diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index a31cd32c4ce9..75266156943f 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -734,6 +734,33 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, */ #define MAX_WAIT_FOR_RECOVERY 300 + +/* Walks the PE tree after processing an event to remove any stale PEs. + * + * NB: This needs to be recursive to ensure the leaf PEs get removed + * before their parents do. Although this is possible to do recursively + * we don't since this is easier to read and we need to garantee + * the leaf nodes will be handled first. + */ +static void eeh_pe_cleanup(struct eeh_pe *pe) +{ + struct eeh_pe *child_pe, *tmp; + + list_for_each_entry_safe(child_pe, tmp, &pe->child_list, child) + eeh_pe_cleanup(child_pe); + + if (pe->state & EEH_PE_KEEP) + return; + + if (!(pe->state & EEH_PE_INVALID)) + return; + + if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) { + list_del(&pe->child); + kfree(pe); + } +} + /** * eeh_handle_normal_event - Handle EEH events on a specific PE * @pe: EEH PE - which should not be used after we return, as it may @@ -772,8 +799,6 @@ void eeh_handle_normal_event(struct eeh_pe *pe) return; } - eeh_pe_state_mark(pe, EEH_PE_RECOVERING); - eeh_pe_update_time_stamp(pe); pe->freeze_count++; if (pe->freeze_count > eeh_max_freezes) { @@ -963,6 +988,12 @@ void eeh_handle_normal_event(struct eeh_pe *pe) return; } } + + /* + * Clean up any PEs without devices. While marked as EEH_PE_RECOVERYING + * we don't want to modify the PE tree structure so we do it here. + */ + eeh_pe_cleanup(pe); eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); } @@ -1035,6 +1066,7 @@ void eeh_handle_special_event(void) */ if (rc == EEH_NEXT_ERR_FROZEN_PE || rc == EEH_NEXT_ERR_FENCED_PHB) { + eeh_pe_state_mark(pe, EEH_PE_RECOVERING); eeh_handle_normal_event(pe); } else { pci_lock_rescan_remove(); diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c index 64cfbe41174b..e36653e5f76b 100644 --- a/arch/powerpc/kernel/eeh_event.c +++ b/arch/powerpc/kernel/eeh_event.c @@ -121,6 +121,14 @@ int __eeh_send_failure_event(struct eeh_pe *pe) } event->pe = pe; + /* + * Mark the PE as recovering before inserting it in the queue. + * This prevents the PE from being free()ed by a hotplug driver + * while the PE is sitting in the event queue. + */ + if (pe) + eeh_pe_state_mark(pe, EEH_PE_RECOVERING); + /* We may or may not be called in an interrupt context */ spin_lock_irqsave(&eeh_eventlist_lock, flags); list_add(&event->list, &eeh_eventlist); diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c index 1a6254bcf056..177852e39a25 100644 --- a/arch/powerpc/kernel/eeh_pe.c +++ b/arch/powerpc/kernel/eeh_pe.c @@ -470,6 +470,7 @@ int eeh_add_to_parent_pe(struct eeh_dev *edev) int eeh_rmv_from_parent_pe(struct eeh_dev *edev) { struct eeh_pe *pe, *parent, *child; + bool keep, recover; int cnt; pe = eeh_dev_to_pe(edev); @@ -490,10 +491,21 @@ int eeh_rmv_from_parent_pe(struct eeh_dev *edev) */ while (1) { parent = pe->parent; + + /* PHB PEs should never be removed */ if (pe->type & EEH_PE_PHB) break; - if (!(pe->state & EEH_PE_KEEP)) { + /* + * XXX: KEEP is set while resetting a PE. I don't think it's + * ever set without RECOVERING also being set. I could + * be wrong though so catch that with a WARN. + */ + keep = !!(pe->state & EEH_PE_KEEP); + recover = !!(pe->state & EEH_PE_RECOVERING); + WARN_ON(keep && !recover); + + if (!keep && !recover) { if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) { list_del(&pe->child); @@ -502,6 +514,15 @@ int eeh_rmv_from_parent_pe(struct eeh_dev *edev) break; } } else { + /* + * Mark the PE as invalid. At the end of the recovery + * process any invalid PEs will be garbage collected. + * + * We need to delay the free()ing of them since we can + * remove edev's while traversing the PE tree which + * might trigger the removal of a PE and we can't + * deal with that (yet). + */ if (list_empty(&pe->edevs)) { cnt = 0; list_for_each_entry(child, &pe->child_list, child) {