From patchwork Thu Feb 25 15:10:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 1444491 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Dmc6Q57KKz9sBy for ; Fri, 26 Feb 2021 02:25:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231439AbhBYPYg (ORCPT ); Thu, 25 Feb 2021 10:24:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:43376 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230010AbhBYPYZ (ORCPT ); Thu, 25 Feb 2021 10:24:25 -0500 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 97E5C64F14; Thu, 25 Feb 2021 15:23:43 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lFIIG-00Fscv-MQ; Thu, 25 Feb 2021 15:11:08 +0000 From: Marc Zyngier To: Lorenzo Pieralisi , Bjorn Helgaas Cc: Frank Wunderlich , Thierry Reding , Thomas Gleixner , Rob Herring , Will Deacon , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Thierry Reding , Jonathan Hunter , Ryder Lee , Marek Vasut , Yoshihiro Shimoda , Michal Simek , Paul Walmsley , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-renesas-soc@vger.kernel.org Subject: [PATCH 10/13] PCI: MSI: Let PCI host bridges declare their reliance on MSI domains Date: Thu, 25 Feb 2021 15:10:20 +0000 Message-Id: <20210225151023.3642391-11-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210225151023.3642391-1-maz@kernel.org> References: <20210225151023.3642391-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: lorenzo.pieralisi@arm.com, bhelgaas@google.com, frank-w@public-files.de, treding@nvidia.com, tglx@linutronix.de, robh@kernel.org, will@kernel.org, kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, thierry.reding@gmail.com, jonathanh@nvidia.com, ryder.lee@mediatek.com, marek.vasut+renesas@gmail.com, yoshihiro.shimoda.uh@renesas.com, michal.simek@xilinx.com, paul.walmsley@sifive.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-tegra@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-renesas-soc@vger.kernel.org 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-pci@vger.kernel.org The new 'no_msi' attribute solves the problem of advertising the lack of MSI capability for host bridges that know for sure that there will be no MSI for their end-points. However, there is a whole class of host bridges that cannot know whether MSIs will be provided or not, as they rely on other blocks to provide the MSI functionnality, using MSI domains. This is the case for example on systems that use the ARM GIC architecture. Introduce a new attribute ('msi_domain') indicating that implicit dependency, and use this property to set the NO_MSI flag when no MSI domain is found at probe time. Signed-off-by: Marc Zyngier --- drivers/pci/probe.c | 2 +- include/linux/pci.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 146bd85c037e..bac9f69a06a8 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -925,7 +925,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) device_enable_async_suspend(bus->bridge); pci_set_bus_of_node(bus); pci_set_bus_msi_domain(bus); - if (bridge->no_msi) + if (bridge->no_msi || (bridge->msi_domain && !bus->dev.msi_domain)) bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; if (!parent) diff --git a/include/linux/pci.h b/include/linux/pci.h index 9db3abf9fd90..accc2454eab0 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -551,6 +551,7 @@ struct pci_host_bridge { unsigned int preserve_config:1; /* Preserve FW resource setup */ unsigned int size_windows:1; /* Enable root bus sizing */ unsigned int no_msi:1; /* Bridge has no MSI support */ + unsigned int msi_domain:1; /* Bridge wants MSI domain */ /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev,