Re: [PATCH v2 2/3] arm64: do not set SWIOTLB_NO_FORCE when swiotlb is required

[Catalin Marinas <catalin.marinas@xxxxxxx>]

On Wed, May 12, 2021 at 01:18:22PM -0700, Stefano Stabellini wrote:
> From: Christoph Hellwig <hch@xxxxxx>
> 
> Although SWIOTLB_NO_FORCE is meant to allow later calls to swiotlb_init,
> today dma_direct_map_page returns error if SWIOTLB_NO_FORCE.
> 
> For now, without a larger overhaul of SWIOTLB_NO_FORCE, the best we can
> do is to avoid setting SWIOTLB_NO_FORCE in mem_init when we know that it
> is going to be required later (e.g. Xen requires it).
> 
> CC: boris.ostrovsky@xxxxxxxxxx
> CC: jgross@xxxxxxxx
> CC: catalin.marinas@xxxxxxx
> CC: will@xxxxxxxxxx
> CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Fixes: 2726bf3ff252 ("swiotlb: Make SWIOTLB_NO_FORCE perform no allocation")
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>