From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 F1CEDC433E2 for ; Mon, 14 Sep 2020 08:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D594221E8 for ; Mon, 14 Sep 2020 08:53:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pwI5R544" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726141AbgINIxI (ORCPT ); Mon, 14 Sep 2020 04:53:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726135AbgINIxG (ORCPT ); Mon, 14 Sep 2020 04:53:06 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46699C06174A; Mon, 14 Sep 2020 01:53:06 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id a8so16013243ilk.1; Mon, 14 Sep 2020 01:53:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=T5blx8lW5RBmUkqia/MfWKUSWxCaOKkHJt1n0OFhjb8=; b=pwI5R544nBDLeZrf6ZYom+3nqKZgTTUGq8yhfwTuop2RItzV7BCkgpCPzFmX8awAT+ +0EHNdBtbADpmqOGDynxt7TCygd8ZhfzYCr4NF938i/Xzv0ImsSrkQm3G3MKjyBBZ+3b 5uAAvG6GgMq4GOXKmD1M3ezGpGjDeVIyPjABU04YL+kmsKoNp1hPtUBxs3cZAoyeN/hp pv9fe3jfXYiFLYYvQVy8ZiAnFtnIL+IeD8mcYVRMU0P3mEw8FOddf1YE4Gg6UbUlL8tp 6vyr4qCNQSmsErj9nQUuv1FrPKlvTXf/bguL//rktufNqeJUUehMSaIPHCTAvK5GolNe Jjgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=T5blx8lW5RBmUkqia/MfWKUSWxCaOKkHJt1n0OFhjb8=; b=czmvVaT1BC8o3rRwSO33FNY0b2/XU3itFfmMfWjbZJw8WR5aanVPxwwe9eWHwx1Z8F 3M6+/4iy7PdKVGv5/j7S94vtHPtlnCTu4o29glzCYAxaFj+2K4f4UhlRGeDNyzoaTgSL eP/hR4iw9+lf+QfLLaLThEqHR1JIv56QqDE6jGgg1A5Pi588nfFKx7YwK92pgtbOZvSk Ryr7GDrEbhGpqbFlx+GVu8z/R20DJ+tF3mh9fO7kijS7VnB33VjIQ6F1fuUjO+Mvcv1G bTBw6vjLuLC6t8gBcG44Q7GHV7oFEmt0CTy3ckLLIsebyISLj4v6b8t+yZkHeCrjz2H4 o7Kg== X-Gm-Message-State: AOAM532Kub4birqnkB87EfaNLW1zmznsvAlrogkwdMcFm7ODK/441j3t PrtnvXBM5HhHrByuMXJVfUZQWAfSOaUnOZ5VanigmZbB6gzNBQ== X-Google-Smtp-Source: ABdhPJw+T5Ark5LxMUndS6SNu7VCFUXc/F2RHXVoAHsK1bYmraQeU5sa2ysv043ZtuHZwITikGt33SyhopnruDg1xz0= X-Received: by 2002:a05:6e02:13ae:: with SMTP id h14mr1587717ilo.208.1600073582860; Mon, 14 Sep 2020 01:53:02 -0700 (PDT) MIME-Version: 1.0 References: <1600070215-3901-1-git-send-email-yangtiezhu@loongson.cn> In-Reply-To: From: Huacai Chen Date: Mon, 14 Sep 2020 16:52:51 +0800 Message-ID: Subject: Re: [RFC PATCH v3] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices To: Tiezhu Yang , Bjorn Helgaas Cc: linux-pci , linux-kernel , "Rafael J. Wysocki" , Konstantin Khlebnikov , Khalid Aziz , Vivek Goyal , Lukas Wunner , "Oliver O'Halloran" , Jiaxun Yang , Xuefeng Li , zhouyanjie , git Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi, Tiezhu, How do you test kexec? kexec -e or systemctl kexec? Or both? P.S., Please also CC my gmail (chenhuacai@gmail.com) since lemote.com has some communication problems. Huacai > > =E9=99=88=E5=8D=8E=E6=89=8D=E6=B1=9F=E8=8B=8F=E8=88=AA=E5=A4=A9=E9=BE=99= =E6=A2=A6=E4=BF=A1=E6=81=AF=E6=8A=80=E6=9C=AF=E6=9C=89=E9=99=90=E5=85=AC=E5= =8F=B8/=E7=A0=94=E5=8F=91=E4=B8=AD=E5=BF=83/=E8=BD=AF=E4=BB=B6=E9=83=A8 -= ----------------- Original ------------------From: "Tiezhu Yang";Date: Mon, Sep 14, 2020 03:57 PMTo: "Bjorn Helgaas"; Cc: "linux-pci"; "linux-kernel"= ; "Rafael J. Wysocki"; "Konstantin Khlebnikov"; "Khalid Aziz"; "Vivek Goyal"; "Lukas Wunner"; "Oliver O'Halloran"; "Huacai Chen"; "Jiaxun Yang"; "Xuefeng Li"; Subject: [RFC PATCH v3] PCI/portdrv: Only disable Bus Master on = kexec reboot and connected PCI devices After commit 745be2e700cd ("PCIe: po= rtdrv: 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 &=3D ~PCI_COMMAND_MASTER; > pci_write_config_word(dev, PCI_COMMAND, pci_command); > } > > pcibios_disable_device(dev); > } > > When remove "pci_command &=3D ~PCI_COMMAND_MASTER;", it can work well whe= n > shutdown or reboot. > > 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 already executed afterwards by the function > pci_device_shutdown(), this is done by commit 4fc9bbf98fd6 ("PCI: Disable > Bus Master only on kexec reboot") and commit 6e0eda3c3898 ("PCI: Don't tr= y > to disable Bus Master on disconnected PCI devices"). > > drivers/pci/pci-driver.c > static void pci_device_shutdown(struct device *dev) > { > ... > if (drv && drv->shutdown) > drv->shutdown(pci_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 <=3D PCI_D3hot)) > pci_clear_master(pci_dev); > } > > [ 36.159446] Call Trace: > [ 36.241688] [] show_stack+0x9c/0x130 > [ 36.326619] [] dump_stack+0xb0/0xf0 > [ 36.410403] [] pcie_portdrv_shutdown+0x18/0x78 > [ 36.495302] [] pci_device_shutdown+0x44/0x90 > [ 36.580027] [] device_shutdown+0x130/0x290 > [ 36.664486] [] kernel_power_off+0x38/0x80 > [ 36.748272] [] __do_sys_reboot+0x1a4/0x258 > [ 36.831985] [] syscall_common+0x34/0x58 > > Signed-off-by: Tiezhu Yang > --- > drivers/pci/pcie/portdrv_core.c | 1 - > drivers/pci/pcie/portdrv_pci.c | 14 +++++++++++++- > 2 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_c= ore.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_pc= i.c > index 3a3ce40..cab37a8 100644 > --- a/drivers/pci/pcie/portdrv_pci.c > +++ b/drivers/pci/pcie/portdrv_pci.c > @@ -143,6 +143,18 @@ 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); > } > > static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, > @@ -211,7 +223,7 @@ static struct pci_driver pcie_portdriver =3D { > > .probe =3D pcie_portdrv_probe, > .remove =3D pcie_portdrv_remove, > - .shutdown =3D pcie_portdrv_remove, > + .shutdown =3D pcie_portdrv_shutdown, > > .err_handler =3D &pcie_portdrv_err_handler, > > -- > 2.1.0