net: fec: Add software TSO support
Add software TSO support for FEC.
This feature allows to improve outbound throughput performance.
Tested on imx6dl sabresd board, running iperf tcp tests shows:
- 16.2% improvement comparing with FEC SG patch
- 82% improvement comparing with NO SG & TSO patch
$ ethtool -K eth0 tso on
$ iperf -c 10.192.242.167 -t 3 &
[ 3] local 10.192.242.108 port 35388 connected with 10.192.242.167 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 3.0 sec 181 MBytes 506 Mbits/sec
During the testing, CPU loading is 30%.
Since imx6dl FEC Bandwidth is limited to SOC system bus bandwidth, the
performance with SW TSO is a milestone.
CC: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: David Laight <David.Laight@ACULAB.COM>
CC: Li Frank <B20596@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index e7ce14d..671d080 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -299,6 +299,12 @@
unsigned short bufdesc_size;
unsigned short tx_ring_size;
unsigned short rx_ring_size;
+ unsigned short tx_stop_threshold;
+ unsigned short tx_wake_threshold;
+
+ /* Software TSO */
+ char *tso_hdrs;
+ dma_addr_t tso_hdrs_dma;
struct platform_device *pdev;