|  | #ifndef _ASM_X86_64_SPARSEMEM_H | 
|  | #define _ASM_X86_64_SPARSEMEM_H 1 | 
|  |  | 
|  | #ifdef CONFIG_SPARSEMEM | 
|  |  | 
|  | /* | 
|  | * generic non-linear memory support: | 
|  | * | 
|  | * 1) we will not split memory into more chunks than will fit into the flags | 
|  | *    field of the struct page | 
|  | * | 
|  | * SECTION_SIZE_BITS		2^n: size of each section | 
|  | * MAX_PHYSADDR_BITS		2^n: max size of physical address space | 
|  | * MAX_PHYSMEM_BITS		2^n: how much memory we can have in that space | 
|  | * | 
|  | */ | 
|  |  | 
|  | #define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */ | 
|  | #define MAX_PHYSADDR_BITS	40 | 
|  | #define MAX_PHYSMEM_BITS	40 | 
|  |  | 
|  | extern int early_pfn_to_nid(unsigned long pfn); | 
|  |  | 
|  | #endif /* CONFIG_SPARSEMEM */ | 
|  |  | 
|  | #endif /* _ASM_X86_64_SPARSEMEM_H */ |