From patchwork Fri Dec 15 15:50:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 10115443 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 7DA5A60231 for ; Fri, 15 Dec 2017 15:56:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A82829E60 for ; Fri, 15 Dec 2017 15:56:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5F5EE29EBB; Fri, 15 Dec 2017 15:56:55 +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=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8A89829E60 for ; Fri, 15 Dec 2017 15:56:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=FYpYXLTi8uzYZ6VbtvQrTEVhgkd0jmrB5f9S7LKexlo=; b=rVYpUE9Mi0My+Ewa52Z8AOG8MR r3LnKvSvkAu1+LR1MXObC9aRrxDFCGWj2FoFT9ADaH7fevkVI2Q02kEHe6+Mmbj5GjCt8hDUPLKRi IuDjaEXmeldvAwMZWEQbgfmBUfVs/T4RgH8GQoJxJReAJ/MlSHLoz1W1f1vv9lN8/8SLgMJO6fFqi /NiEBhxIMX+1+x3VlKsWxIEt5R8WmpEHUeLVA7w/srJGrO2n4H5Pb+EX/XiqGW/658hNlK06RzOaM MvH1JBWgtLJLCKS9SZxT0Nw4ipNIH/aW6soPtlKxm8UY6C5JHb/T72eo9jeK4Zgg7Sv2nnE6udUOl vlnS91pw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1ePsM1-0002aI-08; Fri, 15 Dec 2017 15:56:53 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1ePsJG-0007IC-1y for linux-arm-kernel@lists.infradead.org; Fri, 15 Dec 2017 15:54:15 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 57FDE1650; Fri, 15 Dec 2017 07:53:39 -0800 (PST) Received: from melchizedek.cambridge.arm.com (melchizedek.cambridge.arm.com [10.1.207.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 072843F4FF; Fri, 15 Dec 2017 07:53:36 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 06/13] arm64: kernel: Prepare for a DISR user Date: Fri, 15 Dec 2017 15:50:54 +0000 Message-Id: <20171215155101.23505-7-james.morse@arm.com> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171215155101.23505-1-james.morse@arm.com> References: <20171215155101.23505-1-james.morse@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171215_075402_570594_B4678F37 X-CRM114-Status: GOOD ( 12.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jonathan.Zhang@cavium.com, Xie XiuQi , Marc Zyngier , Catalin Marinas , Suzuki K Poulose , Will Deacon , Dongjiu Geng , James Morse , kvmarm@lists.cs.columbia.edu, Christoffer Dall MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP KVM would like to consume any pending SError (or RAS error) after guest exit. Today it has to unmask SError and use dsb+isb to synchronise the CPU. With the RAS extensions we can use ESB to synchronise any pending SError. Add the necessary macros to allow DISR to be read and converted to an ESR. We clear the DISR register when we enable the RAS cpufeature. The kernel has not executed any ESB instructions, so any value we find in DISR must have belonged to firmware. Executing an ESB instruction is the only way to update DISR, so we can expect firmware to have handled any deferred SError. By the same logic we clear DISR in the idle path. Signed-off-by: James Morse Reviewed-by: Catalin Marinas --- Changes since v4: * Corrected 'we ran ESB()' in the commit message, it not true anymore. arch/arm64/include/asm/assembler.h | 7 +++++++ arch/arm64/include/asm/esr.h | 7 +++++++ arch/arm64/include/asm/exception.h | 14 ++++++++++++++ arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kernel/cpufeature.c | 9 +++++++++ arch/arm64/mm/proc.S | 5 +++++ 7 files changed, 44 insertions(+) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aef72d886677..c17eaab72e03 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -109,6 +109,13 @@ dmb \opt .endm +/* + * RAS Error Synchronization barrier + */ + .macro esb + hint #16 + .endm + /* * NOP sequence */ diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index c367838700fa..803443d74926 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -140,6 +140,13 @@ #define ESR_ELx_WFx_ISS_WFE (UL(1) << 0) #define ESR_ELx_xVC_IMM_MASK ((1UL << 16) - 1) +#define DISR_EL1_IDS (UL(1) << 24) +/* + * DISR_EL1 and ESR_ELx share the bottom 13 bits, but the RES0 bits may mean + * different things in the future... + */ +#define DISR_EL1_ESR_MASK (ESR_ELx_AET | ESR_ELx_EA | ESR_ELx_FSC) + /* ESR value templates for specific events */ /* BRK instruction trap from AArch64 state */ diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index 0c2eec490abf..bc30429d8e91 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -18,6 +18,8 @@ #ifndef __ASM_EXCEPTION_H #define __ASM_EXCEPTION_H +#include + #include #define __exception __attribute__((section(".exception.text"))) @@ -27,4 +29,16 @@ #define __exception_irq_entry __exception #endif +static inline u32 disr_to_esr(u64 disr) +{ + unsigned int esr = ESR_ELx_EC_SERROR << ESR_ELx_EC_SHIFT; + + if ((disr & DISR_EL1_IDS) == 0) + esr |= (disr & DISR_EL1_ESR_MASK); + else + esr |= (disr & ESR_ELx_ISS_MASK); + + return esr; +} + #endif /* __ASM_EXCEPTION_H */ diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 023cacb946c3..cee4ae25a5d1 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -216,6 +216,7 @@ static inline void spin_lock_prefetch(const void *ptr) int cpu_enable_pan(void *__unused); int cpu_enable_cache_maint_trap(void *__unused); +int cpu_clear_disr(void *__unused); /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */ #define SVE_SET_VL(arg) sve_set_current_vl(arg) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 7a55fe0c07be..3f859000439f 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -279,6 +279,7 @@ #define SYS_AMAIR_EL1 sys_reg(3, 0, 10, 3, 0) #define SYS_VBAR_EL1 sys_reg(3, 0, 12, 0, 0) +#define SYS_DISR_EL1 sys_reg(3, 0, 12, 1, 1) #define SYS_ICC_IAR0_EL1 sys_reg(3, 0, 12, 8, 0) #define SYS_ICC_EOIR0_EL1 sys_reg(3, 0, 12, 8, 1) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index cfc7588a380c..932426c7790c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -973,6 +973,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .sign = FTR_UNSIGNED, .field_pos = ID_AA64PFR0_RAS_SHIFT, .min_field_value = ID_AA64PFR0_RAS_V1, + .enable = cpu_clear_disr, }, #endif /* CONFIG_ARM64_RAS_EXTN */ {}, @@ -1399,3 +1400,11 @@ static int __init enable_mrs_emulation(void) } core_initcall(enable_mrs_emulation); + +int cpu_clear_disr(void *__unused) +{ + /* Firmware may have left a deferred SError in this register. */ + write_sysreg_s(0, SYS_DISR_EL1); + + return 0; +} diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index b94886aa8587..b108cd51a8b8 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -124,6 +124,11 @@ ENTRY(cpu_do_resume) ubfx x11, x11, #1, #1 msr oslar_el1, x11 reset_pmuserenr_el0 x0 // Disable PMU access from EL0 + +alternative_if ARM64_HAS_RAS_EXTN + msr_s SYS_DISR_EL1, xzr +alternative_else_nop_endif + isb ret ENDPROC(cpu_do_resume)