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authorMatt Carlson <mcarlson@broadcom.com>2008-11-22 02:16:16 +0100
committerDavid S. Miller <davem@davemloft.net>2008-11-22 02:16:16 +0100
commitad8292681a629cdb16bb19ee7d721b457c32a23a (patch)
tree37f8552bf329967dd3c2e08382216dece0d87913 /drivers/net/tg3.c
parentnet: remove redundant argument comments (diff)
downloadlinux-ad8292681a629cdb16bb19ee7d721b457c32a23a.tar.xz
linux-ad8292681a629cdb16bb19ee7d721b457c32a23a.zip
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/tg3.c')
-rw-r--r--drivers/net/tg3.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 9ba18e1bc341..0a82ea878aea 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;