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

[Christoph Hellwig]

On Mon, Jul 13, 2020 at 02:59:39PM +1000, Alexey Kardashevskiy wrote:
> 
> 
> 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 at 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,

Can you give a formal ACK?