目錄
文章目錄
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- rte_eth_dev_count：獲取被 DPDK App 接管的 eth 網卡數量。
- rte_eth_dev_configure：根據 DPDK App 的需要，配置被 App 接管的 eth 網卡，實際上是配置 eth 網卡的驅動程序。
- rte_eth_rx_queue_setup/rte_eth_tx_queue_setup：爲網卡分配 接收/發送 隊列。
- rte_eth_dev_start：啓動網卡。
- rte_eth_rx_burst/rte_eth_tx_burst：爲指定網卡的指定隊列的 接收/發送 數據包函數。
- ixgbe_dev_*：Intel 82599（Intel x500 系列）網卡的驅動程序，作爲該型號網卡的 PMD 與 igb_uio 驅動一起實現 kernel-bypass 的效果。
rte_eth_dev/rte_eth_dev_data 數據結構
DPDK 定義了一個 rte_eth_devices 數組，元素類型爲 struct rte_eth_dev，一個元素代表一塊網卡。struct rte_eth_dev 有四個重要的成員：
- rx_pkt_burst：網卡的 burst 收包函數；
- tx_pkt_burst：網卡的 burst 發包函數；
- dev_ops：網卡驅動註冊函數表，類型爲 struct eth_dev_ops；
- data：包含了網卡的主要信息，類型爲 struct rte_eth_dev_data。
struct rte_eth_dev {
/* 在 rte_bus_probe() 中註冊 rx/tx_pkt_burst */
eth_rx_burst_t rx_pkt_burst; /**< Pointer to PMD receive function. */
eth_tx_burst_t tx_pkt_burst; /**< Pointer to PMD transmit function. */
eth_tx_prep_t tx_pkt_prepare; /**< Pointer to PMD transmit prepare function. */
struct rte_eth_dev_data *data; /**< Pointer to device data */
/* 在 rte_bus_probe() 中註冊 dev_ops */
const struct eth_dev_ops *dev_ops; /**< Functions exported by PMD */
struct rte_device *device; /**< Backing device */
struct rte_intr_handle *intr_handle; /**< Device interrupt handle */
...
} __rte_cache_aligned;
struct rte_eth_dev_data {
char name[RTE_ETH_NAME_MAX_LEN]; /**< Unique identifier name */
/* 接收隊列數組 */
void **rx_queues; /**< Array of pointers to RX queues. */
/* 發送隊列數組 */
void **tx_queues; /**< Array of pointers to TX queues. */
/* 接收隊列數組長度 */
uint16_t nb_rx_queues; /**< Number of RX queues. */
/* 發送隊列數組長度 */
uint16_t nb_tx_queues; /**< Number of TX queues. */
...
};
struct rte_eth_dev rte_eth_devices[RTE_MAX_ETHPORTS];
static struct rte_eth_dev_data *rte_eth_dev_data;
rte_eth_dev_count 函數
uint8_t
rte_eth_dev_count(void)
{
uint8_t p;
uint8_t count;
count = 0;
RTE_ETH_FOREACH_DEV(p)
count++;
return count;
}
#define RTE_ETH_FOREACH_DEV(p) \
for (p = rte_eth_find_next(0); \
(unsigned int)p < (unsigned int)RTE_MAX_ETHPORTS; \
p = rte_eth_find_next(p + 1))
/**
* 從 port_id 開始遍歷 rte_eth_device 數組，找到第一個狀態爲 RTE_ETH_DEV_ATTACHED 的設備。
* 這些設備使用指令 dpdk-devbind.py --bind 進行綁定。
*/
uint8_t
rte_eth_find_next(uint8_t port_id)
{
while (port_id < RTE_MAX_ETHPORTS &&
rte_eth_devices[port_id].state != RTE_ETH_DEV_ATTACHED)
port_id++;
if (port_id >= RTE_MAX_ETHPORTS)
return RTE_MAX_ETHPORTS;
return port_id;
}
rte_eth_dev_configure 函數
rte_eth_dev_configure 函數的主要工作是分配接收/發送隊列數組，一個數組元素表示一個接收/發送隊列，類型爲 void *。
int
rte_eth_dev_configure(uint8_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
