-/**
- * igb_pull_tail - igb specific version of skb_pull_tail
- * @rx_ring: rx descriptor ring packet is being transacted on
- * @rx_desc: pointer to the EOP Rx descriptor
- * @skb: pointer to current skb being adjusted
- *
- * This function is an igb specific version of __pskb_pull_tail. The
- * main difference between this version and the original function is that
- * this function can make several assumptions about the state of things
- * that allow for significant optimizations versus the standard function.
- * As a result we can do things like drop a frag and maintain an accurate
- * truesize for the skb.
- */
-static void igb_pull_tail(struct igb_ring *rx_ring,
- union e1000_adv_rx_desc *rx_desc,
- struct sk_buff *skb)
-{
- struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
- unsigned char *va;
- unsigned int pull_len;
-
- /* it is valid to use page_address instead of kmap since we are
- * working with pages allocated out of the lomem pool per
- * alloc_page(GFP_ATOMIC)
- */
- va = skb_frag_address(frag);
-
- if (igb_test_staterr(rx_desc, E1000_RXDADV_STAT_TSIP)) {
- /* retrieve timestamp from buffer */
- igb_ptp_rx_pktstamp(rx_ring->q_vector, va, skb);
-
- /* update pointers to remove timestamp header */
- skb_frag_size_sub(frag, IGB_TS_HDR_LEN);
- frag->page_offset += IGB_TS_HDR_LEN;
- skb->data_len -= IGB_TS_HDR_LEN;
- skb->len -= IGB_TS_HDR_LEN;
-
- /* move va to start of packet data */
- va += IGB_TS_HDR_LEN;
- }
-
- /* we need the header to contain the greater of either ETH_HLEN or
- * 60 bytes if the skb->len is less than 60 for skb_pad.
- */
- pull_len = eth_get_headlen(va, IGB_RX_HDR_LEN);
-
- /* align pull length to size of long to optimize memcpy performance */
- skb_copy_to_linear_data(skb, va, ALIGN(pull_len, sizeof(long)));
-
- /* update all of the pointers */
- skb_frag_size_sub(frag, pull_len);
- frag->page_offset += pull_len;
- skb->data_len -= pull_len;
- skb->tail += pull_len;
-}
-