From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

An undocumented alteration :(

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/iommu-helper.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff -puN lib/iommu-helper.c~iommu-sg-add-iommu-helper-functions-for-the-free-area-management-update lib/iommu-helper.c
--- a/lib/iommu-helper.c~iommu-sg-add-iommu-helper-functions-for-the-free-area-management-update
+++ a/lib/iommu-helper.c
@@ -8,15 +8,20 @@
 static unsigned long find_next_zero_area(unsigned long *map,
 					 unsigned long size,
 					 unsigned long start,
-					 unsigned int nr)
+					 unsigned int nr,
+					 unsigned long align_mask)
 {
 	unsigned long index, end, i;
 again:
 	index = find_next_zero_bit(map, size, start);
+
+	/* Align allocation */
+	index = (index + align_mask) & ~align_mask;
+
 	end = index + nr;
-	if (end > size)
+	if (end >= size)
 		return -1;
-	for (i = index + 1; i < end; i++) {
+	for (i = index; i < end; i++) {
 		if (test_bit(i, map)) {
 			start = i+1;
 			goto again;
@@ -50,9 +55,8 @@ unsigned long iommu_area_alloc(unsigned 
 {
 	unsigned long index;
 again:
-	index = find_next_zero_area(map, size, start, nr);
+	index = find_next_zero_area(map, size, start, nr, align_mask);
 	if (index != -1) {
-		index = (index + align_mask) & ~align_mask;
 		if (is_span_boundary(index, nr, shift, boundary_size)) {
 			/* we could do more effectively */
 			start = index + 1;
_