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Diffstat (limited to 'arch')
-rw-r--r--arch/ppc64/kernel/eeh.c98
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");