This is a very early base work, towards VFIO support on ARM platforms with an IOMMU. It forms a base on to which to implement the functionality necessary to enable using device tree devices on ARM (and other platforms based on device trees) with VFIO. This very early work of progress is only published for the sake of openness, and is very far from usable yet. However the driver can bind to devices, and return to userspace the info about the memory regions and IRQs. This patch series has been tested on the Arndale board (with the Exynos 5250 System MMU). It depends on Cho KyongHo's patch series "iommu/exynos: Fixes and Enhancements of System MMU driver with DT", applied on a Linux 3.10.1 kernel, and also my own "iommu/exynos: add devices attached to the System MMU to an IOMMU group". Those patches are required at least in order to test the proposed module on Arndale. This should not be treated as anything more than a work in progress. Numerous functions still need to be implemented properly, e.g. - Proper binding of the VFIO_DT driver to devices; currently to test the driver, one has to edit the device tree and add the "vfio-dt" to the compatible property. However Linux does not support OF drivers that can be dynamically bound to any device. - Most IOCTLs are not implemented yet. Memory region mapping, DMA mapping, IRQFD still need to be added. - The VFIO_IOMMU_TYPE1 is patched to work instead of PCI IOMMU, with platform IOMMUs such as the one that is found on Arndale. This is a proof of concept hack, and a more permanent fix will be proposed as the code matures. The API used is identical to the existing VFIO API that is also used with PCI devices. Only devices that include a basic set of IRQs and memory regions are targeted; devices with complicated relationships with other devices on the device tree are not taken into account at this stage. The API is not extended with device tree specific information; this would complicate the driver unnecessarily as it is not needed for the base use cases. Antonios Motakis (3): VFIO_IOMMU_TYPE1 workaround to build for platform devices Initial skeleton of VFIO support for Device Tree based devices Return info for device and its memory regions and interrupts drivers/vfio/Kconfig | 12 ++- drivers/vfio/Makefile | 1 + drivers/vfio/vfio_dt.c | 233 ++++++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio_iommu_type1.c | 15 ++- include/uapi/linux/vfio.h | 1 + 5 files changed, 258 insertions(+), 4 deletions(-) create mode 100644 drivers/vfio/vfio_dt.c -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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