const struct rte_eth_conf *dev_conf)
{
struct rte_eth_dev *dev;
struct rte_eth_dev_info dev_info;
int diag;
/* 檢查 port_id 是否合法 */
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
/* 檢查接收隊列數是否大於 DPDK 的上限 */
if (nb_rx_q > RTE_MAX_QUEUES_PER_PORT) {
RTE_PMD_DEBUG_TRACE(
"Number of RX queues requested (%u) is greater than max supported(%d)\n",
nb_rx_q, RTE_MAX_QUEUES_PER_PORT);
return -EINVAL;
}
/* 檢查發送隊列數是否大於 DPDK 上限 */
if (nb_tx_q > RTE_MAX_QUEUES_PER_PORT) {
RTE_PMD_DEBUG_TRACE(
"Number of TX queues requested (%u) is greater than max supported(%d)\n",
nb_tx_q, RTE_MAX_QUEUES_PER_PORT);
return -EINVAL;
}
/* 得到 port_id 對應的設備 */
dev = &rte_eth_devices[port_id];
/* 檢查 dev_infos_get 和 dev_configure 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_infos_get, -ENOTSUP);
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_configure, -ENOTSUP);
/* 檢查設備是否已啓動 */
if (dev->data->dev_started) {
RTE_PMD_DEBUG_TRACE(
"port %d must be stopped to allow configuration\n", port_id);
return -EBUSY;
}
/**
* 複製 dev_conf 到 dev->data->dev_conf。
* - dev_conf 由 DPDK App 定義。
* - dev 結構體將傳入到網卡驅動程序。
*/
memcpy(&dev->data->dev_conf, dev_conf, sizeof(dev->data->dev_conf));
/*
* Check that the numbers of RX and TX queues are not greater
* than the maximum number of RX and TX queues supported by the
* configured device.
*/
/**
* dev->dev_ops 註冊了網卡驅動的函數。
* 如果是 ixgbe 驅動，則調用 ixgbe_dev_info_get() 函數。
*/
(*dev->dev_ops->dev_infos_get)(dev, &dev_info);
/* 檢查接收/發送隊列數是否同時爲 0 */
if (nb_rx_q == 0 && nb_tx_q == 0) {
RTE_PMD_DEBUG_TRACE("ethdev port_id=%d both rx and tx queue cannot be 0\n", port_id);
return -EINVAL;
}
/* 檢查接收隊列數是否大於網卡上限 */
if (nb_rx_q > dev_info.max_rx_queues) {
RTE_PMD_DEBUG_TRACE("ethdev port_id=%d nb_rx_queues=%d > %d\n",
port_id, nb_rx_q, dev_info.max_rx_queues);
return -EINVAL;
}
/* 檢查發送隊列數是否大於網卡上限 */
if (nb_tx_q > dev_info.max_tx_queues) {
RTE_PMD_DEBUG_TRACE("ethdev port_id=%d nb_tx_queues=%d > %d\n",
port_id, nb_tx_q, dev_info.max_tx_queues);
return -EINVAL;
}
/* Check that the device supports requested interrupts */
if ((dev_conf->intr_conf.lsc == 1) &&
(!(dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC))) {
RTE_PMD_DEBUG_TRACE("driver %s does not support lsc\n",
dev->device->driver->name);
return -EINVAL;
}
if ((dev_conf->intr_conf.rmv == 1) &&
(!(dev->data->dev_flags & RTE_ETH_DEV_INTR_RMV))) {
RTE_PMD_DEBUG_TRACE("driver %s does not support rmv\n",
dev->device->driver->name);
return -EINVAL;
}
/*
* If jumbo frames are enabled, check that the maximum RX packet
* length is supported by the configured device.
