swiotlb_size_or_default
rc = swiotlb_init_late(swiotlb_size_or_default(),
swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
extern unsigned long swiotlb_size_or_default(void);
return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
unsigned long swiotlb_size_or_default(void);