From: Robin Murphy Date: Thu, 20 Mar 2025 14:21:28 +0000 (+0000) Subject: iommu: Split out and tidy up Arm Kconfig X-Git-Tag: v6.16-rc1~110^2^12~24 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0da188c8468d8fe544d0aa2a5f610c78b8d34819;p=thirdparty%2Fkernel%2Flinux.git iommu: Split out and tidy up Arm Kconfig There are quite a lot of options for the Arm drivers, still all buried in the top-level Kconfig. For ease of use and consistency with all the other subdirectories, break these out into drivers/arm. For similar clarity and self-consistency, also tweak the ARM_SMMU sub-options to use "if" instead of "depends", to match ARM_SMMU_V3. Lastly also clean up the slightly messy description of ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT as highlighted by Geert - by now we really shouldn't need commentary on v4.x kernel behaviour anyway - and downgrade it to EXPERT as the first step in the 6-year-old threat to remove it entirely. Cc: Geert Uytterhoeven Signed-off-by: Robin Murphy Reviewed-by: Pranjal Shrivastava Link: https://lore.kernel.org/r/a614ec86ba78c09cd16e348f633f6bb38793391f.1742480488.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index cd750f512deee..9c3c210c82a2d 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -192,6 +192,7 @@ config MSM_IOMMU If unsure, say N here. source "drivers/iommu/amd/Kconfig" +source "drivers/iommu/arm/Kconfig" source "drivers/iommu/intel/Kconfig" source "drivers/iommu/iommufd/Kconfig" source "drivers/iommu/riscv/Kconfig" @@ -314,150 +315,6 @@ config APPLE_DART Say Y here if you are using an Apple SoC. -# ARM IOMMU support -config ARM_SMMU - tristate "ARM Ltd. System MMU (SMMU) Support" - depends on ARM64 || ARM || COMPILE_TEST - depends on !GENERIC_ATOMIC64 # for IOMMU_IO_PGTABLE_LPAE - select IOMMU_API - select IOMMU_IO_PGTABLE_LPAE - select ARM_DMA_USE_IOMMU if ARM - help - Support for implementations of the ARM System MMU architecture - versions 1 and 2. - - Say Y here if your SoC includes an IOMMU device implementing - the ARM SMMU architecture. - -config ARM_SMMU_LEGACY_DT_BINDINGS - bool "Support the legacy \"mmu-masters\" devicetree bindings" - depends on ARM_SMMU=y && OF - help - Support for the badly designed and deprecated "mmu-masters" - devicetree bindings. This allows some DMA masters to attach - to the SMMU but does not provide any support via the DMA API. - If you're lucky, you might be able to get VFIO up and running. - - If you say Y here then you'll make me very sad. Instead, say N - and move your firmware to the utopian future that was 2016. - -config ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT - bool "Default to disabling bypass on ARM SMMU v1 and v2" - depends on ARM_SMMU - default y - help - Say Y here to (by default) disable bypass streams such that - incoming transactions from devices that are not attached to - an iommu domain will report an abort back to the device and - will not be allowed to pass through the SMMU. - - Any old kernels that existed before this KConfig was - introduced would default to _allowing_ bypass (AKA the - equivalent of NO for this config). However the default for - this option is YES because the old behavior is insecure. - - There are few reasons to allow unmatched stream bypass, and - even fewer good ones. If saying YES here breaks your board - you should work on fixing your board. This KConfig option - is expected to be removed in the future and we'll simply - hardcode the bypass disable in the code. - - NOTE: the kernel command line parameter - 'arm-smmu.disable_bypass' will continue to override this - config. - -config ARM_SMMU_MMU_500_CPRE_ERRATA - bool "Enable errata workaround for CPRE in SMMU reset path" - depends on ARM_SMMU - default y - help - Say Y here (by default) to apply workaround to disable - MMU-500's next-page prefetcher for sake of 4 known errata. - - Say N here only when it is sure that any errata related to - prefetch enablement are not applicable on the platform. - Refer silicon-errata.rst for info on errata IDs. - -config ARM_SMMU_QCOM - def_tristate