diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 18 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pciehp.h | 3 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pciehp_core.c | 2 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pciehp_hpc.c | 19 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pciehp_pci.c | 15 |
5 files changed, 54 insertions, 3 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 63c79e140..f5f201bfc 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -2445,6 +2445,24 @@ static int hv_pci_query_relations(struct hv_device *hdev) if (!ret) ret = wait_for_response(hdev, &comp); + /* + * In the case of fast device addition/removal, it's possible that + * vmbus_sendpacket() or wait_for_response() returns -ENODEV but we + * already got a PCI_BUS_RELATIONS* message from the host and the + * channel callback already scheduled a work to hbus->wq, which can be + * running pci_devices_present_work() -> survey_child_resources() -> + * complete(&hbus->survey_event), even after hv_pci_query_relations() + * exits and the stack variable 'comp' is no longer valid; as a result, + * a hang or a page fault may happen when the complete() calls + * raw_spin_lock_irqsave(). Flush hbus->wq before we exit from + * hv_pci_query_relations() to avoid the issues. Note: if 'ret' is + * -ENODEV, there can't be any more work item scheduled to hbus->wq + * after the flush_workqueue(): see vmbus_onoffer_rescind() -> + * vmbus_reset_channel_cb(), vmbus_rescind_cleanup() -> + * channel->rescind = true. + */ + flush_workqueue(hbus->wq); + return ret; } diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index ef6071807..522719ca1 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -84,6 +84,8 @@ struct slot { * @reset_lock: prevents access to the Data Link Layer Link Active bit in the * Link Status register and to the Presence Detect State bit in the Slot * Status register during a slot reset which may cause them to flap + * @depth: Number of additional hotplug ports in the path to the root bus, + * used as lock subclass for @reset_lock * @slot: pointer to the controller's slot structure * @queue: wait queue to wake up on reception of a Command Completed event, * used for synchronous writes to the Slot Control register @@ -115,6 +117,7 @@ struct controller { struct mutex ctrl_lock; struct pcie_device *pcie; struct rw_semaphore reset_lock; + unsigned int depth; struct slot *slot; wait_queue_head_t queue; u32 slot_cap; diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 518c46f8e..5ebfff935 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -215,7 +215,7 @@ static void pciehp_check_presence(struct controller *ctrl) struct slot *slot = ctrl->slot; u8 occupied; - down_read(&ctrl->reset_lock); + down_read_nested(&ctrl->reset_lock, ctrl->depth); mutex_lock(&slot->lock); pciehp_get_adapter_status(slot, &occupied); diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 279544523..7392b26e9 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -674,7 +674,7 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) * Disable requests have higher priority than Presence Detect Changed * or Data Link Layer State Changed events. */ - down_read(&ctrl->reset_lock); + down_read_nested(&ctrl->reset_lock, ctrl->depth); if (events & DISABLE_SLOT) pciehp_handle_disable_request(slot); else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) @@ -785,7 +785,7 @@ int pciehp_reset_slot(struct slot *slot, int probe) if (probe) return 0; - down_write(&ctrl->reset_lock); + down_write_nested(&ctrl->reset_lock, ctrl->depth); if (!ATTN_BUTTN(ctrl)) { ctrl_mask |= PCI_EXP_SLTCTL_PDCE; @@ -872,6 +872,20 @@ static inline void dbg_ctrl(struct controller *ctrl) #define FLAG(x, y) (((x) & (y)) ? '+' : '-') +static inline int pcie_hotplug_depth(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->bus; + int depth = 0; + + while (bus->parent) { + bus = bus->parent; + if (bus->self && bus->self->is_hotplug_bridge) + depth++; + } + + return depth; +} + struct controller *pcie_init(struct pcie_device *dev) { struct controller *ctrl; @@ -884,6 +898,7 @@ struct controller *pcie_init(struct pcie_device *dev) goto abort; ctrl->pcie = dev; + ctrl->depth = pcie_hotplug_depth(dev->port); pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); if (pdev->hotplug_user_indicators) diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c index 5c58c22e0..a32023afa 100644 --- a/drivers/pci/hotplug/pciehp_pci.c +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -55,7 +55,14 @@ int pciehp_configure_device(struct slot *p_slot) pci_assign_unassigned_bridge_resources(bridge); pcie_bus_configure_settings(parent); + + /* + * Release reset_lock during driver binding + * to avoid AB-BA deadlock with device_lock. + */ + up_read(&ctrl->reset_lock); pci_bus_add_devices(parent); + down_read_nested(&ctrl->reset_lock, ctrl->depth); out: pci_unlock_rescan_remove(); @@ -91,7 +98,15 @@ void pciehp_unconfigure_device(struct slot *p_slot) pci_walk_bus(dev->subordinate, pci_dev_set_disconnected, NULL); } + + /* + * Release reset_lock during driver unbinding + * to avoid AB-BA deadlock with device_lock. + */ + up_read(&ctrl->reset_lock); pci_stop_and_remove_bus_device(dev); + down_read_nested(&ctrl->reset_lock, ctrl->depth); + /* * Ensure that no new Requests will be generated from * the device. |