*/
if (dev_conf->rxmode.jumbo_frame == 1) {
if (dev_conf->rxmode.max_rx_pkt_len >
dev_info.max_rx_pktlen) {
RTE_PMD_DEBUG_TRACE("ethdev port_id=%d max_rx_pkt_len %u"
" > max valid value %u\n",
port_id,
(unsigned)dev_conf->rxmode.max_rx_pkt_len,
(unsigned)dev_info.max_rx_pktlen);
return -EINVAL;
} else if (dev_conf->rxmode.max_rx_pkt_len < ETHER_MIN_LEN) {
RTE_PMD_DEBUG_TRACE("ethdev port_id=%d max_rx_pkt_len %u"
" < min valid value %u\n",
port_id,
(unsigned)dev_conf->rxmode.max_rx_pkt_len,
(unsigned)ETHER_MIN_LEN);
return -EINVAL;
}
} else {
if (dev_conf->rxmode.max_rx_pkt_len < ETHER_MIN_LEN ||
dev_conf->rxmode.max_rx_pkt_len > ETHER_MAX_LEN) /* 小於64或大於1518 */
/* Use default value */
dev->data->dev_conf.rxmode.max_rx_pkt_len =
ETHER_MAX_LEN; /* 默認值爲1518 */
}
/* 分配接收隊列數組，地址賦給 dev->data->rx_queues，長度賦給 dev->data->nb_rx_queues */
diag = rte_eth_dev_rx_queue_config(dev, nb_rx_q);
if (diag != 0) {
RTE_PMD_DEBUG_TRACE("port%d rte_eth_dev_rx_queue_config = %d\n",
port_id, diag);
return diag;
}
/* 分配發送隊列數組，地址賦給 dev->data->tx_queues，長度賦給 dev->data->nb_tx_queues */
diag = rte_eth_dev_tx_queue_config(dev, nb_tx_q);
if (diag != 0) {
RTE_PMD_DEBUG_TRACE("port%d rte_eth_dev_tx_queue_config = %d\n",
port_id, diag);
rte_eth_dev_rx_queue_config(dev, 0);
return diag;
}
/* 註冊了 ixgbe 驅動的 ixgbe_dev_configure() 函數 */
diag = (*dev->dev_ops->dev_configure)(dev);
if (diag != 0) {
RTE_PMD_DEBUG_TRACE("port%d dev_configure = %d\n",
port_id, diag);
rte_eth_dev_rx_queue_config(dev, 0);
rte_eth_dev_tx_queue_config(dev, 0);
return diag;
}
return 0;
}
ixgbe_dev_configure 函數
static int
ixgbe_dev_configure(struct rte_eth_dev *dev)
{
...
/* multipe queue mode checking */
ret = ixgbe_check_mq_mode(dev);
...
/*
* Initialize to TRUE. If any of Rx queues doesn't meet the bulk
* allocation or vector Rx preconditions we will reset it.
*/
adapter->rx_bulk_alloc_allowed = true;
adapter->rx_vec_allowed = true;
...
}
rte_eth_dev_rx_queue_config/rte_eth_dev_tx_queue_config 函數
static int
rte_eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
{
...
dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
sizeof(dev->data->rx_queues[0]) * nb_queues,
RTE_CACHE_LINE_SIZE);
...
dev->data->nb_rx_queues = nb_queues; /* 更新nb_rx_queues */
...
}
static int
rte_eth_dev_tx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
{
...
dev->data->tx_queues = rte_zmalloc("ethdev->tx_queues",
sizeof(dev->data->tx_queues[0]) * nb_queues,
RTE_CACHE_LINE_SIZE);
...
dev->data->nb_tx_queues = nb_queues; /* 更新nb_tx_queues */
...
}
rte_eth_rx_queue_setup 函數
int
rte_eth_rx_queue_setup(uint8_t port_id, uint16_t rx_queue_id,
uint16_t nb_rx_desc, unsigned int socket_id,
const struct rte_eth_rxconf *rx_conf,
struct rte_mempool *mp)
{
int ret;
uint32_t mbp_buf_size;
struct rte_eth_dev *dev;
struct rte_eth_dev_info dev_info;
void **rxq;
/* 檢查 port_id 是否合法 */
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
/* 得到 port_id 對應的設備 */
dev = &rte_eth_devices[port_id];
if (rx_queue_id >= dev->data->nb_rx_queues) {
RTE_PMD_DEBUG_TRACE("Invalid RX queue_id=%d\n", rx_queue_id);
return -EINVAL;
}
/* 檢查設備是否已啓動 */
if (dev->data->dev_started) {
RTE_PMD_DEBUG_TRACE(
"port %d must be stopped to allow configuration\n", port_id);
return -EBUSY;
}
/* 檢查 dev_infos_get 和 rx_queue_setup 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_infos_get, -ENOTSUP);
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_queue_setup, -ENOTSUP);
/*
* Check the size of the mbuf data buffer.
* This value must be provided in the private data of the memory pool.
* First check that the memory pool has a valid private data.
