网卡驱动部分数据结构关系图

struct octeon_droq_desc *desc_ring;// 队列描述符（VP）

char cb[48] __aligned(8);// Control buffer. Free for use by every layer. Put private vars here

struct octeon_recv_buffer

u32 buffer_size;// The size of each buffer pointed by the buffer pointer.

...

zero-copy

u32 poll_mode;

代码注释

struct cavium_pci_device *pci_dev;

struct octeon_skb_page_info *pg_info =((struct octeon_skb_page_info *)(skb->cb));

u32 read_idx;// 读指针

u32 write_idx;// 写指针

struct octeon_skb_page_info

cavium_atomic_t pkts_pending;// 待处理的数据包个数

u64 buffer_ptr;

struct octeon_device

struct sk_buff

cavium_dma_addr_t dma;

struct octeon_recv_buffer *recv_buf_list;

get_rbd(buffer);

u32 q_no;

struct octeon_droq_ops ops;

struct net_device

计算表达式

static void liquidio_napi_drv_callback(void *arg)

struct octeon_droq

struct page *page;

u32 pkt_count;// 记录上一次总的收包数。记录pkts_sent_reg的值

struct octeon_droq_desc// 传输队列描述符

char\t\t\tname[IFNAMSIZ];

u64 info_ptr;

数据结构成员

struct octeon_droq_ops

void cavium_iomem *pkts_sent_reg;// 网卡DMA已完成的数据包的总数，由硬件写入(SLI_PKT(0..63)_CNTS)

struct octeon_device *oct_dev;

void *buffer;

alloc_page(GFP_ATOMIC);

void (*napi_fn)(void *);

自定义数据结构名

buffer_ptr = dma + page_offset;

u32 refill_threshold;// buffer重装阈值

struct octeon_skb_page_info pg_info;

handle

struct page *vmalloc_to_page(const void *vmalloc_addr)

size_t desc_ring_dma;// 队列描述符（DMA映射的总线地址BP）

u8 *data;

颜色图示说明

return

struct octeon_droq *droq[MAX_POSSIBLE_OCTEON_OUTPUT_QUEUES];

no-zero-copy

u32 refill_count;// 待重装的buffer个数

unsigned int page_offset;

函数调用结果返回

u32 max_count;// Number of  descriptors in this ring.

内核数据结构名

u32 drop_on_max;

static inline struct sk_buff *dev_alloc_skb(unsigned int length)return buf;

void *farg;

void cavium_volatile_t cavium_iomem *pkts_credit_reg;// Doorbell寄存器(SLI_PKT(0..63)_SLIST_BAOFF_DBELL)