From 19861ce24f2ea9d9db7b96814de9ca8d522cbe40 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 20 Jul 2012 08:08:33 +0000 Subject: [PATCH] ixgbe: Make pull tail function separate from rest of cleanup_headers This change creates a separate function for functionality similar to pskb_pull_tail. The main motivation for moving it to a separate function is so that later I can just skip this function in the case where we have already copied the buffer into skb->head. Signed-off-by: Alexander Duyck Tested-by: Phil Schmitt Signed-off-by: Peter P Waskiewicz Jr --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 94 ++++++++++++++++----------- 1 file changed, 57 insertions(+), 37 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index b0020fc..d926973 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -1458,6 +1458,61 @@ static bool ixgbe_is_non_eop(struct ixgbe_ring *rx_ring, } /** + * ixgbe_pull_tail - ixgbe specific version of skb_pull_tail + * @rx_ring: rx descriptor ring packet is being transacted on + * @skb: pointer to current skb being adjusted + * + * This function is an ixgbe 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 ixgbe_pull_tail(struct ixgbe_ring *rx_ring, + 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); + + /* + * 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 = skb_frag_size(frag); + if (pull_len > IXGBE_RX_HDR_SIZE) + pull_len = ixgbe_get_headlen(va, IXGBE_RX_HDR_SIZE); + + /* 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; + + /* + * if we sucked the frag empty then we should free it, + * if there are other frags here something is screwed up in hardware + */ + if (skb_frag_size(frag) == 0) { + BUG_ON(skb_shinfo(skb)->nr_frags != 1); + skb_shinfo(skb)->nr_frags = 0; + __skb_frag_unref(frag); + skb->truesize -= ixgbe_rx_bufsz(rx_ring); + } +} + +/** * ixgbe_dma_sync_frag - perform DMA sync for first frag of SKB * @rx_ring: rx descriptor ring packet is being transacted on * @skb: pointer to current skb being updated @@ -1509,10 +1564,7 @@ static bool ixgbe_cleanup_headers(struct ixgbe_ring *rx_ring, union ixgbe_adv_rx_desc *rx_desc, struct sk_buff *skb) { - struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0]; struct net_device *netdev = rx_ring->netdev; - unsigned char *va; - unsigned int pull_len; /* verify that the packet does not have any known errors */ if (unlikely(ixgbe_test_staterr(rx_desc, @@ -1522,40 +1574,8 @@ static bool ixgbe_cleanup_headers(struct ixgbe_ring *rx_ring, return true; } - /* - * 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); - - /* - * 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 = skb_frag_size(frag); - if (pull_len > IXGBE_RX_HDR_SIZE) - pull_len = ixgbe_get_headlen(va, IXGBE_RX_HDR_SIZE); - - /* 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; - - /* - * if we sucked the frag empty then we should free it, - * if there are other frags here something is screwed up in hardware - */ - if (skb_frag_size(frag) == 0) { - BUG_ON(skb_shinfo(skb)->nr_frags != 1); - skb_shinfo(skb)->nr_frags = 0; - __skb_frag_unref(frag); - skb->truesize -= ixgbe_rx_bufsz(rx_ring); - } + /* place header in linear portion of buffer */ + ixgbe_pull_tail(rx_ring, skb); #ifdef IXGBE_FCOE /* do not attempt to pad FCoE Frames as this will disrupt DDP */ -- 2.7.4