[POWERPC] EEH: restructure multi-function support

Rework how multi-function PCI devices are identified and traversed.
This fixes a bug with multi-function recovery on Power4 that was
introduced by a recent Power4 EEH patch.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/eeh.c

@@ -282,7 +282,7 @@ void eeh_mark_slot (struct device_node *dn, int mode_flag)
 	dn = find_device_pe (dn);
 
 	/* Back up one, since config addrs might be shared */
-	if (PCI_DN(dn) && PCI_DN(dn)->eeh_pe_config_addr)
+	if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
 		dn = dn->parent;
 
 	PCI_DN(dn)->eeh_mode |= mode_flag;
@@ -316,7 +316,7 @@ void eeh_clear_slot (struct device_node *dn, int mode_flag)
 	dn = find_device_pe (dn);
 	
 	/* Back up one, since config addrs might be shared */
-	if (PCI_DN(dn) && PCI_DN(dn)->eeh_pe_config_addr)
+	if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
 		dn = dn->parent;
 
 	PCI_DN(dn)->eeh_mode &= ~mode_flag;

arch/powerpc/platforms/pseries/eeh_driver.c

@@ -249,6 +249,7 @@ static void eeh_report_failure(struct pci_dev *dev, void *userdata)
 
 static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
 {
+	struct device_node *dn;
 	int cnt, rc;
 
 	/* pcibios will clear the counter; save the value */
@@ -264,22 +265,19 @@ static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
 	if (rc)
 		return rc;
 
- 	/* New-style config addrs might be shared across multiple devices,
- 	 * Walk over all functions on this device */
- 	if (pe_dn->eeh_pe_config_addr) {
- 		struct device_node *pe = pe_dn->node;
- 		pe = pe->parent->child;
- 		while (pe) {
- 			struct pci_dn *ppe = PCI_DN(pe);
+	/* Walk over all functions on this device.  */
+	dn = pe_dn->node;
+	if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
+		dn = dn->parent->child;
+
+	while (dn) {
+		struct pci_dn *ppe = PCI_DN(dn);
+		/* On Power4, always true because eeh_pe_config_addr=0 */
 		if (pe_dn->eeh_pe_config_addr == ppe->eeh_pe_config_addr) {
 			rtas_configure_bridge(ppe);
 			eeh_restore_bars(ppe);
  		}
- 			pe = pe->sibling;
- 		}
- 	} else {
- 		rtas_configure_bridge(pe_dn);
- 		eeh_restore_bars(pe_dn);
+		dn = dn->sibling;
 	}
 
 	/* Give the system 5 seconds to finish running the user-space