On Thursday 20 June 2013, Hiroshi Doyu wrote: > > If devices allocate via dma-mapping API, physical mem allocation, iova > > allocation and iommu mapping happens internally. > > Devices may allocate physical memory using any allocator (say ION > > including carveout area), use "iommu mapping" API which will do iova > > allocation and iommu mapping. The prot flags could be useful in this > > case as well - not sure whether we would need dma-attrs here. > > I haven't followed ION recently, but can't ION backed by DMA mapping > API instead of using IOMMU API directly? For a GPU with an IOMMU, you typically want per-process IOMMU contexts, which are only available when using the IOMMU API directly, as the dma-mapping abstraction uses only one context for kernel space. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
