Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2d94d8ab authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

igb: use buffer_info->dma instead of shinfo->nr_frags to determine unmap 



This change makes it so that we use buffer_info->dma instead of
shinfo->nr_frags to determine if we need to unmap a received skb.  By doing
this we can avoid a cache miss on small packets since the buffer_info
structure should already be prefetched.

Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4703bf73

drivers/net/igb/igb_main.c

+18 −12
Original line number Diff line number Diff line
@@ -4538,6 +4538,20 @@ static inline void igb_rx_checksum_adv(struct igb_adapter *adapter, 
	adapter->hw_csum_good++;

}



static inline u16 igb_get_hlen(struct igb_adapter *adapter,

                               union e1000_adv_rx_desc *rx_desc)

{

	/* HW will not DMA in data larger than the given buffer, even if it

	 * parses the (NFS, of course) header to be larger.  In that case, it

	 * fills the header buffer and spills the rest into the page.

	 */

	u16 hlen = (le16_to_cpu(rx_desc->wb.lower.lo_dword.hdr_info) &

	           E1000_RXDADV_HDRBUFLEN_MASK) >> E1000_RXDADV_HDRBUFLEN_SHIFT;

	if (hlen > adapter->rx_ps_hdr_size)

		hlen = adapter->rx_ps_hdr_size;

	return hlen;

}



static bool igb_clean_rx_irq_adv(struct igb_ring *rx_ring,

				 int *work_done, int budget)

{
@@ -4552,7 +4566,8 @@ static bool igb_clean_rx_irq_adv(struct igb_ring *rx_ring, 
	int cleaned_count = 0;

	unsigned int total_bytes = 0, total_packets = 0;

	unsigned int i;

	u32 length, hlen, staterr;

	u32 staterr;

	u16 length;



	i = rx_ring->next_to_clean;

	buffer_info = &rx_ring->buffer_info[i];
@@ -4589,17 +4604,8 @@ static bool igb_clean_rx_irq_adv(struct igb_ring *rx_ring, 
			goto send_up;

		}



		/* HW will not DMA in data larger than the given buffer, even

		 * if it parses the (NFS, of course) header to be larger.  In

		 * that case, it fills the header buffer and spills the rest

		 * into the page.

		 */

		hlen = (le16_to_cpu(rx_desc->wb.lower.lo_dword.hdr_info) &

		  E1000_RXDADV_HDRBUFLEN_MASK) >> E1000_RXDADV_HDRBUFLEN_SHIFT;

		if (hlen > adapter->rx_ps_hdr_size)

			hlen = adapter->rx_ps_hdr_size;



		if (!skb_shinfo(skb)->nr_frags) {

		if (buffer_info->dma) {

			u16 hlen = igb_get_hlen(adapter, rx_desc);

			pci_unmap_single(pdev, buffer_info->dma,

					 adapter->rx_ps_hdr_size,

					 PCI_DMA_FROMDEVICE);