From patchwork Thu Jul 14 18:41:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 1656629 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=sIzi7aF/; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by bilbo.ozlabs.org (Postfix) with ESMTP id 4LkNdK4Swkz9s1l for ; Fri, 15 Jul 2022 04:42:13 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238661AbiGNSmL (ORCPT ); Thu, 14 Jul 2022 14:42:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232093AbiGNSmK (ORCPT ); Thu, 14 Jul 2022 14:42:10 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F085959250; Thu, 14 Jul 2022 11:42:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6188EB82885; Thu, 14 Jul 2022 18:42:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 654C1C34114; Thu, 14 Jul 2022 18:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657824125; bh=mDPYepdb8ZMtjYZIy9oLieQo0ev/tUm3Vj50xM8X0vs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sIzi7aF/eVJ0hOZudaNg0t7EaydKlWLoBgQAgqn6wmwiNCxZBn9RfvmAskbV2GRI/ Yj78cZtpmVQxvvKWZ6c4AJ+YJcuiyr582e17YId+zebT7M39boWFHN9HtQatJfnf77 4gGIJwPpJDsNpiYhM+SvgReHBq0kkQiPrMPNVPpV+TGAmTcS9BUrhC4Jt/8lFaPBgw CoTPLlHTGbbRXeTgWlyrqCVFbjUT8Yg+gseWd3SqARsiBGueEWIEX767YofOjoKQP/ 5q9rrxHbeIQn3L3T0MTrvOEgk4Sfz7vmLjnMZsQWIdH1Ot6tCaMDlV2bylEIaxPLDY 6bhl84SG1YLYA== Received: by pali.im (Postfix) id BB5281295; Thu, 14 Jul 2022 20:42:02 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Bjorn Helgaas , Rob Herring , Andrew Lunn , =?utf-8?q?Marek_Beh=C3=BAn?= Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] PCI: Assign PCI domain by ida_alloc() Date: Thu, 14 Jul 2022 20:41:30 +0200 Message-Id: <20220714184130.5436-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220702204737.7719-1-pali@kernel.org> References: <20220702204737.7719-1-pali@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Replace assignment of PCI domain from atomic_inc_return() to ida_alloc(). Use two IDAs, one for static domain allocations (those which are defined in device tree) and second for dynamic allocations (all other). During removal of root bus / host bridge release also allocated domain id. So released id can be reused again, for example in situation when dynamically loading and unloading native PCI host bridge drivers. This change also allows to mix static device tree assignment and dynamic by kernel as all static allocations are reserved in dynamic pool. Signed-off-by: Pali Rohár Tested-by: Jon Hunter --- Idea of this patch comes from the following discussion: https://lore.kernel.org/linux-pci/20210412123936.25555-1-pali@kernel.org/t/#u Changes in v2: * Fix broken compilation --- drivers/pci/pci.c | 103 +++++++++++++++++++++++++------------------ drivers/pci/probe.c | 5 +++ drivers/pci/remove.c | 6 +++ include/linux/pci.h | 1 + 4 files changed, 72 insertions(+), 43 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index cfaf40a540a8..34fdcee6634a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6762,60 +6762,70 @@ static void pci_no_domains(void) } #ifdef CONFIG_PCI_DOMAINS_GENERIC -static atomic_t __domain_nr = ATOMIC_INIT(-1); +static DEFINE_IDA(pci_domain_nr_static_ida); +static DEFINE_IDA(pci_domain_nr_dynamic_ida); -static int pci_get_new_domain_nr(void) +static void of_pci_reserve_static_domain_nr(void) { - return atomic_inc_return(&__domain_nr); + struct device_node *np; + int domain_nr; + + for_each_node_by_type(np, "pci") { + domain_nr = of_get_pci_domain_nr(np); + if (domain_nr < 0) + continue; + /* + * Permanently allocate domain_nr in dynamic_ida + * to prevent it from dynamic allocation. + */ + ida_alloc_range(&pci_domain_nr_dynamic_ida, + domain_nr, domain_nr, GFP_KERNEL); + } } static int of_pci_bus_find_domain_nr(struct device *parent) { - static int use_dt_domains = -1; - int domain = -1; + static bool static_domains_reserved = false; + int domain_nr; - if (parent) - domain = of_get_pci_domain_nr(parent->of_node); + /* On the first call scan device tree for static allocations. */ + if (!static_domains_reserved) { + of_pci_reserve_static_domain_nr(); + static_domains_reserved = true; + } + + if (parent) { + /* + * If domain is in DT then allocate it in static IDA. + * This prevent duplicate static allocations in case + * of errors in