初始化设备硬件地址，mtu等参数 */ 99 ????setup(dev);100 101 ????/* 队列长度为0，则采用默认值 */102 ????if (!dev->tx_queue_len) {103 ????????dev->priv_flags |= IFF_NO_QUEUE;104 ????????dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;105 ????}106 107 ????/* 设置发送队列数 */108 ????dev->num_tx_queues = txqs;109 ????dev->real_num_tx_queues = txqs;110 111 ????/* 分配初始化发送队列 */112 ????if (netif_alloc_netdev_queues(dev))113 ????????goto free_all;114 115 #ifdef CONFIG_SYSFS116 ????/* 设置接收队列数 */117 ????dev->num_rx_queues = rxqs;118 ????dev->real_num_rx_queues = rxqs;119 120 ????/* 分配初始化接收队列 */121 ????if (netif_alloc_rx_queues(dev))122 ????????goto free_all;123 #endif124 125 ????/* 拷贝名字 */126 ????strcpy(dev->name, name);127 128 ????/* 赋值名字赋值类型 */129 ????dev->name_assign_type = name_assign_type;130 131 ????/* 设置设备组 */132 ????dev->group = INIT_NETDEV_GROUP;133 134 ????/* 设置默认ethtool操作 */135 ????if (!dev->ethtool_ops)136 ????????dev->ethtool_ops = &default_ethtool_ops;137 138 ????/* 初始化netfilter入口 */139 ????nf_hook_ingress_init(dev);140 141 ????return dev;142 143 free_all:144 ????free_netdev(dev);145 ????return NULL;146 147 free_pcpu:148 ????free_percpu(dev->pcpu_refcnt);149 free_dev:150 ????netdev_freemem(dev);151 ????return NULL;152 }

 1 /** 2 ?* ether_setup - setup Ethernet network device 3 ?* @dev: network device 4 ?* 5 ?* Fill in the fields of the device structure with Ethernet-generic values. 6 ?*/ 7 void ether_setup(struct net_device *dev) 8 { 9 ????dev->header_ops ???????= &eth_header_ops;10 ????dev->type ???????= ARPHRD_ETHER;11 ????dev->hard_header_len ????= ETH_HLEN;12 ????dev->min_header_len ???= ETH_HLEN;13 ????dev->mtu ???????= ETH_DATA_LEN;14 ????dev->min_mtu ???????= ETH_MIN_MTU;15 ????dev->max_mtu ???????= ETH_DATA_LEN;16 ????dev->addr_len ???????= ETH_ALEN;17 ????dev->tx_queue_len ???= DEFAULT_TX_QUEUE_LEN;18 ????dev->flags ???????= IFF_BROADCAST|IFF_MULTICAST;19 ????dev->priv_flags ???????|= IFF_TX_SKB_SHARING;20 21 ????eth_broadcast_addr(dev->broadcast);22 23 }