find_first_zero_bit
unsigned long offset = find_first_zero_bit(adev->wb.used, adev->wb.num_wb);
ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
i = find_first_zero_bit(ppat->used, ppat->max_entries);
for ((bit) = find_first_zero_bit((addr), (size)); \
unsigned long offset = find_first_zero_bit(rdev->doorbell.used, rdev->doorbell.num_doorbells);