powerpc/eeh: Handle EEH error based on PE

The patch reworks the current implementation so that the eeh errors
will be handled basing on PE instead of eeh device.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/eeh.h

@@ -174,6 +174,7 @@ int eeh_rmv_from_parent_pe(struct eeh_dev *edev);
 void *eeh_pe_dev_traverse(struct eeh_pe *root,
 		eeh_traverse_func fn, void *flag);
 void eeh_pe_restore_bars(struct eeh_pe *pe);
+struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);
 
 void * __devinit eeh_dev_init(struct device_node *dn, void *data);
 void __devinit eeh_dev_phb_init_dynamic(struct pci_controller *phb);

arch/powerpc/include/asm/eeh_event.h

@@ -32,7 +32,7 @@ struct eeh_event {
 };
 
 int eeh_send_failure_event(struct eeh_pe *pe);
-struct eeh_dev *handle_eeh_events(struct eeh_event *);
+void eeh_handle_event(struct eeh_pe *pe);
 
 #endif /* __KERNEL__ */
 #endif /* ASM_POWERPC_EEH_EVENT_H */

arch/powerpc/platforms/pseries/eeh_event.c

@@ -82,7 +82,7 @@ static int eeh_event_handler(void * dummy)
 		pe->phb->global_number, pe->addr);
 
 	set_current_state(TASK_INTERRUPTIBLE);	/* Don't add to load average */
-	handle_eeh_events(event);
+	eeh_handle_event(pe);
 	eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
 
 	kfree(event);

arch/powerpc/platforms/pseries/eeh_pe.c

@@ -561,3 +561,31 @@ void eeh_pe_restore_bars(struct eeh_pe *pe)
 {
 	eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
 }
+
+/**
+ * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
+ * @pe: EEH PE
+ *
+ * Retrieve the PCI bus according to the given PE. Basically,
+ * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
+ * primary PCI bus will be retrieved. The parent bus will be
+ * returned for BUS PE. However, we don't have associated PCI
+ * bus for DEVICE PE.
+ */
+struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
+{
+	struct pci_bus *bus = NULL;
+	struct eeh_dev *edev;
+	struct pci_dev *pdev;
+
+	if (pe->type == EEH_PE_PHB) {
+		bus = pe->phb->bus;
+	} else if (pe->type == EEH_PE_BUS) {
+		edev = list_first_entry(&pe->edevs, struct eeh_dev, list);
+		pdev = eeh_dev_to_pci_dev(edev);
+		if (pdev)
+			bus = pdev->bus;
+	}
+
+	return bus;
+}