3 files changed, 584 insertions, 25 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
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9810f0a60db7..26c9939857fa 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -37,6 +37,8 @@
 #include <linux/vmalloc.h>
 #include <linux/mempolicy.h>
 #include <linux/stop_machine.h>
+#include <linux/sort.h>
+#include <linux/pfn.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -103,6 +105,33 @@ int min_free_kbytes = 1024;
 unsigned long __meminitdata nr_kernel_pages;
 unsigned long __meminitdata nr_all_pages;
 
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+  /*
+   * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct
+   * ranges of memory (RAM) that may be registered with add_active_range().
+   * Ranges passed to add_active_range() will be merged if possible
+   * so the number of times add_active_range() can be called is
+   * related to the number of nodes and the number of holes
+   */
+  #ifdef CONFIG_MAX_ACTIVE_REGIONS
+    /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
+    #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
+  #else
+    #if MAX_NUMNODES >= 32
+      /* If there can be many nodes, allow up to 50 holes per node */
+      #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
+    #else
+      /* By default, allow up to 256 distinct regions */
+      #define MAX_ACTIVE_REGIONS 256
+    #endif
+  #endif
+
+  struct node_active_region __initdata early_node_map[MAX_ACTIVE_REGIONS];
+  int __initdata nr_nodemap_entries;
+  unsigned long __initdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
+  unsigned long __initdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
+
 #ifdef CONFIG_DEBUG_VM
 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 {
@@ -1642,25 +1671,6 @@ static inline unsigned long wait_table_bits(unsigned long size)
 
 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
 
-static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
-                unsigned long *zones_size, unsigned long *zholes_size)
-{
-        unsigned long realtotalpages, totalpages = 0;
-        enum zone_type i;
-
-        for (i = 0; i < MAX_NR_ZONES; i++)
-                totalpages += zones_size[i];
-        pgdat->node_spanned_pages = totalpages;
-
-        realtotalpages = totalpages;
-        if (zholes_size)
-                for (i = 0; i < MAX_NR_ZONES; i++)
-                        realtotalpages -= zholes_size[i];
-        pgdat->node_present_pages = realtotalpages;
-        printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
-}
-
-
 /*
  * Initially all pages are reserved - free ones are freed
  * up by free_all_bootmem() once the early boot process is
@@ -1977,6 +1987,272 @@ __meminit int init_currently_empty_zone(struct zone *zone,
         return 0;
 }
 
