4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx> [ Upstream commit 602d9858f07c72eab64f5f00e2fae55f9902cfbe ] Some drivers do depend on page mappings to be page aligned. Swiotlb already enforces such alignment for mappings greater than page, extend that to page-sized mappings as well. Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine assumes page-aligned mappings. Signed-off-by: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx> Signed-off-by: Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- lib/swiotlb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -456,11 +456,11 @@ phys_addr_t swiotlb_tbl_map_single(struc : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); /* - * For mappings greater than a page, we limit the stride (and - * hence alignment) to a page size. + * For mappings greater than or equal to a page, we limit the stride + * (and hence alignment) to a page size. */ nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; - if (size > PAGE_SIZE) + if (size >= PAGE_SIZE) stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT)); else stride = 1;