diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index bc4c171..9bc9340 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -38,6 +38,7 @@ struct cma {
 	unsigned long	base_pfn;
 	unsigned long	count;
 	unsigned long	*bitmap;
+	int order_per_bit; /* Order of pages represented by one bit */
 	struct mutex	lock;
 };
 
@@ -157,9 +158,38 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
 
 static DEFINE_MUTEX(cma_mutex);
 
+static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
+{
+	return (1 << (align_order >> cma->order_per_bit)) - 1;
+}
+
+static unsigned long cma_bitmap_maxno(struct cma *cma)
+{
+	return cma->count >> cma->order_per_bit;
+}
+
+static unsigned long cma_bitmap_pages_to_bits(struct cma *cma,
+						unsigned long pages)
+{
+	return ALIGN(pages, 1 << cma->order_per_bit) >> cma->order_per_bit;
+}
+
+static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
+{
+	unsigned long bitmapno, nr_bits;
+
+	bitmapno = (pfn - cma->base_pfn) >> cma->order_per_bit;
+	nr_bits = cma_bitmap_pages_to_bits(cma, count);
+
+	mutex_lock(&cma->lock);
+	bitmap_clear(cma->bitmap, bitmapno, nr_bits);
+	mutex_unlock(&cma->lock);
+}
+
 static int __init cma_activate_area(struct cma *cma)
 {
-	int bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long);
+	int bitmap_maxno = cma_bitmap_maxno(cma);
+	int bitmap_size = BITS_TO_LONGS(bitmap_maxno) * sizeof(long);
 	unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
 	unsigned i = cma->count >> pageblock_order;
 	struct zone *zone;
@@ -221,6 +251,7 @@ core_initcall(cma_init_reserved_areas);
  * @base: Base address of the reserved area optional, use 0 for any
  * @limit: End address of the reserved memory (optional, 0 for any).
  * @alignment: Alignment for the contiguous memory area, should be power of 2
+ * @order_per_bit: Order of pages represented by one bit on bitmap.
  * @res_cma: Pointer to store the created cma region.
  * @fixed: hint about where to place the reserved area
  *
@@ -235,7 +266,7 @@ core_initcall(cma_init_reserved_areas);
  */
 static int __init __dma_contiguous_reserve_area(phys_addr_t size,
 				phys_addr_t base, phys_addr_t limit,
-				phys_addr_t alignment,
+				phys_addr_t alignment, int order_per_bit,
 				struct cma **res_cma, bool fixed)
 {
 	struct cma *cma = &cma_areas[cma_area_count];
@@ -269,6 +300,8 @@ static int __init __dma_contiguous_reserve_area(phys_addr_t size,
 	base = ALIGN(base, alignment);
 	size = ALIGN(size, alignment);
 	limit &= ~(alignment - 1);
+	/* size should be aligned with order_per_bit */
+	BUG_ON(!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit));
 
 	/* Reserve memory */
 	if (base && fixed) {
@@ -294,6 +327,7 @@ static int __init __dma_contiguous_reserve_area(phys_addr_t size,
 	 */
 	cma->base_pfn = PFN_DOWN(base);
 	cma->count = size >> PAGE_SHIFT;
+	cma->order_per_bit = order_per_bit;
 	*res_cma = cma;
 	cma_area_count++;
 
@@ -313,7 +347,7 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
 {
 	int ret;
 
-	ret = __dma_contiguous_reserve_area(size, base, limit, 0,
+	ret = __dma_contiguous_reserve_area(size, base, limit, 0, 0,
 						res_cma, fixed);
 	if (ret)
 		return ret;
@@ -324,13 +358,6 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
 	return 0;
 }
 
-static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
-{
-	mutex_lock(&cma->lock);
-	bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
-	mutex_unlock(&cma->lock);
-}
-
 /**
  * dma_alloc_from_contiguous() - allocate pages from contiguous area
  * @dev:   Pointer to device for which the allocation is performed.
@@ -345,7 +372,8 @@ static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
 static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
 				       unsigned int align)
 {
-	unsigned long mask, pfn, pageno, start = 0;
+	unsigned long mask, pfn, start = 0;
+	unsigned long bitmap_maxno, bitmapno, nr_bits;
 	struct page *page = NULL;
 	int ret;
 
@@ -358,18 +386,19 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
 	if (!count)
 		return NULL;
 
-	mask = (1 << align) - 1;
-
+	mask = cma_bitmap_aligned_mask(cma, align);
+	bitmap_maxno = cma_bitmap_maxno(cma);
+	nr_bits = cma_bitmap_pages_to_bits(cma, count);
 
 	for (;;) {
 		mutex_lock(&cma->lock);
-		pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
-						    start, count, mask);
-		if (pageno >= cma->count) {
+		bitmapno = bitmap_find_next_zero_area(cma->bitmap,
+					bitmap_maxno, start, nr_bits, mask);
+		if (bitmapno >= bitmap_maxno) {
 			mutex_unlock(&cma->lock);
 			break;
 		}
-		bitmap_set(cma->bitmap, pageno, count);
+		bitmap_set(cma->bitmap, bitmapno, nr_bits);
 		/*
 		 * It's safe to drop the lock here. We've marked this region for
 		 * our exclusive use. If the migration fails we will take the
@@ -377,7 +406,7 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
 		 */
 		mutex_unlock(&cma->lock);
 
-		pfn = cma->base_pfn + pageno;
+		pfn = cma->base_pfn + (bitmapno << cma->order_per_bit);
 		mutex_lock(&cma_mutex);
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
 		mutex_unlock(&cma_mutex);
@@ -392,7 +421,7 @@ static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
 		pr_debug("%s(): memory range at %p is busy, retrying\n",
 			 __func__, pfn_to_page(pfn));
 		/* try again with a bit different memory target */
-		start = pageno + mask + 1;
+		start = bitmapno + mask + 1;
 	}
 
 	pr_debug("%s(): returned %p\n", __func__, page);
