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 698E5C54E49 for ; Mon, 26 Feb 2024 13:15:49 +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:Message-ID:Date:From:Cc:To :Subject:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=dtJWynyWJmmhiIWjA7kKXh5VbVoozcUN5BXruKprxck=; b=Vb/p6cDrmseWM0 6CuLWaz4gGToolyGgLht60ZjUXBVkxigMAw0ASvlKctSLvHHOfxSK6Gn7xdMdPmDlhCk46gAoP3Bh ZMu0CXr40gDs9qELWIm4VPhIHcgCTfHPkP4SSw/kwDBYNQAJPklA8o0yZarlb2Zw8tU2p9A6MCgXT +WZ7a/UYy1qlDqFhfxz1GhoHIhLTqIbe2amtaCNghSbDic22TyxyCZx/sIxZZ9tWmiqOtLv6pI3OM wjNWdOWWGBHVYN84gMNQVL6u//1e9gDL2AmFECRL+4cqHJd2hlr2NBOJfwIuJfnFaYCvgzNdUMLZ1 VRPJf0dZVqV1DHTm4Qyw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1reapd-00000000mth-2Zbb; Mon, 26 Feb 2024 13:15:45 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1reapZ-00000000msj-2NeA for linux-riscv@lists.infradead.org; Mon, 26 Feb 2024 13:15:43 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 45850CE0E38; Mon, 26 Feb 2024 13:15:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35386C433C7; Mon, 26 Feb 2024 13:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708953338; bh=Z8x3GMxjzCm1bG8he0aKOodAAPGe693zTF2SziVL15Q=; h=Subject:To:Cc:From:Date:From; b=iHyRGSdrqE1hUR7A3sGF7Vf7aj2Ze9Ryksmn54gK0eQYPBrkZz8x1NwChc4oZmNu6 jGRLyU7jqM9/sUWzYUlSNr5c1fBFKNDsgcoudA+NwqwVnFvr5vl6jyw32ZUB0hCa60 +5SLxkJ2cCNvslsSBHArhUiRmZzWVzzlUwxh7hoQ= Subject: Patch "irqchip/sifive-plic: Enable interrupt if needed before EOI" has been added to the 6.7-stable tree To: gregkh@linuxfoundation.org,guoren@kernel.org,linux-riscv@lists.infradead.org,maz@kernel.org,namcao@linutronix.de,palmer@dabbelt.com,paul.walmsley@sifive.com,samuel@sholland.org,tglx@linutronix.de Cc: From: Date: Mon, 26 Feb 2024 14:14:31 +0100 Message-ID: <2024022631-subdivide-rage-2443@gregkh> MIME-Version: 1.0 X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240226_051542_136674_110F8A3A X-CRM114-Status: GOOD ( 20.19 ) 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 This is a note to let you know that I've just added the patch titled irqchip/sifive-plic: Enable interrupt if needed before EOI to the 6.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: irqchip-sifive-plic-enable-interrupt-if-needed-before-eoi.patch and it can be found in the queue-6.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From 9c92006b896c767218aabe8947b62026a571cfd0 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Wed, 31 Jan 2024 09:19:33 +0100 Subject: irqchip/sifive-plic: Enable interrupt if needed before EOI 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 Patches currently in stable-queue which might be from namcao@linutronix.de are queue-6.7/irqchip-sifive-plic-enable-interrupt-if-needed-before-eoi.patch _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv