Linux stmac网卡代码分析----probe

probe

主要分析一下驱动的主要框架，必要地方细致分析下

文件位置：

drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
从文件的最后看起：
module_pci_driver(stmmac_pci_driver);

stmmac_pci_driver结构体如下，里面包含了id_table、probe、remove。id_table里包含了支持设备的vender id、device id，当扫描到支持的pcie设备时（把venderid 和device id 和table里的id对比）就调用probe函数

static struct pci_driver stmmac_pci_driver = { .name = STMMAC_RESOURCE_NAME,.id_table = stmmac_id_table,.probe = stmmac_pci_probe,.remove = stmmac_pci_remove,.driver         = { .pm     = &stmmac_pm_ops,},  
};

以下是stmmac_pci_probe函数的一些主要调用
在这里插入图片描述
主要执行了以下操作

为plat_stmmacenet_data分配了空间
填充plat_stmmacenet_data
使能pci
填充plat_stmmacenet_data中一些网卡参数信息
获取pci的base address
调用stmmac_dvr_probe

接下来就进入到stmmac_dvr_probe函数，在此函数中主要完成net_device结构体的分配，和填充，填充中最重要的是设置了net_device结构体中的netdev_ops，最后使用register_netdev(ndev)注册到内核

stmmac_dvr_probe

在这里插入图片描述

int stmmac_dvr_probe(struct device *device,struct plat_stmmacenet_data *plat_dat,struct stmmac_resources *res)
{struct net_device *ndev = NULL;struct stmmac_priv *priv;u32 queue, maxq;int ret = 0;ndev = alloc_etherdev_mqs(sizeof(struct stmmac_priv),MTL_MAX_TX_QUEUES,MTL_MAX_RX_QUEUES);SET_NETDEV_DEV(ndev, device);/*对priv的填充*/priv = netdev_priv(ndev);priv->device = device;priv->dev = ndev;//对ethtool的支持stmmac_set_ethtool_ops(ndev);priv->pause = pause;priv->plat = plat_dat;priv->ioaddr = res->addr;priv->dev->base_addr = (unsigned long)res->addr;priv->dev->irq = res->irq;priv->wol_irq = res->wol_irq;priv->lpi_irq = res->lpi_irq;/***************/if (res->mac)memcpy(priv->dev->dev_addr, res->mac, ETH_ALEN);dev_set_drvdata(device, priv->dev);/* Verify driver arguments */stmmac_verify_args();/* Allocate workqueue */priv->wq = create_singlethread_workqueue("stmmac_wq");if (!priv->wq) {dev_err(priv->device, "failed to create workqueue\n");ret = -ENOMEM;goto error_wq;}INIT_WORK(&priv->service_task, stmmac_service_task);/* Override with kernel parameters if supplied XXX CRS XXX* this needs to have multiple instances*/if ((phyaddr >= 0) && (phyaddr <= 31))priv->plat->phy_addr = phyaddr;/* Init MAC and get the capabilities */ret = stmmac_hw_init(priv);if (ret)goto error_hw_init;/* Configure real RX and TX queues */netif_set_real_num_rx_queues(ndev, priv->plat->rx_queues_to_use);netif_set_real_num_tx_queues(ndev, priv->plat->tx_queues_to_use);//设置网卡的opsndev->netdev_ops = &stmmac_netdev_ops;ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |NETIF_F_RXCSUM;ret = stmmac_tc_init(priv, priv);if (!ret) {ndev->hw_features |= NETIF_F_HW_TC;}if ((priv->plat->tso_en) && (priv->dma_cap.tsoen)) {ndev->hw_features |= NETIF_F_TSO | NETIF_F_TSO6;priv->tso = true;dev_info(priv->device, "TSO feature enabled\n");}ndev->features |= ndev->hw_features | NETIF_F_HIGHDMA;ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
#ifdef STMMAC_VLAN_TAG_USED/* Both mac100 and gmac support receive VLAN tag detection */ndev->features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX;
#endif
priv->msg_enable = netif_msg_init(debug, default_msg_level);/* MTU range: 46 - hw-specific max */ndev->min_mtu = ETH_ZLEN - ETH_HLEN;if ((priv->plat->enh_desc) || (priv->synopsys_id >= DWMAC_CORE_4_00))ndev->max_mtu = JUMBO_LEN;else if (priv->plat->has_xgmac)ndev->max_mtu = XGMAC_JUMBO_LEN;elsendev->max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);/* Will not overwrite ndev->max_mtu if plat->maxmtu > ndev->max_mtu* as well as plat->maxmtu < ndev->min_mtu which is a invalid range.*/if ((priv->plat->maxmtu < ndev->max_mtu) &&(priv->plat->maxmtu >= ndev->min_mtu))ndev->max_mtu = priv->plat->maxmtu;else if (priv->plat->maxmtu < ndev->min_mtu)dev_warn(priv->device,"%s: warning: maxmtu having invalid value (%d)\n",__func__, priv->plat->maxmtu);if (flow_ctrl)priv->flow_ctrl = FLOW_AUTO;	/* RX/TX pause on *//* Setup channels NAPI */maxq = max(priv->plat->rx_queues_to_use, priv->plat->tx_queues_to_use);for (queue = 0; queue < maxq; queue++) {struct stmmac_channel *ch = &priv->channel[queue];ch->priv_data = priv;ch->index = queue;if (queue < priv->plat->rx_queues_to_use)ch->has_rx = true;if (queue < priv->plat->tx_queues_to_use)ch->has_tx = true;netif_napi_add(ndev, &ch->napi, stmmac_napi_poll,NAPI_POLL_WEIGHT);}mutex_init(&priv->lock);/*如果设置了plat->clk_csr那么CSR clock在运行中将会是固定不变的，如果没有设置，那么click会根据csr实际的时钟输入动态的设置*/if (!priv->plat->clk_csr)stmmac_clk_csr_set(priv);elsepriv->clk_csr = priv->plat->clk_csr;//检查是否支持Physical Coding Sublayerstmmac_check_pcs_mode(priv);if (priv->hw->pcs != STMMAC_PCS_RGMII  &&priv->hw->pcs != STMMAC_PCS_TBI &&priv->hw->pcs != STMMAC_PCS_RTBI) {/* MDIO bus Registration */ret = stmmac_mdio_register(ndev);if (ret < 0) {dev_err(priv->device,"%s: MDIO bus (id: %d) registration failed",__func__, priv->plat->bus_id);goto error_mdio_register;}}ret = register_netdev(ndev);return ret;
error_netdev_register:if (priv->hw->pcs != STMMAC_PCS_RGMII &&priv->hw->pcs != STMMAC_PCS_TBI &&priv->hw->pcs != STMMAC_PCS_RTBI)stmmac_mdio_unregister(ndev);
error_mdio_register:for (queue = 0; queue < maxq; queue++) {struct stmmac_channel *ch = &priv->channel[queue];netif_napi_del(&ch->napi);}
error_hw_init:destroy_workqueue(priv->wq);
error_wq:free_netdev(ndev);return ret;
}
EXPORT_SYMBOL_GPL(stmmac_dvr_probe);

