#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET))
#define pfn_valid(pfn) ((unsigned long)pfn < max_mapnr)
#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET))
#define pfn_valid(pfn) ((unsigned long)pfn < max_mapnr)