linux/include/asm-powerpc/sparsemem.h

#ifndef _ASM_POWERPC_SPARSEMEM_H
#define _ASM_POWERPC_SPARSEMEM_H 1

#ifdef CONFIG_SPARSEMEM
/*
 * SECTION_SIZE_BITS		2^N: how big each section will be
 * MAX_PHYSADDR_BITS		2^N: how much physical address space we have
 * MAX_PHYSMEM_BITS		2^N: how much memory we can have in that space
 */
#define SECTION_SIZE_BITS       24
#define MAX_PHYSADDR_BITS       38
#define MAX_PHYSMEM_BITS        36

#endif /* CONFIG_SPARSEMEM */

#endif /* _ASM_POWERPC_SPARSEMEM_H */