diff options
| -rw-r--r-- | arch/ppc64/kernel/eeh.c | 98 |
1 files changed, 85 insertions, 13 deletions
diff --git a/arch/ppc64/kernel/eeh.c b/arch/ppc64/kernel/eeh.c index 0060934dffd..e7522f6da69 100644 --- a/arch/ppc64/kernel/eeh.c +++ b/arch/ppc64/kernel/eeh.c @@ -96,6 +96,9 @@ static int ibm_slot_error_detail; static int eeh_subsystem_enabled; +/* Lock to avoid races due to multiple reports of an error */ +static DEFINE_SPINLOCK(confirm_error_lock); + /* Buffer for reporting slot-error-detail rtas calls */ static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX]; static DEFINE_SPINLOCK(slot_errbuf_lock); @@ -544,6 +547,55 @@ static inline unsigned long eeh_token_to_phys(unsigned long token) return pa | (token & (PAGE_SIZE-1)); } +/** + * Return the "partitionable endpoint" (pe) under which this device lies + */ +static struct device_node * find_device_pe(struct device_node *dn) +{ + while ((dn->parent) && PCI_DN(dn->parent) && + (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { + dn = dn->parent; + } + return dn; +} + +/** Mark all devices that are peers of this device as failed. + * Mark the device driver too, so that it can see the failure + * immediately; this is critical, since some drivers poll + * status registers in interrupts ... If a driver is polling, + * and the slot is frozen, then the driver can deadlock in + * an interrupt context, which is bad. + */ + +static inline void __eeh_mark_slot (struct device_node *dn) +{ + while (dn) { + PCI_DN(dn)->eeh_mode |= EEH_MODE_ISOLATED; + + if (dn->child) + __eeh_mark_slot (dn->child); + dn = dn->sibling; + } +} + +static inline void __eeh_clear_slot (struct device_node *dn) +{ + while (dn) { + PCI_DN(dn)->eeh_mode &= ~EEH_MODE_ISOLATED; + if (dn->child) + __eeh_clear_slot (dn->child); + dn = dn->sibling; + } +} + +static inline void eeh_clear_slot (struct device_node *dn) +{ + unsigned long flags; + spin_lock_irqsave(&confirm_error_lock, flags); + __eeh_clear_slot (dn); + spin_unlock_irqrestore(&confirm_error_lock, flags); +} + /** * eeh_dn_check_failure - check if all 1's data is due to EEH slot freeze * @dn device node @@ -567,6 +619,8 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) int reset_state; struct eeh_event *event; struct pci_dn *pdn; + struct device_node *pe_dn; + int rc = 0; __get_cpu_var(total_mmio_ffs)++; @@ -594,10 +648,14 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) return 0; } - /* - * If we already have a pending isolation event for this - * slot, we know it's bad already, we don't need to check... + /* If we already have a pending isolation event for this + * slot, we know it's bad already, we don't need to check. + * Do this checking under a lock; as multiple PCI devices + * in one slot might report errors simultaneously, and we + * only want one error recovery routine running. */ + spin_lock_irqsave(&confirm_error_lock, flags); + rc = 1; if (pdn->eeh_mode & EEH_MODE_ISOLATED) { atomic_inc(&eeh_fail_count); if (atomic_read(&eeh_fail_count) >= EEH_MAX_FAILS) { @@ -606,7 +664,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) rets[0] = -1; /* reset state unknown */ eeh_panic(dev, rets[0]); } - return 0; + goto dn_unlock; } /* @@ -623,7 +681,8 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) printk(KERN_WARNING "EEH: read_slot_reset_state() failed; rc=%d dn=%s\n", ret, dn->full_name); __get_cpu_var(false_positives)++; - return 0; + rc = 0; + goto dn_unlock; } /* If EEH is not supported on this device, punt. */ @@ -631,25 +690,33 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n", ret, dn->full_name); __get_cpu_var(false_positives)++; - return 0; + rc = 0; + goto dn_unlock; } /* If not the kind of error we know about, punt. */ if (rets[0] != 2 && rets[0] != 4 && rets[0] != 5) { __get_cpu_var(false_positives)++; - return 0; + rc = 0; + goto dn_unlock; } /* Note that config-io to empty slots may fail; * we recognize empty because they don't have children. */ if ((rets[0] == 5) && (dn->child == NULL)) { __get_cpu_var(false_positives)++; - return 0; + rc = 0; + goto dn_unlock; } - /* prevent repeated reports of this failure */ - pdn->eeh_mode |= EEH_MODE_ISOLATED; - __get_cpu_var(slot_resets)++; + __get_cpu_var(slot_resets)++; + + /* Avoid repeated reports of this failure, including problems + * with other functions on this device, and functions under + * bridges. */ + pe_dn = find_device_pe (dn); + __eeh_mark_slot (pe_dn); + spin_unlock_irqrestore(&confirm_error_lock, flags); reset_state = rets[0]; @@ -678,10 +745,14 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev) if (rets[0] != 5) dump_stack(); schedule_work(&eeh_event_wq); - return 0; + return 1; + +dn_unlock: + spin_unlock_irqrestore(&confirm_error_lock, flags); + return rc; } -EXPORT_SYMBOL(eeh_dn_check_failure); +EXPORT_SYMBOL_GPL(eeh_dn_check_failure); /** * eeh_check_failure - check if all 1's data is due to EEH slot freeze @@ -820,6 +891,7 @@ void __init eeh_init(void) struct device_node *phb, *np; struct eeh_early_enable_info info; + spin_lock_init(&confirm_error_lock); spin_lock_init(&slot_errbuf_lock); np = of_find_node_by_path("/rtas"); |