1 files changed, 69 insertions, 0 deletions
diff --git a/mm/sparse.h b/mm/sparse.h
new file mode 100644
index 000000000000..3b744667a7e6
--- /dev/null
+++ b/mm/sparse.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * sparse.h:
+ *
+ * mm/ internal sparse and sparse-vmemmap declarations
+ */
+
+#ifndef __MM_SPARSE_H
+#define __MM_SPARSE_H
+
+#include <linux/mmzone.h>
+
+/*
+ * mm/sparse.c
+ */
+#ifdef CONFIG_SPARSEMEM
+void sparse_init(void);
+int sparse_index_init(unsigned long section_nr, int nid);
+
+static inline void sparse_init_one_section(struct mem_section *ms,
+		unsigned long pnum, struct page *mem_map,
+		struct mem_section_usage *usage, unsigned long flags)
+{
+	unsigned long coded_mem_map;
+
+	BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
+
+	/*
+	 * We encode the start PFN of the section into the mem_map such that
+	 * page_to_pfn() on !CONFIG_SPARSEMEM_VMEMMAP can simply subtract it
+	 * from the page pointer to obtain the PFN.
+	 */
+	coded_mem_map = (unsigned long)(mem_map - section_nr_to_pfn(pnum));
+	VM_WARN_ON_ONCE(coded_mem_map & ~SECTION_MAP_MASK);
+
+	ms->section_mem_map &= ~SECTION_MAP_MASK;
+	ms->section_mem_map |= coded_mem_map;
+	ms->section_mem_map |= flags | SECTION_HAS_MEM_MAP;
+	ms->usage = usage;
+}
+
+static inline void __section_mark_present(struct mem_section *ms,
+		unsigned long section_nr)
+{
+	if (section_nr > __highest_present_section_nr)
+		__highest_present_section_nr = section_nr;
+
+	ms->section_mem_map |= SECTION_MARKED_PRESENT;
+}
+
+static inline size_t mem_section_usage_size(void)
+{
+	return struct_size_t(struct mem_section_usage, pageblock_flags,
+			     BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS));
+}
+#else
+static inline void sparse_init(void) {}
+#endif /* CONFIG_SPARSEMEM */
+
+/*
+ * mm/sparse-vmemmap.c
+ */
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+void sparse_init_subsection_map(void);
+#else
+static inline void sparse_init_subsection_map(void) {}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+#endif /* __MM_SPARSE_H */