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https://github.com/AsahiLinux/u-boot
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d3db45cb9c
Add a basic implementation of the ARM SMMU. This driver is intended for use on Qualcomm platforms where the SMMU has been configured by a previous bootloader, cannot be turned off, and doesn't support BYPASS streams. It keeps all existing stream mappings and only creates new ones for stream ids that aren't already configured. This driver is necessary to support peripherals that perform DMA which weren't configured by the previous stage bootloader (for example USB). It works by allocating a context bank using identity mapping (as U-Boot doesn't use virtual addresses). Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
43 lines
1.4 KiB
Text
43 lines
1.4 KiB
Text
#
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# IOMMU devices
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#
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menu "IOMMU device drivers"
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config IOMMU
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bool "Enable Driver Model for IOMMU drivers"
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depends on DM
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help
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Enable driver model for IOMMU devices. An IOMMU maps device
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virtiual memory addresses to physical addresses. Devices
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that sit behind an IOMMU can typically only access physical
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memory if the IOMMU has been programmed to allow access to
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that memory.
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config APPLE_DART
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bool "Apple DART support"
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depends on IOMMU && ARCH_APPLE
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default y
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help
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Enable support for the DART on Apple SoCs. The DART is Apple's
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IOMMU implementation. The driver performs the necessary
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configuration to put the DART into bypass mode such that it can
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be used transparently by U-Boot.
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config QCOM_HYP_SMMU
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bool "Qualcomm quirky SMMU support"
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depends on IOMMU && ARCH_SNAPDRAGON
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help
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Enable support for the Qualcomm variant of the Arm System MMU-500.
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Qualcomm boards have a non-standard SMMU where some registers are
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emulated by the hypervisor. It is initialised early in the boot
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process and can't be turned off.
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The main caveat with this hardware is that it doesn't support BYPASS
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streams, attempting to configure once will instead wind up with a
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FAULT stream, and the device will crash when DMA is attempted.
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Say Y here to enable support for non-boot peripherals like USB by
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configuring identity mapped streams for them.
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endmenu
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