1 files changed, 14 insertions, 3 deletions

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 47c3fe55242f..a3c406aca664 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -278,6 +278,7 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
         unsigned long flags;
         struct scatterlist *s, *outs, *segstart;
         int outcount, incount, i;
+        unsigned int align;
         unsigned long handle;
 
         BUG_ON(direction == DMA_NONE);
@@ -309,7 +310,12 @@ int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
                 /* Allocate iommu entries for that segment */
                 vaddr = (unsigned long) sg_virt(s);
                 npages = iommu_num_pages(vaddr, slen);
-                entry = iommu_range_alloc(tbl, npages, &handle, mask >> IOMMU_PAGE_SHIFT, 0);
+                align = 0;
+                if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && slen >= PAGE_SIZE &&
+                    (vaddr & ~PAGE_MASK) == 0)
+                        align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
+                entry = iommu_range_alloc(tbl, npages, &handle,
+                                          mask >> IOMMU_PAGE_SHIFT, align);
 
                 DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
 
@@ -570,7 +576,7 @@ dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
 {
         dma_addr_t dma_handle = DMA_ERROR_CODE;
         unsigned long uaddr;
-        unsigned int npages;
+        unsigned int npages, align;
 
         BUG_ON(direction == DMA_NONE);
 
@@ -578,8 +584,13 @@ dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,
         npages = iommu_num_pages(uaddr, size);
 
         if (tbl) {
+                align = 0;
+                if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && size >= PAGE_SIZE &&
+                    ((unsigned long)vaddr & ~PAGE_MASK) == 0)
+                        align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
+
                 dma_handle = iommu_alloc(tbl, vaddr, npages, direction,
-                                         mask >> IOMMU_PAGE_SHIFT, 0);
+                                         mask >> IOMMU_PAGE_SHIFT, align);
                 if (dma_handle == DMA_ERROR_CODE) {
                         if (printk_ratelimit())  {
                                 printk(KERN_INFO "iommu_alloc failed, "