swiotlb: ensure that page-sized mappings are page-aligned
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@cogentembedded.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 975b8fc..a8d74a7 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -483,11 +483,11 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
: 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;
