diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 9021762..5f62c28 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -32,6 +32,7 @@
 #include <linux/swap.h>
 #include <linux/mm_types.h>
 #include <linux/dma-contiguous.h>
+#include <linux/log2.h>
 
 struct cma {
 	unsigned long	base_pfn;
@@ -215,17 +216,16 @@
 
 static int __init __dma_contiguous_reserve_area(phys_addr_t size,
 				phys_addr_t base, phys_addr_t limit,
+				phys_addr_t alignment,
 				struct cma **res_cma, bool fixed)
 {
 	struct cma *cma = &cma_areas[cma_area_count];
-	phys_addr_t alignment;
 	int ret = 0;
 
-	pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__,
-		 (unsigned long)size, (unsigned long)base,
-		 (unsigned long)limit);
+	pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n",
+		__func__, (unsigned long)size, (unsigned long)base,
+		(unsigned long)limit, (unsigned long)alignment);
 
-	/* Sanity checks */
 	if (cma_area_count == ARRAY_SIZE(cma_areas)) {
 		pr_err("Not enough slots for CMA reserved regions!\n");
 		return -ENOSPC;
@@ -234,8 +234,17 @@
 	if (!size)
 		return -EINVAL;
 
-	/* Sanitise input arguments */
-	alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+	if (alignment && !is_power_of_2(alignment))
+		return -EINVAL;
+
+	/*
+	 * Sanitise input arguments.
+	 * Pages both ends in CMA area could be merged into adjacent unmovable
+	 * migratetype page by page allocator's buddy algorithm. In the case,
+	 * you couldn't get a contiguous memory, which is not what we want.
+	 */
+	alignment = max(alignment,
+		(phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
 	base = ALIGN(base, alignment);
 	size = ALIGN(size, alignment);
 	limit &= ~(alignment - 1);
@@ -299,7 +308,8 @@
 {
 	int ret;
 
-	ret = __dma_contiguous_reserve_area(size, base, limit, res_cma, fixed);
+	ret = __dma_contiguous_reserve_area(size, base, limit, 0,
+						res_cma, fixed);
 	if (ret)
 		return ret;