1. 根目录:
2. arch
3. s390
4. include
5. asm
6. sparsemem.h

#ifndef _ASM_S390_SPARSEMEM_H
#define _ASM_S390_SPARSEMEM_H

#ifdef CONFIG_64BIT

#define SECTION_SIZE_BITS	28
#define MAX_PHYSMEM_BITS	46

#else

#define SECTION_SIZE_BITS	25
#define MAX_PHYSMEM_BITS	31

#endif /* CONFIG_64BIT */

#endif /* _ASM_S390_SPARSEMEM_H */