From mboxrd@z Thu Jan 1 00:00:00 1970 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,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 A0683C433E9 for ; Tue, 2 Mar 2021 10:14:01 +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 2CAFC64F11 for ; Tue, 2 Mar 2021 10:14:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CAFC64F11 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com 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: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=QTWunMJR1REWkyMDgNJ18eMqdSJD9s0C6OF4PWAmbkA=; b=ivMTWRYgJuSZLEQ+bLwku7GQ6B jlGNaK8SeSkMlYN9FaKk2ug8l8cZWur8hKO5LnkFR5Dbcj9vp3Ac9zcowbQAKC1pbNGKnh3iogHHE Ma20TjOzdx966W1aM9SQhft4MmHYIYt8X83R2clrFxtnABblDJ2qcw9+TZZCH6G/ZTA7z0+oAHviX aybgjMXcEI4q7TglS0l0vl4pUdAsdLRPydJuZfsx883HWIGEOsyHyT8AAUBG7PcKkfTbryJp7kyS9 gQcun8cB7TSSND/JwU0XRsiRjkmkGKWOaKXXsWDKQutJMiMF+O8KxC+4c3L/aGPK/QjDSNB9eSv0r 9Q8QoB9g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lH219-0008Nw-5K; Tue, 02 Mar 2021 10:12:39 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lH213-0008MK-Bt for linux-arm-kernel@lists.infradead.org; Tue, 02 Mar 2021 10:12:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D338513A1; Tue, 2 Mar 2021 02:12:31 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9BDA33F70D; Tue, 2 Mar 2021 02:12:30 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCHv2 5/8] arm64: irq: rework root IRQ handler registration Date: Tue, 2 Mar 2021 10:12:08 +0000 Message-Id: <20210302101211.2328-6-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210302101211.2328-1-mark.rutland@arm.com> References: <20210302101211.2328-1-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210302_051233_491938_55989A03 X-CRM114-Status: GOOD ( 15.24 ) 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@arm.com, catalin.marinas@arm.com, marcan@marcan.st, james.morse@arm.com, maz@kernel.org, tglx@linutronix.de, will@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If we accidentally unmask IRQs before we've registered a root IRQ handler, handle_arch_irq will be NULL, and the IRQ exception handler will branch to a bogus address. To make this easier to debug, this patch initialises handle_arch_irq to a default handler which will panic(), making such problems easier to debug. When we add support for FIQ handlers, we can follow the same approach. When we add support for a root FIQ handler, it's possible to have root IRQ handler without an root FIQ handler, and in theory the inverse is also possible. To permit this, and to keep the IRQ/FIQ registration logic similar, this patch removes the panic in the absence of a root IRQ controller. Instead, set_handle_irq() logs when a handler is registered, which is sufficient for debug purposes. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Hector Martin Cc: James Morse Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon --- arch/arm64/kernel/irq.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index ad63bd50fa7b..2fe0b535de30 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -71,14 +71,20 @@ static void init_irq_stacks(void) } #endif -void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; +static void default_handle_irq(struct pt_regs *regs) +{ + panic("IRQ taken without a root IRQ handler\n"); +} + +void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq; int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) { - if (handle_arch_irq) + if (handle_arch_irq != default_handle_irq) return -EBUSY; handle_arch_irq = handle_irq; + pr_info("Root IRQ handler: %ps\n", handle_irq); return 0; } @@ -87,8 +93,6 @@ void __init init_IRQ(void) init_irq_stacks(); init_irq_scs(); irqchip_init(); - if (!handle_arch_irq) - panic("No interrupt controller found."); if (system_uses_irq_prio_masking()) { /* -- 2.11.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel