1 files changed, 63 insertions, 7 deletions

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index d776ec0..34aead7 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -79,19 +79,75 @@ void __init zones_init(void)
 	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
 }
 
+#ifdef CONFIG_HIGHMEM
+static void __init free_area_high(unsigned long pfn, unsigned long end)
+{
+	for (; pfn < end; pfn++)
+		free_highmem_page(pfn_to_page(pfn));
+}
+
+static void __init free_highpages(void)
+{
+	unsigned long max_low = max_low_pfn;
+	struct memblock_region *mem, *res;
+
+	reset_all_zones_managed_pages();
+	/* set highmem page free */
+	for_each_memblock(memory, mem) {
+		unsigned long start = memblock_region_memory_base_pfn(mem);
+		unsigned long end = memblock_region_memory_end_pfn(mem);
+
+		/* Ignore complete lowmem entries */
+		if (end <= max_low)
+			continue;
+
+		if (memblock_is_nomap(mem))
+			continue;
+
+		/* Truncate partial highmem entries */
+		if (start < max_low)
+			start = max_low;
+
+		/* Find and exclude any reserved regions */
+		for_each_memblock(reserved, res) {
+			unsigned long res_start, res_end;
+
+			res_start = memblock_region_reserved_base_pfn(res);
+			res_end = memblock_region_reserved_end_pfn(res);
+
+			if (res_end < start)
+				continue;
+			if (res_start < start)
+				res_start = start;
+			if (res_start > end)
+				res_start = end;
+			if (res_end > end)
+				res_end = end;
+			if (res_start != start)
+				free_area_high(start, res_start);
+			start = res_end;
+			if (start == end)
+				break;
+		}
+
+		/* And now free anything which remains */
+		if (start < end)
+			free_area_high(start, end);
+	}
+}
+#else
+static void __init free_highpages(void)
+{
+}
+#endif
+
 /*
  * Initialize memory pages.
  */
 
 void __init mem_init(void)
 {
-#ifdef CONFIG_HIGHMEM
-	unsigned long tmp;
-
-	reset_all_zones_managed_pages();
-	for (tmp = max_low_pfn; tmp < max_pfn; tmp++)
-		free_highmem_page(pfn_to_page(tmp));
-#endif
+	free_highpages();
 
 	max_mapnr = max_pfn - ARCH_PFN_OFFSET;
 	high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);