下面看看stmmac_hw_init(priv)，这里有硬件相关的设置，特别是设置了操作硬件的ops，函数中主要调用了stmmac_hwif_init函数。

int stmmac_hwif_init(struct stmmac_priv *priv)
{bool needs_xgmac = priv->plat->has_xgmac;bool needs_gmac4 = priv->plat->has_gmac4;bool needs_gmac = priv->plat->has_gmac;const struct stmmac_hwif_entry *entry;struct mac_device_info *mac;bool needs_setup = true;int i, ret;u32 id;if (needs_gmac) {id = stmmac_get_id(priv, GMAC_VERSION);} else if (needs_gmac4 || needs_xgmac) {id = stmmac_get_id(priv, GMAC4_VERSION);} else {id = 0;}/* Save ID for later use */priv->synopsys_id = id;/* Lets assume some safe values first */priv->ptpaddr = priv->ioaddr +(needs_gmac4 ? PTP_GMAC4_OFFSET : PTP_GMAC3_X_OFFSET);priv->mmcaddr = priv->ioaddr +(needs_gmac4 ? MMC_GMAC4_OFFSET : MMC_GMAC3_X_OFFSET);/* Check for HW specific setup first */if (priv->plat->setup) {mac = priv->plat->setup(priv);needs_setup = false;} else {mac = devm_kzalloc(priv->device, sizeof(*mac), GFP_KERNEL);}if (!mac)return -ENOMEM;/* 为网卡设置硬件操作相关的回调函数*/for (i = ARRAY_SIZE(stmmac_hw) - 1; i >= 0; i--) {/*在stmmac_hw数组中选取一个entry*/entry = &stmmac_hw[i];/*进行筛选*/if (needs_gmac ^ entry->gmac)continue;if (needs_gmac4 ^ entry->gmac4)continue;if (needs_xgmac ^ entry->xgmac)continue;/* Use synopsys_id var because some setups can override this */if (priv->synopsys_id < entry->min_id)continue;/* 到这里表示已经选到合适的entry，将它保存到mac结构体 */mac->desc = mac->desc ? : entry->desc;mac->dma = mac->dma ? : entry->dma;mac->mac = mac->mac ? : entry->mac;mac->ptp = mac->ptp ? : entry->hwtimestamp;mac->mode = mac->mode ? : entry->mode;mac->tc = mac->tc ? : entry->tc;/*把mac挂接到priv->hw*/priv->hw = mac;priv->ptpaddr = priv->ioaddr + entry->regs.ptp_off;priv->mmcaddr = priv->ioaddr + entry->regs.mmc_off;/* Save quirks, if needed for posterior use */priv->hwif_quirks = entry->quirks;return 0;}dev_err(priv->device, "Failed to find HW IF (id=0x%x, gmac=%d/%d)\n",id, needs_gmac, needs_gmac4);return -EINVAL;
}