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

Arnd Bergmann arnd at arndb.de
Tue Dec 21 05:54:08 EST 2010


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.

	Arnd



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