y - depends on ARM_SMMU && ARCH_QCOM - select QCOM_SCM - help - When running on a Qualcomm platform that has the custom variant - of the ARM SMMU, this needs to be built into the SMMU driver. - -config ARM_SMMU_QCOM_DEBUG - bool "ARM SMMU QCOM implementation defined debug support" - depends on ARM_SMMU_QCOM=y - help - Support for implementation specific debug features in ARM SMMU - hardware found in QTI platforms. This include support for - the Translation Buffer Units (TBU) that can be used to obtain - additional information when debugging memory management issues - like context faults. - - Say Y here to enable debug for issues such as context faults - or TLB sync timeouts which requires implementation defined - register dumps. - -config ARM_SMMU_V3 - tristate "ARM Ltd. System MMU Version 3 (SMMUv3) Support" - depends on ARM64 - select IOMMU_API - select IOMMU_IO_PGTABLE_LPAE - select GENERIC_MSI_IRQ - select IOMMUFD_DRIVER if IOMMUFD - help - Support for implementations of the ARM System MMU architecture - version 3 providing translation support to a PCIe root complex. - - Say Y here if your system includes an IOMMU device implementing - the ARM SMMUv3 architecture. - -if ARM_SMMU_V3 -config ARM_SMMU_V3_SVA - bool "Shared Virtual Addressing support for the ARM SMMUv3" - select IOMMU_SVA - select IOMMU_IOPF - select MMU_NOTIFIER - help - Support for sharing process address spaces with devices using the - SMMUv3. - - Say Y here if your system supports SVA extensions such as PCIe PASID - and PRI. - -config ARM_SMMU_V3_IOMMUFD - bool "Enable IOMMUFD features for ARM SMMUv3 (EXPERIMENTAL)" - depends on IOMMUFD - help - Support for IOMMUFD features intended to support virtual machines - with accelerated virtual IOMMUs. - - Say Y here if you are doing development and testing on this feature. - -config ARM_SMMU_V3_KUNIT_TEST - tristate "KUnit tests for arm-smmu-v3 driver" if !KUNIT_ALL_TESTS - depends on KUNIT - depends on ARM_SMMU_V3_SVA - default KUNIT_ALL_TESTS - help - Enable this option to unit-test arm-smmu-v3 driver functions. - - If unsure, say N. - -config TEGRA241_CMDQV - bool "NVIDIA Tegra241 CMDQ-V extension support for ARM SMMUv3" - depends on ACPI - help - Support for NVIDIA CMDQ-Virtualization extension for ARM SMMUv3. The - CMDQ-V extension is similar to v3.3 ECMDQ for multi command queues - support, except with virtualization capabilities. - - Say Y here if your system is NVIDIA Tegra241 (Grace) or it has the same - CMDQ-V extension. -endif - config S390_IOMMU def_bool y if S390 && PCI depends on S390 && PCI @@ -494,18 +351,6 @@ config MTK_IOMMU_V1 if unsure, say N here. -config QCOM_IOMMU - # Note: iommu drivers cannot (yet?) be built as modules - bool "Qualcomm IOMMU Support" - depends on ARCH_QCOM || COMPILE_TEST - depends on !GENERIC_ATOMIC64 # for IOMMU_IO_PGTABLE_LPAE - select QCOM_SCM - select IOMMU_API - select IOMMU_IO_PGTABLE_LPAE - select ARM_DMA_USE_IOMMU - help - Support for IOMMU on certain Qualcomm SoCs. - config HYPERV_IOMMU bool "Hyper-V IRQ Handling" depends on HYPERV && X86 diff --git a/drivers/iommu/arm/Kconfig b/drivers/iommu/arm/Kconfig new file mode 100644 index 0000000000000..ef42bbe07dbef --- /dev/null +++ b/drivers/iommu/arm/Kconfig @@ -0,0 +1,144 @@ +# SPDX-License-Identifier: GPL-2.0-only +# ARM IOMMU support +config ARM_SMMU + tristate "ARM Ltd. System MMU (SMMU) Support" + depends on ARM64 || ARM || COMPILE_TEST + depends on !GENERIC_ATOMIC64 # for IOMMU_IO_PGTABLE_LPAE + select IOMMU_API + select IOMMU_IO_PGTABLE_LPAE + select ARM_DMA_USE_IOMMU if ARM + help + Support for implementations of the ARM System MMU architecture + versions 1 and 2. + + Say Y here if your SoC includes an IOMMU device implementing + the ARM SMMU architecture. + +if ARM_SMMU +config ARM_SMMU_LEGACY_DT_BINDINGS + bool "Support the legacy \"mmu-masters\" devicetree bindings" + depends on ARM_SMMU=y && OF + help + Support for the badly designed and deprecated "mmu-masters" + devicetree bindings. This allows some DMA masters to attach + to the SMMU but does not provide any support via