diff options
| -rw-r--r-- | Documentation/arch/arm64/silicon-errata.rst | 3 | ||||
| -rw-r--r-- | drivers/iommu/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 5 |
3 files changed, 17 insertions, 3 deletions
diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index b42fea07c5ce..f074f6219f5c 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -198,7 +198,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ -| ARM | MMU-500 | #841119,826419 | N/A | +| ARM | MMU-500 | #841119,826419 | ARM_SMMU_MMU_500_CPRE_ERRATA| +| | | #562869,1047329 | | +----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-600 | #1076982,1209401| N/A | +----------------+-----------------+-----------------+-----------------------------+ diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 47c46e4b739e..ec1b5e32b972 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -367,6 +367,18 @@ config ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT '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 diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c index 99030e6b16e7..db9b9a8e139c 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c @@ -110,7 +110,6 @@ static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smm int arm_mmu500_reset(struct arm_smmu_device *smmu) { u32 reg, major; - int i; /* * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before * writes to the context bank ACTLRs will stick. And we just hope that @@ -128,11 +127,12 @@ int arm_mmu500_reset(struct arm_smmu_device *smmu) reg |= ARM_MMU500_ACR_SMTNMB_TLBEN | ARM_MMU500_ACR_S2CRB_TLBEN; arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg); +#ifdef CONFIG_ARM_SMMU_MMU_500_CPRE_ERRATA /* * Disable MMU-500's not-particularly-beneficial next-page * prefetcher for the sake of at least 5 known errata. */ - for (i = 0; i < smmu->num_context_banks; ++i) { + for (int i = 0; i < smmu->num_context_banks; ++i) { reg = arm_smmu_cb_read(smmu, i, ARM_SMMU_CB_ACTLR); reg &= ~ARM_MMU500_ACTLR_CPRE; arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_ACTLR, reg); @@ -140,6 +140,7 @@ int arm_mmu500_reset(struct arm_smmu_device *smmu) if (reg & ARM_MMU500_ACTLR_CPRE) dev_warn_once(smmu->dev, "Failed to disable prefetcher for errata workarounds, check SACR.CACHE_LOCK\n"); } +#endif return 0; } |