Hi Vladimir, I tested your changes, it's working fine on stm32f429-disco(armv7m, without cache) board. you can submit a separate patch for dma-direct support on non-mmu platform, i will drop mine. thanks. best regards. Dillon, On Wed, Jun 10, 2020 at 1:34 AM Christoph Hellwig <hch@xxxxxx> wrote: > > On Tue, Jun 09, 2020 at 05:25:04PM +0100, Vladimir Murzin wrote: > > Even though commit mentions ARM, I do not see how mmap would continue > > to work for NOMMU with dma-direct. ARM NOMMU needs it's own DMA operations > > only in cases where caches are implemented or active, in other cases it > > fully relies on dma-direct. > > > It looks to me that we either should provide NOMMU variant for mmap in > > dma/direct or (carefully) fix dma/mapping. > > I think dma-direct is the right place, the common helpers in > dma/mapping.c are basically the red headed stepchilds for misc > IOMMU drivers not covered by dma-iommu only. Yes, thanks Christoph's input.
