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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CD683C04FF3 for ; Mon, 24 May 2021 22:31:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A70D1613D6 for ; Mon, 24 May 2021 22:31:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229503AbhEXWcm (ORCPT ); Mon, 24 May 2021 18:32:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:36208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229532AbhEXWcl (ORCPT ); Mon, 24 May 2021 18:32:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 148BA61400; Mon, 24 May 2021 22:31:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621895472; bh=BgaJ6bBhVMSkPpMM7ztBqXvDF9jcSK5FB4nnN1qd4Yo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=AgHsVEFBenklmyX1hvqgZjknjAn7LHOxyMuGLVu9LNmAYDAtNUj9iKdnYmzFLuiDw Q85vCAkBIAjFjk0VVo8CDUcTKGq04HyBtZwESvE+TrueP/hR0x7H4CRb9SHUQ1Imrj XNrVu9bgAYXShzr/ANMuBCyYck8YKrEJVAkoB3zmPaWIDvH1vbWcS09kBrL3gOouhP nq+5qZLUV/4qYb348My/vhdzv9IYZOsOSiiC+nwavxEUEfAQc8y7qht5WMs8BgTy5+ NDiyRLebtUYPsqnNFFT0EaG3MQPi2R17goboHHtzfyhEx1XjpqlS5AykKG4l4Luy6H S340JNQNSaX4g== Date: Mon, 24 May 2021 17:31:10 -0500 From: Bjorn Helgaas To: Raphael Norwitz Cc: "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "alex.williamson@redhat.com" , "ameynarkhede03@gmail.com" Subject: Re: [PATCH v2] PCI: merge slot and bus reset implementations Message-ID: <20210524223110.GA1127348@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210408182328.12323-1-raphael.norwitz@nutanix.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Apr 08, 2021 at 06:23:40PM +0000, Raphael Norwitz wrote: > Slot resets are bus resets with additional logic to prevent a device > from being removed during the reset. Currently slot and bus resets have > separate implementations in pci.c, complicating higher level logic. As > discussed on the mailing list, they should be combined into a generic > function which performs an SBR. This change adds a function, > pci_reset_bus_function(), which first attempts a slot reset and then > attempts a bus reset if -ENOTTY is returned, such that there is now a > single device agnostic function to perform an SBR. > > This new function is also needed to add SBR reset quirks and therefore > is exposed in pci.h. I dropped this exposure in pci.h because there's no user yet. We can expose it when we add the user. > Link: https://lkml.org/lkml/2021/3/23/911 > > Suggested-by: Alex Williamson > Signed-off-by: Amey Narkhede > Signed-off-by: Raphael Norwitz Applied to pci/reset for v5.14 with subject "PCI: Add pci_reset_bus_function() Secondary Bus Reset interface" I attached the patch as applied. > --- > drivers/pci/pci.c | 19 +++++++++++-------- > include/linux/pci.h | 1 + > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 16a17215f633..a8f8dd588d15 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4982,6 +4982,15 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > } > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > +{ > + int rc = pci_dev_reset_slot_function(dev, probe); > + > + if (rc != -ENOTTY) > + return rc; > + return pci_parent_bus_reset(dev, probe); > +} > + > static void pci_dev_lock(struct pci_dev *dev) > { > pci_cfg_access_lock(dev); > @@ -5102,10 +5111,7 @@ int __pci_reset_function_locked(struct pci_dev *dev) > rc = pci_pm_reset(dev, 0); > if (rc != -ENOTTY) > return rc; > - rc = pci_dev_reset_slot_function(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - return pci_parent_bus_reset(dev, 0); > + return pci_reset_bus_function(dev, 0); > } > EXPORT_SYMBOL_GPL(__pci_reset_function_locked); > > @@ -5135,13 +5141,10 @@ int pci_probe_reset_function(struct pci_dev *dev) > if (rc != -ENOTTY) > return rc; > rc = pci_pm_reset(dev, 1); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_dev_reset_slot_function(dev, 1); > if (rc != -ENOTTY) > return rc; > > - return pci_parent_bus_reset(dev, 1); > + return pci_reset_bus_function(dev, 1); > } > > /** > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 86c799c97b77..979d54335ac1 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1228,6 +1228,7 @@ int pci_probe_reset_bus(struct pci_bus *bus); > int pci_reset_bus(struct pci_dev *dev); > void pci_reset_secondary_bus(struct pci_dev *dev); > void pcibios_reset_secondary_bus(struct pci_dev *dev); > +int pci_reset_bus_function(struct pci_dev *dev, int probe); > void pci_update_resource(struct pci_dev *dev, int resno); > int __must_check pci_assign_resource(struct pci_dev *dev, int i); > int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); > -- > 2.20.1 commit 0dad3ce523c2 ("PCI: Add pci_reset_bus_function() Secondary Bus Reset interface") Author: Raphael Norwitz Date: Thu Apr 8 18:23:40 2021 +0000 PCI: Add pci_reset_bus_function() Secondary Bus Reset interface pci_parent_bus_reset() resets a device by performing a Secondary Bus Reset on a PCI-to-PCI bridge leading to the device. pci_dev_reset_slot_function() does the same, except that it uses a hotplug driver to keep the reset from looking like a hot-remove followed by a hot-add. Add a pci_reset_bus_function() wrapper, which attempts the hotplug driver slot reset and falls back to the parent bus reset if that fails. This provides a single interface for performing a Secondary Bus Reset. [bhelgaas: commit log, don't expose yet] Suggested-by: Alex Williamson Link: https://lore.kernel.org/r/20210323100625.0021a943@omen.home.shazbot.org/ Link: https://lore.kernel.org/r/20210408182328.12323-1-raphael.norwitz@nutanix.com Signed-off-by: Amey Narkhede Signed-off-by: Raphael Norwitz Signed-off-by: Bjorn Helgaas Reviewed-by: Leon Romanovsky diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b717680377a9..452351025a09 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5020,6 +5020,16 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) return pci_reset_hotplug_slot(dev->slot->hotplug, probe); } +static int pci_reset_bus_function(struct pci_dev *dev, int probe) +{ + int rc; + + rc = pci_dev_reset_slot_function(dev, probe); + if (rc != -ENOTTY) + return rc; + return pci_parent_bus_reset(dev, probe); +} + static void pci_dev_lock(struct pci_dev *dev) { pci_cfg_access_lock(dev); @@ -5140,10 +5150,7 @@ int __pci_reset_function_locked(struct pci_dev *dev) rc = pci_pm_reset(dev, 0); if (rc != -ENOTTY) return rc; - rc = pci_dev_reset_slot_function(dev, 0); - if (rc != -ENOTTY) - return rc; - return pci_parent_bus_reset(dev, 0); + return pci_reset_bus_function(dev, 0); } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); @@ -5173,13 +5180,10 @@ int pci_probe_reset_function(struct pci_dev *dev) if (rc != -ENOTTY) return rc; rc = pci_pm_reset(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_dev_reset_slot_function(dev, 1); if (rc != -ENOTTY) return rc; - return pci_parent_bus_reset(dev, 1); + return pci_reset_bus_function(dev, 1); } /**