linux/net/dsa/Kconfig
Alexander Lobakin e131a56348 net: dsa: add GRO support via gro_cells
gro_cells lib is used by different encapsulating netdevices, such as
geneve, macsec, vxlan etc. to speed up decapsulated traffic processing.
CPU tag is a sort of "encapsulation", and we can use the same mechs to
greatly improve overall DSA performance.
skbs are passed to the GRO layer after removing CPU tags, so we don't
need any new packet offload types as it was firstly proposed by me in
the first GRO-over-DSA variant [1].

The size of struct gro_cells is sizeof(void *), so hot struct
dsa_slave_priv becomes only 4/8 bytes bigger, and all critical fields
remain in one 32-byte cacheline.
The other positive side effect is that drivers for network devices
that can be shipped as CPU ports of DSA-driven switches can now use
napi_gro_frags() to pass skbs to kernel. Packets built that way are
completely non-linear and are likely being dropped without GRO.

This was tested on to-be-mainlined-soon Ethernet driver that uses
napi_gro_frags(), and the overall performance was on par with the
variant from [1], sometimes even better due to minimal overhead.
net.core.gro_normal_batch tuning may help to push it to the limit
on particular setups and platforms.

iperf3 IPoE VLAN NAT TCP forwarding (port1.218 -> port0) setup
on 1.2 GHz MIPS board:

5.7-rc2 baseline:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  9.00 GBytes  644 Mbits/sec  413  sender
[ 5]  0.00-120.00 sec  8.99 GBytes  644 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       7097731     7097702
port0      426050      6671829
port1      6671681     425862
port1.218  6671677     425851

With this patch:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  12.2 GBytes  870 Mbits/sec  122  sender
[ 5]  0.00-120.00 sec  12.2 GBytes  870 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       9474792     9474777
port0      455200      353288
port1      9019592     455035
port1.218  353144      455024

v2:
 - Add some performance examples in the commit message;
 - No functional changes.

[1] https://lore.kernel.org/netdev/20191230143028.27313-1-alobakin@dlink.ru/

Signed-off-by: Alexander Lobakin <bloodyreaper@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-23 12:32:13 -07:00

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# SPDX-License-Identifier: GPL-2.0-only
config HAVE_NET_DSA
def_bool y
depends on INET && NETDEVICES && !S390
# Drivers must select NET_DSA and the appropriate tagging format
menuconfig NET_DSA
tristate "Distributed Switch Architecture"
depends on HAVE_NET_DSA
depends on BRIDGE || BRIDGE=n
select GRO_CELLS
select NET_SWITCHDEV
select PHYLINK
select NET_DEVLINK
---help---
Say Y if you want to enable support for the hardware switches supported
by the Distributed Switch Architecture.
if NET_DSA
# tagging formats
config NET_DSA_TAG_8021Q
tristate
select VLAN_8021Q
help
Unlike the other tagging protocols, the 802.1Q config option simply
provides helpers for other tagging implementations that might rely on
VLAN in one way or another. It is not a complete solution.
Drivers which use these helpers should select this as dependency.
config NET_DSA_TAG_AR9331
tristate "Tag driver for Atheros AR9331 SoC with built-in switch"
help
Say Y or M if you want to enable support for tagging frames for
the Atheros AR9331 SoC with built-in switch.
config NET_DSA_TAG_BRCM_COMMON
tristate
default n
config NET_DSA_TAG_BRCM
tristate "Tag driver for Broadcom switches using in-frame headers"
select NET_DSA_TAG_BRCM_COMMON
help
Say Y if you want to enable support for tagging frames for the
Broadcom switches which place the tag after the MAC source address.
config NET_DSA_TAG_BRCM_PREPEND
tristate "Tag driver for Broadcom switches using prepended headers"
select NET_DSA_TAG_BRCM_COMMON
help
Say Y if you want to enable support for tagging frames for the
Broadcom switches which places the tag before the Ethernet header
(prepended).
config NET_DSA_TAG_GSWIP
tristate "Tag driver for Lantiq / Intel GSWIP switches"
help
Say Y or M if you want to enable support for tagging frames for the
Lantiq / Intel GSWIP switches.
config NET_DSA_TAG_DSA
tristate "Tag driver for Marvell switches using DSA headers"
help
Say Y or M if you want to enable support for tagging frames for the
Marvell switches which use DSA headers.
config NET_DSA_TAG_EDSA
tristate "Tag driver for Marvell switches using EtherType DSA headers"
help
Say Y or M if you want to enable support for tagging frames for the
Marvell switches which use EtherType DSA headers.
config NET_DSA_TAG_MTK
tristate "Tag driver for Mediatek switches"
help
Say Y or M if you want to enable support for tagging frames for
Mediatek switches.
config NET_DSA_TAG_KSZ
tristate "Tag driver for Microchip 8795/9477/9893 families of switches"
help
Say Y if you want to enable support for tagging frames for the
Microchip 8795/9477/9893 families of switches.
config NET_DSA_TAG_OCELOT
tristate "Tag driver for Ocelot family of switches"
select PACKING
help
Say Y or M if you want to enable support for tagging frames for the
Ocelot switches (VSC7511, VSC7512, VSC7513, VSC7514, VSC9959).
config NET_DSA_TAG_QCA
tristate "Tag driver for Qualcomm Atheros QCA8K switches"
help
Say Y or M if you want to enable support for tagging frames for
the Qualcomm Atheros QCA8K switches.
config NET_DSA_TAG_LAN9303
tristate "Tag driver for SMSC/Microchip LAN9303 family of switches"
help
Say Y or M if you want to enable support for tagging frames for the
SMSC/Microchip LAN9303 family of switches.
config NET_DSA_TAG_SJA1105
tristate "Tag driver for NXP SJA1105 switches"
select NET_DSA_TAG_8021Q
select PACKING
help
Say Y or M if you want to enable support for tagging frames with the
NXP SJA1105 switch family. Both the native tagging protocol (which
is only for link-local traffic) as well as non-native tagging (based
on a custom 802.1Q VLAN header) are available.
config NET_DSA_TAG_TRAILER
tristate "Tag driver for switches using a trailer tag"
help
Say Y or M if you want to enable support for tagging frames at
with a trailed. e.g. Marvell 88E6060.
endif