root/include/asm-generic/memory_model.h

INCLUDED FROM

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_MEMORY_MODEL_H
   3 #define __ASM_MEMORY_MODEL_H
   4 
   5 #include <linux/pfn.h>
   6 
   7 #ifndef __ASSEMBLY__
   8 
   9 #if defined(CONFIG_FLATMEM)
  10 
  11 #ifndef ARCH_PFN_OFFSET
  12 #define ARCH_PFN_OFFSET         (0UL)
  13 #endif
  14 
  15 #elif defined(CONFIG_DISCONTIGMEM)
  16 
  17 #ifndef arch_pfn_to_nid
  18 #define arch_pfn_to_nid(pfn)    pfn_to_nid(pfn)
  19 #endif
  20 
  21 #ifndef arch_local_page_offset
  22 #define arch_local_page_offset(pfn, nid)        \
  23         ((pfn) - NODE_DATA(nid)->node_start_pfn)
  24 #endif
  25 
  26 #endif /* CONFIG_DISCONTIGMEM */
  27 
  28 /*
  29  * supports 3 memory models.
  30  */
  31 #if defined(CONFIG_FLATMEM)
  32 
  33 #define __pfn_to_page(pfn)      (mem_map + ((pfn) - ARCH_PFN_OFFSET))
  34 #define __page_to_pfn(page)     ((unsigned long)((page) - mem_map) + \
  35                                  ARCH_PFN_OFFSET)
  36 #elif defined(CONFIG_DISCONTIGMEM)
  37 
  38 #define __pfn_to_page(pfn)                      \
  39 ({      unsigned long __pfn = (pfn);            \
  40         unsigned long __nid = arch_pfn_to_nid(__pfn);  \
  41         NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
  42 })
  43 
  44 #define __page_to_pfn(pg)                                               \
  45 ({      const struct page *__pg = (pg);                                 \
  46         struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg));     \
  47         (unsigned long)(__pg - __pgdat->node_mem_map) +                 \
  48          __pgdat->node_start_pfn;                                       \
  49 })
  50 
  51 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
  52 
  53 /* memmap is virtually contiguous.  */
  54 #define __pfn_to_page(pfn)      (vmemmap + (pfn))
  55 #define __page_to_pfn(page)     (unsigned long)((page) - vmemmap)
  56 
  57 #elif defined(CONFIG_SPARSEMEM)
  58 /*
  59  * Note: section's mem_map is encoded to reflect its start_pfn.
  60  * section[i].section_mem_map == mem_map's address - start_pfn;
  61  */
  62 #define __page_to_pfn(pg)                                       \
  63 ({      const struct page *__pg = (pg);                         \
  64         int __sec = page_to_section(__pg);                      \
  65         (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
  66 })
  67 
  68 #define __pfn_to_page(pfn)                              \
  69 ({      unsigned long __pfn = (pfn);                    \
  70         struct mem_section *__sec = __pfn_to_section(__pfn);    \
  71         __section_mem_map_addr(__sec) + __pfn;          \
  72 })
  73 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
  74 
  75 /*
  76  * Convert a physical address to a Page Frame Number and back
  77  */
  78 #define __phys_to_pfn(paddr)    PHYS_PFN(paddr)
  79 #define __pfn_to_phys(pfn)      PFN_PHYS(pfn)
  80 
  81 #define page_to_pfn __page_to_pfn
  82 #define pfn_to_page __pfn_to_page
  83 
  84 #endif /* __ASSEMBLY__ */
  85 
  86 #endif