diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 35155258a7e2da70ead2311a3ae92b982b984392..d7fbba8b470039c347d7bd5760f181f5d9324a8e 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;