+#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+#define early_pfn_to_nid(nid) (0UL)
+#endif
+
+#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
+#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
+
+#ifdef CONFIG_SPARSEMEM
+
+/*
+ * SECTION_SHIFT #bits space required to store a section #
+ *
+ * PA_SECTION_SHIFT physical address to/from section number
+ * PFN_SECTION_SHIFT pfn to/from section number
+ */
+#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
+
+#define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
+#define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
+
+#define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
+
+#define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
+#define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
+
+#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
+#error Allocator MAX_ORDER exceeds SECTION_SIZE
+#endif
+
+struct page;
+struct mem_section {
+ /*
+ * This is, logically, a pointer to an array of struct
+ * pages. However, it is stored with some other magic.
+ * (see sparse.c::sparse_init_one_section())
+ *
+ * Making it a UL at least makes someone do a cast
+ * before using it wrong.
+ */
+ unsigned long section_mem_map;
+};
+
+extern struct mem_section mem_section[NR_MEM_SECTIONS];
+
+static inline struct mem_section *__nr_to_section(unsigned long nr)
+{
+ return &mem_section[nr];
+}
+
+/*
+ * We use the lower bits of the mem_map pointer to store
+ * a little bit of information. There should be at least
+ * 3 bits here due to 32-bit alignment.
+ */
+#define SECTION_MARKED_PRESENT (1UL<<0)
+#define SECTION_HAS_MEM_MAP (1UL<<1)
+#define SECTION_MAP_LAST_BIT (1UL<<2)
+#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
+
+static inline struct page *__section_mem_map_addr(struct mem_section *section)
+{
+ unsigned long map = section->section_mem_map;
+ map &= SECTION_MAP_MASK;
+ return (struct page *)map;
+}
+
+static inline int valid_section(struct mem_section *section)
+{
+ return (section->section_mem_map & SECTION_MARKED_PRESENT);
+}
+
+static inline int section_has_mem_map(struct mem_section *section)
+{
+ return (section->section_mem_map & SECTION_HAS_MEM_MAP);
+}
+
+static inline int valid_section_nr(unsigned long nr)
+{
+ return valid_section(__nr_to_section(nr));
+}
+
+/*
+ * Given a kernel address, find the home node of the underlying memory.
+ */
+#define kvaddr_to_nid(kaddr) pfn_to_nid(__pa(kaddr) >> PAGE_SHIFT)
+
+static inline struct mem_section *__pfn_to_section(unsigned long pfn)
+{
+ return __nr_to_section(pfn_to_section_nr(pfn));
+}
+
+#define pfn_to_page(pfn) \
+({ \
+ unsigned long __pfn = (pfn); \
+ __section_mem_map_addr(__pfn_to_section(__pfn)) + __pfn; \
+})
+#define page_to_pfn(page) \
+({ \
+ page - __section_mem_map_addr(__nr_to_section( \
+ page_to_section(page))); \
+})
+
+static inline int pfn_valid(unsigned long pfn)
+{
+ if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+ return 0;
+ return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
+}
+
+/*
+ * These are _only_ used during initialisation, therefore they
+ * can use __initdata ... They could have names to indicate
+ * this restriction.
+ */
+#ifdef CONFIG_NUMA
+#define pfn_to_nid early_pfn_to_nid
+#endif
+
+#define pfn_to_pgdat(pfn) \
+({ \
+ NODE_DATA(pfn_to_nid(pfn)); \
+})
+
+#define early_pfn_valid(pfn) pfn_valid(pfn)
+void sparse_init(void);
+#else
+#define sparse_init() do {} while (0)
+#endif /* CONFIG_SPARSEMEM */
+
+#ifdef CONFIG_NODES_SPAN_OTHER_NODES
+#define early_pfn_in_nid(pfn, nid) (early_pfn_to_nid(pfn) == (nid))
+#else
+#define early_pfn_in_nid(pfn, nid) (1)
+#endif
+
+#ifndef early_pfn_valid
+#define early_pfn_valid(pfn) (1)
+#endif
+
+void memory_present(int nid, unsigned long start, unsigned long end);
+unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
+