Re: [PATCH v1 10/16] s390/pci: return error code from s390_dma_map_sg()

2021-07-16 Thread Niklas Schnelle
On Thu, 2021-07-15 at 10:45 -0600, Logan Gunthorpe wrote:
> From: Martin Oliveira 
> 
> The .map_sg() op now expects an error code instead of zero on failure.
> 
> So propagate the error from __s390_dma_map_sg() up.
> 
> Signed-off-by: Martin Oliveira 
> Signed-off-by: Logan Gunthorpe 
> Cc: Niklas Schnelle 
> Cc: Gerald Schaefer 
> Cc: Heiko Carstens 
> Cc: Vasily Gorbik 
> Cc: Christian Borntraeger 
> ---
>  arch/s390/pci/pci_dma.c | 12 +++-
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
> index ebc9a49523aa..c78b02012764 100644
> --- a/arch/s390/pci/pci_dma.c
> +++ b/arch/s390/pci/pci_dma.c
> @@ -487,7 +487,7 @@ static int s390_dma_map_sg(struct device *dev, struct 
> scatterlist *sg,
>   unsigned int max = dma_get_max_seg_size(dev);
>   unsigned int size = s->offset + s->length;
>   unsigned int offset = s->offset;
> - int count = 0, i;
> + int count = 0, i, ret;
>  
>   for (i = 1; i < nr_elements; i++) {
>   s = sg_next(s);
> @@ -497,8 +497,9 @@ static int s390_dma_map_sg(struct device *dev, struct 
> scatterlist *sg,
>  
>   if (s->offset || (size & ~PAGE_MASK) ||
>   size + s->length > max) {
> - if (__s390_dma_map_sg(dev, start, size,
> -   >dma_address, dir))
> + ret = __s390_dma_map_sg(dev, start, size,
> + >dma_address, dir);
> + if (ret)
>   goto unmap;
>  
>   dma->dma_address += offset;
> @@ -511,7 +512,8 @@ static int s390_dma_map_sg(struct device *dev, struct 
> scatterlist *sg,
>   }
>   size += s->length;
>   }
> - if (__s390_dma_map_sg(dev, start, size, >dma_address, dir))
> + ret = __s390_dma_map_sg(dev, start, size, >dma_address, dir);
> + if (ret)
>   goto unmap;
>  
>   dma->dma_address += offset;
> @@ -523,7 +525,7 @@ static int s390_dma_map_sg(struct device *dev, struct 
> scatterlist *sg,
>   s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
>dir, attrs);
>  
> - return 0;
> + return ret;
>  }
>  
>  static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,

So the error codes we return are -ENOMEM if allocating a DMA
translation entry fails and -EINVAL if the DMA translation table hasn't
been initialized or the caller tries to map 0 sized memory. Are these
error codes that you would expect? If yes then this change looks good
to me.

Acked-by: Niklas Schnelle 



[PATCH v1 10/16] s390/pci: return error code from s390_dma_map_sg()

2021-07-15 Thread Logan Gunthorpe
From: Martin Oliveira 

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

So propagate the error from __s390_dma_map_sg() up.

Signed-off-by: Martin Oliveira 
Signed-off-by: Logan Gunthorpe 
Cc: Niklas Schnelle 
Cc: Gerald Schaefer 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
---
 arch/s390/pci/pci_dma.c | 12 +++-
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index ebc9a49523aa..c78b02012764 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -487,7 +487,7 @@ static int s390_dma_map_sg(struct device *dev, struct 
scatterlist *sg,
unsigned int max = dma_get_max_seg_size(dev);
unsigned int size = s->offset + s->length;
unsigned int offset = s->offset;
-   int count = 0, i;
+   int count = 0, i, ret;
 
for (i = 1; i < nr_elements; i++) {
s = sg_next(s);
@@ -497,8 +497,9 @@ static int s390_dma_map_sg(struct device *dev, struct 
scatterlist *sg,
 
if (s->offset || (size & ~PAGE_MASK) ||
size + s->length > max) {
-   if (__s390_dma_map_sg(dev, start, size,
- >dma_address, dir))
+   ret = __s390_dma_map_sg(dev, start, size,
+   >dma_address, dir);
+   if (ret)
goto unmap;
 
dma->dma_address += offset;
@@ -511,7 +512,8 @@ static int s390_dma_map_sg(struct device *dev, struct 
scatterlist *sg,
}
size += s->length;
}
-   if (__s390_dma_map_sg(dev, start, size, >dma_address, dir))
+   ret = __s390_dma_map_sg(dev, start, size, >dma_address, dir);
+   if (ret)
goto unmap;
 
dma->dma_address += offset;
@@ -523,7 +525,7 @@ static int s390_dma_map_sg(struct device *dev, struct 
scatterlist *sg,
s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
 dir, attrs);
 
-   return 0;
+   return ret;
 }
 
 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
-- 
2.20.1