linux/drivers
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
..
accessibility
acpi Merge branches 'acpi-pmic', 'acpi-bus', 'acpi-wdat' and 'acpi-properties' 2017-09-22 23:38:45 +02:00
amba
android ANDROID: binder: don't queue async transactions to thread. 2017-09-01 09:22:50 +02:00
ata Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2017-09-06 22:41:21 -07:00
atm
auxdisplay
base Power management fixes for v4.14-rc2 2017-09-22 17:28:59 -10:00
bcma
block The highlights include: 2017-09-12 20:03:53 -07:00
bluetooth
bus ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
cdrom
char dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
clk The diff is dominated by the Allwinner A10/A20 SoCs getting converted to 2017-09-13 11:04:14 -07:00
clocksource Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
connector
cpufreq cpufreq: ti-cpufreq: Support additional am43xx platforms 2017-09-20 00:51:01 +02:00
cpuidle ARM: cpuidle: Avoid memleak if init fail 2017-09-19 23:10:51 +02:00
crypto crypto: caam - fix LS1021A support on ARMv7 multiplatform kernel 2017-09-20 17:42:42 +08:00
dax - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dca
devfreq
dio
dma dmaengine updates for 4.14-rc1 2017-09-07 14:03:05 -07:00
dma-buf
edac
eisa
extcon
firewire
firmware dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
fmc
fpga
fsi
gpio - New Drivers 2017-09-07 13:51:13 -07:00
gpu Merge tag 'exynos-drm-fixes-for-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes 2017-09-21 08:02:39 +10:00
hid media updates for v4.14-rc1 2017-09-07 12:53:14 -07:00
hsi
hv Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-07 09:25:15 -07:00
hwmon dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
hwspinlock
hwtracing
i2c i2c: i2c-stm32f7: add driver 2017-09-14 17:34:43 +02:00
ide Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block 2017-09-07 11:59:42 -07:00
idle Power management updates for v4.14-rc1 2017-09-05 12:19:08 -07:00
iio - New Drivers 2017-09-07 13:51:13 -07:00
infiniband First -rc update for 4.14 kernel 2017-09-23 05:47:04 -10:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2017-09-22 17:23:41 -10:00
iommu iommu/of: Remove PCI host bridge node check 2017-09-22 12:05:43 +02:00
ipack
irqchip Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
isdn isdn/i4l: fetch the ppp_write buffer in one shot 2017-09-20 16:01:36 -07:00
leds dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
lightnvm
macintosh powerpc/macintosh: constify wf_sensor_ops structures 2017-09-01 16:42:54 +10:00
mailbox Just behavorial changes to a controller driver: 2017-09-07 13:23:37 -07:00
mcb Char/Misc drivers for 4.14-rc1 2017-09-05 11:08:17 -07:00
md Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2017-09-19 08:39:32 -07:00
media Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
memory ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
memstick
message scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough 2017-08-29 21:51:45 -04:00
mfd dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
misc mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
mmc mmc: cavium: Fix use-after-free in of_platform_device_destroy 2017-09-08 15:38:22 +02:00
mtd mtd: nand: remove unused blockmask variable 2017-09-18 14:51:02 +02:00
mux mux: make device_type const 2017-08-29 13:46:35 +02:00
net ravb: RX checksum offload 2017-10-04 10:26:05 -07:00
nfc
ntb
nubus
nvdimm libnvdimm, namespace: fix btt claim class crash 2017-09-18 17:29:01 -07:00
nvme nvme-pci: implement the HMB entry number and size limitations 2017-09-11 12:29:40 -04:00
nvmem
of dma-mapping updates for 4.14: 2017-09-12 13:30:06 -07:00
oprofile
parisc
parport Char/Misc drivers for 4.14-rc1 2017-09-05 11:08:17 -07:00
pci PCI: endpoint: Use correct "end of test" interrupt 2017-09-20 13:56:06 -05:00
pcmcia MIPS: Alchemy: Threaded carddetect irqs for devboards 2017-08-29 15:21:53 +02:00
perf drivers/perf: arm_pmu_acpi: Release memory obtained by kasprintf 2017-09-22 15:11:46 +01:00
phy Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
pinctrl pinctrl/amd: save pin registers over suspend/resume 2017-09-12 15:58:45 +02:00
platform dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
pnp dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
power power supply and reset changes for the v4.14 series 2017-09-09 14:44:39 -07:00
powercap
pps drivers/pps: use surrounding "if PPS" to remove numerous dependency checks 2017-09-08 18:26:51 -07:00
ps3
ptp
pwm pwm: Changes for v4.14-rc1 2017-09-11 13:04:32 -07:00
rapidio
ras
regulator - New Drivers 2017-09-07 13:51:13 -07:00
remoteproc rpmsg updates for v4.14 2017-09-09 14:34:38 -07:00
reset Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
rpmsg rpmsg: glink: initialize ret to zero to ensure error status check is correct 2017-09-04 10:52:30 -07:00
rtc RTC for 4.14 2017-09-13 10:56:00 -07:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-09-23 10:16:53 -07:00
sbus
scsi scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE 2017-09-15 15:16:49 -04:00
sfi
sh
sn
soc Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
spi ACPI updates for v4.14-rc1 2017-09-05 12:45:03 -07:00
spmi
ssb
staging Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:54:01 -07:00
target Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
tc
tee
thermal Merge branches 'thermal-core', 'thermal-soc', 'thermal-intel' and 'const-thermal-zone-structure' into next 2017-09-08 11:20:04 +08:00
thunderbolt thunderbolt: Allocate ring HopID automatically if requested 2017-10-02 11:24:41 -07:00
tty dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
uio
usb Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
uwb
vfio vfio: platform: constify amba_id 2017-08-30 14:03:42 -06:00
vhost lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
video fbdev changes for v4.14: 2017-09-14 13:33:33 -07:00
virt virt: Convert to using %pOF instead of full_name 2017-08-29 08:52:51 -05:00
virtio SCSI misc on 20170907 2017-09-07 21:11:05 -07:00
vlynq
vme
w1 power supply and reset changes for the v4.14 series 2017-09-09 14:44:39 -07:00
watchdog Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
xen xen: Fixes for rc2 2017-09-22 06:40:47 -10:00
zorro
Kconfig
Makefile