Simon Horman 4d86d38186 ravb: RX checksum offload ... Add support for RX checksum offload. This is enabled by default and may be disabled and re-enabled using ethtool: # ethtool -K eth0 rx off # ethtool -K eth0 rx on The RAVB provides a simple checksumming scheme which appears to be completely compatible with CHECKSUM_COMPLETE: sum of all packet data after the L2 header is appended to packet data; this may be trivially read by the driver and used to update the skb accordingly. In terms of performance throughput is close to gigabit line-rate both with and without RX checksum offload enabled. Perf output, however, appears to indicate that significantly less time is spent in do_csum(). This is as expected. Test results with RX checksum offload enabled: # /usr/bin/perf_3.16 record -o /run/perf.data -a netperf -t TCP_MAERTS -H 10.4.3.162 MIGRATED TCP MAERTS TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.4.3.162 () port 0 AF_INET : demo enable_enobufs failed: getprotobyname Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 937.54 Summary of output of perf report: 18.28% ksoftirqd/0 [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 10.34% ksoftirqd/0 [kernel.kallsyms] [k] __pi_memcpy 9.83% ksoftirqd/0 [kernel.kallsyms] [k] ravb_poll 7.89% ksoftirqd/0 [kernel.kallsyms] [k] skb_put 4.01% ksoftirqd/0 [kernel.kallsyms] [k] dev_gro_receive 3.37% netperf [kernel.kallsyms] [k] __arch_copy_to_user 3.17% swapper [kernel.kallsyms] [k] arch_cpu_idle 2.55% swapper [kernel.kallsyms] [k] tick_nohz_idle_enter 2.04% ksoftirqd/0 [kernel.kallsyms] [k] __pi___inval_dcache_area 2.03% swapper [kernel.kallsyms] [k] _raw_spin_unlock_irq 1.96% ksoftirqd/0 [kernel.kallsyms] [k] __netdev_alloc_skb 1.59% ksoftirqd/0 [kernel.kallsyms] [k] __slab_alloc.isra.83 Test results without RX checksum offload enabled: # /usr/bin/perf_3.16 record -o /run/perf.data -a netperf -t TCP_MAERTS -H 10.4.3.162 MIGRATED TCP MAERTS TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.4.3.162 () port 0 AF_INET : demo enable_enobufs failed: getprotobyname Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 940.20 Summary of output of perf report: 17.10% ksoftirqd/0 [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 10.99% ksoftirqd/0 [kernel.kallsyms] [k] __pi_memcpy 8.87% ksoftirqd/0 [kernel.kallsyms] [k] ravb_poll 8.16% ksoftirqd/0 [kernel.kallsyms] [k] skb_put 7.42% ksoftirqd/0 [kernel.kallsyms] [k] do_csum 3.91% ksoftirqd/0 [kernel.kallsyms] [k] dev_gro_receive 2.31% swapper [kernel.kallsyms] [k] arch_cpu_idle 2.16% ksoftirqd/0 [kernel.kallsyms] [k] __pi___inval_dcache_area 2.14% ksoftirqd/0 [kernel.kallsyms] [k] __netdev_alloc_skb 1.93% netperf [kernel.kallsyms] [k] __arch_copy_to_user 1.79% swapper [kernel.kallsyms] [k] tick_nohz_idle_enter 1.63% ksoftirqd/0 [kernel.kallsyms] [k] __slab_alloc.isra.83 Above results collected on an R-Car Gen 3 Salvator-X/r8a7796 ES1.0. Also tested on a R-Car Gen 3 Salvator-X/r8a7795 ES1.0. By inspection this also appears to be compatible with the ravb found on R-Car Gen 2 SoCs, however, this patch is currently untested on such hardware. Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: David S. Miller <davem@davemloft.net>		2017-10-04 10:26:05 -07:00
..
Kconfig	ptp_clock: Allow for it to be optional	2016-11-16 09:26:34 +01:00
Makefile	Renesas Ethernet AVB PTP clock driver	2015-06-11 00:24:12 -07:00
ravb.h	ravb: add wake-on-lan support via magic packet	2017-08-01 17:54:38 -07:00
ravb_main.c	ravb: RX checksum offload	2017-10-04 10:26:05 -07:00
ravb_ptp.c	ravb: make ravb_ptp_interrupt() *void*	2016-04-14 00:48:33 -04:00
sh_eth.c	net: sh_eth: constify platform_device_id	2017-08-13 20:12:23 -07:00
sh_eth.h	sh_eth: add missing EESIPR bits	2017-01-30 22:05:43 -05:00