[PATCH v3 21/21] dma-mapping: Disallow .map_sg operations from returning zero on error

Logan Gunthorpe
2021-07-29T20:15:39Z

Now that all the .map_sg operations have been converted to returning
proper error codes, drop the code to handle a zero return value,
add a warning if a zero is returned.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
kernel/dma/mapping.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 9f0bb56eb9aa..cbcbdc877458 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -196,8 +196,8 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,

if (ents > 0)
debug_dma_map_sg(dev, sg, nents, ents, dir);
- else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
- ents != -EIO && ents != 0))
+ else if (WARN_ON_ONCE((ents != -EINVAL && ents != -ENOMEM &&
+ ents != -EIO) || ents = 0))
return -EIO;

return ents;
@@ -262,9 +262,7 @@ int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
int nents;

nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
- if (nents = 0)
- return -EIO;
- else if (nents < 0)
+ if (nents < 0)
return nents;

sgt->nents = nents;
--
2.20.1