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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 1AC7DC04AB5 for ; Thu, 6 Jun 2019 07:10:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEDC52083D for ; Thu, 6 Jun 2019 07:10:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726829AbfFFHKC (ORCPT ); Thu, 6 Jun 2019 03:10:02 -0400 Received: from esa2.microchip.iphmx.com ([68.232.149.84]:30692 "EHLO esa2.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725782AbfFFHKA (ORCPT ); Thu, 6 Jun 2019 03:10:00 -0400 Received-SPF: SoftFail (esa2.microchip.iphmx.com: domain of kelvin.cao@microchip.com is inclined to not designate 208.19.100.22 as permitted sender) identity=mailfrom; client-ip=208.19.100.22; receiver=esa2.microchip.iphmx.com; envelope-from="kelvin.cao@microchip.com"; x-sender="kelvin.cao@microchip.com"; x-conformance=spf_only; x-record-type="v=spf1"; x-record-text="v=spf1 mx a:ushub1.microchip.com a:smtpout.microchip.com a:mx1.microchip.iphmx.com a:mx2.microchip.iphmx.com include:servers.mcsv.net include:mktomail.com include:spf.protection.outlook.com ~all" Received-SPF: None (esa2.microchip.iphmx.com: no sender authenticity information available from domain of postmaster@smtp.microsemi.com) identity=helo; client-ip=208.19.100.22; receiver=esa2.microchip.iphmx.com; envelope-from="kelvin.cao@microchip.com"; x-sender="postmaster@smtp.microsemi.com"; x-conformance=spf_only Authentication-Results: esa2.microchip.iphmx.com; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=kelvin.cao@microchip.com; spf=None smtp.helo=postmaster@smtp.microsemi.com; dmarc=fail (p=none dis=none) d=microchip.com X-IronPort-AV: E=Sophos;i="5.63,558,1557212400"; d="scan'208";a="36174409" Received: from unknown (HELO smtp.microsemi.com) ([208.19.100.22]) by esa2.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 06 Jun 2019 00:09:59 -0700 Received: from AVMBX3.microsemi.net (10.100.34.33) by AVMBX2.microsemi.net (10.100.34.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 6 Jun 2019 00:09:58 -0700 Received: from AVMBX3.microsemi.net (10.100.34.33) by AVMBX3.microsemi.net (10.100.34.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 6 Jun 2019 00:09:58 -0700 Received: from NTB-Peer.microsemi.net (10.188.116.183) by avmbx3.microsemi.net (10.100.34.33) with Microsoft SMTP Server id 15.1.1713.5 via Frontend Transport; Thu, 6 Jun 2019 00:09:55 -0700 From: Kelvin Cao To: , , , , , , , CC: , Subject: [PATCH 3/3] ntb_hw_switchtec: Fix setup MW with failure bug Date: Thu, 6 Jun 2019 15:09:44 +0800 Message-ID: <1559804984-24698-4-git-send-email-kelvin.cao@microchip.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559804984-24698-1-git-send-email-kelvin.cao@microchip.com> References: <1559804984-24698-1-git-send-email-kelvin.cao@microchip.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joey Zhang Switchtec does not support setting multiple MWs simultaneously. The driver takes a hardware lock to ensure that two peers are not doing this simultaneously and it fails if someone else takes the lock. In most cases, this is fine as clients only setup the MWs once on one side of the link. However, there's a race condition when a re-initialization is caused by a link event. The driver will re-setup the shared memory window asynchronously and this races with the client setting up it's memory windows on the link up event. To fix this we ensure do the entire initialization in a work queue and signal the client once it's done. Signed-off-by: Joey Zhang Signed-off-by: Wesley Sheng --- drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 66 ++++++++++++++++++++-------------- 1 file changed, 39 insertions(+), 27 deletions(-) diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c index 6cf15c18..fffff9a 100644 --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c @@ -95,7 +95,8 @@ struct switchtec_ntb { bool link_is_up; enum ntb_speed link_speed; enum