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=-17.5 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=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 141B2C433F5 for ; Mon, 20 Sep 2021 20:37:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB792604DC for ; Mon, 20 Sep 2021 20:37:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231481AbhITUjG (ORCPT ); Mon, 20 Sep 2021 16:39:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:52408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229697AbhITUhF (ORCPT ); Mon, 20 Sep 2021 16:37:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 22A1E604DC; Mon, 20 Sep 2021 20:35:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632170138; bh=voQEBfP9XzUDzXjG0DL0BLZOIItOzN1mK1/I5iKEvUE=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=CavUB91uBNFDnMchx2C9ZotlZ2lp7cLpSEIrhMu8L5ixnwF1So13GBAG2Nh+Q5hbm nXyvIb0HsQqjaLzgzCJwLzGBRa8jHrYs7i1JKhHraTi5sLA5fzrgB+ZZ5PaZvExidK Dlab+C+lHdvYWm/UxZcjrP1ZCoA+cg/eB3DYLPv9RkaHlbBR0gdxan5awocdBsrhQ2 wcmiy6UAl8B8IwNhLuZu+CAIZonGpmKxMUIHoIdewx5w9qWgYlYW1xNrKpDL5XAU5l fgqo37Am9WDcRCwVm6ujaOoZXvkuRsmRDGscGvldKxM523PV138P8D8eFnygxyGtAp yuLscK4aXPOhQ== Date: Mon, 20 Sep 2021 15:35:36 -0500 From: Bjorn Helgaas To: Jan Kiszka Cc: linux-pci@vger.kernel.org, Bjorn Helgaas , Linux Kernel Mailing List Subject: Re: [PATCH v2] PCI/portdrv: Do not setup up IRQs if there are no users Message-ID: <20210920203536.GA37479@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8f9a13ac-8ab1-15ac-06cb-c131b488a36f@siemens.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 30, 2021 at 10:08:10AM +0200, Jan Kiszka wrote: > From: Jan Kiszka > > Avoid registering service IRQs if there is no service that offers them > or no driver to register a handler against them. This saves IRQ vectors > when they are limited (e.g. on x86) and also avoids that spurious events > could hit a missing handler. Such spurious events need to be generated > by the Jailhouse hypervisor for active MSI vectors when enabling or > disabling itself. > > Signed-off-by: Jan Kiszka Applied to pci/portdrv for v5.16, thanks! > --- > > Changes in v2: > - move initialization of irqs to address test bot finding > > drivers/pci/pcie/portdrv_core.c | 47 +++++++++++++++++++++------------ > 1 file changed, 30 insertions(+), 17 deletions(-) > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > index e1fed6649c41..0e2556269429 100644 > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -166,9 +166,6 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) > { > int ret, i; > > - for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) > - irqs[i] = -1; > - > /* > * If we support PME but can't use MSI/MSI-X for it, we have to > * fall back to INTx or other interrupts, e.g., a system shared > @@ -312,8 +309,10 @@ static int pcie_device_init(struct pci_dev *pdev, int service, int irq) > */ > int pcie_port_device_register(struct pci_dev *dev) > { > - int status, capabilities, i, nr_service; > - int irqs[PCIE_PORT_DEVICE_MAXSERVICES]; > + int status, capabilities, irq_services, i, nr_service; > + int irqs[PCIE_PORT_DEVICE_MAXSERVICES] = { > + [0 ... PCIE_PORT_DEVICE_MAXSERVICES-1] = -1 > + }; > > /* Enable PCI Express port device */ > status = pci_enable_device(dev); > @@ -326,18 +325,32 @@ int pcie_port_device_register(struct pci_dev *dev) > return 0; > > pci_set_master(dev); > - /* > - * Initialize service irqs. Don't use service devices that > - * require interrupts if there is no way to generate them. > - * However, some drivers may have a polling mode (e.g. pciehp_poll_mode) > - * that can be used in the absence of irqs. Allow them to determine > - * if that is to be used. > - */ > - status = pcie_init_service_irqs(dev, irqs, capabilities); > - if (status) { > - capabilities &= PCIE_PORT_SERVICE_HP; > - if (!capabilities) > - goto error_disable; > + > + irq_services = 0; > + if (IS_ENABLED(CONFIG_PCIE_PME)) > + irq_services |= PCIE_PORT_SERVICE_PME; > + if (IS_ENABLED(CONFIG_PCIEAER)) > + irq_services |= PCIE_PORT_SERVICE_AER; > + if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) > + irq_services |= PCIE_PORT_SERVICE_HP; > + if (IS_ENABLED(CONFIG_PCIE_DPC)) > + irq_services |= PCIE_PORT_SERVICE_DPC; > + irq_services &= capabilities; > + > + if (irq_services) { > + /* > + * Initialize service irqs. Don't use service devices that > + * require interrupts if there is no way to generate them. > + * However, some drivers may have a polling mode (e.g. > + * pciehp_poll_mode) that can be used in the absence of irqs. > + * Allow them to determine if that is to be used. > + */ > + status = pcie_init_service_irqs(dev, irqs, irq_services); > + if (status) { > + irq_services &= PCIE_PORT_SERVICE_HP; > + if (!irq_services) > + goto error_disable; > + } > } > > /* Allocate child services if any */ > -- > 2.31.1