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+/*
+ * Basic iterator support. Return the first range of PFNs for a node
+ * Note: nid == MAX_NUMNODES returns first region regardless of node
+ */
+static int __init first_active_region_index_in_nid(int nid)
+{
+        int i;
+
+        for (i = 0; i < nr_nodemap_entries; i++)
+                if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
+                        return i;
+
+        return -1;
+}
+
+/*
+ * Basic iterator support. Return the next active range of PFNs for a node
+ * Note: nid == MAX_NUMNODES returns next region regardles of node
+ */
+static int __init next_active_region_index_in_nid(int index, int nid)
+{
+        for (index = index + 1; index < nr_nodemap_entries; index++)
+                if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
+                        return index;
+
+        return -1;
+}
+
+#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+/*
+ * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
+ * Architectures may implement their own version but if add_active_range()
+ * was used and there are no special requirements, this is a convenient
+ * alternative
+ */
+int __init early_pfn_to_nid(unsigned long pfn)
+{
+        int i;
+
+        for (i = 0; i < nr_nodemap_entries; i++) {
+                unsigned long start_pfn = early_node_map[i].start_pfn;
+                unsigned long end_pfn = early_node_map[i].end_pfn;
+
+                if (start_pfn <= pfn && pfn < end_pfn)
+                        return early_node_map[i].nid;
+        }
+
+        return 0;
+}
+#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
+
+/* Basic iterator support to walk early_node_map[] */
+#define for_each_active_range_index_in_nid(i, nid) \
+        for (i = first_active_region_index_in_nid(nid); i != -1; \
+                                i = next_active_region_index_in_nid(i, nid))
+
+/**
+ * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
+ * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed
+ * @max_low_pfn: The highest PFN that till be passed to free_bootmem_node
+ *
+ * If an architecture guarantees that all ranges registered with
+ * add_active_ranges() contain no holes and may be freed, this
+ * this function may be used instead of calling free_bootmem() manually.
+ */
+void __init free_bootmem_with_active_regions(int nid,
+                                                unsigned long max_low_pfn)
+{
+        int i;
+
+        for_each_active_range_index_in_nid(i, nid) {
+                unsigned long size_pages = 0;
+                unsigned long end_pfn = early_node_map[i].end_pfn;
+
+                if (early_node_map[i].start_pfn >= max_low_pfn)
+                        continue;
+
+                if (end_pfn > max_low_pfn)
+                        end_pfn = max_low_pfn;
+
+                size_pages = end_pfn - early_node_map[i].start_pfn;
+                free_bootmem_node(NODE_DATA(early_node_map[i].nid),
+                                PFN_PHYS(early_node_map[i].start_pfn),
+                                size_pages << PAGE_SHIFT);
+        }
+}
+
+/**
+ * sparse_memory_present_with_active_regions - Call memory_present for each active range
+ * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used
+ *
+ * If an architecture guarantees that all ranges registered with
+ * add_active_ranges() contain no holes and may be freed, this
+ * this function may be used instead of calling memory_present() manually.
+ */
+void __init sparse_memory_present_with_active_regions(int nid)
+{
+        int i;
+
+        for_each_active_range_index_in_nid(i, nid)
+                memory_present(early_node_map[i].nid,
+                                early_node_map[i].start_pfn,
+                                early_node_map[i].end_pfn);
+}
+
+/**
+ * get_pfn_range_for_nid - Return the start and end page frames for a node
+ * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned
+ * @start_pfn: Passed by reference. On return, it will have the node start_pfn
+ * @end_pfn: Passed by reference. On return, it will have the node end_pfn
+ *
+ * It returns the start and end page frame of a node based on information
+ * provided by an arch calling add_active_range(). If called for a node
+ * with no available memory, a warning is printed and the start and end
+ * PFNs will be 0
+ */
+void __init get_pfn_range_for_nid(unsigned int nid,
+                        unsigned long *start_pfn, unsigned long *end_pfn)
+{
+        int i;
+        *start_pfn = -1UL;
+        *end_pfn = 0;
+
+        for_each_active_range_index_in_nid(i, nid) {
+                *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
+                *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
+        }
+
+        if (*start_pfn == -1UL) {
+                printk(KERN_WARNING "Node %u active with no memory\n", nid);
+                *start_pfn = 0;
+        }
+}
+
+/*
+ * Return the number of pages a zone spans in a node, including holes
+ * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
+ */
+unsigned long __init zone_spanned_pages_in_node(int nid,
+                                        unsigned long zone_type,
