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authorDivy Le Ray <divy@chelsio.com>2007-08-21 20:49:15 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-10 16:50:48 -0700
commit27186dc325c3bbb937a27a2467cefd64e2505158 (patch)
tree20dab934c51ce84b400e99dd8f61d89411d692d8
parent6e3f03b72c1e11e19ea233a411a782f7231ba13f (diff)
cxgb3 - use immediate data for offload Tx
Send small TX_DATA work requests as immediate data even when there are fragments. this avoids doing multiple DMAs for small fragmented packets. The driver already implements this optimization for small contiguous packets. Signed-off-by: Divy Le Ray <divy@chelsio.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
-rw-r--r--drivers/net/cxgb3/sge.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 9233bbba9e9..540ce5fa1d3 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -1179,8 +1179,8 @@ int t3_eth_xmit(struct sk_buff *skb, struct net_device *dev)
*
* Writes a packet as immediate data into a Tx descriptor. The packet
* contains a work request at its beginning. We must write the packet
- * carefully so the SGE doesn't read accidentally before it's written in
- * its entirety.
+ * carefully so the SGE doesn't read it accidentally before it's written
+ * in its entirety.
*/
static inline void write_imm(struct tx_desc *d, struct sk_buff *skb,
unsigned int len, unsigned int gen)
@@ -1188,7 +1188,11 @@ static inline void write_imm(struct tx_desc *d, struct sk_buff *skb,
struct work_request_hdr *from = (struct work_request_hdr *)skb->data;
struct work_request_hdr *to = (struct work_request_hdr *)d;
- memcpy(&to[1], &from[1], len - sizeof(*from));
+ if (likely(!skb->data_len))
+ memcpy(&to[1], &from[1], len - sizeof(*from));
+ else
+ skb_copy_bits(skb, sizeof(*from), &to[1], len - sizeof(*from));
+
to->wr_hi = from->wr_hi | htonl(F_WR_SOP | F_WR_EOP |
V_WR_BCNTLFLT(len & 7));
wmb();
@@ -1258,7 +1262,7 @@ static inline void reclaim_completed_tx_imm(struct sge_txq *q)
static inline int immediate(const struct sk_buff *skb)
{
- return skb->len <= WR_LEN && !skb->data_len;
+ return skb->len <= WR_LEN;
}
/**
@@ -1464,12 +1468,13 @@ static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb,
*/
static inline unsigned int calc_tx_descs_ofld(const struct sk_buff *skb)
{
- unsigned int flits, cnt = skb_shinfo(skb)->nr_frags;
+ unsigned int flits, cnt;
- if (skb->len <= WR_LEN && cnt == 0)
+ if (skb->len <= WR_LEN)
return 1; /* packet fits as immediate data */
flits = skb_transport_offset(skb) / 8; /* headers */
+ cnt = skb_shinfo(skb)->nr_frags;
if (skb->tail != skb->transport_header)
cnt++;
return flits_to_desc(flits + sgl_len(cnt));