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: 6228691 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 49EE29F2EC for ; Fri, 17 Apr 2015 07:18:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4675A20306 for ; Fri, 17 Apr 2015 07:18:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E12A20353 for ; Fri, 17 Apr 2015 07:18:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753686AbbDQHRs (ORCPT ); Fri, 17 Apr 2015 03:17:48 -0400 Received: from mail-la0-f52.google.com ([209.85.215.52]:34762 "EHLO mail-la0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752742AbbDQHPo (ORCPT ); Fri, 17 Apr 2015 03:15:44 -0400 Received: by laat2 with SMTP id t2so73588384laa.1 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=l55ZvnRYvNuLHMncSMIUSXQI1U5XFFY5I6mGjZM6REeJJ0gm4kZIItf89GLN1zy1jM UUvyJfH4WVmiP4sJKhTA1NQHLHl0LKKMK/5nxLPDK8qrTqwXbr916WNflWTzJEmx9D7E 6C339YttZaqAoCaRiHCDdt2B2Mua3qJFaNZg9aCVuBOSKnb/gk8zNs1+CQyppHAcj6T5 5FnYuNh9r/saB2F/xbl6QqYwqROgshzXS8o1tbQ+I8340sAHP9/A8GyT98xVjbwPa+3L QrNR5/YRBhH+aXQgzMUsZ4/LOY3gC1IlW1vtFT9ThWfOqpZ6HppMMvypM9NUi2EOMCSM 9Vxg== X-Gm-Message-State: ALoCoQlv2ibQEdib8Da7eyKQUZxBAmpWYCAsB+v/7Q54/zjTr4YmOyU7eMm3xe5zq7+oNU4LDdpx 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-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@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; }