From patchwork Fri Oct 30 22:34:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kelley, Sean V" X-Patchwork-Id: 1391344 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; 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 [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CNHDl4RCcz9sS8 for ; Sat, 31 Oct 2020 09:34:47 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725815AbgJ3Weq (ORCPT ); Fri, 30 Oct 2020 18:34:46 -0400 Received: from mga11.intel.com ([192.55.52.93]:45232 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725791AbgJ3Weq (ORCPT ); Fri, 30 Oct 2020 18:34:46 -0400 IronPort-SDR: uLCYMrqCohM5ae6V4tRtqwXID2uJq2+YtcExJMq9dE2jb3q+JrJAwkuE2v7fs8URCYX7zu18s9 1+QBkb6KMl7Q== X-IronPort-AV: E=McAfee;i="6000,8403,9790"; a="165176478" X-IronPort-AV: E=Sophos;i="5.77,434,1596524400"; d="scan'208";a="165176478" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 15:34:46 -0700 IronPort-SDR: E2KERoBIA73u1mSIH5D9pwc2LmTUiiDVEFkjwfMpIe5DFfFfN6/mQZvD9Sv6u27QX/BkowLmel /kpfgZ4xoB1g== X-IronPort-AV: E=Sophos;i="5.77,434,1596524400"; d="scan'208";a="305077169" Received: from divyameh-mobl1.amr.corp.intel.com (HELO arch-ashland-svkelley.intel.com) ([10.209.172.53]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 15:34:45 -0700 From: Sean V Kelley To: bhelgaas@google.com, Jonathan.Cameron@huawei.com, rafael.j.wysocki@intel.com, ashok.raj@intel.com, tony.luck@intel.com, sathyanarayanan.kuppuswamy@intel.com, qiuxu.zhuo@intel.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Sean V Kelley Subject: [PATCH] AER: aer_root_reset() non-native handling Date: Fri, 30 Oct 2020 15:34:43 -0700 Message-Id: <20201030223443.165783-1-sean.v.kelley@intel.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org If an OS has not been granted AER control via _OSC, then the OS should not make changes to PCI_ERR_ROOT_COMMAND and PCI_ERR_ROOT_STATUS related registers. Per section 4.5.1 of the System Firmware Intermediary (SFI) _OSC and DPC Updates ECN [1], this bit also covers these aspects of the PCI Express Advanced Error Reporting. Further, the handling of clear/enable of PCI_ERROR_ROOT_COMMAND when wrapped around PCI_ERR_ROOT_STATUS should have no effect and be removed. Based on the above and earlier discussion [2], make the following changes: Add a check for the native case (i.e., AER control via _OSC) Re-order and remove some of the handling: - clear PCI_ERR_ROOT_COMMAND ROOT_PORT_INTR_ON_MESG_MASK - do reset - clear PCI_ERR_ROOT_STATUS - enable PCI_ERR_ROOT_COMMAND ROOT_PORT_INTR_ON_MESG_MASK to this: - clear PCI_ERR_ROOT_STATUS - do reset The current "clear, reset, enable" order suggests that the reset might cause errors that we should ignore. But I am unable to find a reference and the clearing of PCI_ERR_ROOT_STATUS does not require them. [1] System Firmware Intermediary (SFI) _OSC and DPC Updates ECN, Feb 24, 2020, affecting PCI Firmware Specification, Rev. 3.2 https://members.pcisig.com/wg/PCI-SIG/document/14076 [2] https://lore.kernel.org/linux-pci/20201020162820.GA370938@bjorn-Precision-5520/ Signed-off-by: Sean V Kelley --- drivers/pci/pcie/aer.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index 65dff5f3457a..bbfb07842d89 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -1361,23 +1361,14 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) u32 reg32; int rc; - - /* Disable Root's interrupt in response to error messages */ - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, ®32); - reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32); + if (pcie_aer_is_native(dev)) { + /* Clear Root Error Status */ + pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, ®32); + pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, reg32); + } rc = pci_bus_error_reset(dev); - pci_info(dev, "Root Port link has been reset\n"); - - /* Clear Root Error Status */ - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, ®32); - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, reg32); - - /* Enable Root Port's interrupt in response to error messages */ - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, ®32); - reg32 |= ROOT_PORT_INTR_ON_MESG_MASK; - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32); + pci_info(dev, "Root Port link has been reset (%d)\n", rc); return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED; }