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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7AC55C433ED for ; Tue, 11 May 2021 00:56:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FE1961613 for ; Tue, 11 May 2021 00:56:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230124AbhEKA51 (ORCPT ); Mon, 10 May 2021 20:57:27 -0400 Received: from terminus.zytor.com ([198.137.202.136]:45457 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229934AbhEKA5H (ORCPT ); Mon, 10 May 2021 20:57:07 -0400 Received: from tazenda.hos.anvin.org ([IPv6:2601:646:8602:8be0:7285:c2ff:fefb:fd4]) (authenticated bits=0) by mail.zytor.com (8.16.1/8.15.2) with ESMTPSA id 14B0tdwA2504247 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 10 May 2021 17:55:51 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 14B0tdwA2504247 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2021042801; t=1620694551; bh=xkymiY+8+CNIxsNAedZC22OCKPl0xAPTK6wwAANss68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g4zQdja8QHTFnL5/D4O+bxSzoMo6fsDRfirHuEUrYDS32Z3kZoiwhT2+5XLiXLLL6 aMDRJOQA9uCDjc8lqmzQ23eFSzTSLS3Qq062NUbS4f8r79vpqPTgZHk09SY0j30JR3 oRgVE8RvTH07O7p6OofskwgTwbhwkBsWlVw5sK2F3znd62nE6qiUR5aXphG8AgHJXp YJz8zj6Ji3Rn7Frb57TFPiBnp9TtSycMsoeGj8ggCK6158+3z8u0oEQmw/tTpoeYCq NvpRU+ByegS5QW3QwL90ML0Z0nFxN5fK4iqLT6Ld2bo7Diye0tuG34uacW7C3XfZf5 i9KDuWZvbyQ4w== From: "H. Peter Anvin" To: Ingo Molnar , Thomas Gleixner , Borislav Petkov , Andy Lutomirski Cc: Steve Wahl , Mike Travis , Dimitri Sivanich , Russ Anderson , Linux Kernel Mailing List , "H. Peter Anvin (Intel)" Subject: [PATCH 5/6] x86/irq: WARN_ONCE() if irq_move_cleanup is called on a pending interrupt Date: Mon, 10 May 2021 17:55:30 -0700 Message-Id: <20210511005531.1065536-6-hpa@zytor.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210511005531.1065536-1-hpa@zytor.com> References: <20210511005531.1065536-1-hpa@zytor.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin (Intel)" The current IRQ vector allocation code should be "clean" and never issue a IRQ_MOVE_CLEANUP_VECTOR IPI for an interrupt that could still be pending. This should make it possible to move it to the "normal" system IRQ vector range. This should probably be a three-step process: 1. Introduce this WARN_ONCE() on this event ever occurring. 2. Move the IRQ_MOVE_CLEANUP_VECTOR to the sysvec range. 3. Remove the self-IPI hack. This implements step 1. Suggested-by: Thomas Gleixner Signed-off-by: H. Peter Anvin (Intel) --- arch/x86/kernel/apic/vector.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 6dbdc7c22bb7..7ba2982a3585 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -939,9 +939,14 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_irq_move_cleanup) * to this CPU. IRQ_MOVE_CLEANUP_VECTOR is the lowest * priority external vector, so on return from this * interrupt the device interrupt will happen first. + * + * *** This should never happen with the current IRQ + * cleanup code, so WARN_ONCE() for now, and + * eventually get rid of this hack. */ irr = apic_read(APIC_IRR + (vector / 32 * 0x10)); if (irr & (1U << (vector % 32))) { + WARN_ONCE(1, "irq_move_cleanup called on still pending interrupt\n"); apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR); continue; } -- 2.31.1