From patchwork Fri Apr 17 07:14:52 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomasz Nowicki X-Patchwork-Id: 6228701 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 52217BF4A6 for ; Fri, 17 Apr 2015 07:18:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4608F20328 for ; Fri, 17 Apr 2015 07:18:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 515F22035C for ; Fri, 17 Apr 2015 07:18:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753687AbbDQHRs (ORCPT ); Fri, 17 Apr 2015 03:17:48 -0400 Received: from mail-la0-f45.google.com ([209.85.215.45]:33714 "EHLO mail-la0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752800AbbDQHPo (ORCPT ); Fri, 17 Apr 2015 03:15:44 -0400 Received: by layy10 with SMTP id y10so73570745lay.0 for ; Fri, 17 Apr 2015 00:15:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+Aif80GFCian/+NBIr6Yx21wWbH6DUrSdb5JidIMlms=; b=G5QPfbaWbv6JG/NsyeY64qg4vM6yNGeVQQZyqVSUzLGQueE3fVR4zgZhEmLEtdb4C0 3JRrk683R059YaqveDxM6CFuUeCWQdDi1JI10nxZn7aP0KYEsxsA4UOkDJPPEkSvnMQb 3qD4glRMqHqupRqfQZYo/fvakhgYTMvWkS2uWYL6D9u08eyNm4oJDqnHr3O2iLNHQDDN lLEPepUT64VgjLQGWt8Hz6cc0+PhXr1R7TumUe1GXmsNUq4RaHlXqL4yCqjsMR99XTVE jXjXAd4g+HemcGUWqrorIncscWMA06RaqbZF03j8Qp8Cie5UM72bKugChjM1KQL9weih 9arg== X-Gm-Message-State: ALoCoQm1Lh/a8InUEMdcqTz2RnowgFvZztZxL3t+u7FoA3Q3cQqmLDC7xGqpiIef0yMnsWvqJs0V X-Received: by 10.152.120.70 with SMTP id la6mr1334875lab.65.1429254943099; Fri, 17 Apr 2015 00:15:43 -0700 (PDT) Received: from tn-HP-4.semihalf.local ([80.82.22.190]) by mx.google.com with ESMTPSA id yq18sm2215742lbb.47.2015.04.17.00.15.41 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 17 Apr 2015 00:15:42 -0700 (PDT) From: Tomasz Nowicki To: bhelgaas@google.com, wangyijing@huawei.com, arnd@arndb.de, hanjun.guo@linaro.org, Liviu.Dudau@arm.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, rjw@rjwysocki.net, al.stone@linaro.org, lorenzo.pieralisi@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linaro-acpi@lists.linaro.org, Tomasz Nowicki Subject: [PATCH v5 3/9] x86, pci: Reorder logic of pci_mmconfig_insert() function Date: Fri, 17 Apr 2015 09:14:52 +0200 Message-Id: <1429254898-32743-4-git-send-email-tomasz.nowicki@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1429254898-32743-1-git-send-email-tomasz.nowicki@linaro.org> References: <1429254898-32743-1-git-send-email-tomasz.nowicki@linaro.org> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is the first step for MMCONFIG refactoring process. Code that uses pci_mmcfg_lock will be moved to common file and become accessible for all architectures. pci_mmconfig_insert() cannot be moved so easily since it is mixing generic mmconfig code with x86 specific logic inside of mutual exclusive block guarded by pci_mmcfg_lock. To get rid of that constraint, we reorder actions as follow: 1. sanity check for mmconfig region presence, if we already have such region it doesn't make snese to alloc new mmconfig list entry 2. mmconfig entry allocation, no need to lock 3. insertion to iomem_resource has its own lock, no need to wrap it into mutex 4. insertion to mmconfig list can be done as the final step in separate function (candidate for further refactoring) and needs another mmconfig lookup to avoid race condition. Signed-off-by: Tomasz Nowicki --- arch/x86/pci/mmconfig-shared.c | 99 +++++++++++++++++++++++++----------------- 1 file changed, 58 insertions(+), 41 deletions(-) diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c index 8b3bc4f..4e001c2 100644 --- a/arch/x86/pci/mmconfig-shared.c +++ b/arch/x86/pci/mmconfig-shared.c @@ -834,6 +834,39 @@ static int __init pci_mmcfg_late_insert_resources(void) */ late_initcall(pci_mmcfg_late_insert_resources); +static int pci_mmconfig_inject(struct pci_mmcfg_region *cfg) +{ + struct pci_mmcfg_region *cfg_conflict; + int err = 0; + + mutex_lock(&pci_mmcfg_lock); + cfg_conflict = pci_mmconfig_lookup(cfg->segment, cfg->start_bus); + if (cfg_conflict) { + if (cfg_conflict->end_bus < cfg->end_bus) + pr_info(FW_INFO "MMCONFIG for " + "domain %04x [bus %02x-%02x] " + "only partially covers this bridge\n", + cfg_conflict->segment, cfg_conflict->start_bus, + cfg_conflict->end_bus); + err = -EEXIST; + goto out; + } + + if (pci_mmcfg_arch_map(cfg)) { + pr_warn("fail to map MMCONFIG %pR.\n", &cfg->res); + err = -ENOMEM; + goto out; + } else { + list_add_sorted(cfg); + pr_info("MMCONFIG at %pR (base %#lx)\n", + &cfg->res, (unsigned long)cfg->address); + + } +out: + mutex_unlock(&pci_mmcfg_lock); + return err; +} + /* Add MMCFG information for host bridges */ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end, phys_addr_t addr) @@ -848,63 +881,47 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end, if (start > end) return -EINVAL; - mutex_lock(&pci_mmcfg_lock); + rcu_read_lock(); cfg = pci_mmconfig_lookup(seg, start); - if (cfg) { - if (cfg->end_bus < end) - dev_info(dev, FW_INFO - "MMCONFIG for " - "domain %04x [bus %02x-%02x] " - "only partially covers this bridge\n", - cfg->segment, cfg->start_bus, cfg->end_bus); - mutex_unlock(&pci_mmcfg_lock); + rcu_read_unlock(); + if (cfg) return -EEXIST; - } - if (!addr) { - mutex_unlock(&pci_mmcfg_lock); - return -EINVAL; - } + if (!addr) + return -EINVAL; rc = -EBUSY; cfg = pci_mmconfig_alloc(seg, start, end, addr); if (cfg == NULL) { dev_warn(dev, "fail to add MMCONFIG (out of memory)\n"); - rc = -ENOMEM; + return -ENOMEM; } else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) { dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n", &cfg->res); - } else { - /* Insert resource if it's not in boot stage */ - if (pci_mmcfg_running_state) - tmp = insert_resource_conflict(&iomem_resource, - &cfg->res); - - if (tmp) { - dev_warn(dev, - "MMCONFIG %pR conflicts with " - "%s %pR\n", - &cfg->res, tmp->name, tmp); - } else if (pci_mmcfg_arch_map(cfg)) { - dev_warn(dev, "fail to map MMCONFIG %pR.\n", - &cfg->res); - } else { - list_add_sorted(cfg); - dev_info(dev, "MMCONFIG at %pR (base %#lx)\n", - &cfg->res, (unsigned long)addr); - cfg = NULL; - rc = 0; - } + goto error; } - if (cfg) { - if (cfg->res.parent) - release_resource(&cfg->res); - kfree(cfg); + /* Insert resource if it's not in boot stage */ + if (pci_mmcfg_running_state) + tmp = insert_resource_conflict(&iomem_resource, &cfg->res); + + if (tmp) { + dev_warn(dev, + "MMCONFIG %pR conflicts with %s %pR\n", + &cfg->res, tmp->name, tmp); + goto error; } - mutex_unlock(&pci_mmcfg_lock); + rc = pci_mmconfig_inject(cfg); + if (rc) + goto error; + + return 0; +error: + if (cfg->res.parent) + release_resource(&cfg->res); + kfree(cfg); return rc; }