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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 DEC14C433FF for ; Wed, 14 Aug 2019 17:10:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4D30208C2 for ; Wed, 14 Aug 2019 17:10:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565802628; bh=zwjdXstRbcb7XY6j3orW5Z8Zd9eGdQ/B8Hkyos/oTN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wXdsugxC+vMCl3HM2HMpzZxfTCcW1FO9ADqyNE0R1dVL5IS/Qyb2XwQUCMsJqHFQp SCZ2WVaLDdr5xScqX3i1ITQc4qCEeCGK5cPQ1xDaRk3P92nezJQSJi3hEvsYEHxbIa 24pmPQEy/IM/xiIncMpvYsuensvYSRBrlq4diozE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730484AbfHNRK0 (ORCPT ); Wed, 14 Aug 2019 13:10:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:32916 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730448AbfHNRKQ (ORCPT ); Wed, 14 Aug 2019 13:10:16 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5F82F2133F; Wed, 14 Aug 2019 17:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565802615; bh=zwjdXstRbcb7XY6j3orW5Z8Zd9eGdQ/B8Hkyos/oTN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wNeWzHPHWIw2sLG3ELTuqlNkYiH6eGqewfub9sOoPUL86RNjmMmY664fZZtyJnvtJ y2/eQohT1h3xX2xGbUjwN9piG2pltMa3LiO38oO5UjmUhC9LO83teAoqO3lI2AE3r/ wTgxlXNXjYxJZlcwqM8SKrbphnuFWtQh5TDdWVuw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julian Wiedmann , Jens Remus , Heiko Carstens , Sasha Levin Subject: [PATCH 4.19 51/91] s390/qdio: add sanity checks to the fast-requeue path Date: Wed, 14 Aug 2019 19:01:14 +0200 Message-Id: <20190814165751.724832660@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190814165748.991235624@linuxfoundation.org> References: <20190814165748.991235624@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit a6ec414a4dd529eeac5c3ea51c661daba3397108 ] If the device driver were to send out a full queue's worth of SBALs, current code would end up discovering the last of those SBALs as PRIMED and erroneously skip the SIGA-w. This immediately stalls the queue. Add a check to not attempt fast-requeue in this case. While at it also make sure that the state of the previous SBAL was successfully extracted before inspecting it. Signed-off-by: Julian Wiedmann Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- drivers/s390/cio/qdio_main.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 4ac4a73037f59..4b7cc8d425b1c 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -1569,13 +1569,13 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags, rc = qdio_kick_outbound_q(q, phys_aob); } else if (need_siga_sync(q)) { rc = qdio_siga_sync_q(q); + } else if (count < QDIO_MAX_BUFFERS_PER_Q && + get_buf_state(q, prev_buf(bufnr), &state, 0) > 0 && + state == SLSB_CU_OUTPUT_PRIMED) { + /* The previous buffer is not processed yet, tack on. */ + qperf_inc(q, fast_requeue); } else { - /* try to fast requeue buffers */ - get_buf_state(q, prev_buf(bufnr), &state, 0); - if (state != SLSB_CU_OUTPUT_PRIMED) - rc = qdio_kick_outbound_q(q, 0); - else - qperf_inc(q, fast_requeue); + rc = qdio_kick_outbound_q(q, 0); } /* in case of SIGA errors we must process the error immediately */ -- 2.20.1