include/asm-x86_64/sparsemem.h

   1 #ifndef _ASM_X86_64_SPARSEMEM_H
   2 #define _ASM_X86_64_SPARSEMEM_H 1
   3
   4 #ifdef CONFIG_SPARSEMEM
   5
   6 /*
   7  * generic non-linear memory support:
   8  *
   9  * 1) we will not split memory into more chunks than will fit into the flags
  10  *    field of the struct page
  11  *
  12  * SECTION_SIZE_BITS            2^n: size of each section
  13  * MAX_PHYSADDR_BITS            2^n: max size of physical address space
  14  * MAX_PHYSMEM_BITS             2^n: how much memory we can have in that space
  15  *
  16  */
  17
  18 #define SECTION_SIZE_BITS       27 /* matt - 128 is convenient right now */
  19 #define MAX_PHYSADDR_BITS       40
  20 #define MAX_PHYSMEM_BITS        40
  21
  22 extern int early_pfn_to_nid(unsigned long pfn);
  23
  24 #endif /* CONFIG_SPARSEMEM */
  25
  26 #endif /* _ASM_X86_64_SPARSEMEM_H */