Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758580Ab3E1CA2 (ORCPT ); Mon, 27 May 2013 22:00:28 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:41518 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758534Ab3E1CA0 (ORCPT ); Mon, 27 May 2013 22:00:26 -0400 MIME-Version: 1.0 In-Reply-To: <1369489718-25869-10-git-send-email-jiang.liu@huawei.com> References: <1369489718-25869-1-git-send-email-jiang.liu@huawei.com> <1369489718-25869-10-git-send-email-jiang.liu@huawei.com> Date: Mon, 27 May 2013 19:00:26 -0700 X-Google-Sender-Auth: prQSJDKMIyk6L1jveBstSpX7jaI Message-ID: Subject: Re: [PATCH v3, part1 09/10] PCI, IOV: simplify IOV implementation From: Yinghai Lu To: Jiang Liu Cc: Bjorn Helgaas , Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List , Donald Dutile , Ram Pai Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5112 Lines: 149 On Sat, May 25, 2013 at 6:48 AM, Jiang Liu wrote: > Trivial changes to IOV: > 1) use new PCI interfaces to simplify IOV implementation > 2) fix some reference count related race windows > > Signed-off-by: Jiang Liu > Cc: Donald Dutile > Cc: Yinghai Lu > Cc: Ram Pai > Cc: linux-pci@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/pci/iov.c | 58 +++++++++++++++++++++---------------------------------- > 1 file changed, 22 insertions(+), 36 deletions(-) > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > index 8f1e117..3e33499 100644 > --- a/drivers/pci/iov.c > +++ b/drivers/pci/iov.c > @@ -51,43 +51,30 @@ static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr) > return child; > } > > -static void virtfn_remove_bus(struct pci_bus *bus, int busnr) > +static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus) > { > - struct pci_bus *child; > - > - if (bus->number == busnr) > - return; > - > - child = pci_find_bus(pci_domain_nr(bus), busnr); > - BUG_ON(!child); > - > - if (list_empty(&child->devices)) > - pci_remove_bus(child); > + if (physbus != virtbus && list_empty(&virtbus->devices)) > + pci_remove_bus(virtbus); > } > > static int virtfn_add(struct pci_dev *dev, int id, int reset) > { > int i; > - int rc; > + int rc = -ENOMEM; > u64 size; > char buf[VIRTFN_ID_LEN]; > - struct pci_dev *virtfn; > + struct pci_dev *virtfn = NULL; > struct resource *res; > struct pci_sriov *iov = dev->sriov; > struct pci_bus *bus; > > - virtfn = pci_alloc_dev(NULL); > - if (!virtfn) > - return -ENOMEM; > - > mutex_lock(&iov->dev->sriov->lock); > bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id)); > - if (!bus) { > - kfree(virtfn); > - mutex_unlock(&iov->dev->sriov->lock); > - return -ENOMEM; > - } > - virtfn->bus = pci_bus_get(bus); > + if (bus) > + virtfn = pci_alloc_dev(bus); > + if (!virtfn) > + goto failed0; > + > virtfn->devfn = virtfn_devfn(dev, id); > virtfn->vendor = dev->vendor; > pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device); > @@ -136,7 +123,8 @@ failed1: > pci_dev_put(dev); > mutex_lock(&iov->dev->sriov->lock); > pci_stop_and_remove_bus_device(virtfn); > - virtfn_remove_bus(dev->bus, virtfn_bus(dev, id)); > + virtfn_remove_bus(dev->bus, bus); > +failed0: need to swap above two lines. otherwise virtual bus could not be removed. > mutex_unlock(&iov->dev->sriov->lock); > > return rc; > @@ -145,20 +133,15 @@ failed1: > static void virtfn_remove(struct pci_dev *dev, int id, int reset) > { > char buf[VIRTFN_ID_LEN]; > - struct pci_bus *bus; > struct pci_dev *virtfn; > struct pci_sriov *iov = dev->sriov; > > - bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id)); > - if (!bus) > - return; > - > - virtfn = pci_get_slot(bus, virtfn_devfn(dev, id)); > + virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), > + virtfn_bus(dev, id), > + virtfn_devfn(dev, id)); > if (!virtfn) > return; > > - pci_dev_put(virtfn); > - > if (reset) { > device_release_driver(&virtfn->dev); > __pci_reset_function(virtfn); > @@ -176,9 +159,11 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset) > > mutex_lock(&iov->dev->sriov->lock); > pci_stop_and_remove_bus_device(virtfn); > - virtfn_remove_bus(dev->bus, virtfn_bus(dev, id)); > + virtfn_remove_bus(dev->bus, virtfn->bus); > mutex_unlock(&iov->dev->sriov->lock); > > + /* balance pci_get_domain_bus_and_slot() */ > + pci_dev_put(virtfn); > pci_dev_put(dev); > } > > @@ -335,13 +320,14 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn) > if (!pdev) > return -ENODEV; > > - pci_dev_put(pdev); > - > - if (!pdev->is_physfn) > + if (!pdev->is_physfn) { > + pci_dev_put(pdev); > return -ENODEV; > + } > > rc = sysfs_create_link(&dev->dev.kobj, > &pdev->dev.kobj, "dep_link"); > + pci_dev_put(pdev); > if (rc) > return rc; > } > -- > 1.8.1.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/