*/
rte_eth_dev_info_get(port_id, &dev_info);
if (mp->private_data_size < sizeof(struct rte_pktmbuf_pool_private)) {
RTE_PMD_DEBUG_TRACE("%s private_data_size %d < %d\n",
mp->name, (int) mp->private_data_size,
(int) sizeof(struct rte_pktmbuf_pool_private));
return -ENOSPC;
}
mbp_buf_size = rte_pktmbuf_data_room_size(mp);
if ((mbp_buf_size - RTE_PKTMBUF_HEADROOM) < dev_info.min_rx_bufsize) {
RTE_PMD_DEBUG_TRACE("%s mbuf_data_room_size %d < %d "
"(RTE_PKTMBUF_HEADROOM=%d + min_rx_bufsize(dev)"
"=%d)\n",
mp->name,
(int)mbp_buf_size,
(int)(RTE_PKTMBUF_HEADROOM +
dev_info.min_rx_bufsize),
(int)RTE_PKTMBUF_HEADROOM,
(int)dev_info.min_rx_bufsize);
return -EINVAL;
}
/* 檢查 nb_rx_desc 是否大於網卡上限 */
if (nb_rx_desc > dev_info.rx_desc_lim.nb_max ||
nb_rx_desc < dev_info.rx_desc_lim.nb_min ||
nb_rx_desc % dev_info.rx_desc_lim.nb_align != 0) {
RTE_PMD_DEBUG_TRACE("Invalid value for nb_rx_desc(=%hu), "
"should be: <= %hu, = %hu, and a product of %hu\n",
nb_rx_desc,
dev_info.rx_desc_lim.nb_max,
dev_info.rx_desc_lim.nb_min,
dev_info.rx_desc_lim.nb_align);
return -EINVAL;
}
/* 得到接收隊列數組 */
rxq = dev->data->rx_queues;
if (rxq[rx_queue_id]) {
/* 檢查 rx_queue_release 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_queue_release,
-ENOTSUP);
/* ixgbe 驅動程序註冊了 ixgbe_dev_rx_queue_release() 函數 */
(*dev->dev_ops->rx_queue_release)(rxq[rx_queue_id]);
rxq[rx_queue_id] = NULL;
}
if (rx_conf == NULL)
rx_conf = &dev_info.default_rxconf;
/* ixgbe 驅動程序註冊了 ixgbe_dev_rx_queue_setup() 函數 */
ret = (*dev->dev_ops->rx_queue_setup)(dev, rx_queue_id, nb_rx_desc,
socket_id, rx_conf, mp);
if (!ret) {
if (!dev->data->min_rx_buf_size ||
dev->data->min_rx_buf_size > mbp_buf_size)
dev->data->min_rx_buf_size = mbp_buf_size;
}
return ret;
}
ixgbe_dev_rx_queue_setup 函數
int __attribute__((cold))
ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
uint16_t queue_idx,
uint16_t nb_desc,
unsigned int socket_id,
const struct rte_eth_rxconf *rx_conf,
struct rte_mempool *mp)
{
...
/* 分配 ixgbe_rx_queue */
rxq = rte_zmalloc_socket("ethdev RX queue", sizeof(struct ixgbe_rx_queue),
RTE_CACHE_LINE_SIZE, socket_id);
...
/* 初始化 rxq */
rxq->mb_pool = mp;
rxq->nb_rx_desc = nb_desc;
rxq->rx_free_thresh = rx_conf->rx_free_thresh;
rxq->queue_id = queue_idx;
rxq->reg_idx = (uint16_t)((RTE_ETH_DEV_SRIOV(dev).active == 0) ?
queue_idx : RTE_ETH_DEV_SRIOV(dev).def_pool_q_idx + queue_idx);
rxq->port_id = dev->data->port_id;
rxq->crc_len = (uint8_t) ((dev->data->dev_conf.rxmode.hw_strip_crc) ?
0 : ETHER_CRC_LEN);
rxq->drop_en = rx_conf->rx_drop_en;
rxq->rx_deferred_start = rx_conf->rx_deferred_start;
...
/**
* 分配 desc（skb 描述符）數組，數組元素類型爲 union ixgbe_adv_rx_desc1
* (IXGBE_MAX_RING_DESC + RTE_PMD_IXGBE_RX_MAX_BURST) * sizeof(union ixgbe_adv_rx_desc)
* (4096 + 32) * sizeof(union ixgbe_adv_rx_desc)
*/
rz = rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx,
RX_RING_SZ, IXGBE_ALIGN, socket_id);
...
/* 清零 desc 數組 */
memset(rz->addr, 0, RX_RING_SZ);
...
/* 設置 rdt_reg_addr 爲 RDT 寄存器的地址 */
rxq->rdt_reg_addr =
IXGBE_PCI_REG_ADDR(hw, IXGBE_RDT(rxq->reg_idx));
/* 設置 rdh_reg_addr 爲 RDH 寄存器的地址 */
rxq->rdh_reg_addr =
IXGBE_PCI_REG_ADDR(hw, IXGBE_RDH(rxq->reg_idx));
...
