mm/cma_debug: correct size input to bitmap function

In CMA, 1 bit in bitmap means 1 << order_per_bits pages so size of
bitmap is cma->count >> order_per_bits rather than just cma->count.
This patch fixes it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Stefan Strogin <stefan.strogin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/cma_debug.c

@@ -39,7 +39,7 @@ static int cma_used_get(void *data, u64 *val)
 
 	mutex_lock(&cma->lock);
 	/* pages counter is smaller than sizeof(int) */
-	used = bitmap_weight(cma->bitmap, (int)cma->count);
+	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
 	mutex_unlock(&cma->lock);
 	*val = (u64)used << cma->order_per_bit;
 
@@ -52,13 +52,14 @@ static int cma_maxchunk_get(void *data, u64 *val)
 	struct cma *cma = data;
 	unsigned long maxchunk = 0;
 	unsigned long start, end = 0;
+	unsigned long bitmap_maxno = cma_bitmap_maxno(cma);
 
 	mutex_lock(&cma->lock);
 	for (;;) {
-		start = find_next_zero_bit(cma->bitmap, cma->count, end);
+		start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
 		if (start >= cma->count)
 			break;
-		end = find_next_bit(cma->bitmap, cma->count, start);
+		end = find_next_bit(cma->bitmap, bitmap_maxno, start);
 		maxchunk = max(end - start, maxchunk);
 	}
 	mutex_unlock(&cma->lock);