Re: [PATCH 19/33] dma-mapping: warn when there is no coherent_dma_mask

[Konrad Rzeszutek Wilk]

On Wed, Jan 10, 2018 at 09:00:13AM +0100, Christoph Hellwig wrote:
> These days all devices should have a DMA coherent mask, and most dma_ops
> implementations rely on that fact.  But just to be sure add an assert to
> ring the warning bell if that is not the case.
> 
> Signed-off-by: Christoph Hellwig 

Reviewed-by: Konrad Rzeszutek Wilk 
> ---
>  include/linux/dma-mapping.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index d84951865be7..9f28b2fa329e 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -513,6 +513,7 @@ static inline void *dma_alloc_attrs(struct device *dev, 
> size_t size,
>   void *cpu_addr;
>  
>   BUG_ON(!ops);
> + WARN_ON_ONCE(!dev->coherent_dma_mask);
>  
>   if (dma_alloc_from_dev_coherent(dev, size, dma_handle, _addr))
>   return cpu_addr;
> -- 
> 2.14.2
> 

[PATCH 19/33] dma-mapping: warn when there is no coherent_dma_mask

[Christoph Hellwig]

These days all devices should have a DMA coherent mask, and most dma_ops
implementations rely on that fact.  But just to be sure add an assert to
ring the warning bell if that is not the case.

Signed-off-by: Christoph Hellwig 
---
 include/linux/dma-mapping.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d84951865be7..9f28b2fa329e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -513,6 +513,7 @@ static inline void *dma_alloc_attrs(struct device *dev, 
size_t size,
void *cpu_addr;
 
BUG_ON(!ops);
+   WARN_ON_ONCE(!dev->coherent_dma_mask);
 
if (dma_alloc_from_dev_coherent(dev, size, dma_handle, _addr))
return cpu_addr;
-- 
2.14.2