From nobody Sat Feb 7 15:15:30 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D76C7C001B3 for ; Mon, 3 Jul 2023 18:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230000AbjGCSbj (ORCPT ); Mon, 3 Jul 2023 14:31:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230097AbjGCSbg (ORCPT ); Mon, 3 Jul 2023 14:31:36 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18D3A121 for ; Mon, 3 Jul 2023 11:31:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A0B2260FFB for ; Mon, 3 Jul 2023 18:31:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06BA7C433C7; Mon, 3 Jul 2023 18:31:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688409095; bh=xOd6z6GLzShOy0vSnm82XHqZ/VJeHK3iTQUpUdu1pXQ=; h=From:To:Cc:Subject:Date:From; b=kBgGE0ZKDk2FVPCeBvzCxuOo+OjbOzJobgivXBkW9io+6Zfoa3Vo6Y54wjHjHSq4z 9SqHoqh/ipjUQhNtVpwRiKmTWNoyUs6iJbvFapn3+dcLDexh0UkFF3TGRuFyK37NZt Kmk1jLDRGHPURtXygJTIXuAl4dz/hF0l5OEHdrxEJHrWd0z/TAjNIY8i1B5QBnYgeA bi/u2hoNDrIx6EXKsHMQN7W0x06hOcO5t8gppm0ax5CK1z5CkxcLRFmaX50CuxfVMp oZVP6MvrKEZti3KsxrFC0r51d5VE9Q/UQ+JNsfIbtk31ZB0lV0VRz8gzYwZ95vCqxU kDEcCpnKoaUrA== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qGOKi-00AEn7-K8; Mon, 03 Jul 2023 19:31:32 +0100 From: Marc Zyngier To: linux-kernel@vger.kernel.org Cc: Conor Dooley , Anup Patel , Palmer Dabbelt , Linus Torvalds Subject: [PATCH] risc-v: Fix order of IPI enablement vs RCU startup Date: Mon, 3 Jul 2023 19:31:26 +0100 Message-Id: <20230703183126.1567625-1-maz@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, conor@kernel.org, apatel@ventanamicro.com, palmer@rivosinc.com, torvalds@linux-foundation.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Conor reports that risc-v tries to enable IPIs before telling the core code to enable RCU. With the introduction of the mapple tree as a backing store for the irq descriptors, this results in a very shouty boot sequence, as RCU is legitimately upset. Restore some sanity by moving the risc_ipi_enable() call after notify_cpu_starting(), which explicitly enables RCU on the calling CPU. Fixes: 832f15f42646 ("RISC-V: Treat IPIs as normal Linux IRQs") Reported-by: Conor Dooley Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud Cc: Anup Patel Cc: Palmer Dabbelt Cc: Linus Torvalds Tested-by: Conor Dooley --- arch/riscv/kernel/smpboot.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index bb0b76e1a6d4..f4d6acb38dd0 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -238,10 +238,11 @@ asmlinkage __visible void smp_callin(void) mmgrab(mm); current->active_mm =3D mm; =20 - riscv_ipi_enable(); - store_cpu_topology(curr_cpuid); notify_cpu_starting(curr_cpuid); + + riscv_ipi_enable(); + numa_add_cpu(curr_cpuid); set_cpu_online(curr_cpuid, 1); probe_vendor_features(curr_cpuid); --=20 2.34.1