BBR_SCALE
rate >>= BBR_SCALE;
bdp = (((w * gain) >> BBR_SCALE) + BW_UNIT - 1) / BW_UNIT;
>> BBR_SCALE;
if (!delivered || (lost << BBR_SCALE) < bbr_lt_loss_thresh * delivered)
#define BBR_UNIT (1 << BBR_SCALE)
bw_thresh = (u64)bbr->full_bw * bbr_full_bw_thresh >> BBR_SCALE;