From patchwork Fri Aug 18 14:11:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dongjiu Geng X-Patchwork-Id: 9908919 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 316506038C for ; Fri, 18 Aug 2017 13:51:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2A17328CD0 for ; Fri, 18 Aug 2017 13:51:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1EB5428CCC; Fri, 18 Aug 2017 13:51:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A87E628CC4 for ; Fri, 18 Aug 2017 13:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753215AbdHRNtr (ORCPT ); Fri, 18 Aug 2017 09:49:47 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4504 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341AbdHRNtn (ORCPT ); Fri, 18 Aug 2017 09:49:43 -0400 Received: from 172.30.72.59 (EHLO DGGEMS414-HUB.china.huawei.com) ([172.30.72.59]) by dggrg04-dlp.huawei.com (MOS 4.4.6-GA FastPath queued) with ESMTP id DFK73374; Fri, 18 Aug 2017 21:48:34 +0800 (CST) Received: from linux.huawei.com (10.67.187.203) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.301.0; Fri, 18 Aug 2017 21:48:22 +0800 From: Dongjiu Geng To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: , , , , Subject: [PATCH v5 1/7] arm64: cpufeature: Detect CPU RAS Extentions Date: Fri, 18 Aug 2017 22:11:51 +0800 Message-ID: <1503065517-7920-2-git-send-email-gengdongjiu@huawei.com> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1503065517-7920-1-git-send-email-gengdongjiu@huawei.com> References: <1503065517-7920-1-git-send-email-gengdongjiu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.187.203] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090203.5996F035.0037, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 4eb99659c7eb0972d845800cfbb8250c Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 esb and config option, reworded commit message] Signed-off-by: James Morse --- arch/arm64/Kconfig | 16 ++++++++++++++++ arch/arm64/include/asm/barrier.h | 1 + arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/sysreg.h | 2 ++ arch/arm64/kernel/cpufeature.c | 13 +++++++++++++ arch/arm64/kernel/process.c | 3 +++ 6 files changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index dfd908630631..4d87aa963d83 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -960,6 +960,22 @@ config ARM64_UAO regular load/store instructions if the cpu does not implement the feature. +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/barrier.h b/arch/arm64/include/asm/barrier.h index 0fe7e43b7fbc..8b0a0eb67625 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -30,6 +30,7 @@ #define isb() asm volatile("isb" : : : "memory") #define dmb(opt) asm volatile("dmb " #opt : : : "memory") #define dsb(opt) asm volatile("dsb " #opt : : : "memory") +#define esb() asm volatile("hint #16" : : : "memory") #define mb() dsb(sy) #define rmb() dsb(ld) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 8d2272c6822c..f93bf77f1f74 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -39,7 +39,8 @@ #define ARM64_WORKAROUND_QCOM_FALKOR_E1003 18 #define ARM64_WORKAROUND_858921 19 #define ARM64_WORKAROUND_CAVIUM_30115 20 +#define ARM64_HAS_RAS_EXTN 21 -#define ARM64_NCAPS 21 +#define ARM64_NCAPS 22 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 248339e4aaf5..35b786b43ee4 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -331,6 +331,7 @@ #define ID_AA64ISAR1_JSCVT_SHIFT 12 /* 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 @@ -339,6 +340,7 @@ #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 9f9e0064c8c1..a807ab55ee10 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -124,6 +124,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { }; 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), @@ -888,6 +889,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = 0, .matches = has_no_fpsimd, }, +#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 */ {}, }; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 659ae8094ed5..2def5ce75867 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -363,6 +363,9 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, */ dsb(ish); + /* Deliver any pending SError from prev */ + esb(); + /* the actual thread switch */ last = cpu_switch_to(prev, next);