LXR linux/include/asm-generic/memory

   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
  87