On Falkor CPU, we’ve discovered a hardware issue which might lead to a kernel crash or the unexpected behavior. The Falkor core may errantly access memory locations on speculative instruction fetches. This may happen whenever MMU translation state, SCTLR_ELn[M] bit is being changed from enabled to disabled for the currently running exception level. To prevent the errant hardware behavior, software must execute an ISB immediately prior to executing the MSR that changes SCTLR_ELn[M] from a value of 1 to 0. To simplify the complexity of a workaround, this patch series issues an ISB whenever SCTLR_ELn[M] is changed to 0 to fix the Falkor erratum 1041. Patch2 from V1 series got dropped to accommodate review comments. Apply the workaround where it's required. Posted wrong the patches in v2. Patch1: - CPUTYPE definitions for Falkor CPU. Patch2: - Actual workaround changes for erratum E1041. Shanker Donthineni (2): arm64: Define cputype macros for Falkor CPU arm64: Add software workaround for Falkor erratum 1041 Documentation/arm64/silicon-errata.txt | 1 + arch/arm64/Kconfig | 10 ++++++++++ arch/arm64/include/asm/assembler.h | 18 ++++++++++++++++++ arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/cputype.h | 2 ++ arch/arm64/kernel/cpu-reset.S | 1 + arch/arm64/kernel/cpu_errata.c | 16 ++++++++++++++++ arch/arm64/kernel/efi-entry.S | 2 ++ arch/arm64/kernel/head.S | 1 + arch/arm64/kernel/relocate_kernel.S | 1 + arch/arm64/kvm/hyp-init.S | 1 + 11 files changed, 55 insertions(+), 1 deletion(-) -- Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
