diff options
| author |   Alexander Duyck <alexander.h.duyck@intel.com> | 2009-07-23 18:10:06 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2009-07-26 09:47:01 -0700 |
| commit | 2d94d8ab76ea6c858c6e2eb0ab0403b00b031039 (patch) | |
| tree | db8f6f4b56dfd3261ea6ce018ba6f571f1c3ccbb /drivers/net/igb | |
| parent | igb: add support for 82576 mezzanine card (diff) | |
| download | linux-dev-2d94d8ab76ea6c858c6e2eb0ab0403b00b031039.tar.xz linux-dev-2d94d8ab76ea6c858c6e2eb0ab0403b00b031039.zip | |
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: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/igb')
| -rw-r--r-- | drivers/net/igb/igb_main.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 2ffb51d6c959..12d8683c231e 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -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); |