From patchwork Mon Feb 3 23:20:18 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 3572771 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E74D1C02DC for ; Mon, 3 Feb 2014 23:30:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 21B052017B for ; Mon, 3 Feb 2014 23:30:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4159D20176 for ; Mon, 3 Feb 2014 23:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753886AbaBCXa4 (ORCPT ); Mon, 3 Feb 2014 18:30:56 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:65318 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753755AbaBCX23 (ORCPT ); Mon, 3 Feb 2014 18:28:29 -0500 Received: from afcm78.neoplus.adsl.tpnet.pl [95.49.64.78] (HELO vostro.rjw.lan) by serwer1319399.home.pl [79.96.170.134] with SMTP (IdeaSmtpServer v0.80) id 2e1e81fc2256bf19; Tue, 4 Feb 2014 00:28:27 +0100 From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: Mika Westerberg , Bjorn Helgaas , Aaron Lu , Linux Kernel Mailing List , Linux PCI Subject: [PATCH 6/24][Resend] ACPI / hotplug / PCI: Simplify disable_slot() Date: Tue, 04 Feb 2014 00:20:18 +0100 Message-ID: <2631964.LdI8Nm3YsY@vostro.rjw.lan> User-Agent: KMail/4.11.4 (Linux/3.13.0+; KDE/4.11.4; x86_64; ; ) In-Reply-To: <7532948.aJNUotNMpR@vostro.rjw.lan> References: <2217793.001RY6hKlo@vostro.rjw.lan> <20140203104408.GQ18029@intel.com> <7532948.aJNUotNMpR@vostro.rjw.lan> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki After recent PCI core changes related to the rescan/remove locking, the ACPIPHP's disable_slot() function is only called under the general PCI rescan/remove lock, so it doesn't have to use dev_in_slot() any more to avoid race conditions. Make it simply walk the devices on the bus and drop the ones in the slot being disabled and drop dev_in_slot() which has no more users. Moreover, to avoid problems described in the changelog of commit 29ed1f29b68a (PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device), make disable_slot() carry out the list walk in reverse order. Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg --- drivers/pci/hotplug/acpiphp_glue.c | 28 +++++----------------------- 1 file changed, 5 insertions(+), 23 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -625,32 +625,15 @@ static void __ref enable_slot(struct acp } } -/* return first device in slot, acquiring a reference on it */ -static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot) -{ - struct pci_bus *bus = slot->bus; - struct pci_dev *dev; - struct pci_dev *ret = NULL; - - down_read(&pci_bus_sem); - list_for_each_entry(dev, &bus->devices, bus_list) - if (PCI_SLOT(dev->devfn) == slot->device) { - ret = pci_dev_get(dev); - break; - } - up_read(&pci_bus_sem); - - return ret; -} - /** * disable_slot - disable a slot * @slot: ACPI PHP slot */ static void disable_slot(struct acpiphp_slot *slot) { + struct pci_bus *bus = slot->bus; + struct pci_dev *dev, *prev; struct acpiphp_func *func; - struct pci_dev *pdev; /* * enable_slot() enumerates all functions in this device via @@ -658,10 +641,9 @@ static void disable_slot(struct acpiphp_ * methods (_EJ0, etc.) or not. Therefore, we remove all functions * here. */ - while ((pdev = dev_in_slot(slot))) { - pci_stop_and_remove_bus_device(pdev); - pci_dev_put(pdev); - } + list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list) + if (PCI_SLOT(dev->devfn) == slot->device) + pci_stop_and_remove_bus_device(dev); list_for_each_entry(func, &slot->funcs, sibling) acpiphp_bus_trim(func_to_handle(func));