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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81775C433FE for ; Fri, 1 Apr 2022 15:29:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245372AbiDAPa5 (ORCPT ); Fri, 1 Apr 2022 11:30:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349867AbiDAO6L (ORCPT ); Fri, 1 Apr 2022 10:58:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1599816BCFB; Fri, 1 Apr 2022 07:45:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A4FA560BAF; Fri, 1 Apr 2022 14:45:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4610DC34113; Fri, 1 Apr 2022 14:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648824324; bh=6V1nHrd8TUXwtn53KUZGT9jm7BI/3WXv0EB7DP4s+YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OPR8RNh1yCg+04uyNs74IQ2F/AjbFf7adBatziNocS9zDrlIeyXFNyBEbNsygaHU2 679iQ33J70SJLDymxmpBpDLH+b7hLMh21qiSRIyhxJxwhtqH+7QJhnd02kRo5gLif9 hEPBgkje6+8OVHpuIjwNaJqIPM0uzjo8DVudtgXlabYb2Iuzx2eXirqs2c7vpMi/TM YEYoI7nx7RfjC+lcgy6KCrAqEAuCwZbFKahk/Nl2E9bVRnSzuoSjuk1SPUqfvfdtjr gsTnOhjQeS/kpmB52B2myW1UFnGV6xJg/gYyJy/5HYNGSQpwpytHgvr8XSIGJ9kr48 1l9h0nLbJ0Otg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhou Guanghui , Will Deacon , Sasha Levin , joro@8bytes.org, iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.4 14/37] iommu/arm-smmu-v3: fix event handling soft lockup Date: Fri, 1 Apr 2022 10:44:23 -0400 Message-Id: <20220401144446.1954694-14-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220401144446.1954694-1-sashal@kernel.org> References: <20220401144446.1954694-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhou Guanghui [ Upstream commit 30de2b541af98179780054836b48825fcfba4408 ] During event processing, events are read from the event queue one by one until the queue is empty.If the master device continuously requests address access at the same time and the SMMU generates events, the cyclic processing of the event takes a long time and softlockup warnings may be reported. arm-smmu-v3 arm-smmu-v3.34.auto: event 0x0a received: arm-smmu-v3 arm-smmu-v3.34.auto: 0x00007f220000280a arm-smmu-v3 arm-smmu-v3.34.auto: 0x000010000000007e arm-smmu-v3 arm-smmu-v3.34.auto: 0x00000000034e8670 watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [irq/268-arm-smm:247] Call trace: _dev_info+0x7c/0xa0 arm_smmu_evtq_thread+0x1c0/0x230 irq_thread_fn+0x30/0x80 irq_thread+0x128/0x210 kthread+0x134/0x138 ret_from_fork+0x10/0x1c Kernel panic - not syncing: softlockup: hung tasks Fix this by calling cond_resched() after the event information is printed. Signed-off-by: Zhou Guanghui Link: https://lore.kernel.org/r/20220119070754.26528-1-zhouguanghui1@huawei.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/arm-smmu-v3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index ef6af714a7e6..02c2fb551f38 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1708,6 +1708,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) dev_info(smmu->dev, "\t0x%016llx\n", (unsigned long long)evt[i]); + cond_resched(); } /* -- 2.34.1