the DMA API. + If you're lucky, you might be able to get VFIO up and running. + + If you say Y here then you'll make me very sad. Instead, say N + and move your firmware to the utopian future that was 2016. + +config ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT + bool "Disable unmatched stream bypass by default" if EXPERT + default y + help + If your firmware is broken and fails to describe StreamIDs which + Linux should know about in order to manage the SMMU correctly and + securely, and you don't want to boot with the 'arm-smmu.disable_bypass=0' + command line parameter, then as a last resort you can turn it off + by default here. But don't. This option may be removed at any time. + + Note that 'arm-smmu.disable_bypass=1' will still take precedence. + +config ARM_SMMU_MMU_500_CPRE_ERRATA + bool "Enable errata workaround for CPRE in SMMU reset path" + default y + help + Say Y here (by default) to apply workaround to disable + MMU-500's next-page prefetcher for sake of 4 known errata. + + Say N here only when it is sure that any errata related to + prefetch enablement are not applicable on the platform. + Refer silicon-errata.rst for info on errata IDs. + +config ARM_SMMU_QCOM + def_tristate y + depends on ARCH_QCOM + select QCOM_SCM + help + When running on a Qualcomm platform that has the custom variant + of the ARM SMMU, this needs to be built into the SMMU driver. + +config ARM_SMMU_QCOM_DEBUG + bool "ARM SMMU QCOM implementation defined debug support" + depends on ARM_SMMU_QCOM=y + help + Support for implementation specific debug features in ARM SMMU + hardware found in QTI platforms. This include support for + the Translation Buffer Units (TBU) that can be used to obtain + additional information when debugging memory management issues + like context faults. + + Say Y here to enable debug for issues such as context faults + or TLB sync timeouts which requires implementation defined + register dumps. +endif + +config ARM_SMMU_V3 + tristate "ARM Ltd. System MMU Version 3 (SMMUv3) Support" + depends on ARM64 + select IOMMU_API + select IOMMU_IO_PGTABLE_LPAE + select GENERIC_MSI_IRQ + select IOMMUFD_DRIVER if IOMMUFD + help + Support for implementations of the ARM System MMU architecture + version 3 providing translation support to a PCIe root complex. + + Say Y here if your system includes an IOMMU device implementing + the ARM SMMUv3 architecture. + +if ARM_SMMU_V3 +config ARM_SMMU_V3_SVA + bool "Shared Virtual Addressing support for the ARM SMMUv3" + select IOMMU_SVA + select IOMMU_IOPF + select MMU_NOTIFIER + help + Support for sharing process address spaces with devices using the + SMMUv3. + + Say Y here if your system supports SVA extensions such as PCIe PASID + and PRI. + +config ARM_SMMU_V3_IOMMUFD + bool "Enable IOMMUFD features for ARM SMMUv3 (EXPERIMENTAL)" + depends on IOMMUFD + help + Support for IOMMUFD features intended to support virtual machines + with accelerated virtual IOMMUs. + + Say Y here if you are doing development and testing on this feature. + +config ARM_SMMU_V3_KUNIT_TEST + tristate "KUnit tests for arm-smmu-v3 driver" if !KUNIT_ALL_TESTS + depends on KUNIT + depends on ARM_SMMU_V3_SVA + default KUNIT_ALL_TESTS + help + Enable this option to unit-test arm-smmu-v3 driver functions. + + If unsure, say N. + +config TEGRA241_CMDQV + bool "NVIDIA Tegra241 CMDQ-V extension support for ARM SMMUv3" + depends on ACPI + help + Support for NVIDIA CMDQ-Virtualization extension for ARM SMMUv3. The + CMDQ-V extension is similar to v3.3 ECMDQ for multi command queues + support, except with virtualization capabilities. + + Say Y here if your system is NVIDIA Tegra241 (Grace) or it has the same + CMDQ-V extension. +endif + +config QCOM_IOMMU + # Note: iommu drivers cannot (yet?) be built as modules + bool "Qualcomm IOMMU Support" + depends on ARCH_QCOM || COMPILE_TEST + depends on !GENERIC_ATOMIC64 # for IOMMU_IO_PGTABLE_LPAE + select QCOM_SCM + select IOMMU_API + select IOMMU_IO_PGTABLE_LPAE + select ARM_DMA_USE_IOMMU + help + Support for IOMMU on certain Qualcomm SoCs.