2 files changed, 56 insertions, 1 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 856f0ee7e84a..c0402da7cce0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -937,6 +937,53 @@ extern void free_area_init(unsigned long * zones_size);
 extern void free_area_init_node(int nid, pg_data_t *pgdat,
         unsigned long * zones_size, unsigned long zone_start_pfn, 
         unsigned long *zholes_size);
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+/*
+ * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
+ * zones, allocate the backing mem_map and account for memory holes in a more
+ * architecture independent manner. This is a substitute for creating the
+ * zone_sizes[] and zholes_size[] arrays and passing them to
+ * free_area_init_node()
+ *
+ * An architecture is expected to register range of page frames backed by
+ * physical memory with add_active_range() before calling
+ * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
+ * usage, an architecture is expected to do something like
+ *
+ * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
+ *                                                       max_highmem_pfn};
+ * for_each_valid_physical_page_range()
+ *      add_active_range(node_id, start_pfn, end_pfn)
+ * free_area_init_nodes(max_zone_pfns);
+ *
+ * If the architecture guarantees that there are no holes in the ranges
+ * registered with add_active_range(), free_bootmem_active_regions()
+ * will call free_bootmem_node() for each registered physical page range.
+ * Similarly sparse_memory_present_with_active_regions() calls
+ * memory_present() for each range when SPARSEMEM is enabled.
+ *
+ * See mm/page_alloc.c for more information on each function exposed by
+ * CONFIG_ARCH_POPULATES_NODE_MAP
+ */
+extern void free_area_init_nodes(unsigned long *max_zone_pfn);
+extern void add_active_range(unsigned int nid, unsigned long start_pfn,
+                                        unsigned long end_pfn);
+extern void shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
+                                                unsigned long new_end_pfn);
+extern void remove_all_active_ranges(void);
+extern unsigned long absent_pages_in_range(unsigned long start_pfn,
+                                                unsigned long end_pfn);
+extern void get_pfn_range_for_nid(unsigned int nid,
+                        unsigned long *start_pfn, unsigned long *end_pfn);
+extern unsigned long find_min_pfn_with_active_regions(void);
+extern unsigned long find_max_pfn_with_active_regions(void);
+extern void free_bootmem_with_active_regions(int nid,
+                                                unsigned long max_low_pfn);
+extern void sparse_memory_present_with_active_regions(int nid);
+#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+extern int early_pfn_to_nid(unsigned long pfn);
+#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
 extern void setup_per_zone_pages_min(void);
 extern void mem_init(void);
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 3693f1a52788..7fa1cbe9fa7a 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -305,6 +305,13 @@ struct zonelist {
         struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited
 };
 
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+struct node_active_region {
+        unsigned long start_pfn;
+        unsigned long end_pfn;
+        int nid;
+};
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 
 /*
  * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
@@ -518,7 +525,8 @@ extern struct zone *next_zone(struct zone *zone);
 
 #endif
 
-#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
+        !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
 #define early_pfn_to_nid(nid)  (0UL)
 #endif