diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 793204b..f004d8e 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -407,13 +407,77 @@ static unsigned long __init init_range_memory_mapping(
 
 /* (PUD_SHIFT-PMD_SHIFT)/2 */
 #define STEP_SIZE_SHIFT 5
-void __init init_mem_mapping(void)
+
+#ifdef CONFIG_MOVABLE_NODE
+/**
+ * memory_map_from_low - Map [start, end) from low to high
+ * @start: start address of the target memory range
+ * @end: end address of the target memory range
+ *
+ * This function will setup direct mapping for memory range [start, end) in a
+ * heuristic way. In the beginning, step_size is small. The more memory we map
+ * memory in the next loop.
+ */
+static void __init memory_map_from_low(unsigned long start, unsigned long end)
+{
+	unsigned long next, new_mapped_ram_size;
+	unsigned long mapped_ram_size = 0;
+	/* step_size need to be small so pgt_buf from BRK could cover it */
+	unsigned long step_size = PMD_SIZE;
+
+	while (start < end) {
+		if (end - start > step_size) {
+			next = round_up(start + 1, step_size);
+			if (next > end)
+				next = end;
+		} else
+			next = end;
+
+		new_mapped_ram_size = init_range_memory_mapping(start, next);
+		start = next;
+
+		if (new_mapped_ram_size > mapped_ram_size)
+			step_size <<= STEP_SIZE_SHIFT;
+		mapped_ram_size += new_mapped_ram_size;
+	}
+}
+#endif /* CONFIG_MOVABLE_NODE */
+
+/**
+ * memory_map_from_high - Map [start, end) from high to low
+ * @start: start address of the target memory range
+ * @end: end address of the target memory range
+ *
+ * This function is similar to memory_map_from_low() except it maps memory
+ * from high to low.
+ */
+static void __init memory_map_from_high(unsigned long start, unsigned long end)
 {
-	unsigned long end, real_end, start, last_start;
-	unsigned long step_size;
-	unsigned long addr;
+	unsigned long prev, new_mapped_ram_size;
 	unsigned long mapped_ram_size = 0;
-	unsigned long new_mapped_ram_size;
+	/* step_size need to be small so pgt_buf from BRK could cover it */
+	unsigned long step_size = PMD_SIZE;
+
+	while (start < end) {
+		if (end > step_size) {
+			prev = round_down(end - 1, step_size);
+			if (prev < start)
+				prev = start;
+		} else
+			prev = start;
+
+		new_mapped_ram_size = init_range_memory_mapping(prev, end);
+		end = prev;
+
+		if (new_mapped_ram_size > mapped_ram_size)
+			step_size <<= STEP_SIZE_SHIFT;
+		mapped_ram_size += new_mapped_ram_size;
+	}
+}
+
+void __init init_mem_mapping(void)
+{
+	unsigned long end;
 
 	probe_page_size_mask();
 
@@ -423,44 +487,43 @@ void __init init_mem_mapping(void)
 	end = max_low_pfn << PAGE_SHIFT;
 #endif
 
-	/* the ISA range is always mapped regardless of memory holes */
-	init_memory_mapping(0, ISA_END_ADDRESS);
+	max_pfn_mapped = 0; /* will get exact value next */
+	min_pfn_mapped = end >> PAGE_SHIFT;
+
+#ifdef CONFIG_MOVABLE_NODE
+	unsigned long kernel_end;
+
+	if (movablenode_enable_srat &&
+	    memblock.current_order == MEMBLOCK_ORDER_LOW_TO_HIGH) {
+		kernel_end = round_up(__pa_symbol(_end), PMD_SIZE);
+
+		memory_map_from_low(kernel_end, end);
+		memory_map_from_low(ISA_END_ADDRESS, kernel_end);
+		goto out;
+	}
+#endif /* CONFIG_MOVABLE_NODE */
+
+	unsigned long addr, real_end;
 
 	/* xen has big range in reserved near end of ram, skip it at first.*/
 	addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE, PMD_SIZE);
 	real_end = addr + PMD_SIZE;
 
-	/* step_size need to be small so pgt_buf from BRK could cover it */
-	step_size = PMD_SIZE;
-	max_pfn_mapped = 0; /* will get exact value next */
-	min_pfn_mapped = real_end >> PAGE_SHIFT;
-	last_start = start = real_end;
-
 	/*
 	 * We start from the top (end of memory) and go to the bottom.
 	 * The memblock_find_in_range() gets us a block of RAM from the
 	 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
 	 * for page table.
 	 */
-	while (last_start > ISA_END_ADDRESS) {
-		if (last_start > step_size) {
-			start = round_down(last_start - 1, step_size);
-			if (start < ISA_END_ADDRESS)
-				start = ISA_END_ADDRESS;
-		} else
-			start = ISA_END_ADDRESS;
-		new_mapped_ram_size = init_range_memory_mapping(start,
-							last_start);
-		last_start = start;
-		/* only increase step_size after big range get mapped */
-		if (new_mapped_ram_size > mapped_ram_size)
-			step_size <<= STEP_SIZE_SHIFT;
-		mapped_ram_size += new_mapped_ram_size;
-	}
+	memory_map_from_high(ISA_END_ADDRESS, real_end);
 
 	if (real_end < end)
 		init_range_memory_mapping(real_end, end);
 
+out:
+	/* the ISA range is always mapped regardless of memory holes */
+	init_memory_mapping(0, ISA_END_ADDRESS);
+
 #ifdef CONFIG_X86_64
 	if (max_pfn > max_low_pfn) {
 		/* can we preseve max_low_pfn ?*/
