irq_calc_affinity_vectors
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,