+                                        unsigned long *ignored)
+{
+        unsigned long node_start_pfn, node_end_pfn;
+        unsigned long zone_start_pfn, zone_end_pfn;
+
+        /* Get the start and end of the node and zone */
+        get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+        zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
+        zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
+
+        /* Check that this node has pages within the zone's required range */
+        if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
+                return 0;
+
+        /* Move the zone boundaries inside the node if necessary */
+        zone_end_pfn = min(zone_end_pfn, node_end_pfn);
+        zone_start_pfn = max(zone_start_pfn, node_start_pfn);
+
+        /* Return the spanned pages */
+        return zone_end_pfn - zone_start_pfn;
+}
+
+/*
+ * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
+ * then all holes in the requested range will be accounted for
+ */
+unsigned long __init __absent_pages_in_range(int nid,
+                                unsigned long range_start_pfn,
+                                unsigned long range_end_pfn)
+{
+        int i = 0;
+        unsigned long prev_end_pfn = 0, hole_pages = 0;
+        unsigned long start_pfn;
+
+        /* Find the end_pfn of the first active range of pfns in the node */
+        i = first_active_region_index_in_nid(nid);
+        if (i == -1)
+                return 0;
+
+        prev_end_pfn = early_node_map[i].start_pfn;
+
+        /* Find all holes for the zone within the node */
+        for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
+
+                /* No need to continue if prev_end_pfn is outside the zone */
+                if (prev_end_pfn >= range_end_pfn)
+                        break;
+
+                /* Make sure the end of the zone is not within the hole */
+                start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
+                prev_end_pfn = max(prev_end_pfn, range_start_pfn);
+
+                /* Update the hole size cound and move on */
+                if (start_pfn > range_start_pfn) {
+                        BUG_ON(prev_end_pfn > start_pfn);
+                        hole_pages += start_pfn - prev_end_pfn;
+                }
+                prev_end_pfn = early_node_map[i].end_pfn;
+        }
+
+        return hole_pages;
+}
+
+/**
+ * absent_pages_in_range - Return number of page frames in holes within a range
+ * @start_pfn: The start PFN to start searching for holes
+ * @end_pfn: The end PFN to stop searching for holes
+ *
+ * It returns the number of pages frames in memory holes within a range
+ */
+unsigned long __init absent_pages_in_range(unsigned long start_pfn,
+                                                        unsigned long end_pfn)
+{
+        return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
+}
+
+/* Return the number of page frames in holes in a zone on a node */
+unsigned long __init zone_absent_pages_in_node(int nid,
+                                        unsigned long zone_type,
+                                        unsigned long *ignored)
+{
+        return __absent_pages_in_range(nid,
+                                arch_zone_lowest_possible_pfn[zone_type],
+                                arch_zone_highest_possible_pfn[zone_type]);
+}
+#else
+static inline unsigned long zone_spanned_pages_in_node(int nid,
+                                        unsigned long zone_type,
+                                        unsigned long *zones_size)
+{
+        return zones_size[zone_type];
+}
+
+static inline unsigned long zone_absent_pages_in_node(int nid,
+                                                unsigned long zone_type,
+                                                unsigned long *zholes_size)
+{
+        if (!zholes_size)
+                return 0;
+
+        return zholes_size[zone_type];
+}
+#endif
+
+static void __init calculate_node_totalpages(struct pglist_data *pgdat,
+                unsigned long *zones_size, unsigned long *zholes_size)
+{
+        unsigned long realtotalpages, totalpages = 0;
+        enum zone_type i;
+
+        for (i = 0; i < MAX_NR_ZONES; i++)
+                totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
+                                                                zones_size);
+        pgdat->node_spanned_pages = totalpages;
+
+        realtotalpages = totalpages;
+        for (i = 0; i < MAX_NR_ZONES; i++)
+                realtotalpages -=
+                        zone_absent_pages_in_node(pgdat->node_id, i,
+                                                                zholes_size);
+        pgdat->node_present_pages = realtotalpages;
+        printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
+                                                        realtotalpages);
+}
+
 /*
  * Set up the zone data structures:
  *   - mark all pages reserved
@@ -2000,9 +2276,9 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
                 struct zone *zone = pgdat->node_zones + j;
                 unsigned long size, realsize;
 
