From 64c02720ea3598bf5143b672274d923a941b8053 Mon Sep 17 00:00:00 2001 From: Xie XiuQi Date: Mon, 15 Jan 2018 19:38:56 +0000 Subject: [PATCH] arm64: cpufeature: Detect CPU RAS Extentions ARM's v8.2 Extentions add support for Reliability, Availability and Serviceability (RAS). On CPUs with these extensions system software can use additional barriers to isolate errors and determine if faults are pending. Add cpufeature detection. Platform level RAS support may require additional firmware support. Reviewed-by: Suzuki K Poulose Signed-off-by: Xie XiuQi [Rebased added config option, reworded commit message] Signed-off-by: James Morse Reviewed-by: Catalin Marinas Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig | 16 ++++++++++++++++ arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/sysreg.h | 2 ++ arch/arm64/kernel/cpufeature.c | 13 +++++++++++++ 4 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 664fadc2aa2e..1d51c8edf34b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1062,6 +1062,22 @@ config ARM64_PMEM operations if DC CVAP is not supported (following the behaviour of DC CVAP itself if the system does not define a point of persistence). +config ARM64_RAS_EXTN + bool "Enable support for RAS CPU Extensions" + default y + help + CPUs that support the Reliability, Availability and Serviceability + (RAS) Extensions, part of ARMv8.2 are able to track faults and + errors, classify them and report them to software. + + On CPUs with these extensions system software can use additional + barriers to determine if faults are pending and read the + classification from a new set of registers. + + Selecting this feature will allow the kernel to use these barriers + and access the new registers if the system supports the extension. + Platform RAS features may additionally depend on firmware support. + endmenu config ARM64_SVE diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 7049b4802587..bb263820de13 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -44,7 +44,8 @@ #define ARM64_UNMAP_KERNEL_AT_EL0 23 #define ARM64_HARDEN_BRANCH_PREDICTOR 24 #define ARM64_HARDEN_BP_POST_GUEST_EXIT 25 +#define ARM64_HAS_RAS_EXTN 26 -#define ARM64_NCAPS 26 +#define ARM64_NCAPS 27 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 1a8108f84932..321622e9f9c3 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -498,6 +498,7 @@ #define ID_AA64PFR0_CSV3_SHIFT 60 #define ID_AA64PFR0_CSV2_SHIFT 56 #define ID_AA64PFR0_SVE_SHIFT 32 +#define ID_AA64PFR0_RAS_SHIFT 28 #define ID_AA64PFR0_GIC_SHIFT 24 #define ID_AA64PFR0_ASIMD_SHIFT 20 #define ID_AA64PFR0_FP_SHIFT 16 @@ -507,6 +508,7 @@ #define ID_AA64PFR0_EL0_SHIFT 0 #define ID_AA64PFR0_SVE 0x1 +#define ID_AA64PFR0_RAS_V1 0x1 #define ID_AA64PFR0_FP_NI 0xf #define ID_AA64PFR0_FP_SUPPORTED 0x0 #define ID_AA64PFR0_ASIMD_NI 0xf diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 630a40ec1332..116a5c9443a7 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -149,6 +149,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI), @@ -1028,6 +1029,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .enable = sve_kernel_enable, }, #endif /* CONFIG_ARM64_SVE */ +#ifdef CONFIG_ARM64_RAS_EXTN + { + .desc = "RAS Extension Support", + .capability = ARM64_HAS_RAS_EXTN, + .def_scope = SCOPE_SYSTEM, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64PFR0_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64PFR0_RAS_SHIFT, + .min_field_value = ID_AA64PFR0_RAS_V1, + }, +#endif /* CONFIG_ARM64_RAS_EXTN */ {}, }; -- GitLab