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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F1DA1C432BE for ; Wed, 25 Aug 2021 13:30:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA04E61153 for ; Wed, 25 Aug 2021 13:30:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241199AbhHYNax (ORCPT ); Wed, 25 Aug 2021 09:30:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:58214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231995AbhHYNaw (ORCPT ); Wed, 25 Aug 2021 09:30:52 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 99B8F6113A; Wed, 25 Aug 2021 13:30:06 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mIsyi-00798k-Ia; Wed, 25 Aug 2021 14:30:04 +0100 Date: Wed, 25 Aug 2021 14:30:04 +0100 Message-ID: <87czq1ps83.wl-maz@kernel.org> From: Marc Zyngier To: Barry Song <21cnbao@gmail.com> Cc: bhelgaas@google.com, tglx@linutronix.de, Jonathan.Cameron@huawei.com, bilbao@vt.edu, corbet@lwn.net, gregkh@linuxfoundation.org, leon@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxarm@huawei.com, luzmaximilian@gmail.com, mchehab+huawei@kernel.org, schnelle@linux.ibm.com, jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, intel-wired-lan@lists.osuosl.org, Barry Song Subject: Re: [PATCH v3 2/3] PCI/sysfs: Don't depend on pci_dev.irq for IRQ entry In-Reply-To: <20210825102636.52757-3-21cnbao@gmail.com> References: <20210825102636.52757-1-21cnbao@gmail.com> <20210825102636.52757-3-21cnbao@gmail.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: 21cnbao@gmail.com, bhelgaas@google.com, tglx@linutronix.de, Jonathan.Cameron@huawei.com, bilbao@vt.edu, corbet@lwn.net, gregkh@linuxfoundation.org, leon@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxarm@huawei.com, luzmaximilian@gmail.com, mchehab+huawei@kernel.org, schnelle@linux.ibm.com, jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, intel-wired-lan@lists.osuosl.org, song.bao.hua@hisilicon.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 25 Aug 2021 11:26:35 +0100, Barry Song <21cnbao@gmail.com> wrote: > > From: Barry Song > > Explicitly use IRQ number from MSI list for IRQ sysfs entry. Then sysfs > will decouple with the odd implementation depending on pci_dev.irq. > > Signed-off-by: Barry Song > --- > drivers/pci/pci-sysfs.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index 7bbf2673..f5a06b9 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include > #include "pci.h" > > @@ -49,7 +50,27 @@ static DEVICE_ATTR_RO(field) > pci_config_attr(subsystem_device, "0x%04x\n"); > pci_config_attr(revision, "0x%02x\n"); > pci_config_attr(class, "0x%06x\n"); > -pci_config_attr(irq, "%u\n"); > + > +static ssize_t irq_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > +#ifdef CONFIG_PCI_MSI > + /* > + * For MSI, return the 1st IRQ in IRQ vector; for all other cases > + * including MSI-X, return legacy INTx > + */ > + if (pdev->msi_enabled) { > + struct msi_desc *desc = first_pci_msi_entry(pdev); > + > + return sysfs_emit(buf, "%u\n", desc->irq); > + } > +#endif nit: It would be worth adding a comment indicating that we only do this to preserve an existing userspace ABI. Just in case someone thinks it is pointless and remove it... ;-) M. -- Without deviation from the norm, progress is not possible.