diff options
| -rw-r--r-- | Documentation/arm64/silicon-errata.rst | 2 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 13 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 26 | ||||
| -rw-r--r-- | arch/arm64/tools/cpucaps | 1 |
4 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index fda97b3fcf01..17d9fc5d14fb 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -110,6 +110,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A510 | #2441009 | ARM64_ERRATUM_2441009 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A510 | #2658417 | ARM64_ERRATUM_2658417 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A710 | #2119858 | ARM64_ERRATUM_2119858 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A710 | #2054223 | ARM64_ERRATUM_2054223 | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9fb9fff08c94..526ab76cd233 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -733,6 +733,19 @@ config ARM64_ERRATUM_2077057 If unsure, say Y. +config ARM64_ERRATUM_2658417 + bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" + default y + help + This option adds the workaround for ARM Cortex-A510 erratum 2658417. + Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for + BFMMLA or VMMLA instructions in rare circumstances when a pair of + A510 CPUs are using shared neon hardware. As the sharing is not + discoverable by the kernel, hide the BF16 HWCAP to indicate that + user-space should not be using these instructions. + + If unsure, say Y. + config ARM64_ERRATUM_2119858 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" default y diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 53b973b6059f..58ca4f6b25d6 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -121,6 +121,22 @@ cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCI, 0); } +static DEFINE_RAW_SPINLOCK(reg_user_mask_modification); +static void __maybe_unused +cpu_clear_bf16_from_user_emulation(const struct arm64_cpu_capabilities *__unused) +{ + struct arm64_ftr_reg *regp; + + regp = get_arm64_ftr_reg(SYS_ID_AA64ISAR1_EL1); + if (!regp) + return; + + raw_spin_lock(®_user_mask_modification); + if (regp->user_mask & ID_AA64ISAR1_EL1_BF16_MASK) + regp->user_mask &= ~ID_AA64ISAR1_EL1_BF16_MASK; + raw_spin_unlock(®_user_mask_modification); +} + #define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \ .matches = is_affected_midr_range, \ .midr_range = MIDR_RANGE(model, v_min, r_min, v_max, r_max) @@ -692,6 +708,16 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, }, #endif +#ifdef CONFIG_ARM64_ERRATUM_2658417 + { + .desc = "ARM erratum 2658417", + .capability = ARM64_WORKAROUND_2658417, + /* Cortex-A510 r0p0 - r1p1 */ + ERRATA_MIDR_RANGE(MIDR_CORTEX_A510, 0, 0, 1, 1), + MIDR_FIXED(MIDR_CPU_VAR_REV(1,1), BIT(25)), + .cpu_enable = cpu_clear_bf16_from_user_emulation, + }, +#endif { } }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 63b2484ce6c3..f553a7cb1b07 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -68,6 +68,7 @@ WORKAROUND_2038923 WORKAROUND_2064142 WORKAROUND_2077057 WORKAROUND_2457168 +WORKAROUND_2658417 WORKAROUND_TRBE_OVERWRITE_FILL_MODE WORKAROUND_TSB_FLUSH_FAILURE WORKAROUND_TRBE_WRITE_OUT_OF_RANGE |