From patchwork Thu Jun 6 09:31:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10978917 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B28721398 for ; Thu, 6 Jun 2019 09:33:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A127227F97 for ; Thu, 6 Jun 2019 09:33:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94D8F27F9F; Thu, 6 Jun 2019 09:33:08 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E998E2883C for ; Thu, 6 Jun 2019 09:33:07 +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=DbkXFaY9ng0hnu1Sui+VNL4BVhr+T0hH0gJZcuX4yaU=; b=mHZKX+itD4wC/587Wex3NOjnW5 JdQ9b9DnzBNykP8GkZzY0Ogs3MjcMd1Gt4LvUZEQAiQwctmoxzNZfQVD8zx8zVbDZuLIpH4uGMrgQ k8WYRm1Wpg5VS++GfjC/vvuJqY/NkiVOLqIS13sFttGybS36oeeAz81A1c9WO3GKWlfX72B/iU9vq +X29ukXPdgqMAzyNPVt4HyxD6hyHJqoFDhiberGelL6n5QOzXG8X3TMsqovOoOiWHzrYgzzEfWiyd ruw3otQMj1u1hcEAjLhAmmMXChSuDzRTEgYtJ//g/Z6PtSLPADVK4xnARDDyjS/zN77PJHFHh+wSy 1932f2Nw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYolY-0007a7-Va; Thu, 06 Jun 2019 09:33:00 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYokt-0006f4-GT for linux-arm-kernel@lists.infradead.org; Thu, 06 Jun 2019 09:32:25 +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 482A31684; Thu, 6 Jun 2019 02:32:19 -0700 (PDT) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 34AE33F690; Thu, 6 Jun 2019 02:32:17 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 6/8] arm64: irqflags: Introduce explicit debugging for IRQ priorities Date: Thu, 6 Jun 2019 10:31:55 +0100 Message-Id: <1559813517-41540-7-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1559813517-41540-1-git-send-email-julien.thierry@arm.com> References: <1559813517-41540-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190606_023220_307340_0B96C9C6 X-CRM114-Status: GOOD ( 13.16 ) 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: mark.rutland@arm.com, Julien Thierry , marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, james.morse@arm.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com, liwei391@huawei.com 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 Using IRQ priority masking to enable/disable interrupts is a bit sensitive as it requires to deal with both ICC_PMR_EL1 and PSR.I. Introduce some validity checks to both highlight the states in which functions dealing with IRQ enabling/disabling can (not) be called, and bark a warning when called in an unexpected state. Since these checks are done on hotpaths, introduce a build option to choose whether to do the checking. Signed-off-by: Julien Thierry Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/Kconfig | 11 +++++++++++ arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/include/asm/daifflags.h | 7 +++++++ arch/arm64/include/asm/irqflags.h | 14 +++++++++++++- 4 files changed, 37 insertions(+), 1 deletion(-) -- 1.9.1 diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 697ea05..8acc40e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1436,6 +1436,17 @@ config ARM64_PSEUDO_NMI If unsure, say N +if ARM64_PSEUDO_NMI +config ARM64_DEBUG_PRIORITY_MASKING + bool "Debug interrupt priority masking" + help + This adds runtime checks to functions enabling/disabling + interrupts when using priority masking. The additional checks verify + the validity of ICC_PMR_EL1 when calling concerned functions. + + If unsure, say N +endif + config RELOCATABLE bool help diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index bc895c8..693a086 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -617,6 +617,12 @@ static inline bool system_uses_irq_prio_masking(void) cpus_have_const_cap(ARM64_HAS_IRQ_PRIO_MASKING); } +static inline bool system_has_prio_mask_debugging(void) +{ + return IS_ENABLED(CONFIG_ARM64_DEBUG_PRIORITY_MASKING) && + system_uses_irq_prio_masking(); +} + #define ARM64_SSBD_UNKNOWN -1 #define ARM64_SSBD_FORCE_DISABLE 0 #define ARM64_SSBD_KERNEL 1 diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h index f93204f..eca5bee 100644 --- a/arch/arm64/include/asm/daifflags.h +++ b/arch/arm64/include/asm/daifflags.h @@ -28,6 +28,10 @@ /* mask/save/unmask/restore all exceptions, including interrupts. */ static inline void local_daif_mask(void) { + WARN_ON(system_has_prio_mask_debugging() && + (read_sysreg_s(SYS_ICC_PMR_EL1) == (GIC_PRIO_IRQOFF | + GIC_PRIO_PSR_I_SET))); + asm volatile( "msr daifset, #0xf // local_daif_mask\n" : @@ -62,6 +66,9 @@ static inline void local_daif_restore(unsigned long flags) { bool irq_disabled = flags & PSR_I_BIT; + WARN_ON(system_has_prio_mask_debugging() && + !(read_sysreg(daif) & PSR_I_BIT)); + if (!irq_disabled) { trace_hardirqs_on(); diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h index b6f757f..cac2d2a 100644 --- a/arch/arm64/include/asm/irqflags.h +++ b/arch/arm64/include/asm/irqflags.h @@ -40,6 +40,12 @@ */ static inline void arch_local_irq_enable(void) { + if (system_has_prio_mask_debugging()) { + u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1); + + WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF); + } + asm volatile(ALTERNATIVE( "msr daifclr, #2 // arch_local_irq_enable\n" "nop", @@ -53,6 +59,12 @@ static inline void arch_local_irq_enable(void) static inline void arch_local_irq_disable(void) { + if (system_has_prio_mask_debugging()) { + u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1); + + WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF); + } + asm volatile(ALTERNATIVE( "msr daifset, #2 // arch_local_irq_disable", __msr_s(SYS_ICC_PMR_EL1, "%0"), @@ -86,7 +98,7 @@ static inline int arch_irqs_disabled_flags(unsigned long flags) asm volatile(ALTERNATIVE( "and %w0, %w1, #" __stringify(PSR_I_BIT), - "eor %w0, %w1, #" __stringify(GIC_PRIO_IRQOFF), + "eor %w0, %w1, #" __stringify(GIC_PRIO_IRQON), ARM64_HAS_IRQ_PRIO_MASKING) : "=&r" (res) : "r" ((int) flags)