On Mon, 2019-10-14 at 21:59 +0100, Catalin Marinas wrote: > On Mon, Oct 14, 2019 at 08:31:02PM +0200, Nicolas Saenz Julienne wrote: > > the Raspberry Pi 4 offers up to 4GB of memory, of which only the first > > is DMA capable device wide. This forces us to use of bounce buffers, > > which are currently not very well supported by ARM's custom DMA ops. > > Among other things the current mechanism (see dmabounce.c) isn't > > suitable for high memory. Instead of fixing it, this series introduces a > > way of selecting dma-direct as the default DMA ops provider which allows > > for the Raspberry Pi to make use of swiotlb. > > I presume these patches go on top of this series: > > http://lkml.kernel.org/r/20190911182546.17094-1-nsaenzjulienne@suse.de Yes, forgot to mention it. It's relevant for the first patch. > > which I queued here: > > https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/zone-dma Thanks! A little off topic but I was wondering if you have a preferred way to refer to the arm architecture in a way that it unambiguously excludes arm64 (for example arm32 would work). Regards, Nicolas