ntb_width link_width; - struct work_struct link_reinit_work; + struct work_struct check_link_status_work; + bool link_force_down; }; static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb) @@ -494,33 +495,11 @@ enum switchtec_msg { static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev); -static void link_reinit_work(struct work_struct *work) -{ - struct switchtec_ntb *sndev; - - sndev = container_of(work, struct switchtec_ntb, link_reinit_work); - - switchtec_ntb_reinit_peer(sndev); -} - -static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, - enum switchtec_msg msg) +static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev) { int link_sta; int old = sndev->link_is_up; - if (msg == MSG_LINK_FORCE_DOWN) { - schedule_work(&sndev->link_reinit_work); - - if (sndev->link_is_up) { - sndev->link_is_up = 0; - ntb_link_event(&sndev->ntb); - dev_info(&sndev->stdev->dev, "ntb link forced down\n"); - } - - return; - } - link_sta = sndev->self_shared->link_sta; if (link_sta) { u64 peer = ioread64(&sndev->peer_shared->magic); @@ -545,6 +524,38 @@ static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, } } +static void check_link_status_work(struct work_struct *work) +{ + struct switchtec_ntb *sndev; + + sndev = container_of(work, struct switchtec_ntb, + check_link_status_work); + + if (sndev->link_force_down) { + sndev->link_force_down = false; + switchtec_ntb_reinit_peer(sndev); + + if (sndev->link_is_up) { + sndev->link_is_up = 0; + ntb_link_event(&sndev->ntb); + dev_info(&sndev->stdev->dev, "ntb link forced down\n"); + } + + return; + } + + switchtec_ntb_link_status_update(sndev); +} + +static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, + enum switchtec_msg msg) +{ + if (msg == MSG_LINK_FORCE_DOWN) + sndev->link_force_down = true; + + schedule_work(&sndev->check_link_status_work); +} + static void switchtec_ntb_link_notification(struct switchtec_dev *stdev) { struct switchtec_ntb *sndev = stdev->sndev; @@ -577,7 +588,7 @@ static int switchtec_ntb_link_enable(struct ntb_dev *ntb, sndev->self_shared->link_sta = 1; switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP); - switchtec_ntb_check_link(sndev, MSG_CHECK_LINK); + switchtec_ntb_link_status_update(sndev); return 0; } @@ -591,7 +602,7 @@ static int switchtec_ntb_link_disable(struct ntb_dev *ntb) sndev->self_shared->link_sta = 0; switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN); - switchtec_ntb_check_link(sndev, MSG_CHECK_LINK); + switchtec_ntb_link_status_update(sndev); return 0; } @@ -844,7 +855,8 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev) sndev->ntb.topo = NTB_TOPO_SWITCH; sndev->ntb.ops = &switchtec_ntb_ops; - INIT_WORK(&sndev->link_reinit_work, link_reinit_work); + INIT_WORK(&sndev->check_link_status_work, check_link_status_work); + sndev->link_force_down = false; sndev->self_partition = sndev->stdev->partition; -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.microchip.iphmx.com (esa2.microchip.iphmx.com. [68.232.149.84]) by gmr-mx.google.com with ESMTPS id o123si101194itc.3.2019.06.06.00.09.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Jun 2019 00:10:00 -0700 (PDT) From: Kelvin Cao Subject: [PATCH 3/3] ntb_hw_switchtec: Fix setup MW with failure bug Date: Thu, 6 Jun 2019 15:09:44 +0800 Message-ID: <1559804984-24698-4-git-send-email-kelvin.cao@microchip.com> In-Reply-To: <1559804984-24698-1-git-send-email-kelvin.cao@microchip.com> References: <1559804984-24698-1-git-send-email-kelvin.cao@microchip.com> Return-Path: kelvin.cao@microchip.com MIME-Version: 1.0 Content-Type: text/plain To: kurt.schwemmer@microsemi.com, logang@deltatee.com, jdmason@kudzu.us, dave.jiang@intel.com, allenbh@gmail.com, linux-pci@vger.kernel.org, linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org Cc: kelvin.cao@microchip.com, kelvincao@outlook.com List-ID: From: Joey Zhang Switchtec does not support setting multiple MWs