[ofa-general] [V2][PATCH 0/3]ib/ipoib: Enable IPoIB-UD 4K MTU support

[Shirley Ma]

Hello Roland,

Please review below approach as early as you can. Thanks

This patch is based on Eli and Roland's input. The idea is to keep
IPoIB-UD 2K MTU current implementation and allows IPoIB-UD link MTU up
to 4092 (4K - IPOB_ENCAP_LEN) when HCAs support 4K MTU. For IPoIB-UD 4K
MTU, if the PAGE_SIZE is greater than IB MTU + GRH HEAD + 4, then no S/G
is needed, use IPoIB-UD 2K MTU implementation, if PAGE_SIZE is smaller,
then two buffers need to be used. One of the API IPoIB-CM RX S/G code
has been made more generic, so it can be reused.

This patchset includes three patches:
1. Make one IPoIB-CM RX S/G API generic.
2. Set up IPoIB-UD RX S/G ready.
3. Enable IPoIB-UD RX S/G when needed.

Shirley