/* rx_ring_phys_addr 指向 desc 數組的總線地址 */
rxq->rx_ring_phys_addr = rte_mem_phy2mch(rz->memseg_id, rz->phys_addr);
/* rx_ring 指向 desc 數組的虛擬地址 */
rxq->rx_ring = (union ixgbe_adv_rx_desc *) rz->addr;
...
/* 分配 entry 數組，地址賦給 sw_ring */
rxq->sw_ring = rte_zmalloc_socket("rxq->sw_ring",
sizeof(struct ixgbe_rx_entry) * len,
RTE_CACHE_LINE_SIZE, socket_id);
...
/* rx_queues[queue_idx] 指向 ixgbe_rx_queue */
dev->data->rx_queues[queue_idx] = rxq;
...
/* 設置接收隊列參數 */
ixgbe_reset_rx_queue(adapter, rxq);
...
}
static void __attribute__((cold))
ixgbe_reset_rx_queue(struct ixgbe_adapter *adapter, struct ixgbe_rx_queue *rxq)
{
...
rxq->rx_nb_avail = 0;
rxq->rx_next_avail = 0;
rxq->rx_free_trigger = (uint16_t)(rxq->rx_free_thresh - 1);
rxq->rx_tail = 0;
rxq->nb_rx_hold = 0;
rxq->pkt_first_seg = NULL;
rxq->pkt_last_seg = NULL;
...
}
rte_eth_tx_queue_setup 函數
int
rte_eth_tx_queue_setup(uint8_t port_id, uint16_t tx_queue_id,
uint16_t nb_tx_desc, unsigned int socket_id,
const struct rte_eth_txconf *tx_conf)
{
struct rte_eth_dev *dev;
struct rte_eth_dev_info dev_info;
void **txq;
/* 檢查 port_id 是否合法 */
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
/* 得到 port_id 對應的設備 */
dev = &rte_eth_devices[port_id];
if (tx_queue_id >= dev->data->nb_tx_queues) {
RTE_PMD_DEBUG_TRACE("Invalid TX queue_id=%d\n", tx_queue_id);
return -EINVAL;
}
/* 檢查設備是否已啓動 */
if (dev->data->dev_started) {
RTE_PMD_DEBUG_TRACE(
"port %d must be stopped to allow configuration\n", port_id);
return -EBUSY;
}
/* 檢查 dev_infos_get 和 tx_queue_setup 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_infos_get, -ENOTSUP);
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->tx_queue_setup, -ENOTSUP);
rte_eth_dev_info_get(port_id, &dev_info);
/* 檢查 nb_tx_desc 是否大於網卡上限 */
if (nb_tx_desc > dev_info.tx_desc_lim.nb_max ||
nb_tx_desc < dev_info.tx_desc_lim.nb_min ||
nb_tx_desc % dev_info.tx_desc_lim.nb_align != 0) {
RTE_PMD_DEBUG_TRACE("Invalid value for nb_tx_desc(=%hu), "
"should be: <= %hu, = %hu, and a product of %hu\n",
nb_tx_desc,
dev_info.tx_desc_lim.nb_max,
dev_info.tx_desc_lim.nb_min,
dev_info.tx_desc_lim.nb_align);
return -EINVAL;
}
/* 得到發送隊列數組 */
txq = dev->data->tx_queues;
if (txq[tx_queue_id]) {
/* 檢查 tx_queue_release 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->tx_queue_release,
-ENOTSUP);
/* ixgbe 驅動程序註冊了 ixgbe_dev_tx_queue_release() 函數 */
(*dev->dev_ops->tx_queue_release)(txq[tx_queue_id]);
txq[tx_queue_id] = NULL;
}
if (tx_conf == NULL)
tx_conf = &dev_info.default_txconf;
/* ixgbe 驅動程序註冊了 ixgbe_dev_tx_queue_setup() 函數 */
return (*dev->dev_ops->tx_queue_setup)(dev, tx_queue_id, nb_tx_desc,
socket_id, tx_conf);
}
ixgbe_dev_tx_queue_setup 函數
int __attribute__((cold))
ixgbe_dev_tx_queue_setup(struct rte_eth_dev *dev,
uint16_t queue_idx,
uint16_t nb_desc,
unsigned int socket_id,
const struct rte_eth_txconf *tx_conf)
{
...
