This review ports mlx5 driver, kernel's OFED stack (userland is already enabled), KTLS and krping to powerpc64 and powerpc64le.
krping requires a small change since it uses assembly for amd64 / i386.
NOTE: On powerpc64le RDMA works fine in the userspace with libmlx5, but on powerpc64 it does not. The problem is that contrib/ofed/libmlx5/doorbell.h checks for SIZEOF_LONG but this macro exists on neither powerpc64* nor amd64. Thus, the file silently goes to the fallback function written for 32-bit architectures. It works fine on little-endian architectures, but causes a hard fail on big-endian. It's possible it may also cause some runtime issues on little-endian.
Thus, on powerpc64 I verified that RDMA works with krping.