From patchwork Sun Sep 13 20:29:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 11772465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1044D6CA for ; Sun, 13 Sep 2020 20:29:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA580221EB for ; Sun, 13 Sep 2020 20:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725941AbgIMU30 (ORCPT ); Sun, 13 Sep 2020 16:29:26 -0400 Received: from mail.loongson.cn ([114.242.206.163]:43988 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725940AbgIMU3Y (ORCPT ); Sun, 13 Sep 2020 16:29:24 -0400 Received: from linux.localdomain (unknown [117.136.50.205]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dx78cQgV5fOgYVAA--.4954S2; Mon, 14 Sep 2020 04:29:07 +0800 (CST) From: Tiezhu Yang To: Bjorn Helgaas Cc: Konstantin Khlebnikov , Khalid Aziz , Vivek Goyal , Lukas Wunner , oohall@gmail.com, rafael.j.wysocki@intel.com, Xuefeng Li , Huacai Chen , Jiaxun Yang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices Date: Mon, 14 Sep 2020 04:29:10 +0800 Message-Id: <1600028950-10644-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 1.8.3.1 X-CM-TRANSID: AQAAf9Dx78cQgV5fOgYVAA--.4954S2 X-Coremail-Antispam: 1UD129KBjvJXoWxWF1fKFyxGFyUCF4xKF4xXrb_yoWrGw43pF WDGFZayrWFqFy2gw43ZFyxZa45JanFy348tryxG343Wr4fAFy8trWftF90va4kXrZYvFy7 JFZxt348GFWUJF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv014x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Jr0_Gr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4j6r 4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F4 0E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFyl IxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxV AFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAFwI0_ Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUb XdbUUUUUU== X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown"), it also calls pci_disable_device() during shutdown, this leads to shutdown or reboot failure occasionally due to clear PCI_COMMAND_MASTER on the device in do_pci_disable_device(). drivers/pci/pci.c static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); } When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well. As Oliver O'Halloran said, no need to call pci_disable_device() when actually shutting down, but we should call pci_disable_device() before handing over to the new kernel on kexec reboot, so we can do some condition checks which are similar with pci_device_shutdown(), this is done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master on disconnected PCI devices"). drivers/pci/pci-driver.c static void pci_device_shutdown(struct device *dev) { ... /* * If this is a kexec reboot, turn off Bus Master bit on the * device to tell it to not continue to do DMA. Don't touch * devices in D3cold or unknown states. * If it is not a kexec reboot, firmware will hit the PCI * devices with big hammer and stop their DMA any way. */ if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); } Signed-off-by: Tiezhu Yang --- drivers/pci/pcie/portdrv_core.c | 1 - drivers/pci/pcie/portdrv_pci.c | 25 ++++++++++++++++++++++++- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); - pci_disable_device(dev); } /** diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 3a3ce40..ce89a9e8 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "../pci.h" #include "portdrv.h" @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev) } pcie_port_device_remove(dev); + pci_disable_device(dev); +} + +static void pcie_portdrv_shutdown(struct pci_dev *dev) +{ + if (pci_bridge_d3_possible(dev)) { + pm_runtime_forbid(&dev->dev); + pm_runtime_get_noresume(&dev->dev); + pm_runtime_dont_use_autosuspend(&dev->dev); + } + + pcie_port_device_remove(dev); + + /* + * If this is a kexec reboot, turn off Bus Master bit on the + * device to tell it to not continue to do DMA. Don't touch + * devices in D3cold or unknown states. + * If it is not a kexec reboot, firmware will hit the PCI + * devices with big hammer and stop their DMA any way. + */ + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) + pci_disable_device(dev); } static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, @@ -211,7 +234,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev) .probe = pcie_portdrv_probe, .remove = pcie_portdrv_remove, - .shutdown = pcie_portdrv_remove, + .shutdown = pcie_portdrv_shutdown, .err_handler = &pcie_portdrv_err_handler,