Re: [PATCH 07/21] dma-iommu: move the arm64 wrappers to common code

[Robin Murphy]

On 09/04/2019 18:23, Christoph Hellwig wrote:
> On Tue, Apr 09, 2019 at 04:07:02PM +0100, Robin Murphy wrote:
> > > -static inline int iommu_dma_init(void)
> > > +static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
> > > +		u64 size, const struct iommu_ops *ops)
> > >    {
> > > -	return 0;
> > >    }
> >
> > I don't think it makes sense to have a stub for that - AFAICS it should
> > only ever be called form arch code with an inherent "select IOMMU_DMA"
> > (much like the stuff which isn't stubbed currently).
> >
> > Otherwise, I'm about 97% sure the rest of the move looks OK - thanks for
> > splitting things up.
>
> arm64 only selects IOMMU_DMA if IOMMU_SUPPORT is selected, which can
> be disabled.  So to keep some (unusual) arm64 configs compiling we'll need
> the stub..

Urgh, right, it worked out before because arm64 stubbed its own caller 
of iommu_dma_init_domain() internally... Oh well - I guess there's no 
nicer alternative, and we have always treated arch_setup_dma_ops() that way.

Robin.