1 files changed, 104 insertions, 0 deletions
diff --git a/mm/memblock.c b/mm/memblock.c
index 8b63a04e8cca..3dd9cfef996c 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -82,6 +82,16 @@
  * initialization compltes.
  */
 
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+struct pglist_data __refdata contig_page_data;
+EXPORT_SYMBOL(contig_page_data);
+#endif
+
+unsigned long max_low_pfn;
+unsigned long min_low_pfn;
+unsigned long max_pfn;
+unsigned long long max_possible_pfn;
+
 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
 static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
@@ -1877,6 +1887,100 @@ static int __init early_memblock(char *p)
 }
 early_param("memblock", early_memblock);
 
+static void __init __free_pages_memory(unsigned long start, unsigned long end)
+{
+	int order;
+
+	while (start < end) {
+		order = min(MAX_ORDER - 1UL, __ffs(start));
+
+		while (start + (1UL << order) > end)
+			order--;
+
+		memblock_free_pages(pfn_to_page(start), start, order);
+
+		start += (1UL << order);
+	}
+}
+
+static unsigned long __init __free_memory_core(phys_addr_t start,
+				 phys_addr_t end)
+{
+	unsigned long start_pfn = PFN_UP(start);
+	unsigned long end_pfn = min_t(unsigned long,
+				      PFN_DOWN(end), max_low_pfn);
+
+	if (start_pfn >= end_pfn)
+		return 0;
+
+	__free_pages_memory(start_pfn, end_pfn);
+
+	return end_pfn - start_pfn;
+}
+
+static unsigned long __init free_low_memory_core_early(void)
+{
+	unsigned long count = 0;
+	phys_addr_t start, end;
+	u64 i;
+
+	memblock_clear_hotplug(0, -1);
+
+	for_each_reserved_mem_region(i, &start, &end)
+		reserve_bootmem_region(start, end);
+
+	/*
+	 * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
+	 *  because in some case like Node0 doesn't have RAM installed
+	 *  low ram will be on Node1
+	 */
+	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
+				NULL)
+		count += __free_memory_core(start, end);
+
+	return count;
+}
+
+static int reset_managed_pages_done __initdata;
+
+void reset_node_managed_pages(pg_data_t *pgdat)
+{
+	struct zone *z;
+
+	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
+		z->managed_pages = 0;
+}
+
+void __init reset_all_zones_managed_pages(void)
+{
+	struct pglist_data *pgdat;
+
+	if (reset_managed_pages_done)
+		return;
+
+	for_each_online_pgdat(pgdat)
+		reset_node_managed_pages(pgdat);
+
+	reset_managed_pages_done = 1;
+}
+
+/**
+ * memblock_free_all - release free pages to the buddy allocator
+ *
+ * Return: the number of pages actually released.
+ */
+unsigned long __init memblock_free_all(void)
+{
+	unsigned long pages;
+
+	reset_all_zones_managed_pages();
+
+	pages = free_low_memory_core_early();
+	totalram_pages += pages;
+
+	return pages;
+}
+
 #if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
 
 static int memblock_debug_show(struct seq_file *m, void *private)