diff options
| author | Matt Carlson <mcarlson@broadcom.com> | 2008-11-21 17:16:16 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-11-21 17:16:16 -0800 |
| commit | ad8292681a629cdb16bb19ee7d721b457c32a23a (patch) | |
| tree | 37f8552bf329967dd3c2e08382216dece0d87913 /drivers/net | |
| parent | cf005b1d0e34d8c964347331c43de089c674a5a1 (diff) | |
tg3: Use NET_IP_ALIGN
This patch replaces hardcoded 2's with the NET_IP_ALIGN constant or
TG3_RAW_IP_ALIGN where appropriate. Some platforms can redefine the
NET_IP_ALIGN definition to zero if unaligned DMA transfers cost more
than the IP header alignment gains. This patch represents a
performance improvement when using the 5701 on these platforms.
The copy path can be avoided.
TG3_RAW_IP_ALIGN is used in cases where we always want to align the
IP header on dword boundaries.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/tg3.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index 9ba18e1bc34..0a82ea878ae 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -132,6 +132,8 @@ /* minimum number of free TX descriptors required to wake up TX process */ #define TG3_TX_WAKEUP_THRESH(tp) ((tp)->tx_pending / 4) +#define TG3_RAW_IP_ALIGN 2 + /* number of ETHTOOL_GSTATS u64's */ #define TG3_NUM_STATS (sizeof(struct tg3_ethtool_stats)/sizeof(u64)) @@ -4231,12 +4233,15 @@ static int tg3_rx(struct tg3 *tp, int budget) goto next_pkt; } - len = ((desc->idx_len & RXD_LEN_MASK) >> RXD_LEN_SHIFT) - 4; /* omit crc */ + len = ((desc->idx_len & RXD_LEN_MASK) >> RXD_LEN_SHIFT) - + ETH_FCS_LEN; if (len > RX_COPY_THRESHOLD - && tp->rx_offset == 2 - /* rx_offset != 2 iff this is a 5701 card running - * in PCI-X mode [see tg3_get_invariants()] */ + && tp->rx_offset == NET_IP_ALIGN + /* rx_offset will likely not equal NET_IP_ALIGN + * if this is a 5701 card running in PCI-X mode + * [see tg3_get_invariants()] + */ ) { int skb_size; @@ -4256,11 +4261,12 @@ static int tg3_rx(struct tg3 *tp, int budget) tg3_recycle_rx(tp, opaque_key, desc_idx, *post_ptr); - copy_skb = netdev_alloc_skb(tp->dev, len + 2); + copy_skb = netdev_alloc_skb(tp->dev, + len + TG3_RAW_IP_ALIGN); if (copy_skb == NULL) goto drop_it_no_recycle; - skb_reserve(copy_skb, 2); + skb_reserve(copy_skb, TG3_RAW_IP_ALIGN); skb_put(copy_skb, len); pci_dma_sync_single_for_cpu(tp->pdev, dma_addr, len, PCI_DMA_FROMDEVICE); skb_copy_from_linear_data(skb, copy_skb->data, len); @@ -12614,7 +12620,7 @@ static int __devinit tg3_get_invariants(struct tg3 *tp) else tp->tg3_flags &= ~TG3_FLAG_POLL_SERDES; - tp->rx_offset = 2; + tp->rx_offset = NET_IP_ALIGN; if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5701 && (tp->tg3_flags & TG3_FLAG_PCIX_MODE) != 0) tp->rx_offset = 0; |