/* 分配 ixgbe_tx_queue */
txq = rte_zmalloc_socket("ethdev TX queue", sizeof(struct ixgbe_tx_queue),
RTE_CACHE_LINE_SIZE, socket_id);
...
/**
* 分配 desc（skb 描述符）數組，數組元素類型爲 union ixgbe_adv_tx_desc
* sizeof(union ixgbe_adv_tx_desc) * 4096
*/
tz = rte_eth_dma_zone_reserve(dev, "tx_ring", queue_idx,
sizeof(union ixgbe_adv_tx_desc) * IXGBE_MAX_RING_DESC,
IXGBE_ALIGN, socket_id);
...
/* 初始化 txq */
txq->nb_tx_desc = nb_desc;
txq->tx_rs_thresh = tx_rs_thresh;
txq->tx_free_thresh = tx_free_thresh;
txq->pthresh = tx_conf->tx_thresh.pthresh;
txq->hthresh = tx_conf->tx_thresh.hthresh;
txq->wthresh = tx_conf->tx_thresh.wthresh;
txq->queue_id = queue_idx;
txq->reg_idx = (uint16_t)((RTE_ETH_DEV_SRIOV(dev).active == 0) ?
queue_idx : RTE_ETH_DEV_SRIOV(dev).def_pool_q_idx + queue_idx);
txq->port_id = dev->data->port_id;
txq->txq_flags = tx_conf->txq_flags;
txq->ops = &def_txq_ops;
txq->tx_deferred_start = tx_conf->tx_deferred_start;
...
/* 設置 tdt_reg_addr 爲 TDT 寄存器的地址 */
txq->tdt_reg_addr = IXGBE_PCI_REG_ADDR(hw, IXGBE_TDT(txq->reg_idx));
...
/* tx_ring_phys_addr 指向 desc 數組的總線地址 */
txq->tx_ring_phys_addr = rte_mem_phy2mch(tz->memseg_id, tz->phys_addr);
/* tx_ring 指向 desc 數組的虛擬地址 */
txq->tx_ring = (union ixgbe_adv_tx_desc *) tz->addr;
...
/* 分配 entry 數組，地址賦給 sw_ring */
txq->sw_ring = rte_zmalloc_socket("txq->sw_ring",
sizeof(struct ixgbe_tx_entry) * nb_desc,
RTE_CACHE_LINE_SIZE, socket_id);
...
/**
* ixgbe_reset_tx_queue() 設置發送隊列參數
*/
txq->ops->reset(txq);
...
/* tx_queues[queue_idx] 指向 ixgbe_tx_queue */
dev->data->tx_queues[queue_idx] = txq;
...
}
static void __attribute__((cold))
ixgbe_reset_tx_queue(struct ixgbe_tx_queue *txq)
{
...
prev = (uint16_t) (txq->nb_tx_desc - 1);
for (i = 0; i < txq->nb_tx_desc; i++) {
...
txd->wb.status = rte_cpu_to_le_32(IXGBE_TXD_STAT_DD);
txe[i].mbuf = NULL;
txe[i].last_id = i;
txe[prev].next_id = i;
prev = i;
}
...
txq->tx_next_dd = (uint16_t)(txq->tx_rs_thresh - 1);
txq->tx_next_rs = (uint16_t)(txq->tx_rs_thresh - 1);
...
txq->tx_tail = 0;
txq->nb_tx_used = 0;
...
txq->last_desc_cleaned = (uint16_t)(txq->nb_tx_desc - 1);
txq->nb_tx_free = (uint16_t)(txq->nb_tx_desc - 1);
...
}
rte_eth_dev_start 函數
int
rte_eth_dev_start(uint8_t port_id)
{
struct rte_eth_dev *dev;
int diag;
/* 檢查 port_id 是否合法 */
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
/* 得到 port_id 對應的設備 */
dev = &rte_eth_devices[port_id];
/* 檢查 dev_start 是否定義 */
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_start, -ENOTSUP);
/* 檢查設備是否已啓動 */
if (dev->data->dev_started != 0) {
RTE_PMD_DEBUG_TRACE("Device with port_id=%" PRIu8
" already started\n",
port_id);
return 0;
}
/* ixgbe 驅動程序註冊了 ixgbe_dev_start() 函數 */
diag = (*dev->dev_ops->dev_start)(dev);
if (diag == 0)
dev->data->dev_started = 1;
else
return diag;
/* 保存配置 */
rte_eth_dev_config_restore(port_id);
if (dev->data->dev_conf.intr_conf.lsc == 0) {
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->link_update, -ENOTSUP);
(*dev->dev_ops->link_update)(dev, 0);
}
return 0;
}
ixgbe_dev_start 函數
static int
ixgbe_dev_start(struct rte_eth_dev *dev)
{
...