DT. + */ + domain_nr = of_get_pci_domain_nr(parent->of_node); + if (domain_nr >= 0) + return ida_alloc_range(&pci_domain_nr_static_ida, + domain_nr, domain_nr, + GFP_KERNEL); + } /* - * Check DT domain and use_dt_domains values. - * - * If DT domain property is valid (domain >= 0) and - * use_dt_domains != 0, the DT assignment is valid since this means - * we have not previously allocated a domain number by using - * pci_get_new_domain_nr(); we should also update use_dt_domains to - * 1, to indicate that we have just assigned a domain number from - * DT. - * - * If DT domain property value is not valid (ie domain < 0), and we - * have not previously assigned a domain number from DT - * (use_dt_domains != 1) we should assign a domain number by - * using the: - * - * pci_get_new_domain_nr() - * - * API and update the use_dt_domains value to keep track of method we - * are using to assign domain numbers (use_dt_domains = 0). - * - * All other combinations imply we have a platform that is trying - * to mix domain numbers obtained from DT and pci_get_new_domain_nr(), - * which is a recipe for domain mishandling and it is prevented by - * invalidating the domain value (domain = -1) and printing a - * corresponding error. + * If domain was not specified in DT then choose free id from dynamic + * allocations. All domain numbers from DT are permanently in dynamic + * allocations to prevent assigning them to other DT nodes without + * static domain. */ - if (domain >= 0 && use_dt_domains) { - use_dt_domains = 1; - } else if (domain < 0 && use_dt_domains != 1) { - use_dt_domains = 0; - domain = pci_get_new_domain_nr(); - } else { - if (parent) - pr_err("Node %pOF has ", parent->of_node); - pr_err("Inconsistent \"linux,pci-domain\" property in DT\n"); - domain = -1; - } + return ida_alloc(&pci_domain_nr_dynamic_ida, GFP_KERNEL); +} - return domain; +static void of_pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent) +{ + if (bus->domain_nr < 0) + return; + + /* Release domain from ida in which was it allocated. */ + if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr) + ida_free(&pci_domain_nr_static_ida, bus->domain_nr); + else + ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr); } int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) @@ -6823,6 +6833,13 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) return acpi_disabled ? of_pci_bus_find_domain_nr(parent) : acpi_pci_bus_find_domain_nr(bus); } + +void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent) +{ + if (!acpi_disabled) + return; + of_pci_bus_release_domain_nr(bus, parent); +} #endif /** diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 17a969942d37..12092d238403 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -906,6 +906,8 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) bus->domain_nr = pci_bus_find_domain_nr(bus, parent); else bus->domain_nr = bridge->domain_nr; + if (bus->domain_nr < 0) + goto free; #endif b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); @@ -1030,6 +1032,9 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) device_del(&bridge->dev); free: +#ifdef CONFIG_PCI_DOMAINS_GENERIC + pci_bus_release_domain_nr(bus, parent); +#endif kfree(bus); return err; } diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 4c54c75050dc..0145aef1b930 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -160,6 +160,12 @@ void pci_remove_root_bus(struct pci_bus *bus) pci_remove_bus(bus); host_bridge->bus = NULL; +#ifdef CONFIG_PCI_DOMAINS_GENERIC + /* Release domain_nr if it was dynamically allocated */ + if (host_bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) + pci_bus_release_domain_nr(bus, host_bridge->dev.parent); +#endif + /* remove the host bridge */ device_del(&host_bridge->dev); } diff --git a/include/linux/pci.h b/include/linux/pci.h index 81a57b498f22..6c7f27e62bcc 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1723,6 +1723,7 @@ static inline int acpi_pci_bus_find_domain_nr(struct pci_bus *bus) { return 0; } #endif int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent); +void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent); #endif /* Some architectures require additional setup to direct VGA traffic */