Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755927AbeAHHzf (ORCPT + 1 other); Mon, 8 Jan 2018 02:55:35 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:58788 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755837AbeAHHzb (ORCPT ); Mon, 8 Jan 2018 02:55:31 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 2DB4360B6B Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=poza@codeaurora.org From: Oza Pawandeep To: Bjorn Helgaas , Philippe Ombredanne , Thomas Gleixner , Greg Kroah-Hartman , Kate Stewart , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dongdong Liu , Gabriele Paoloni , Keith Busch , Wei Zhang , Sinan Kaya , Timur Tabi Cc: Oza Pawandeep Subject: [PATCH v3 3/3] PCI/DPC: Enumerate the devices after DPC trigger event Date: Mon, 8 Jan 2018 13:25:05 +0530 Message-Id: <1515398105-10329-4-git-send-email-poza@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1515398105-10329-1-git-send-email-poza@codeaurora.org> References: <1515398105-10329-1-git-send-email-poza@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Implement error_resume callback in DPC, which, after DPC trigger event enumerates the devices beneath. Signed-off-by: Oza Pawandeep diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c index 68296ec..4c6bef3 100644 --- a/drivers/pci/pcie/pcie-dpc.c +++ b/drivers/pci/pcie/pcie-dpc.c @@ -161,6 +161,43 @@ static void dpc_wait_link_inactive(struct dpc_dev *dpc) dev_warn(dev, "Link state not disabled for DPC event\n"); } +static bool dpc_wait_link_active(struct pci_dev *pdev) +{ + unsigned long timeout = jiffies + HZ; + u16 lnk_status; + bool ret = true; + + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + + while (!(lnk_status & PCI_EXP_LNKSTA_DLLLA) && + !time_after(jiffies, timeout)) { + msleep(10); + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + } + + if (!(lnk_status & PCI_EXP_LNKSTA_DLLLA)) { + dev_warn(&pdev->dev, "Link state not enabled after DPC event\n"); + ret = false; + } + + return ret; +} + +/** + * dpc_error_resume - enumerate the devices beneath + * @dev: pointer to Root Port's pci_dev data structure + * + * Invoked by Port Bus driver during nonfatal recovery. + */ +static void dpc_error_resume(struct pci_dev *pdev) +{ + if (dpc_wait_link_active(pdev)) { + pci_lock_rescan_remove(); + pci_rescan_bus(pdev->bus); + pci_unlock_rescan_remove(); + } +} + /** * dpc_reset_link - reset link DPC routine * @dev: pointer to Root Port's pci_dev data structure @@ -419,6 +456,7 @@ static void dpc_remove(struct pcie_device *dev) .service = PCIE_PORT_SERVICE_DPC, .probe = dpc_probe, .remove = dpc_remove, + .error_resume = dpc_error_resume, .reset_link = dpc_reset_link, }; diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c index 858c94c..7d1d20e 100644 --- a/drivers/pci/pcie/pcie-err.c +++ b/drivers/pci/pcie/pcie-err.c @@ -238,7 +238,8 @@ pci_ers_result_t pci_reset_link(struct pci_dev *dev, int severity) pci_ers_result_t pci_broadcast_error_message(struct pci_dev *dev, enum pci_channel_state state, char *error_mesg, - int (*cb)(struct pci_dev *, void *)) + int (*cb)(struct pci_dev *, void *), + int severity) { struct pci_err_broadcast_data result_data; @@ -250,6 +251,15 @@ pci_ers_result_t pci_broadcast_error_message(struct pci_dev *dev, result_data.result = PCI_ERS_RESULT_RECOVERED; if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + /* If DPC is triggered, call resume error hanlder + * because, at this point we can safely assume that + * link recovery has happened. + */ + if ((severity == PCI_ERR_DPC_FATAL) && + (cb == pci_report_resume)) { + cb(dev, NULL); + return PCI_ERS_RESULT_RECOVERED; + } /* * If the error is reported by a bridge, we think this error * is related to the downstream link of the bridge, so we @@ -299,7 +309,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity) status = pci_broadcast_error_message(dev, state, "error_detected", - pci_report_error_detected); + pci_report_error_detected, + severity); if ((severity == PCI_ERR_AER_FATAL) || (severity == PCI_ERR_DPC_FATAL)) { @@ -308,11 +319,15 @@ void pci_do_recovery(struct pci_dev *dev, int severity) goto failed; } + if (severity == PCI_ERR_DPC_FATAL) + goto resume; + if (status == PCI_ERS_RESULT_CAN_RECOVER) status = pci_broadcast_error_message(dev, state, "mmio_enabled", - pci_report_mmio_enabled); + pci_report_mmio_enabled, + severity); if (status == PCI_ERS_RESULT_NEED_RESET) { /* @@ -323,16 +338,19 @@ void pci_do_recovery(struct pci_dev *dev, int severity) status = pci_broadcast_error_message(dev, state, "slot_reset", - pci_report_slot_reset); + pci_report_slot_reset, + severity); } if (status != PCI_ERS_RESULT_RECOVERED) goto failed; +resume: pci_broadcast_error_message(dev, state, "resume", - pci_report_resume); + pci_report_resume, + severity); dev_info(&dev->dev, "Device recovery successful\n"); mutex_unlock(&pci_err_recovery_lock); diff --git a/include/linux/pci.h b/include/linux/pci.h index 123ee15..46e2526 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -2010,7 +2010,8 @@ static inline resource_size_t pci_iov_resource_size(struct pci_dev *dev, int res pci_ers_result_t pci_broadcast_error_message(struct pci_dev *dev, enum pci_channel_state state, char *error_mesg, - int (*cb)(struct pci_dev *, void *)); + int (*cb)(struct pci_dev *, void *), + int severity); int pci_report_mmio_enabled(struct pci_dev *dev, void *data); int pci_report_slot_reset(struct pci_dev *dev, void *data); int pci_report_resume(struct pci_dev *dev, void *data); -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc., a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.