On Thu, Aug 12, 2021 at 1:46 PM Huacai Chen <chenhuacai@xxxxxxxxx> wrote:
> > > diff --git a/arch/loongarch/loongson64/dma.c b/arch/loongarch/loongson64/dma.c
> > > new file mode 100644
> > > index 000000000000..f259f70c75fa
> > > --- /dev/null
> > > +++ b/arch/loongarch/loongson64/dma.c
> > > @@ -0,0 +1,59 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> >
> > Same for this file.
> We only need a custom dma.c in the NUMA case, because we need
> phys_to_dma()/dma_to_phys() to convert between 48bit physical address
> and 40bit DMA address. Without NUMA there is only one node, and its
> physical address will not exceed 40bit.
Ok, makes sense.
Arnd
