From patchwork Wed Sep 5 20:35:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10589447 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 00F685A4 for ; Wed, 5 Sep 2018 20:38:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E5FEF2ABB0 for ; Wed, 5 Sep 2018 20:38:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DA5BD2ABB8; Wed, 5 Sep 2018 20:38:45 +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 738B92ABB0 for ; Wed, 5 Sep 2018 20:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727781AbeIFBKg (ORCPT ); Wed, 5 Sep 2018 21:10:36 -0400 Received: from mga04.intel.com ([192.55.52.120]:41429 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727477AbeIFBKg (ORCPT ); Wed, 5 Sep 2018 21:10:36 -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 fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Sep 2018 13:38:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,334,1531810800"; d="scan'208";a="260165546" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by fmsmga005.fm.intel.com with ESMTP; 05 Sep 2018 13:38:37 -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 16/20] PCI/pciehp: Implement error handling callbacks Date: Wed, 5 Sep 2018 14:35:42 -0600 Message-Id: <20180905203546.21921-17-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 Error handling may trigger spurious link events, which may trigger hotplug handling to re-enumerate the topology. This patch temporarily disables notification during such error handling and checks the topology for changes after reset. Signed-off-by: Keith Busch --- drivers/pci/hotplug/pciehp.h | 1 + drivers/pci/hotplug/pciehp_core.c | 39 +++++++++++++++++++++++++++++++++++++++ drivers/pci/hotplug/pciehp_hpc.c | 9 +++++++++ 3 files changed, 49 insertions(+) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 3a53a24f22f0..f43bcf291c4e 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -194,6 +194,7 @@ void pciehp_get_attention_status(struct slot *slot, u8 *status); void pciehp_set_attention_status(struct slot *slot, u8 status); void pciehp_get_latch_status(struct slot *slot, u8 *status); void pciehp_get_adapter_status(struct slot *slot, u8 *status); +void pciehp_get_adapter_changed(struct slot *slot, u8 *changed); int pciehp_query_power_fault(struct slot *slot); void pciehp_green_led_on(struct slot *slot); void pciehp_green_led_off(struct slot *slot); diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index ec48c9433ae5..7181fd991068 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -301,6 +301,43 @@ static void pciehp_remove(struct pcie_device *dev) pciehp_release_ctrl(ctrl); } +static void pciehp_error_detected(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + + /* + * Shutdown notification to ignore hotplug events during error + * handling. We'll recheck the status when error handling completes. + * + * It is possible link event related to this error handling may have + * triggered a the hotplug interrupt ahead of this notification, but we + * can't do anything about that race. + */ + pcie_shutdown_notification(ctrl); +} + +static void pciehp_slot_reset(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + u8 changed; + + /* + * Cache presence detect change, but ignore other hotplug events that + * may occur during error handling. Ports that implement only in-band + * presence detection may inadvertently believe the device has changed, + * so those devices will have to be re-enumerated. + */ + pciehp_get_adapter_changed(ctrl->slot, &changed); + pcie_clear_hotplug_events(ctrl); + pcie_init_notification(ctrl); + + if (changed) { + pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC); + __pci_walk_bus(parent, pci_dev_set_disconnected, NULL); + } else if (atomic_read(&ctrl->pending_events) && !pciehp_poll_mode) + irq_wake_thread(ctrl->pcie->irq, ctrl); +} + #ifdef CONFIG_PM static int pciehp_suspend(struct pcie_device *dev) { @@ -340,6 +377,8 @@ static struct pcie_port_service_driver hpdriver_portdrv = { .probe = pciehp_probe, .remove = pciehp_remove, + .error_detected = pciehp_error_detected, + .slot_reset = pciehp_slot_reset, #ifdef CONFIG_PM .suspend = pciehp_suspend, diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 52a18a7ec2a2..5ec2bc871a9c 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -382,6 +382,15 @@ void pciehp_get_adapter_status(struct slot *slot, u8 *status) *status = !!(slot_status & PCI_EXP_SLTSTA_PDS); } +void pciehp_get_adapter_changed(struct slot *slot, u8 *changed) +{ + struct pci_dev *pdev = ctrl_dev(slot->ctrl); + u16 slot_status; + + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + *changed = !!(slot_status & PCI_EXP_SLTSTA_PDC); +} + int pciehp_query_power_fault(struct slot *slot) { struct pci_dev *pdev = ctrl_dev(slot->ctrl);