[PATCH v3 17/21] xen: swiotlb: return error code from xen_swiotlb_map_sg()

From: Martin Oliveira <redacted>

The .map_sg() op now expects an error code instead of zero on failure.

xen_swiotlb_map_sg() may only fail if xen_swiotlb_map_page() fails, but
xen_swiotlb_map_page() only supports returning errors as
DMA_MAPPING_ERROR. So coalesce all errors into EIO per the documentation
for dma_map_sgtable().

Signed-off-by: Martin Oliveira <redacted>
Signed-off-by: Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
Reviewed-by: Boris Ostrovsky <redacted>
Cc: Konrad Rzeszutek Wilk <redacted>
Cc: Juergen Gross <jgross-IBi9RG/b67k@public.gmane.org>
Cc: Stefano Stabellini <redacted>
---
 drivers/xen/swiotlb-xen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 24d11861ac7d..85d58b720a24 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c

@@ -509,7 +509,7 @@ xen_swiotlb_map_sg(struct device *dev, struct scatterlist *sgl, int nelems,
 out_unmap:
 	xen_swiotlb_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
 	sg_dma_len(sgl) = 0;
-	return 0;
+	return -EIO;
 }
 
 static void

-- 
2.20.1