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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 EA779C3F2D6 for ; Fri, 6 Mar 2020 08:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5D8D208C3 for ; Fri, 6 Mar 2020 08:13:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726166AbgCFINZ (ORCPT ); Fri, 6 Mar 2020 03:13:25 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:3550 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725853AbgCFINY (ORCPT ); Fri, 6 Mar 2020 03:13:24 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02689Iup008395 for ; Fri, 6 Mar 2020 03:13:23 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ykd49hhd6-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 06 Mar 2020 03:13:23 -0500 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 6 Mar 2020 08:13:18 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0268DHiA39322104 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 6 Mar 2020 08:13:17 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 23051A405F; Fri, 6 Mar 2020 08:13:17 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D7EA0A4066; Fri, 6 Mar 2020 08:13:16 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 6 Mar 2020 08:13:16 +0000 (GMT) From: Julian Wiedmann To: David Miller Cc: netdev , linux-s390 , Heiko Carstens , Ursula Braun , Julian Wiedmann , Qian Cai Subject: [PATCH net-next 1/2] s390/qdio: add tighter controls for IRQ polling Date: Fri, 6 Mar 2020 09:13:10 +0100 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200306081311.50635-1-jwi@linux.ibm.com> References: <20200306081311.50635-1-jwi@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 20030608-0016-0000-0000-000002EDB2BD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20030608-0017-0000-0000-0000335109C0 Message-Id: <20200306081311.50635-2-jwi@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-03-06_02:2020-03-05,2020-03-06 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=27 phishscore=0 mlxscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 bulkscore=0 priorityscore=1501 mlxlogscore=971 adultscore=0 impostorscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003060057 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Once the call to qdio_establish() has completed, qdio is free to deliver data IRQs to the device driver's IRQ poll handler. For qeth (the only qdio driver that currently uses IRQ polling) this is problematic, since the IRQs can arrive before its NAPI instance is even registered. Calling napi_schedule() from qeth_qdio_start_poll() then crashes in various nasty ways. Until recently qeth checked for IFF_UP to drop such early interrupts, but that's fragile as well since it doesn't enforce any ordering. Fix this properly by bringing up the qdio device in IRQS_DISABLED mode, and have the driver explicitly opt-in to receive data IRQs. qeth does so from qeth_open(), which kick-starts a NAPI poll and then calls qdio_start_irq() from qeth_poll(). Also add a matching qdio_stop_irq() in qeth_stop() to switch the qdio dataplane back into a disabled state. Fixes: 3d35dbe6224e ("s390/qeth: don't check for IFF_UP when scheduling napi") CC: Qian Cai Reported-by: Qian Cai Signed-off-by: Julian Wiedmann Acked-by: Vasily Gorbik --- drivers/s390/cio/qdio_setup.c | 11 +++++++++-- drivers/s390/net/qeth_core_main.c | 5 ++--- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index e115623b86b2..66e4bdca9d89 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -224,8 +224,15 @@ static void setup_queues(struct qdio_irq *irq_ptr, setup_queues_misc(q, irq_ptr, qdio_init->input_handler, i); q->is_input_q = 1; - q->u.in.queue_start_poll = qdio_init->queue_start_poll_array ? - qdio_init->queue_start_poll_array[i] : NULL; + if (qdio_init->queue_start_poll_array && + qdio_init->queue_start_poll_array[i]) { + q->u.in.queue_start_poll = + qdio_init->queue_start_poll_array[i]; + set_bit(QDIO_QUEUE_IRQS_DISABLED, + &q->u.in.queue_irq_state); + } else { + q->u.in.queue_start_poll = NULL; + } setup_storage_lists(q, irq_ptr, input_sbal_array, i); input_sbal_array += QDIO_MAX_BUFFERS_PER_Q; diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index fdc50543ce9a..37c17ad8ee25 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -6582,9 +6582,6 @@ int qeth_open(struct net_device *dev) QETH_CARD_TEXT(card, 4, "qethopen"); - if (qdio_stop_irq(CARD_DDEV(card), 0) < 0) - return -EIO; - card->data.state = CH_STATE_UP; netif_tx_start_all_queues(dev); @@ -6634,6 +6631,8 @@ int qeth_stop(struct net_device *dev) } napi_disable(&card->napi); + qdio_stop_irq(CARD_DDEV(card), 0); + return 0; } EXPORT_SYMBOL_GPL(qeth_stop); -- 2.17.1