/* 爲每個 ixgbe_tx_queue 配置網卡的 TDBAL、TDBAH、TDLEN、TDH、TDT */
ixgbe_dev_tx_init(dev);
...
/* 爲每個 ixgbe_rx_queue 配置網卡的 RDBAL、RDBAH、RDLEN、RDH、RDT */
err = ixgbe_dev_rx_init(dev);
...
err = ixgbe_dev_rxtx_start(dev);
...
}
void __attribute__((cold))
ixgbe_dev_tx_init(struct rte_eth_dev *dev)
{
...
for (i = 0; i < dev->data->nb_tx_queues; i++) {
txq = dev->data->tx_queues[i];
...
/* desc 數組的總線地址 */
bus_addr = txq->tx_ring_phys_addr;
/* 將 desc 數組的總線地址寫入網卡寄存器
* TDBAL（TX Descriptor Base Address Low）
* TDBAH（TX Descriptor Base Address High）
* TDLEN（TX Descriptor Length）
* TDH（TX Descriptor Head）
* TDT（TX Descriptor Tail）
* #define IXGBE_TDBAL(_i) (0x06000 + ((_i) * 0x40))
* #define IXGBE_TDBAH(_i) (0x06004 + ((_i) * 0x40))
* #define IXGBE_TDLEN(_i) (0x06008 + ((_i) * 0x40))
* #define IXGBE_TDH(_i) (0x06010 + ((_i) * 0x40))
* #define IXGBE_TDT(_i) (0x06018 + ((_i) * 0x40)) */
IXGBE_WRITE_REG(hw, IXGBE_TDBAL(txq->reg_idx),
(uint32_t)(bus_addr & 0x00000000ffffffffULL));
IXGBE_WRITE_REG(hw, IXGBE_TDBAH(txq->reg_idx),
(uint32_t)(bus_addr >> 32));
IXGBE_WRITE_REG(hw, IXGBE_TDLEN(txq->reg_idx),
txq->nb_tx_desc * sizeof(union ixgbe_adv_tx_desc)); /* desc 數組的長度 */
/* Setup the HW Tx Head and TX Tail descriptor pointers */
IXGBE_WRITE_REG(hw, IXGBE_TDH(txq->reg_idx), 0); /* 寫 TDH 爲 0 */
IXGBE_WRITE_REG(hw, IXGBE_TDT(txq->reg_idx), 0); /* 寫 TDT 爲 0 */
...
}
...
}
int __attribute__((cold))
ixgbe_dev_rx_init(struct rte_eth_dev *dev)
{
...
for (i = 0; i < dev->data->nb_rx_queues; i++) {
rxq = dev->data->rx_queues[i];
...
/* desc 數組的總線地址 */
bus_addr = rxq->rx_ring_phys_addr;
/* 將 desc 數組的總線地址寫入網卡寄存器
* RDBAL（RX Descriptor Base Address Low）
* RDBAH（RX Descriptor Base Address High）
* RDLEN（RX Descriptor Length）
* RDH（RX Descriptor Head）
* RDT（RX Descriptor Tail）
* #define IXGBE_RDBAL(_i) (((_i) < 64) ? (0x01000 + ((_i) * 0x40)) : \
* (0x0D000 + (((_i) - 64) * 0x40)))
* #define IXGBE_RDBAH(_i) (((_i) < 64) ? (0x01004 + ((_i) * 0x40)) : \
* (0x0D004 + (((_i) - 64) * 0x40)))
* #define IXGBE_RDLEN(_i) (((_i) < 64) ? (0x01008 + ((_i) * 0x40)) : \
* (0x0D008 + (((_i) - 64) * 0x40)))
* #define IXGBE_RDH(_i) (((_i) < 64) ? (0x01010 + ((_i) * 0x40)) : \
* (0x0D010 + (((_i) - 64) * 0x40)))
* #define IXGBE_RDT(_i) (((_i) < 64) ? (0x01018 + ((_i) * 0x40)) : \
* (0x0D018 + (((_i) - 64) * 0x40))) */
IXGBE_WRITE_REG(hw, IXGBE_RDBAL(rxq->reg_idx),
(uint32_t)(bus_addr & 0x00000000ffffffffULL));
IXGBE_WRITE_REG(hw, IXGBE_RDBAH(rxq->reg_idx),
(uint32_t)(bus_addr >> 32));
IXGBE_WRITE_REG(hw, IXGBE_RDLEN(rxq->reg_idx),
rxq->nb_rx_desc * sizeof(union ixgbe_adv_rx_desc)); /* desc 數組的長度 */
IXGBE_WRITE_REG(hw, IXGBE_RDH(rxq->reg_idx), 0); /* 寫 RDH 爲 0 */
IXGBE_WRITE_REG(hw, IXGBE_RDT(rxq->reg_idx), 0); /* 寫 RDT 爲 0 */
...