-                realsize = size = zones_size[j];
-                if (zholes_size)
-                        realsize -= zholes_size[j];
+                size = zone_spanned_pages_in_node(nid, j, zones_size);
+                realsize = size - zone_absent_pages_in_node(nid, j,
+                                                                zholes_size);
 
                 if (!is_highmem_idx(j))
                         nr_kernel_pages += realsize;
@@ -2073,8 +2349,13 @@ static void __init alloc_node_mem_map(struct pglist_data *pgdat)
         /*
          * With no DISCONTIG, the global mem_map is just set as node 0's
          */
-        if (pgdat == NODE_DATA(0))
+        if (pgdat == NODE_DATA(0)) {
                 mem_map = NODE_DATA(0)->node_mem_map;
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+                if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
+                        mem_map -= pgdat->node_start_pfn;
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
+        }
 #endif
 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
 }
@@ -2085,13 +2366,236 @@ void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
 {
         pgdat->node_id = nid;
         pgdat->node_start_pfn = node_start_pfn;
-        calculate_zone_totalpages(pgdat, zones_size, zholes_size);
+        calculate_node_totalpages(pgdat, zones_size, zholes_size);
 
         alloc_node_mem_map(pgdat);
 
         free_area_init_core(pgdat, zones_size, zholes_size);
 }
 
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+/**
+ * add_active_range - Register a range of PFNs backed by physical memory
+ * @nid: The node ID the range resides on
+ * @start_pfn: The start PFN of the available physical memory
+ * @end_pfn: The end PFN of the available physical memory
+ *
+ * These ranges are stored in an early_node_map[] and later used by
+ * free_area_init_nodes() to calculate zone sizes and holes. If the
+ * range spans a memory hole, it is up to the architecture to ensure
+ * the memory is not freed by the bootmem allocator. If possible
+ * the range being registered will be merged with existing ranges.
+ */
+void __init add_active_range(unsigned int nid, unsigned long start_pfn,
+                                                unsigned long end_pfn)
+{
+        int i;
+
+        printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
+                          "%d entries of %d used\n",
+                          nid, start_pfn, end_pfn,
+                          nr_nodemap_entries, MAX_ACTIVE_REGIONS);
+
+        /* Merge with existing active regions if possible */
+        for (i = 0; i < nr_nodemap_entries; i++) {
+                if (early_node_map[i].nid != nid)
+                        continue;
+
+                /* Skip if an existing region covers this new one */
+                if (start_pfn >= early_node_map[i].start_pfn &&
+                                end_pfn <= early_node_map[i].end_pfn)
+                        return;
+
+                /* Merge forward if suitable */
+                if (start_pfn <= early_node_map[i].end_pfn &&
+                                end_pfn > early_node_map[i].end_pfn) {
+                        early_node_map[i].end_pfn = end_pfn;
+                        return;
+                }
+
+                /* Merge backward if suitable */
+                if (start_pfn < early_node_map[i].end_pfn &&
+                                end_pfn >= early_node_map[i].start_pfn) {
+                        early_node_map[i].start_pfn = start_pfn;
+                        return;
+                }
+        }
+
+        /* Check that early_node_map is large enough */
+        if (i >= MAX_ACTIVE_REGIONS) {
+                printk(KERN_CRIT "More than %d memory regions, truncating\n",
+                                                        MAX_ACTIVE_REGIONS);
+                return;
+        }
+
+        early_node_map[i].nid = nid;
+        early_node_map[i].start_pfn = start_pfn;
+        early_node_map[i].end_pfn = end_pfn;
+        nr_nodemap_entries = i + 1;
+}
+
+/**
+ * shrink_active_range - Shrink an existing registered range of PFNs
+ * @nid: The node id the range is on that should be shrunk
+ * @old_end_pfn: The old end PFN of the range
+ * @new_end_pfn: The new PFN of the range
+ *
+ * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
+ * The map is kept at the end physical page range that has already been
+ * registered with add_active_range(). This function allows an arch to shrink
+ * an existing registered range.
+ */
+void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
+                                                unsigned long new_end_pfn)
+{
+        int i;
+
+        /* Find the old active region end and shrink */
+        for_each_active_range_index_in_nid(i, nid)
+                if (early_node_map[i].end_pfn == old_end_pfn) {
+                        early_node_map[i].end_pfn = new_end_pfn;
+                        break;
+                }
+}
+
+/**
+ * remove_all_active_ranges - Remove all currently registered regions
+ * During discovery, it may be found that a table like SRAT is invalid
+ * and an alternative discovery method must be used. This function removes
