From patchwork Sun Nov 22 01:42:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ashok Raj X-Patchwork-Id: 11923719 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13F94C388F9 for ; Sun, 22 Nov 2020 01:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBC2520855 for ; Sun, 22 Nov 2020 01:42:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726913AbgKVBmJ (ORCPT ); Sat, 21 Nov 2020 20:42:09 -0500 Received: from mga14.intel.com ([192.55.52.115]:45385 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726862AbgKVBmI (ORCPT ); Sat, 21 Nov 2020 20:42:08 -0500 IronPort-SDR: sDTV7WweHfdSQM85vxyNYjlncRk//DNif8/thokN8mUKwIH7wmLHjY38cf+c2JdBMiItkJXr98 heeTxHMvLmsA== X-IronPort-AV: E=McAfee;i="6000,8403,9812"; a="170839150" X-IronPort-AV: E=Sophos;i="5.78,360,1599548400"; d="scan'208";a="170839150" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Nov 2020 17:42:07 -0800 IronPort-SDR: x8rt2gW6FNs0ErfjroCYGoJpVzrM2RBK4de4OXfXGz5U7g4bX0C24d6jwx1FJZ3YxBHZ9HBfE+ OPVx365BLahA== X-IronPort-AV: E=Sophos;i="5.78,360,1599548400"; d="scan'208";a="360961567" Received: from araj-mobl1.jf.intel.com (HELO localhost) ([10.252.131.178]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Nov 2020 17:42:07 -0800 From: Ashok Raj To: Lukas Wunner , Bjorn Helgaas Cc: Ashok Raj , linux-pci@vger.kernel.org, Sathyanarayanan Kuppuswamy , linux-kernel@vger.kernel.org Subject: [Patch v2 1/1] PCI: pciehp: Add support for handling MRL events Date: Sat, 21 Nov 2020 17:42:03 -0800 Message-Id: <20201122014203.4706-1-ashok.raj@intel.com> X-Mailer: git-send-email 2.13.6 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When Mechanical Retention Lock (MRL) is present, Linux doesn't process those change events. Support for these can be found starting Icelake Server. The following changes need to be enabled when MRL is present. 1. Subscribe to MRL change events in SlotControl. 2. When MRL is closed, - If there is no ATTN button, then POWER on the slot. - If there is ATTN button, and an MRL event pending, ignore Presence Detect. Since we want ATTN button to drive the hotplug event. - If currently slot is powered on, but MRL is open, PCIe Base Spec 5.0 Chapter 6.7.1.3 states. If an MRL Sensor is implemented without a corresponding MRL Sensor input on the Hot-Plug Controller, it is recommended that the MRL Sensor be routed to power fault input of the Hot-Plug Controller. This allows an active adapter to be powered off when the MRL is opened." This seems to suggest that the slot should be brought down as soon as MRL is opened. Signed-off-by: Ashok Raj Co-developed-by: Kuppuswamy Sathyanarayanan --- Changes since v1: - Changes suggested by Lucas Wunner https://lore.kernel.org/linux-pci/20201119223749.GA103783@otc-nc-03/T/#m1f661ae901e7dedad73dea370bb63abd52c610eb - Consolidate MRL handling in pciehp_handle_presence_or_link_change() - Added helped latch_closed() - Add comments why MRL open should function as hot-remove. - Don't nuke PDC, it might mask a button PUSH synthesized event after 5 secs. - Bjorn: Fix Subject to be consistent with other commits. --- drivers/pci/hotplug/pciehp_ctrl.c | 36 +++++++++++++++++++++++++++++++++++- drivers/pci/hotplug/pciehp_hpc.c | 14 ++++++++++++-- 2 files changed, 47 insertions(+), 3 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index 9f85815b4f53..aa8b187ff769 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -224,9 +224,22 @@ void pciehp_handle_disable_request(struct controller *ctrl) ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL); } +static bool latch_closed(struct controller *ctrl) +{ + u8 getstatus = 0; + + if (!MRL_SENS(ctrl)) + return true; + + pciehp_get_latch_status(ctrl, &getstatus); + + return (getstatus == 0 ? true : false); +} + void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events) { int present, link_active; + u8 getstatus = 0; /* * If the slot is on and presence or link has changed, turn it off. @@ -246,6 +259,20 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events) if (events & PCI_EXP_SLTSTA_PDC) ctrl_info(ctrl, "Slot(%s): Card not present\n", slot_name(ctrl)); + if (events & PCI_EXP_SLTSTA_MRLSC) + ctrl_info(ctrl, "Slot(%s): Latch %s\n", + slot_name(ctrl), getstatus ? "Open" : "Closed"); + /* + * PCIe Base Spec 5.0 Chapter 6.7.1.3 states. + * + * If an MRL Sensor is implemented without a corresponding MRL Sensor input + * on the Hot-Plug Controller, it is recommended that the MRL Sensor be + * routed to power fault input of the Hot-Plug Controller. + * This allows an active adapter to be powered off when the MRL is opened." + * + * This seems to suggest that the slot should be brought down as soon as MRL + * is opened. + */ pciehp_disable_slot(ctrl, SURPRISE_REMOVAL); break; default: @@ -257,7 +284,7 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events) mutex_lock(&ctrl->state_lock); present = pciehp_card_present(ctrl); link_active = pciehp_check_link_active(ctrl); - if (present <= 0 && link_active <= 0) { + if ((present <= 0 && link_active <= 0) || !latch_closed(ctrl)) { mutex_unlock(&ctrl->state_lock); return; } @@ -275,6 +302,13 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events) if (link_active) ctrl_info(ctrl, "Slot(%s): Link Up\n", slot_name(ctrl)); + /* + * If slot is closed && ATTN button exists + * don't continue, let the ATTN button + * drive the hot-plug + */ + if (((events & PCI_EXP_SLTSTA_MRLSC) && ATTN_BUTTN(ctrl))) + return; ctrl->request_result = pciehp_enable_slot(ctrl); break; default: diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 53433b37e181..7cfa27bcf951 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -605,7 +605,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) */ status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC | - PCI_EXP_SLTSTA_DLLSC; + PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_MRLSC; /* * If we've already reported a power fault, don't report it again @@ -710,8 +710,10 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) down_read(&ctrl->reset_lock); if (events & DISABLE_SLOT) pciehp_handle_disable_request(ctrl); - else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) + else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC | + PCI_EXP_SLTSTA_MRLSC)) pciehp_handle_presence_or_link_change(ctrl, events); + up_read(&ctrl->reset_lock); ret = IRQ_HANDLED; @@ -768,6 +770,14 @@ static void pcie_enable_notification(struct controller *ctrl) cmd |= PCI_EXP_SLTCTL_ABPE; else cmd |= PCI_EXP_SLTCTL_PDCE; + + /* + * If MRL sensor is present, then subscribe for MRL + * Changes to be notified as well. + */ + if (MRL_SENS(ctrl)) + cmd |= PCI_EXP_SLTCTL_MRLSCE; + if (!pciehp_poll_mode) cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;