simultaneously. The driver takes a hardware lock to ensure that two peers are not doing this simultaneously and it fails if someone else takes the lock. In most cases, this is fine as clients only setup the MWs once on one side of the link. However, there's a race condition when a re-initialization is caused by a link event. The driver will re-setup the shared memory window asynchronously and this races with the client setting up it's memory windows on the link up event. To fix this we ensure do the entire initialization in a work queue and signal the client once it's done. Signed-off-by: Joey Zhang Signed-off-by: Wesley Sheng --- drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 66 ++++++++++++++++++++-------------- 1 file changed, 39 insertions(+), 27 deletions(-) diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c index 6cf15c18..fffff9a 100644 --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c @@ -95,7 +95,8 @@ struct switchtec_ntb { bool link_is_up; enum ntb_speed link_speed; enum ntb_width link_width; - struct work_struct link_reinit_work; + struct work_struct check_link_status_work; + bool link_force_down; }; static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb) @@ -494,33 +495,11 @@ enum switchtec_msg { static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev); -static void link_reinit_work(struct work_struct *work) -{ - struct switchtec_ntb *sndev; - - sndev = container_of(work, struct switchtec_ntb, link_reinit_work); - - switchtec_ntb_reinit_peer(sndev); -} - -static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, - enum switchtec_msg msg) +static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev) { int link_sta; int old = sndev->link_is_up; - if (msg == MSG_LINK_FORCE_DOWN) { - schedule_work(&sndev->link_reinit_work); - - if (sndev->link_is_up) { - sndev->link_is_up = 0; - ntb_link_event(&sndev->ntb); - dev_info(&sndev->stdev->dev, "ntb link forced down\n"); - } - - return; - } - link_sta = sndev->self_shared->link_sta; if (link_sta) { u64 peer = ioread64(&sndev->peer_shared->magic); @@ -545,6 +524,38 @@ static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, } } +static void check_link_status_work(struct work_struct *work) +{ + struct switchtec_ntb *sndev; + + sndev = container_of(work, struct switchtec_ntb, + check_link_status_work); + + if (sndev->link_force_down) { + sndev->link_force_down = false; + switchtec_ntb_reinit_peer(sndev); + + if (sndev->link_is_up) { + sndev->link_is_up = 0; + ntb_link_event(&sndev->ntb); + dev_info(&sndev->stdev->dev, "ntb link forced down\n"); + } + + return; + } + + switchtec_ntb_link_status_update(sndev); +} + +static void switchtec_ntb_check_link(struct switchtec_ntb *sndev, + enum switchtec_msg msg) +{ + if (msg == MSG_LINK_FORCE_DOWN) + sndev->link_force_down = true; + + schedule_work(&sndev->check_link_status_work); +} + static void switchtec_ntb_link_notification(struct switchtec_dev *stdev) { struct switchtec_ntb *sndev = stdev->sndev; @@ -577,7 +588,7 @@ static int switchtec_ntb_link_enable(struct ntb_dev *ntb, sndev->self_shared->link_sta = 1; switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP); - switchtec_ntb_check_link(sndev, MSG_CHECK_LINK); + switchtec_ntb_link_status_update(sndev); return 0; } @@ -591,7 +602,7 @@ static int switchtec_ntb_link_disable(struct ntb_dev *ntb) sndev->self_shared->link_sta = 0; switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN); - switchtec_ntb_check_link(sndev, MSG_CHECK_LINK); + switchtec_ntb_link_status_update(sndev); return 0; } @@ -844,7 +855,8 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev) sndev->ntb.topo = NTB_TOPO_SWITCH; sndev->ntb.ops = &switchtec_ntb_ops; - INIT_WORK(&sndev->link_reinit_work, link_reinit_work); + INIT_WORK(&sndev->check_link_status_work, check_link_status_work); + sndev->link_force_down = false; sndev->self_partition = sndev->stdev->partition; -- 2.7.4