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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F211FC54798 for ; Tue, 27 Feb 2024 13:37:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lktGuomb2UMp93+4llN9J37i5hOCCRNzfZsgwvQb9c0=; b=EM+i4ocbfX7CAY 6PYwl7OEHuiXfMkS//nQi6DjhtbK9UaPvVY9u9XYQ8boYdxIe2j8+juJDeHTKAF1tcXr1XtdE+3R9 TutQaihXjkfdLlYujXRq2YgtGshRWxNc6z9UNQwBPDJuIOfv6Mruti1kCVlSWt5Rr/e1QJe9jojWq 8v9dJWYyeggUECcnFr63MdisvcfqcAs72nlDhHDb3ldDJKHadkOYj3LGQqkIhOiEPqBglFnjZnrX6 pLFrAL0EuQicgAkY4Y2LATVQoHj9rjUOacjJND13F48JR+nWSSNfsKg+QxQ0UfTF1Mg+5u9uYWF/u RppAkTPe1ozARllSjjsg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rexdx-00000005PTL-470T; Tue, 27 Feb 2024 13:37:13 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rexdv-00000005PSs-0dO5 for linux-riscv@lists.infradead.org; Tue, 27 Feb 2024 13:37:12 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 8490461298; Tue, 27 Feb 2024 13:37:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA02EC43394; Tue, 27 Feb 2024 13:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709041030; bh=SneoRjlM6zUV40W9zc/OoFWLTf9jOV3p2OMdqL65wOc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UFMgQd/1MoX9Oas83jiu6xeCkJJddUGeETaTVfY2ylNS42MatSt0hyDiXEuuB6zA+ oQZTZ3oyUq060UObSRUqAkgymHSJ674UfEy1oaYj/alNogwO7GGO/G/LoS2qKDxcpV co5N1cRKIhqDbFJrCQVQcZ8/V+XlEDFcjoMOtQG8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nam Cao , Thomas Gleixner , Palmer Dabbelt , Paul Walmsley , Samuel Holland , Marc Zyngier , Guo Ren , linux-riscv@lists.infradead.org Subject: [PATCH 6.7 195/334] irqchip/sifive-plic: Enable interrupt if needed before EOI Date: Tue, 27 Feb 2024 14:20:53 +0100 Message-ID: <20240227131636.995384543@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131630.636392135@linuxfoundation.org> References: <20240227131630.636392135@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240227_053711_295164_4CA10FAB X-CRM114-Status: GOOD ( 17.37 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nam Cao commit 9c92006b896c767218aabe8947b62026a571cfd0 upstream. RISC-V PLIC cannot "end-of-interrupt" (EOI) disabled interrupts, as explained in the description of Interrupt Completion in the PLIC spec: "The PLIC signals it has completed executing an interrupt handler by writing the interrupt ID it received from the claim to the claim/complete register. The PLIC does not check whether the completion ID is the same as the last claim ID for that target. If the completion ID does not match an interrupt source that *is currently enabled* for the target, the completion is silently ignored." Commit 69ea463021be ("irqchip/sifive-plic: Fixup EOI failed when masked") ensured that EOI is successful by enabling interrupt first, before EOI. Commit a1706a1c5062 ("irqchip/sifive-plic: Separate the enable and mask operations") removed the interrupt enabling code from the previous commit, because it assumes that interrupt should already be enabled at the point of EOI. However, this is incorrect: there is a window after a hart claiming an interrupt and before irq_desc->lock getting acquired, interrupt can be disabled during this window. Thus, EOI can be invoked while the interrupt is disabled, effectively nullify this EOI. This results in the interrupt never gets asserted again, and the device who uses this interrupt appears frozen. Make sure that interrupt is really enabled before EOI. Fixes: a1706a1c5062 ("irqchip/sifive-plic: Separate the enable and mask operations") Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Samuel Holland Cc: Marc Zyngier Cc: Guo Ren Cc: linux-riscv@lists.infradead.org Cc: Link: https://lore.kernel.org/r/20240131081933.144512-1-namcao@linutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/irqchip/irq-sifive-plic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/irqchip/irq-sifive-plic.c +++ b/drivers/irqchip/irq-sifive-plic.c @@ -148,7 +148,13 @@ static void plic_irq_eoi(struct irq_data { struct plic_handler *handler = this_cpu_ptr(&plic_handlers); - writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + if (unlikely(irqd_irq_disabled(d))) { + plic_toggle(handler, d->hwirq, 1); + writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + plic_toggle(handler, d->hwirq, 0); + } else { + writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + } } #ifdef CONFIG_SMP _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv