HMM_BO_MASK
bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_FREE;
bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_FREE;
bo->status = (bo->status & ~HMM_BO_MASK) | HMM_BO_ALLOCED;
(prev_bo->status & HMM_BO_MASK) == HMM_BO_FREE) {
(next_bo->status & HMM_BO_MASK) == HMM_BO_FREE) {
if ((bo->status & HMM_BO_MASK) == HMM_BO_FREE)