| Message ID | 20241112165454.2698269-2-quic_bibekkum@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iommu/arm-smmu: introduction of ACTLR implementation for Qualcomm SoCs | expand |
Hi Bibek,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on joro-iommu/next v6.12-rc7 next-20241113]
[cannot apply to arm64/for-next/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Bibek-Kumar-Patro/iommu-arm-smmu-re-enable-context-caching-in-smmu-reset-operation/20241113-042646
base: linus/master
patch link: https://lore.kernel.org/r/20241112165454.2698269-2-quic_bibekkum%40quicinc.com
patch subject: [PATCH v17 1/5] iommu/arm-smmu: re-enable context caching in smmu reset operation
config: powerpc64-randconfig-r064-20241114 (https://download.01.org/0day-ci/archive/20241114/202411140748.6mcFdJdO-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241114/202411140748.6mcFdJdO-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411140748.6mcFdJdO-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from drivers/iommu/arm/arm-smmu/arm-smmu-impl.c:10:
In file included from drivers/iommu/arm/arm-smmu/arm-smmu.h:18:
In file included from include/linux/io-64-nonatomic-hi-lo.h:5:
In file included from include/linux/io.h:14:
In file included from arch/powerpc/include/asm/io.h:24:
In file included from include/linux/mm.h:2213:
include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
>> drivers/iommu/arm/arm-smmu/arm-smmu-impl.c:113:6: warning: unused variable 'i' [-Wunused-variable]
113 | int i;
| ^
2 warnings generated.
vim +/i +113 drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 109
759aaa10c76cba drivers/iommu/arm-smmu-impl.c Vivek Gautam 2019-09-20 110 int arm_mmu500_reset(struct arm_smmu_device *smmu)
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 111 {
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 112 u32 reg, major;
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 @113 int i;
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 114 /*
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 115 * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 116 * writes to the context bank ACTLRs will stick. And we just hope that
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 117 * Secure has also cleared SACR.CACHE_LOCK for this to take effect...
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 118 */
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 119 reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_ID7);
fba6e960772b7b drivers/iommu/arm-smmu-impl.c Will Deacon 2020-01-10 120 major = FIELD_GET(ARM_SMMU_ID7_MAJOR, reg);
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 121 reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sACR);
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 122 if (major >= 2)
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 123 reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 124 /*
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 125 * Allow unmatched Stream IDs to allocate bypass
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 126 * TLB entries for reduced latency.
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 127 */
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 128 reg |= ARM_MMU500_ACR_SMTNMB_TLBEN | ARM_MMU500_ACR_S2CRB_TLBEN;
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 129 arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg);
62b993a36e4c2d drivers/iommu/arm-smmu-impl.c Robin Murphy 2019-08-15 130
diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index 65bfab1b1861..92207d55fd1c 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 ade4e8cf2a3e..90ba5818af81 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..632f1667ceb3 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c @@ -128,6 +128,7 @@ 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. @@ -140,6 +141,7 @@ 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; }
Default MMU-500 reset operation disables context caching in prefetch buffer. It is however expected for context banks using the ACTLR register to retain their prefetch value during reset and runtime suspend. Add config 'ARM_SMMU_MMU_500_CPRE_ERRATA' to gate this errata workaround in default MMU-500 reset operation which defaults to 'Y' and provide option to disable workaround for context caching in prefetch buffer as and when needed. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Bibek Kumar Patro <quic_bibekkum@quicinc.com> --- Documentation/arch/arm64/silicon-errata.rst | 3 ++- drivers/iommu/Kconfig | 12 ++++++++++++ drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 2 ++ 3 files changed, 16 insertions(+), 1 deletion(-) -- 2.34.1