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-rw-r--r--drivers/xen/swiotlb-xen.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 35155258a7e2..d7fbba8b4700 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -78,9 +78,15 @@ static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
{
unsigned long next_bfn, xen_pfn = XEN_PFN_DOWN(p);
unsigned int i, nr_pages = XEN_PFN_UP(xen_offset_in_page(p) + size);
+ phys_addr_t algn = 1ULL << (get_order(size) + PAGE_SHIFT);
next_bfn = pfn_to_bfn(xen_pfn);
+ /* If buffer is physically aligned, ensure DMA alignment. */
+ if (IS_ALIGNED(p, algn) &&
+ !IS_ALIGNED((phys_addr_t)next_bfn << XEN_PAGE_SHIFT, algn))
+ return 1;
+
for (i = 1; i < nr_pages; i++)
if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
return 1;