gpu: ion: Align va address to biggest buffer size

Align the virtual address to the max buffer size to
allow IOMMU mappings at the biggest buffer size.

Change-Id: I74ba665c1782e2f0631274766c5caeeb192224e0
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/drivers/gpu/ion/ion_iommu_heap.c b/drivers/gpu/ion/ion_iommu_heap.c
index ba48b50..9ab6b85 100644
--- a/drivers/gpu/ion/ion_iommu_heap.c
+++ b/drivers/gpu/ion/ion_iommu_heap.c
@@ -330,6 +330,14 @@
 	data->mapped_size = iova_length;
 	extra = iova_length - buffer->size;
 
+	/* Use the biggest alignment to allow bigger IOMMU mappings.
+	 * Use the first entry since the first entry will always be the
+	 * biggest entry. To take advantage of bigger mapping sizes both the
+	 * VA and PA addresses have to be aligned to the biggest size.
+	 */
+	if (buffer->sg_table->sgl->length > align)
+		align = buffer->sg_table->sgl->length;
+
 	ret = msm_allocate_iova_address(domain_num, partition_num,
 						data->mapped_size, align,
 						&data->iova_addr);