From patchwork Wed Sep 5 20:35:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10589423 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A638813BB for ; Wed, 5 Sep 2018 20:35:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95AA72AB9C for ; Wed, 5 Sep 2018 20:35:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 867DF2ABB3; Wed, 5 Sep 2018 20:35:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BDEFB2AB9C for ; Wed, 5 Sep 2018 20:35:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727758AbeIFBHk (ORCPT ); Wed, 5 Sep 2018 21:07:40 -0400 Received: from mga12.intel.com ([192.55.52.136]:28624 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727599AbeIFBHk (ORCPT ); Wed, 5 Sep 2018 21:07:40 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Sep 2018 13:35:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,334,1531810800"; d="scan'208";a="260164911" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by fmsmga005.fm.intel.com with ESMTP; 05 Sep 2018 13:35:29 -0700 From: Keith Busch To: Linux PCI , Bjorn Helgaas Cc: Benjamin Herrenschmidt , Sinan Kaya , Thomas Tai , poza@codeaurora.org, Lukas Wunner , Christoph Hellwig , Keith Busch Subject: [PATCHv2 05/20] PCI/ERR: Use slot reset if available Date: Wed, 5 Sep 2018 14:35:31 -0600 Message-Id: <20180905203546.21921-6-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180905203546.21921-1-keith.busch@intel.com> References: <20180905203546.21921-1-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The secondary bus reset may have link side effects that a hot plug capable port may incorrectly react to. This patch will use the slot specific reset for hotplug ports, fixing the undesirable link down-up handling during error recovering. Signed-off-by: Keith Busch --- drivers/pci/pci.c | 33 +++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 2 ++ drivers/pci/pcie/aer.c | 2 +- drivers/pci/pcie/err.c | 2 +- drivers/pci/slot.c | 2 +- 5 files changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8eb1d869fc98..1d3b7248e5b9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5164,6 +5164,39 @@ static int pci_bus_reset(struct pci_bus *bus, int probe) return ret; } +/** + * pci_bus_error_reset - reset the bridge's subordinate bus + * @bridge: The parent device that connects to the bus to reset + * + * This function will first try to reset the slots on this bus if the method is + * available. If slot reset fails or is not available, this will fall back to a + * secondary bus reset. + */ +int pci_bus_error_reset(struct pci_dev *bridge) +{ + struct pci_bus *bus = bridge->subordinate; + + if (!bus) + return -ENOTTY; + + mutex_lock(&pci_slot_mutex); + if (!list_empty(&bus->slots)) { + struct pci_slot *slot; + + list_for_each_entry(slot, &bus->slots, list) + if (pci_probe_reset_slot(slot)) + goto bus_reset; + list_for_each_entry(slot, &bus->slots, list) + if (pci_slot_reset(slot, 0)) + goto bus_reset; + } + mutex_unlock(&pci_slot_mutex); + return 0; +bus_reset: + mutex_unlock(&pci_slot_mutex); + return pci_bus_reset(bridge->subordinate, 0); +} + /** * pci_probe_reset_bus - probe whether a PCI bus can be reset * @bus: PCI bus to probe diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 6e0d1528d471..21bfa30db18d 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -35,6 +35,7 @@ int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai, int pci_probe_reset_function(struct pci_dev *dev); int pci_bridge_secondary_bus_reset(struct pci_dev *dev); +int pci_bus_error_reset(struct pci_dev *dev); /** * struct pci_platform_pm_ops - Firmware PM callbacks @@ -136,6 +137,7 @@ static inline void pci_remove_legacy_files(struct pci_bus *bus) { return; } /* Lock for read/write access to pci device and bus lists */ extern struct rw_semaphore pci_bus_sem; +extern struct mutex pci_slot_mutex; extern raw_spinlock_t pci_lock; diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index a95ceba977bb..a96cea39ee80 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -1526,7 +1526,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32); - rc = pci_bridge_secondary_bus_reset(dev); + rc = pci_bus_error_reset(dev); pci_printk(KERN_DEBUG, dev, "Root Port link has been reset\n"); /* Clear Root Error Status */ diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index 708fd3a0d646..12c1205e1d80 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -177,7 +177,7 @@ static pci_ers_result_t default_reset_link(struct pci_dev *dev) { int rc; - rc = pci_bridge_secondary_bus_reset(dev); + rc = pci_bus_error_reset(dev); pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n"); return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED; } diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index e634229ece89..193c909bdd45 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -14,7 +14,7 @@ struct kset *pci_slots_kset; EXPORT_SYMBOL_GPL(pci_slots_kset); -static DEFINE_MUTEX(pci_slot_mutex); +DEFINE_MUTEX(pci_slot_mutex); static ssize_t pci_slot_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)