From 94bb346480f8646871e5547491b5746ae0a643c3 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 20 Sep 2012 17:09:48 -0600 Subject: [PATCH 1/2] Revert "PCI: Use hotplug-safe pci_get_domain_bus_and_slot()" This reverts commit 433efd2247b0cbf5e7e86275e1f21281d3b99047. When we remove an SR-IOV device, we have this call chain: driver .remove() method pci_disable_sriov() sriov_disable() virtfn_remove() pci_get_domain_bus_and_slot() sriov_disable() is only called for PFs, not for VFs. When it's called for a PF, it loops through all the VFs and calls virtfn_remove() for each. But we stop and remove VFs before PFs, so by the time we get to virtfn_remove(), the VFs have already been stopped and deleted from the device list. Now pci_get_domain_bus_and_slot(), which uses bus_find_device() and relies on that device list, doesn't find the VFs, so the VF references aren't released correctly. Reported-by: Yinghai Lu Signed-off-by: Bjorn Helgaas --- drivers/pci/iov.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index b0fe7712b4d4b..aeccc911abb82 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -152,11 +152,15 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset) 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; - virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), - virtfn_bus(dev, id), virtfn_devfn(dev, id)); + 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)); if (!virtfn) return; From 3891b6acb4f443cbe2e99367ee5e67c6bc29d446 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 19 Sep 2012 11:54:20 -0700 Subject: [PATCH 2/2] PCI: Stop all children first, before removing all children This restores the previous behavior of stopping all child devices before removing any of them. The current SR-IOV design, where removing the PF also drops references on all the VFs, depends on having the VFs continue to exist after having been stopped. [bhelgaas: changelog] Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas --- drivers/pci/remove.c | 51 ++++++++++++++++++++++++++++++-------------- 1 file changed, 35 insertions(+), 16 deletions(-) diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 4f9ca9162895e..513972f3ed136 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -56,25 +56,13 @@ void pci_remove_bus(struct pci_bus *bus) } EXPORT_SYMBOL(pci_remove_bus); -/** - * pci_stop_and_remove_bus_device - remove a PCI device and any children - * @dev: the device to remove - * - * Remove a PCI device from the device lists, informing the drivers - * that the device has been removed. We also remove any subordinate - * buses and children in a depth-first manner. - * - * For each device we remove, delete the device structure from the - * device lists, remove the /proc entry, and notify userspace - * (/sbin/hotplug). - */ -void pci_stop_and_remove_bus_device(struct pci_dev *dev) +static void pci_stop_bus_device(struct pci_dev *dev) { struct pci_bus *bus = dev->subordinate; struct pci_dev *child, *tmp; /* - * Removing an SR-IOV PF device removes all the associated VFs, + * Stopping an SR-IOV PF device removes all the associated VFs, * which will update the bus->devices list and confuse the * iterator. Therefore, iterate in reverse so we remove the VFs * first, then the PF. @@ -82,13 +70,44 @@ void pci_stop_and_remove_bus_device(struct pci_dev *dev) if (bus) { list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list) - pci_stop_and_remove_bus_device(child); + pci_stop_bus_device(child); + } + + pci_stop_dev(dev); +} + +static void pci_remove_bus_device(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->subordinate; + struct pci_dev *child, *tmp; + + if (bus) { + list_for_each_entry_safe(child, tmp, + &bus->devices, bus_list) + pci_remove_bus_device(child); pci_remove_bus(bus); dev->subordinate = NULL; } - pci_stop_dev(dev); pci_destroy_dev(dev); } + +/** + * pci_stop_and_remove_bus_device - remove a PCI device and any children + * @dev: the device to remove + * + * Remove a PCI device from the device lists, informing the drivers + * that the device has been removed. We also remove any subordinate + * buses and children in a depth-first manner. + * + * For each device we remove, delete the device structure from the + * device lists, remove the /proc entry, and notify userspace + * (/sbin/hotplug). + */ +void pci_stop_and_remove_bus_device(struct pci_dev *dev) +{ + pci_stop_bus_device(dev); + pci_remove_bus_device(dev); +} EXPORT_SYMBOL(pci_stop_and_remove_bus_device);