On 09/19/2012 07:44 PM, Krishna Reddy wrote: >> When a device driver would only use the IOMMU-API and needs small DMA- >> able areas it has to re-implement something like the DMA-API (basically an >> address allocator) for that. So I don't see a reason why both can't be used in a >> device driver. > > On Tegra, the following use cases need specific IOVA mapping. > 1. Few MMIO blocks need IOVA=PA mapping setup. In that case, why would we enable the IOMMU for that one device; IOMMU disabled means VA==PA, right? Perhaps isolation of the device so it can only access certain PA ranges for security? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>