Re: [PATCH v5 11/13] xen: introduce xen_alloc/free_coherent_pages

[Stefano Stabellini]

On Thu, 5 Sep 2013, Catalin Marinas wrote:
> On Thu, Aug 29, 2013 at 07:32:32PM +0100, Stefano Stabellini wrote:
> > xen_swiotlb_alloc_coherent needs to allocate a coherent buffer for cpu
> > and devices. On native x86 and ARMv8 is sufficient to call
> > __get_free_pages in order to get a coherent buffer, while on ARM we need
> > to call arm_dma_ops.alloc.
> 
> Don't bet on this for ARMv8. It's not mandated for the architecture, so
> at some point some SoC will require non-cacheable buffers for coherency.

I see.
Would it be better if I implemented xen_alloc_coherent_pages on armv8 by
calling arm64_swiotlb_dma_ops.alloc?
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