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 16233C43461 for ; Mon, 14 Sep 2020 09:46:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC27D206C9 for ; Mon, 14 Sep 2020 09:46:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qeiS4KEP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726239AbgINJqf (ORCPT ); Mon, 14 Sep 2020 05:46:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726123AbgINJqe (ORCPT ); Mon, 14 Sep 2020 05:46:34 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0F32C06174A; Mon, 14 Sep 2020 02:46:33 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id h11so16058485ilj.11; Mon, 14 Sep 2020 02:46:33 -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=/9I43OVYVT+SBSF0odPJ52ZAVfnV0eE37Qzcr9mvLBI=; b=qeiS4KEPYYj02Rd4Ha3R8PvWiE9fUK7saHD5H4Xtui5wPazYavwYDvx0fw/Lw2nDs3 9hc8B5vvbqmjS1tCX6rcZL3WZoQJGiwTDBJ5FEaqk0LTto3FiFevzFIvExt66EWjF3ku aR1nK4SLEtdu21j+aan9iMr+Z1WCvL4XrcvFN2D66Q24OBT4TrmeI5J/4qOeINCAT4hj cw15cUM4k/QwheE3PpJ2ayM/zNf8Yx+89k3tXwPd5j3p5kpdWei+VVgqojlS4nHJN4Nz tSBdixybSoaLPLOO+T7ADS0iPFXu8wxB+hgfVov4GCzxWE2/DOgIbF+Adwmqs5NkjAB6 6PTA== 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=/9I43OVYVT+SBSF0odPJ52ZAVfnV0eE37Qzcr9mvLBI=; b=ICOu6GORoPih1jt+Ik7hwmW2OU0KuD0qPEUmvS1wqnurCAobxWNDzwNlIRh2dK9HQ5 ka9XMA8N871+hxVb3Dyq3E4+D0/13jYUdytt98nHITLcUo8uS4S4ayKD9F4mN9eQgLaK ICMkeO0pHw3nzstujH67gwU7vWiCe3kLgOCew52CGFlDhJCuiXCW70fFHD0OUGzOJfUU MevPWNOmX0lrz6y9Q8jhRjsj3m5Rf1476UzdazVEIpkyxI41NG6auXdC+koBIinJ6epx hV7uQQ17Mibvls1p7vcqyZ271DFypLWgZlitvdtAXxV5oj4Qx3VLcl+Q/2iwscLh+ZfE IlXA== X-Gm-Message-State: AOAM533b052Uzn8gq3Iw2Pq1zxdQJB4yjKhPxK6Xcv7PR/rKIdqWA7eE K24ECayncHXXm861LLc9R6CSwX3SaYn7np1FXi8= X-Google-Smtp-Source: ABdhPJwNXpSkr/63NMwPPV3POlpuMOEgYSEme7+UQwIuz7MEZemwqDXCkms4WI+anyndmMAWZE+vZiBf6VEU5QUAjCI= X-Received: by 2002:a92:d1d0:: with SMTP id u16mr6354316ilg.171.1600076791491; Mon, 14 Sep 2020 02:46:31 -0700 (PDT) MIME-Version: 1.0 References: <1600070215-3901-1-git-send-email-yangtiezhu@loongson.cn> <45a3e3a0-3dc6-e60e-9381-b436a7d6889a@loongson.cn> In-Reply-To: <45a3e3a0-3dc6-e60e-9381-b436a7d6889a@loongson.cn> From: Huacai Chen Date: Mon, 14 Sep 2020 17:46:19 +0800 Message-ID: Subject: Re: [RFC PATCH v3] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices To: Tiezhu Yang Cc: Bjorn Helgaas , 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, On Mon, Sep 14, 2020 at 5:30 PM Tiezhu Yang wrote: > > On 09/14/2020 04:52 PM, Huacai Chen wrote: > > Hi, Tiezhu, > > > > How do you test kexec? kexec -e or systemctl kexec? Or both? > > kexec -l vmlinux --append=3D"root=3D/dev/sda2 console=3DttyS0,115200" > kexec -e So you haven't tested "systemctl kexec"? Huacai > > > P.S., Please also CC my gmail (chenhuacai@gmail.com) since lemote.com > > has some communication problems. > > OK, no problem. > > > > > 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-kern= el"; "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:= 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 &=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 = when > >> 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: Disa= ble > >> 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 (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_D3h= ot)) > >> 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/portdr= v_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..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 *d= ev) > >> } > >> > >> 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 >