powerpc/eeh: Create eeh_dev from pci_dn instead of device_node

The patch adds function traverse_pci_dn(), which is similar to
traverse_pci_devices() except it takes pci_dn, not device_node
as parameter. The pci_dev.c has been reworked to create eeh_dev
from pci_dn, instead of device_node.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/pci_dn.c

@@ -246,6 +246,46 @@ void *traverse_pci_devices(struct device_node *start, traverse_func pre,
 	return NULL;
 }
 
+static struct pci_dn *pci_dn_next_one(struct pci_dn *root,
+				      struct pci_dn *pdn)
+{
+	struct list_head *next = pdn->child_list.next;
+
+	if (next != &pdn->child_list)
+		return list_entry(next, struct pci_dn, list);
+
+	while (1) {
+		if (pdn == root)
+			return NULL;
+
+		next = pdn->list.next;
+		if (next != &pdn->parent->child_list)
+			break;
+
+		pdn = pdn->parent;
+	}
+
+	return list_entry(next, struct pci_dn, list);
+}
+
+void *traverse_pci_dn(struct pci_dn *root,
+		      void *(*fn)(struct pci_dn *, void *),
+		      void *data)
+{
+	struct pci_dn *pdn = root;
+	void *ret;
+
+	/* Only scan the child nodes */
+	for (pdn = pci_dn_next_one(root, pdn); pdn;
+	     pdn = pci_dn_next_one(root, pdn)) {
+		ret = fn(pdn, data);
+		if (ret)
+			return ret;
+	}
+
+	return NULL;
+}
+
 /** 
  * pci_devs_phb_init_dynamic - setup pci devices under this PHB
  * phb: pci-to-host bridge (top-level bridge connecting to cpu)