Re: [PATCH 4/5] dma-mapping: add a dma_ops_bypass flag to struct device

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 09/07/2020 01:24, Christoph Hellwig wrote:
> Several IOMMU drivers have a bypass mode where they can use a direct
> mapping if the devices DMA mask is large enough.  Add generic support
> to the core dma-mapping code to do that to switch those drivers to
> a common solution.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/linux/device.h |  8 +++++
>  kernel/dma/Kconfig     |  8 +++++
>  kernel/dma/mapping.c   | 74 +++++++++++++++++++++++++++++-------------
>  3 files changed, 68 insertions(+), 22 deletions(-)
> 
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 4c4af98321ebd6..1f71acf37f78d7 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -523,6 +523,11 @@ struct dev_links_info {
>   *		  sync_state() callback.
>   * @dma_coherent: this particular device is dma coherent, even if the
>   *		architecture supports non-coherent devices.
> + * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
> + *		streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
> + *		and optionall (if the coherent mask is large enough) also


s/optionall/optional/g

Otherwise the series looks good and works well on powernv and pseries.
Thanks,



-- 
Alexey