include/asm-generic/memory_model.h

   1 #ifndef __ASM_MEMORY_MODEL_H
   2 #define __ASM_MEMORY_MODEL_H
   3
   4 #ifndef __ASSEMBLY__
   5
   6 #if defined(CONFIG_FLATMEM)
   7
   8 #ifndef ARCH_PFN_OFFSET
   9 #define ARCH_PFN_OFFSET         (0UL)
  10 #endif
  11
  12 #elif defined(CONFIG_DISCONTIGMEM)
  13
  14 #ifndef arch_pfn_to_nid
  15 #define arch_pfn_to_nid(pfn)    pfn_to_nid(pfn)
  16 #endif
  17
  18 #ifndef arch_local_page_offset
  19 #define arch_local_page_offset(pfn, nid)        \
  20         ((pfn) - NODE_DATA(nid)->node_start_pfn)
  21 #endif
  22
  23 #endif /* CONFIG_DISCONTIGMEM */
  24
  25 /*
  26  * supports 3 memory models.
  27  */
  28 #if defined(CONFIG_FLATMEM)
  29
  30 #define __pfn_to_page(pfn)      (mem_map + ((pfn) - ARCH_PFN_OFFSET))
  31 #define __page_to_pfn(page)     ((unsigned long)((page) - mem_map) + \
  32                                  ARCH_PFN_OFFSET)
  33 #elif defined(CONFIG_DISCONTIGMEM)
  34
  35 #define __pfn_to_page(pfn)                      \
  36 ({      unsigned long __pfn = (pfn);            \
  37         unsigned long __nid = arch_pfn_to_nid(pfn);  \
  38         NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
  39 })
  40
  41 #define __page_to_pfn(pg)                                               \
  42 ({      struct page *__pg = (pg);                                       \
  43         struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg));     \
  44         (unsigned long)(__pg - __pgdat->node_mem_map) +                 \
  45          __pgdat->node_start_pfn;                                       \
  46 })
  47
  48 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
  49
  50 /* memmap is virtually contigious.  */
  51 #define __pfn_to_page(pfn)      (vmemmap + (pfn))
  52 #define __page_to_pfn(page)     ((page) - vmemmap)
  53
  54 #elif defined(CONFIG_SPARSEMEM)
  55 /*
  56  * Note: section's mem_map is encorded to reflect its start_pfn.
  57  * section[i].section_mem_map == mem_map's address - start_pfn;
  58  */
  59 #define __page_to_pfn(pg)                                       \
  60 ({      struct page *__pg = (pg);                               \
  61         int __sec = page_to_section(__pg);                      \
  62         (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
  63 })
  64
  65 #define __pfn_to_page(pfn)                              \
  66 ({      unsigned long __pfn = (pfn);                    \
  67         struct mem_section *__sec = __pfn_to_section(__pfn);    \
  68         __section_mem_map_addr(__sec) + __pfn;          \
  69 })
  70 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
  71
  72 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
  73 struct page;
  74 /* this is useful when inlined pfn_to_page is too big */
  75 extern struct page *pfn_to_page(unsigned long pfn);
  76 extern unsigned long page_to_pfn(struct page *page);
  77 #else
  78 #define page_to_pfn __page_to_pfn
  79 #define pfn_to_page __pfn_to_page
  80 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
  81
  82 #endif /* __ASSEMBLY__ */
  83
  84 #endif