Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752683AbeAFH6N (ORCPT + 1 other); Sat, 6 Jan 2018 02:58:13 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:3748 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751841AbeAFH6I (ORCPT ); Sat, 6 Jan 2018 02:58:08 -0500 From: Dongjiu Geng To: , , , , , , , , , , , , , , , , CC: , Subject: [PATCH v9 1/7] arm64: cpufeature: Detect CPU RAS Extentions Date: Sun, 7 Jan 2018 00:02:51 +0800 Message-ID: <1515254577-6460-2-git-send-email-gengdongjiu@huawei.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1515254577-6460-1-git-send-email-gengdongjiu@huawei.com> References: <1515254577-6460-1-git-send-email-gengdongjiu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.143.28.90] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Xie XiuQi 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 and a barrier in the context-switch code. There is no need to use alternatives for this as CPUs that don't support this feature will treat the instruction as a nop. Platform level RAS support may require additional firmware support. Signed-off-by: Xie XiuQi [Rebased added config option, reworded commit message] Signed-off-by: James Morse Signed-off-by: Dongjiu Geng Reviewed-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 0df64a6..cc00d10 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -973,6 +973,22 @@ 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_MODULE_CMODEL_LARGE diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 8da6216..4820d44 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -40,7 +40,8 @@ #define ARM64_WORKAROUND_858921 19 #define ARM64_WORKAROUND_CAVIUM_30115 20 #define ARM64_HAS_DCPOP 21 +#define ARM64_HAS_RAS_EXTN 22 -#define ARM64_NCAPS 22 +#define ARM64_NCAPS 23 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index f707fed..64e2a80 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -332,6 +332,7 @@ #define ID_AA64ISAR1_DPB_SHIFT 0 /* id_aa64pfr0 */ +#define ID_AA64PFR0_RAS_SHIFT 28 #define ID_AA64PFR0_GIC_SHIFT 24 #define ID_AA64PFR0_ASIMD_SHIFT 20 #define ID_AA64PFR0_FP_SHIFT 16 @@ -340,6 +341,7 @@ #define ID_AA64PFR0_EL1_SHIFT 4 #define ID_AA64PFR0_EL0_SHIFT 0 +#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 21e2c95..4846974 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -125,6 +125,7 @@ static int __init register_cpu_hwcaps_dumper(void) }; static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_RAS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 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), @@ -900,6 +901,18 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus .min_field_value = 1, }, #endif +#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 */ {}, }; -- 1.9.1