+ * all currently registered regions.
+ */
+void __init remove_all_active_ranges()
+{
+        memset(early_node_map, 0, sizeof(early_node_map));
+        nr_nodemap_entries = 0;
+}
+
+/* Compare two active node_active_regions */
+static int __init cmp_node_active_region(const void *a, const void *b)
+{
+        struct node_active_region *arange = (struct node_active_region *)a;
+        struct node_active_region *brange = (struct node_active_region *)b;
+
+        /* Done this way to avoid overflows */
+        if (arange->start_pfn > brange->start_pfn)
+                return 1;
+        if (arange->start_pfn < brange->start_pfn)
+                return -1;
+
+        return 0;
+}
+
+/* sort the node_map by start_pfn */
+static void __init sort_node_map(void)
+{
+        sort(early_node_map, (size_t)nr_nodemap_entries,
+                        sizeof(struct node_active_region),
+                        cmp_node_active_region, NULL);
+}
+
+/* Find the lowest pfn for a node. This depends on a sorted early_node_map */
+unsigned long __init find_min_pfn_for_node(unsigned long nid)
+{
+        int i;
+
+        /* Assuming a sorted map, the first range found has the starting pfn */
+        for_each_active_range_index_in_nid(i, nid)
+                return early_node_map[i].start_pfn;
+
+        printk(KERN_WARNING "Could not find start_pfn for node %lu\n", nid);
+        return 0;
+}
+
+/**
+ * find_min_pfn_with_active_regions - Find the minimum PFN registered
+ *
+ * It returns the minimum PFN based on information provided via
+ * add_active_range()
+ */
+unsigned long __init find_min_pfn_with_active_regions(void)
+{
+        return find_min_pfn_for_node(MAX_NUMNODES);
+}
+
+/**
+ * find_max_pfn_with_active_regions - Find the maximum PFN registered
+ *
+ * It returns the maximum PFN based on information provided via
+ * add_active_range()
+ */
+unsigned long __init find_max_pfn_with_active_regions(void)
+{
+        int i;
+        unsigned long max_pfn = 0;
+
+        for (i = 0; i < nr_nodemap_entries; i++)
+                max_pfn = max(max_pfn, early_node_map[i].end_pfn);
+
+        return max_pfn;
+}
+
+/**
+ * free_area_init_nodes - Initialise all pg_data_t and zone data
+ * @arch_max_dma_pfn: The maximum PFN usable for ZONE_DMA
+ * @arch_max_dma32_pfn: The maximum PFN usable for ZONE_DMA32
+ * @arch_max_low_pfn: The maximum PFN usable for ZONE_NORMAL
+ * @arch_max_high_pfn: The maximum PFN usable for ZONE_HIGHMEM
+ *
+ * This will call free_area_init_node() for each active node in the system.
+ * Using the page ranges provided by add_active_range(), the size of each
+ * zone in each node and their holes is calculated. If the maximum PFN
+ * between two adjacent zones match, it is assumed that the zone is empty.
+ * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
+ * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
+ * starts where the previous one ended. For example, ZONE_DMA32 starts
+ * at arch_max_dma_pfn.
+ */
+void __init free_area_init_nodes(unsigned long *max_zone_pfn)
+{
+        unsigned long nid;
+        enum zone_type i;
+
+        /* Record where the zone boundaries are */
+        memset(arch_zone_lowest_possible_pfn, 0,
+                                sizeof(arch_zone_lowest_possible_pfn));
+        memset(arch_zone_highest_possible_pfn, 0,
+                                sizeof(arch_zone_highest_possible_pfn));
+        arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
+        arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
+        for (i = 1; i < MAX_NR_ZONES; i++) {
+                arch_zone_lowest_possible_pfn[i] =
+                        arch_zone_highest_possible_pfn[i-1];
+                arch_zone_highest_possible_pfn[i] =
+                        max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
+        }
+
+        /* Regions in the early_node_map can be in any order */
+        sort_node_map();
+
+        /* Print out the zone ranges */
+        printk("Zone PFN ranges:\n");
+        for (i = 0; i < MAX_NR_ZONES; i++)
+                printk("  %-8s %8lu -> %8lu\n",
+                                zone_names[i],
+                                arch_zone_lowest_possible_pfn[i],
+                                arch_zone_highest_possible_pfn[i]);
+
+        /* Print out the early_node_map[] */
+        printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
+        for (i = 0; i < nr_nodemap_entries; i++)
+                printk("  %3d: %8lu -> %8lu\n", early_node_map[i].nid,
+                                                early_node_map[i].start_pfn,
+                                                early_node_map[i].end_pfn);
+
+        /* Initialise every node */
+        for_each_online_node(nid) {
+                pg_data_t *pgdat = NODE_DATA(nid);
+                free_area_init_node(nid, pgdat, NULL,
+                                find_min_pfn_for_node(nid), NULL);
+        }
+}
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
+
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 static bootmem_data_t contig_bootmem_data;
 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };