[PATCH 1/2] ARM: convert dma-mapping to asm-generic API

Russell King - ARM Linux
2010-12-21T10:59:46Z

On Tue, Dec 21, 2010 at 11:54:08AM +0100, Arnd Bergmann wrote:
> On Tuesday 21 December 2010 11:20:01 Jamie Iles wrote:
> > This converts ARM to use the asm-generic/dma-mapping-common API for
> > the DMA API. As a side effect, this also allows us to take advantage
> > of DMA API debugging (CONFIG_DMA_API_DEBUG).
> >
> > We have dma_map_ops for normal, non-coherent architectures, fully
> > coherent architectures and architectures that require dmabounce
> > support. A dma_ops field is added to struct dev_archdata so platforms
> > using an ACP can override the dma operations for that device to be
> > fully coherent e.g.
> >
> > struct device *my_coherent_device;
> > my_coherent_device->dev_archdata.dma_ops = &coherent_dma_ops;
>
> I think what's more important here is the ability to use an IOMMU on
> some devices while other devices are mapped statically.
>
> I believe at the moment, at least MSM and OMAP support an IOMMU, but
> we don't provide support for that in the DMA mapping interface yet.