From patchwork Thu Apr 18 08:57:28 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gu Zheng X-Patchwork-Id: 237482 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0CFE52C01D6 for ; Thu, 18 Apr 2013 18:59:10 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754375Ab3DRI7I (ORCPT ); Thu, 18 Apr 2013 04:59:08 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:36577 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754422Ab3DRI7H (ORCPT ); Thu, 18 Apr 2013 04:59:07 -0400 X-IronPort-AV: E=Sophos;i="4.87,500,1363104000"; d="scan'208,223";a="7086245" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 18 Apr 2013 16:56:24 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id r3I8x441017198; Thu, 18 Apr 2013 16:59:04 +0800 Received: from [10.167.233.218] ([10.167.233.218]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2013041816574078-653078 ; Thu, 18 Apr 2013 16:57:40 +0800 Message-ID: <516FB578.7090802@cn.fujitsu.com> Date: Thu, 18 Apr 2013 16:57:28 +0800 From: Gu Zheng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: linux-pci@vger.kernel.org CC: Bjorn Helgaas , Yasuaki Ishimatsu , Taku Izumi , Yinghai Lu , Jiang Liu , tangchen , "'Lin Feng'" , li guang Subject: [PATCH 1/3] PCI: take a reference on the bus object when we capture the struct pci_bus pointer X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/04/18 16:57:40, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/04/18 16:57:41, Serialize complete at 2013/04/18 16:57:41 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From 067ec31ba1cb52c78c24196d5dea5ab0cb86dd9b Mon Sep 17 00:00:00 2001 From: Gu Zheng Date: Thu, 18 Apr 2013 16:51:48 +0900 Subject: [PATCH 1/3] PCI: take a reference on the bus object when we capture the struct pci_bus pointer Take a reference on the bus object when we alloc a pci device on a target pci bus, in order to keep the pci bus valid during the lifetime of devices downstream from it. And introduce pci_bus_get()/pci_bus_put() to hide pci_bus' reference management. Signed-off-by: Gu Zheng Reviewed-by: Tang Chen Reviewed-by: Li Guang --- arch/powerpc/kernel/pci_of_scan.c | 2 +- drivers/pci/bus.c | 14 ++++++++++++++ drivers/pci/iov.c | 4 +++- drivers/pci/probe.c | 2 +- include/linux/pci.h | 3 +++ 5 files changed, 22 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c index 2a67e9b..9e0f6fd 100644 --- a/arch/powerpc/kernel/pci_of_scan.c +++ b/arch/powerpc/kernel/pci_of_scan.c @@ -137,7 +137,7 @@ struct pci_dev *of_create_pci_dev(struct device_node *node, pr_debug(" create device, devfn: %x, type: %s\n", devfn, type); - dev->bus = bus; + dev->bus = pci_bus_get(bus); dev->dev.of_node = of_node_get(node); dev->dev.parent = bus->bridge; dev->dev.bus = &pci_bus_type; diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 8647dc6..8e812bb 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -17,6 +17,20 @@ #include #include "pci.h" +struct pci_bus *pci_bus_get(struct pci_bus *bus) +{ + if (bus) + get_device(&bus->dev); + return bus; +} +EXPORT_SYMBOL(pci_bus_get); + +void pci_bus_put(struct pci_bus *bus) +{ + if (bus) + put_device(&bus->dev); +} +EXPORT_SYMBOL(pci_bus_put); void pci_add_resource_offset(struct list_head *resources, struct resource *res, resource_size_t offset) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee599f2..18798a7 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -73,6 +73,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset) u64 size; char buf[VIRTFN_ID_LEN]; struct pci_dev *virtfn; + struct pci_bus *bus; struct resource *res; struct pci_sriov *iov = dev->sriov; @@ -81,7 +82,8 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset) return -ENOMEM; mutex_lock(&iov->dev->sriov->lock); - virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id)); + bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id)); + virtfn->bus = pci_bus_get(bus); if (!virtfn->bus) { kfree(virtfn); mutex_unlock(&iov->dev->sriov->lock); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b494066..44a6f7d 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1265,7 +1265,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) if (!dev) return NULL; - dev->bus = bus; + dev->bus = pci_bus_get(bus); dev->devfn = devfn; dev->vendor = l & 0xffff; dev->device = (l >> 16) & 0xffff; diff --git a/include/linux/pci.h b/include/linux/pci.h index 710067f..c4d064d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1000,6 +1000,9 @@ int pci_request_selected_regions_exclusive(struct pci_dev *, int, const char *); void pci_release_selected_regions(struct pci_dev *, int); /* drivers/pci/bus.c */ +extern struct pci_bus *pci_bus_get(struct pci_bus *); +extern void pci_bus_put(struct pci_bus *); + void pci_add_resource(struct list_head *resources, struct resource *res); void pci_add_resource_offset(struct list_head *resources, struct resource *res, resource_size_t offset);