Messages in this thread | | | Date | Tue, 9 Jun 2020 17:36:46 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH 2/2] arm-nommu: Add use_reserved_mem() to check if device support reserved memory |
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On Tue, Jun 09, 2020 at 11:22:24PM +0800, dillon min wrote: > Hi Vladimir, > > Thanks for reviewing. > > Hi Christoph Hellwig, > > I just want to know if kernel dma mapping/direct is focused on > platforms with MMU. > leave arch code to handle dma coherent memory management themself for > no-MMU platform.
No, I'd really like to consolidate everything that isn't overly arch specific eventually.
> > so, you just return error code in kernel/dma/mapping.c,direct.c > without CONFIG_MMU defined ? > which means dma-direct mapping doesn't support !CONFIG_MMU is not a > bug, but design as it's. > or, just return error code currently, will add dma direct mapping > support for !CONFIG_MMU in the > future? > > As Vladimir Murzin's suggestion has changes in kernel code, I need > your input to get > the design goal about dma-direct mapping, thanks.
Can someone repost the whole patch?
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