Merge branch 'add-hw-checksum-offload-support-for-rz-g2l-gbethernet-ip'

Biju Das says:

====================
Add HW checksum offload support for RZ/G2L GbEthernet IP

This patch series aims to add HW checksum offload supported by TOE module
found on the RZ/G2L Gb ethernet IP.

TOE has hardware support for calculating IP header and TCP/UDP/ICMP
checksum for both IPv4 and IPv6.

For Rx, the 4-byte result of checksum calculation is attached to the
Ethernet frames.First 2-bytes is result of IPv4 header checksum and next
2-bytes is TCP/UDP/ICMP checksum.

If a frame does not have checksum error, 0x0000 is attached as checksum
calculation result. For unsupported frames 0xFFFF is attached as checksum
calculation result. In case of an IPv6 packet, IPv4 checksum is always set
to 0xFFFF.

For Tx, the result of checksum calculation is set to the checksum field of
each IPv4 Header/TCP/UDP/ICMP of ethernet frames. For the unsupported
frames, those fields are not changed. If a transmission frame is an UDPv4
frame and its checksum value in the UDP header field is 0x0000, TOE does
not calculate checksum for UDP part of this frame as it is optional
function as per standards.

Add Tx/Rx checksum offload supported by TOE for IPv4 and TCP/UDP protocols.

Results of iperf3 in Mbps

RZ/V2L:
TCP(Tx/Rx) results with checksum offload Enabled:	{921,932}
TCP(Tx/Rx) results with checksum offload Disabled:	{867,612}

UDP(Tx/Rx) results with checksum offload Enabled:	{950,946}
UDP(Tx/Rx) results with checksum offload Disabled:	{952,920}

RZ/G2L:
TCP(Tx/Rx) results with checksum offload Enabled:	{920,936}
TCP(Tx/Rx) results with checksum offload Disabled:	{871,626}

UDP(Tx/Rx) results with checksum offload Enabled:	{953,950}
UDP(Tx/Rx) results with checksum offload Disabled:	{954,920}

RZ/G2LC:
TCP(Tx/Rx) results with checksum offload Enabled:	{927,936}
TCP(Tx/Rx) results with checksum offload Disabled:	{889,626}

UDP(Tx/Rx) results with checksum offload Enabled:	{950,946}
UDP(Tx/Rx) results with checksum offload Disabled:	{949,944}
====================

Link: https://lore.kernel.org/r/20240207092838.160627-1-biju.das.jz@bp.renesas.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>