[PATCH v7 05/21] dma-mapping: allow EREMOTEIO return code for P2PDMA transfers

Logan Gunthorpe
2022-06-15T16:15:22Z

Add EREMOTEIO error return to dma_map_sgtable() which will be used
by .map_sg() implementations that detect P2PDMA pages that the
underlying DMA device cannot access.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
kernel/dma/mapping.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index db7244291b74..9f65d1041638 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -197,7 +197,7 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
if (ents > 0)
debug_dma_map_sg(dev, sg, nents, ents, dir, attrs);
else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
- ents != -EIO))
+ ents != -EIO && ents != -EREMOTEIO))
return -EIO;

return ents;
@@ -255,6 +255,8 @@ EXPORT_SYMBOL(dma_map_sg_attrs);
* complete the mapping. Should succeed if retried later.
* -EIO Legacy error code with an unknown meaning. eg. this is
* returned if a lower level call returned DMA_MAPPING_ERROR.
+ * -EREMOTEIO The DMA device cannot access P2PDMA memory specified in
+ * the sg_table. This will not succeed if retried.
*/
int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
enum dma_data_direction dir, unsigned long attrs)
--
2.30.2