diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index e8c2ce1f9df6..fa16b895c997 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -35,8 +35,9 @@ can be triggered by Linux). For software workarounds that may adversely impact systems unaffected by the erratum in question, a Kconfig entry is added under "Kernel Features" -> "ARM errata workarounds via the alternatives framework". -These are enabled by default and patched in at runtime when an affected -CPU is detected. For less-intrusive workarounds, a Kconfig option is not +With the exception of workarounds for errata deemed "rare" by Arm, these +are enabled by default and patched in at runtime when an affected CPU is +detected. For less-intrusive workarounds, a Kconfig option is not available and the code is structured (preferably with a comment) in such a way that the erratum will not be hit. diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index aa7c1d435139..430fabf20f17 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -547,9 +547,8 @@ config ARM64_ERRATUM_832075 If unsure, say Y. config ARM64_ERRATUM_834220 - bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" + bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" depends on KVM - default y help This option adds an alternative code sequence to work around ARM erratum 834220 on Cortex-A57 parts up to r1p2. @@ -565,7 +564,7 @@ config ARM64_ERRATUM_834220 as it depends on the alternative framework, which will only patch the kernel if an affected CPU is detected. - If unsure, say Y. + If unsure, say N. config ARM64_ERRATUM_1742098 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" @@ -692,8 +691,7 @@ config ARM64_WORKAROUND_REPEAT_TLBI bool config ARM64_ERRATUM_2441007 - bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" - default y + bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" select ARM64_WORKAROUND_REPEAT_TLBI help This option adds a workaround for ARM Cortex-A55 erratum #2441007. @@ -706,11 +704,10 @@ config ARM64_ERRATUM_2441007 Work around this by adding the affected CPUs to the list that needs TLB sequences to be done twice. - If unsure, say Y. + If unsure, say N. config ARM64_ERRATUM_1286807 - bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" - default y + bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" select ARM64_WORKAROUND_REPEAT_TLBI help This option adds a workaround for ARM Cortex-A76 erratum 1286807. @@ -724,6 +721,8 @@ config ARM64_ERRATUM_1286807 invalidated has been observed by other observers. The workaround repeats the TLBI+DSB operation. + If unsure, say N. + config ARM64_ERRATUM_1463225 bool "Cortex-A76: Software Step might prevent interrupt recognition" default y @@ -743,8 +742,7 @@ config ARM64_ERRATUM_1463225 If unsure, say Y. config ARM64_ERRATUM_1542419 - bool "Neoverse-N1: workaround mis-ordering of instruction fetches" - default y + bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" help This option adds a workaround for ARM Neoverse-N1 erratum 1542419. @@ -756,7 +754,7 @@ config ARM64_ERRATUM_1542419 Workaround the issue by hiding the DIC feature from EL0. This forces user-space to perform cache maintenance. - If unsure, say Y. + If unsure, say N. config ARM64_ERRATUM_1508412 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" @@ -931,8 +929,7 @@ config ARM64_ERRATUM_2224489 If unsure, say Y. config ARM64_ERRATUM_2441009 - bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" - default y + bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" select ARM64_WORKAROUND_REPEAT_TLBI help This option adds a workaround for ARM Cortex-A510 erratum #2441009. @@ -945,7 +942,7 @@ config ARM64_ERRATUM_2441009 Work around this by adding the affected CPUs to the list that needs TLB sequences to be done twice. - If unsure, say Y. + If unsure, say N. config ARM64_ERRATUM_2064142 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"