}
...
}
int __attribute__((cold))
ixgbe_dev_rxtx_start(struct rte_eth_dev *dev)
{
...
for (i = 0; i < dev->data->nb_tx_queues; i++) {
...
ret = ixgbe_dev_tx_queue_start(dev, i);
...
}
...
for (i = 0; i < dev->data->nb_rx_queues; i++) {
...
ret = ixgbe_dev_rx_queue_start(dev, i);
...
}
...
}
int __attribute__((cold))
ixgbe_dev_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id)
{
...
/* 使能發送 */
txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(txq->reg_idx));
txdctl |= IXGBE_TXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(txq->reg_idx), txdctl);
...
/* 寫 TDH 爲 0 */
IXGBE_WRITE_REG(hw, IXGBE_TDH(txq->reg_idx), 0);
/* 寫 TDT 爲 0 */
IXGBE_WRITE_REG(hw, IXGBE_TDT(txq->reg_idx), 0);
/* 設置發送隊列狀態爲 RTE_ETH_QUEUE_STATE_STARTED */
dev->data->tx_queue_state[tx_queue_id] = RTE_ETH_QUEUE_STATE_STARTED;
...
}
int __attribute__((cold))
ixgbe_dev_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)
{
...
/* 爲每個接收隊列分配 mbuf */
if (ixgbe_alloc_rx_queue_mbufs(rxq) != 0) {
...
/* 使能接收 */
rxdctl = IXGBE_READ_REG(hw, IXGBE_RXDCTL(rxq->reg_idx));
rxdctl |= IXGBE_RXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_RXDCTL(rxq->reg_idx), rxdctl);
...
/* 寫 RDH 爲 0 */
IXGBE_WRITE_REG(hw, IXGBE_RDH(rxq->reg_idx), 0);
/* 寫 RDT 爲 rxq->nb_rx_desc - 1 */
IXGBE_WRITE_REG(hw, IXGBE_RDT(rxq->reg_idx), rxq->nb_rx_desc - 1);
/* 設置接收隊列狀態爲 RTE_ETH_QUEUE_STATE_STARTED */
dev->data->rx_queue_state[rx_queue_id] = RTE_ETH_QUEUE_STATE_STARTED;
...
}
static int __attribute__((cold))
ixgbe_alloc_rx_queue_mbufs(struct ixgbe_rx_queue *rxq)
{
struct ixgbe_rx_entry *rxe = rxq->sw_ring;
uint64_t dma_addr;
unsigned int i;
/* Initialize software ring entries */
for (i = 0; i < rxq->nb_rx_desc; i++) {
volatile union ixgbe_adv_rx_desc *rxd;
struct rte_mbuf *mbuf = rte_mbuf_raw_alloc(rxq->mb_pool); /* 分配mbuf */
if (mbuf == NULL) {
PMD_INIT_LOG(ERR, "RX mbuf alloc failed queue_id=%u",
(unsigned) rxq->queue_id);
return -ENOMEM;
}
mbuf->data_off = RTE_PKTMBUF_HEADROOM;
mbuf->port = rxq->port_id;
dma_addr =
rte_cpu_to_le_64(rte_mbuf_data_dma_addr_default(mbuf)); /* mbuf的總線地址 */
rxd = &rxq->rx_ring[i];
rxd->read.hdr_addr = 0;
rxd->read.pkt_addr = dma_addr; /* 總線地址賦給 rxd->read.pkt_addr */
rxe[i].mbuf = mbuf; /* 將 mbuf 掛載到 rxe */
}
return 0;
}
參考文檔
https://blog.csdn.net/hz5034/article/details/88367518