From patchwork Mon Feb 15 12:16:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 12088047 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE57CC433E9 for ; Mon, 15 Feb 2021 12:20:22 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7BADA60200 for ; Mon, 15 Feb 2021 12:20:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7BADA60200 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=marcan.st Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version: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=Gn2QYUvoHdjVzyGYFasODc/da2+O/68UMKNQPhEMXas=; b=FtcT0zOIM9QV/ZxuSid68zxue RHBNhFAWB4zoA7HqhjhqL97X8kdJag1zaGFH9AISZ3MAB5cM5MjUN8skPUUsvPkt47CyYFOl+wCys cYoYZlANHZDLHqEubzRW4rrCBCpNbOJXBgOxX5LsyGbu4PXoPVOeAZCTgOQ68aYxH5i3s/8ie4hvX pDF0C6JqetPR4dbBnmYbHGQ79RZHQzFF65kbqzST2dkT/EF2CJanw+/UCwnzLnXmkXgKABwHpfQ4F wORv7TwbaIoOEY0N0zMoGJqfRCiuiJnVJTRPp6+Yi1CDgtb+0nGRxhHqH5Jjdwz01Aj/XJP71ertZ 88vykI7Iw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lBcpq-0005MJ-NK; Mon, 15 Feb 2021 12:18:39 +0000 Received: from marcansoft.com ([212.63.210.85] helo=mail.marcansoft.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lBcpX-0005G5-HH for linux-arm-kernel@lists.infradead.org; Mon, 15 Feb 2021 12:18:21 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 913F8424A1; Mon, 15 Feb 2021 12:18:13 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 08/25] arm64: Always keep DAIF.[IF] in sync Date: Mon, 15 Feb 2021 21:16:56 +0900 Message-Id: <20210215121713.57687-9-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210215121713.57687-1-marcan@marcan.st> References: <20210215121713.57687-1-marcan@marcan.st> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210215_071819_846640_40BC1D89 X-CRM114-Status: GOOD ( 19.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Arnd Bergmann , Rob Herring , Tony Lindgren , Marc Zyngier , Linus Walleij , Hector Martin , linux-kernel@vger.kernel.org, Krzysztof Kozlowski , devicetree@vger.kernel.org, Alexander Graf , Olof Johansson , Mohamed Mediouni , Stan Skowronek , Will Deacon , Mark Kettenis Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Apple SoCs (A11 and newer) have some interrupt sources hardwired to the FIQ line. We implement support for this by simply treating IRQs and FIQs the same way in the interrupt vectors. To support these systems, the FIQ mask bit needs to be kept in sync with the IRQ mask bit, so both kinds of exceptions are masked together. No other platforms should be delivering FIQ exceptions right now, and we already unmask FIQ in normal process context, so this should not have an effect on other systems - if spurious FIQs were arriving, they would already panic the kernel. Root irqchip drivers can discriminate between IRQs and FIQs by checking the ISR_EL1 system register. Signed-off-by: Hector Martin --- arch/arm64/include/asm/assembler.h | 6 +++--- arch/arm64/include/asm/daifflags.h | 4 ++-- arch/arm64/include/asm/irqflags.h | 19 +++++++++++-------- arch/arm64/kernel/entry.S | 6 +++--- 4 files changed, 19 insertions(+), 16 deletions(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index bf125c591116..ac4c823bf2b6 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -40,9 +40,9 @@ msr daif, \flags .endm - /* IRQ is the lowest priority flag, unconditionally unmask the rest. */ - .macro enable_da_f - msr daifclr, #(8 | 4 | 1) + /* IRQ/FIQ are the lowest priority flags, unconditionally unmask the rest. */ + .macro enable_da + msr daifclr, #(8 | 4) .endm /* diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h index 1c26d7baa67f..9d1d4ab98585 100644 --- a/arch/arm64/include/asm/daifflags.h +++ b/arch/arm64/include/asm/daifflags.h @@ -13,8 +13,8 @@ #include #define DAIF_PROCCTX 0 -#define DAIF_PROCCTX_NOIRQ PSR_I_BIT -#define DAIF_ERRCTX (PSR_I_BIT | PSR_A_BIT) +#define DAIF_PROCCTX_NOIRQ (PSR_I_BIT | PSR_F_BIT) +#define DAIF_ERRCTX (PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) #define DAIF_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h index ff328e5bbb75..125201dced5f 100644 --- a/arch/arm64/include/asm/irqflags.h +++ b/arch/arm64/include/asm/irqflags.h @@ -12,15 +12,18 @@ /* * Aarch64 has flags for masking: Debug, Asynchronous (serror), Interrupts and - * FIQ exceptions, in the 'daif' register. We mask and unmask them in 'dai' + * FIQ exceptions, in the 'daif' register. We mask and unmask them in 'daif' * order: * Masking debug exceptions causes all other exceptions to be masked too/ - * Masking SError masks irq, but not debug exceptions. Masking irqs has no - * side effects for other flags. Keeping to this order makes it easier for - * entry.S to know which exceptions should be unmasked. + * Masking SError masks IRQ/FIQ, but not debug exceptions. IRQ and FIQ are + * always masked and unmasked together, and have no side effects for other + * flags. Keeping to this order makes it easier for entry.S to know which + * exceptions should be unmasked. * - * FIQ is never expected, but we mask it when we disable debug exceptions, and - * unmask it at all other times. + * FIQ is never expected on most platforms, but we keep it synchronized + * with the IRQ mask status. On platforms that do not expect FIQ, that vector + * triggers a kernel panic. On platforms that do, the FIQ vector is unified + * with the IRQ vector. */ /* @@ -35,7 +38,7 @@ static inline void arch_local_irq_enable(void) } asm volatile(ALTERNATIVE( - "msr daifclr, #2 // arch_local_irq_enable", + "msr daifclr, #3 // arch_local_irq_enable", __msr_s(SYS_ICC_PMR_EL1, "%0"), ARM64_HAS_IRQ_PRIO_MASKING) : @@ -54,7 +57,7 @@ static inline void arch_local_irq_disable(void) } asm volatile(ALTERNATIVE( - "msr daifset, #2 // arch_local_irq_disable", + "msr daifset, #3 // arch_local_irq_disable", __msr_s(SYS_ICC_PMR_EL1, "%0"), ARM64_HAS_IRQ_PRIO_MASKING) : diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c9bae73f2621..ba5f9aa379ce 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -661,7 +661,7 @@ SYM_CODE_END(el1_sync) SYM_CODE_START_LOCAL_NOALIGN(el1_irq) kernel_entry 1 gic_prio_irq_setup pmr=x20, tmp=x1 - enable_da_f + enable_da mov x0, sp bl enter_el1_irq_or_nmi @@ -727,7 +727,7 @@ SYM_CODE_START_LOCAL_NOALIGN(el0_irq) el0_irq_naked: gic_prio_irq_setup pmr=x20, tmp=x0 user_exit_irqoff - enable_da_f + enable_da tbz x22, #55, 1f bl do_el0_irq_bp_hardening @@ -757,7 +757,7 @@ el0_error_naked: mov x0, sp mov x1, x25 bl do_serror - enable_da_f + enable_da b ret_to_user SYM_CODE_END(el0_error)