From patchwork Fri Aug 31 21:26:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 964715 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 422C7y3yLMz9sBn for ; Sat, 1 Sep 2018 07:25:34 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727453AbeIABeu (ORCPT ); Fri, 31 Aug 2018 21:34:50 -0400 Received: from mga12.intel.com ([192.55.52.136]:14103 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727442AbeIABeu (ORCPT ); Fri, 31 Aug 2018 21:34:50 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Aug 2018 14:25:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,313,1531810800"; d="scan'208";a="86663847" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by orsmga001.jf.intel.com with ESMTP; 31 Aug 2018 14:25:29 -0700 From: Keith Busch To: Linux PCI , Bjorn Helgaas Cc: Benjamin Herrenschmidt , Sinan Kaya , Thomas Tai , poza@codeaurora.org, Lukas Wunner , Keith Busch Subject: [PATCH 13/16] PCI/pciehp: Implement error handling callbacks Date: Fri, 31 Aug 2018 15:26:36 -0600 Message-Id: <20180831212639.10196-14-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180831212639.10196-1-keith.busch@intel.com> References: <20180831212639.10196-1-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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 | 51 +++++++++++++++++++++++++++++++++++++++ drivers/pci/hotplug/pciehp_hpc.c | 9 +++++++ 3 files changed, 61 insertions(+) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 811cf83f956d..27abfb504b35 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -195,6 +195,7 @@ 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..acb4d864b4e7 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -301,6 +301,55 @@ static void pciehp_remove(struct pcie_device *dev) pciehp_release_ctrl(ctrl); } +static void pciehp_error_detected(struct pci_dev *dev) +{ + struct controller *ctrl; + struct pcie_device *pcie_dev; + struct device *device = pcie_port_find_device(dev, PCIE_PORT_SERVICE_HP); + + if (!device) + return; + + pcie_dev = to_pcie_device(device); + ctrl = get_service_data(pcie_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 pci_dev *dev) +{ + u8 changed; + struct controller *ctrl; + struct pcie_device *pcie_dev; + struct device *device = pcie_port_find_device(dev, PCIE_PORT_SERVICE_HP); + + if (!device) + return; + + pcie_dev = to_pcie_device(device); + ctrl = get_service_data(pcie_dev); + + /* + * 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); + if (changed) + pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC); + pcie_init_notification(ctrl); +} + #ifdef CONFIG_PM static int pciehp_suspend(struct pcie_device *dev) { @@ -340,6 +389,8 @@ 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 c6116e516e1e..7c43336e08ba 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -398,6 +398,15 @@ 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);