From patchwork Tue Aug 28 15:43:56 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 180513 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 5B7872C009D for ; Wed, 29 Aug 2012 01:45:56 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753366Ab2H1Poq (ORCPT ); Tue, 28 Aug 2012 11:44:46 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:56281 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752900Ab2H1Poo (ORCPT ); Tue, 28 Aug 2012 11:44:44 -0400 Received: by mail-pb0-f46.google.com with SMTP id rr13so9582872pbb.19 for ; Tue, 28 Aug 2012 08:44:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=JEVz/iNVRy3V1/JZa0Xzi93YMdiza2nke0ZxEgVPcbA=; b=A+NWfXA9jpjjcVKsjgFyVNmn9k9r+8ZLGnZxegpr7LqT5LlEVxw/bnDv39dSO4mLmy HJQPlUpjtl5KGiJB5snwiEe+n1e+xSkxQzs/QCn3W0cwmdoyUQQ+W+cRZRAgDkku20bi iiJfOfHV6g279KBQ6St5TNnIHrQFAUU8mx241EdV23xXt/EMhTjSynPMR94bUzMqejnC Hf/6MbdD1v1rfMYs6SCm/9Aa71eJT4rPBDGjQAex0u4M6H8X5DifL5DQRLJxd9wbKmlj Oyledpfe744ISq0DAWIzIlqCqpsUDJHWQQIcksNd/xu9ZVDie4BirC3hB/0TYGClzoaW AOSA== Received: by 10.68.135.39 with SMTP id pp7mr23941903pbb.127.1346168683872; Tue, 28 Aug 2012 08:44:43 -0700 (PDT) Received: from localhost.localdomain ([58.250.81.2]) by mx.google.com with ESMTPS id tq4sm17276577pbc.11.2012.08.28.08.44.37 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 28 Aug 2012 08:44:41 -0700 (PDT) From: Jiang Liu To: Bjorn Helgaas , Scott Murray Cc: Jiang Liu , Don Dutile , Yinghai Lu , Kenji Kaneshige , Yijing Wang , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH 3/5] PCI/cpcihp: simplify code by hotplug safe pci_get_domain_bus_and_slot() Date: Tue, 28 Aug 2012 23:43:56 +0800 Message-Id: <1346168638-32724-4-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1346168638-32724-1-git-send-email-jiang.liu@huawei.com> References: <1346168638-32724-1-git-send-email-jiang.liu@huawei.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Following code has a race window between pci_find_bus() and pci_get_slot() if PCI hotplug operation happens between them which removes the pci_bus. So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead, which also reduces code complexity. struct pci_bus *pci_bus = pci_find_bus(domain, busno); struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn); Signed-off-by: Jiang Liu --- drivers/pci/hotplug/cpcihp_generic.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/pci/hotplug/cpcihp_generic.c b/drivers/pci/hotplug/cpcihp_generic.c index 81af764..a6a71c4 100644 --- a/drivers/pci/hotplug/cpcihp_generic.c +++ b/drivers/pci/hotplug/cpcihp_generic.c @@ -154,12 +154,8 @@ static int __init cpcihp_generic_init(void) if(!r) return -EBUSY; - bus = pci_find_bus(0, bridge_busnr); - if (!bus) { - err("Invalid bus number %d", bridge_busnr); - return -EINVAL; - } - dev = pci_get_slot(bus, PCI_DEVFN(bridge_slot, 0)); + dev = pci_get_domain_bus_and_slot(0, bridge_busnr, + PCI_DEVFN(bridge_slot, 0)); if(!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) { err("Invalid bridge device %s", bridge); pci_dev_put(dev);