From: Marc Zyngier <marc.zyngier@xxxxxxx> commit 95b861a4a6d94f64d5242605569218160ebacdbe upstream. When running on Cortex-A76, a timer access from an AArch32 EL0 task may end up with a corrupted value or register. The workaround for this is to trap these accesses at EL1/EL2 and execute them there. This only affects versions r0p0, r1p0 and r2p0 of the CPU. Acked-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: James Morse <james.morse@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/Kconfig | 12 ++++++++++++ arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/cputype.h | 2 ++ arch/arm64/kernel/cpu_errata.c | 8 ++++++++ drivers/clocksource/arm_arch_timer.c | 15 +++++++++++++++ 5 files changed, 39 insertions(+), 1 deletion(-) --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -441,6 +441,18 @@ config ARM64_ERRATUM_1024718 If unsure, say Y. +config ARM64_ERRATUM_1188873 + bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" + default y + help + This option adds work arounds for ARM Cortex-A76 erratum 1188873 + + Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause + register corruption when accessing the timer registers from + AArch32 userspace. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -38,7 +38,8 @@ #define ARM64_HARDEN_BRANCH_PREDICTOR 17 #define ARM64_SSBD 18 #define ARM64_MISMATCHED_CACHE_TYPE 19 +#define ARM64_WORKAROUND_1188873 20 -#define ARM64_NCAPS 20 +#define ARM64_NCAPS 21 #endif /* __ASM_CPUCAPS_H */ --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -85,6 +85,7 @@ #define ARM_CPU_PART_CORTEX_A75 0xD0A #define ARM_CPU_PART_CORTEX_A35 0xD04 #define ARM_CPU_PART_CORTEX_A55 0xD05 +#define ARM_CPU_PART_CORTEX_A76 0xD0B #define APM_CPU_PART_POTENZA 0x000 @@ -102,6 +103,7 @@ #define MIDR_CORTEX_A75 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A75) #define MIDR_CORTEX_A35 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A35) #define MIDR_CORTEX_A55 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A55) +#define MIDR_CORTEX_A76 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A76) #define MIDR_THUNDERX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX) #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX) #define MIDR_CAVIUM_THUNDERX2 MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX2) --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -533,6 +533,14 @@ const struct arm64_cpu_capabilities arm6 .matches = has_ssbd_mitigation, }, #endif +#ifdef CONFIG_ARM64_ERRATUM_1188873 + { + /* Cortex-A76 r0p0 to r2p0 */ + .desc = "ARM erratum 1188873", + .capability = ARM64_WORKAROUND_1188873, + ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0), + }, +#endif { } }; --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -130,6 +130,13 @@ static u64 notrace fsl_a008585_read_cntv } #endif +#ifdef CONFIG_ARM64_ERRATUM_1188873 +static u64 notrace arm64_1188873_read_cntvct_el0(void) +{ + return read_sysreg(cntvct_el0); +} +#endif + #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround = NULL; EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround); @@ -148,6 +155,14 @@ static const struct arch_timer_erratum_w .read_cntvct_el0 = fsl_a008585_read_cntvct_el0, }, #endif +#ifdef CONFIG_ARM64_ERRATUM_1188873 + { + .match_type = ate_match_local_cap_id, + .id = (void *)ARM64_WORKAROUND_1188873, + .desc = "ARM erratum 1188873", + .read_cntvct_el0 = arm64_1188873_read_cntvct_el0, + }, +#endif }; typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *, Patches currently in stable-queue which might be from james.morse@xxxxxxx are queue-4.9/clocksource-drivers-arm_arch_timer-remove-fsl-a008585-parameter.patch queue-4.9/arm64-capabilities-clean-up-midr-range-helpers.patch queue-4.9/arm64-entry-add-macro-for-reading-symbol-addresses-from-the-trampoline.patch queue-4.9/arm64-use-the-clearbhb-instruction-in-mitigations.patch queue-4.9/arm64-add-percpu-vectors-for-el1.patch queue-4.9/arm64-arch_timer-add-workaround-for-arm-erratum-1188873.patch queue-4.9/arm64-capabilities-add-support-for-checks-based-on-a-list-of-midrs.patch queue-4.9/arm64-arch_timer-add-infrastructure-for-multiple-erratum-detection-methods.patch queue-4.9/arm64-entry-free-up-another-register-on-kpti-s-tramp_exit-path.patch queue-4.9/arm64-entry-don-t-assume-tramp_vectors-is-the-start-of-the-vectors.patch queue-4.9/arm64-entry-make-the-trampoline-cleanup-optional.patch queue-4.9/arm64-add-silicon-errata.txt-entry-for-arm-erratum-1188873.patch queue-4.9/clocksource-drivers-arm_arch_timer-introduce-generic-errata-handling-infrastructure.patch queue-4.9/kvm-arm64-add-templates-for-bhb-mitigation-sequences.patch queue-4.9/arm64-entry-add-non-kpti-__bp_harden_el1_vectors-for-mitigations.patch queue-4.9/arm64-add-id_aa64isar2_el1-sys-register.patch queue-4.9/kvm-arm64-allow-smccc_arch_workaround_3-to-be-discovered-and-migrated.patch queue-4.9/arm64-capabilities-update-prototype-for-enable-call-back.patch queue-4.9/arm64-add-neoverse-n2-cortex-a710-cpu-part-definition.patch queue-4.9/arm64-add-midr-encoding-for-arm-cortex-a55-and-cortex-a35.patch queue-4.9/arm64-capabilities-move-errata-processing-code.patch queue-4.9/arm64-arch_timer-add-erratum-handler-for-cpu-specific-capability.patch queue-4.9/arm64-errata-provide-macro-for-major-and-minor-cpu-revisions.patch queue-4.9/arm64-arch_timer-avoid-unused-function-warning.patch queue-4.9/arm64-capabilities-move-errata-work-around-check-on-boot-cpu.patch queue-4.9/arm64-add-helpers-for-checking-cpu-midr-against-a-range.patch queue-4.9/arm64-entry-move-trampoline-macros-out-of-ifdef-d-section.patch queue-4.9/arm64-entry-allow-tramp_alias-to-access-symbols-after-the-4k-boundary.patch queue-4.9/arm64-add-part-number-for-arm-cortex-a77.patch queue-4.9/arm64-capabilities-add-flags-to-handle-the-conflicts-on-late-cpu.patch queue-4.9/arm64-entry-move-the-trampoline-data-page-before-the-text-page.patch queue-4.9/arm64-entry.s-add-ventry-overflow-sanity-checks.patch queue-4.9/arm64-add-part-number-for-neoverse-n1.patch queue-4.9/arm64-entry-add-vectors-that-have-the-bhb-mitigation-sequences.patch queue-4.9/arm64-make-arm64_erratum_1188873-depend-on-compat.patch queue-4.9/arm64-mitigate-spectre-style-branch-history-side-channels.patch queue-4.9/arm64-move-arm64_update_smccc_conduit-out-of-ssbd-ifdef.patch queue-4.9/arm64-entry-allow-the-trampoline-text-to-occupy-multiple-pages.patch queue-4.9/arm64-add-cortex-x2-cpu-part-definition.patch queue-4.9/arm64-add-helper-to-decode-register-from-instruction.patch queue-4.9/arm64-capabilities-prepare-for-fine-grained-capabilities.patch queue-4.9/arm64-remove-useless-uao-ipi-and-describe-how-this-gets-enabled.patch queue-4.9/arm64-entry-make-the-kpti-trampoline-s-kpti-sequence-optional.patch