  Under the self-consistent mean-field approach for the BCS-BEC crossover
problem, we derive a closed-form analytical expression for the general spin
response of noncentrosymmetric Fermi superfluids with arbitrary spin-orbit
coupling and Zeeman fields. In addition to the paramagnetic, i.e., the Pauli
intra-helicity and Van Vleck type inter-helicity, contributions to the
spin-susceptibility tensor that have normal-state counterparts, we identify a
diamagnetic inter-helicity contribution that is unique to the superfluid state.
Our extensive numerical calculations for the Weyl, Rashba and equal
Rashba-Dresselhaus spin-orbit couplings illustrate that it is this diamagnetic
contribution that grows gradually with pairing and cancels precisely the Van
Vleck contribution away from the BCS regime in general.
