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/include/asm/eeh.h

@@ -30,6 +30,7 @@
 struct pci_dev;
 struct pci_bus;
 struct device_node;
+struct pci_dn;
 
 #ifdef CONFIG_EEH
 
@@ -137,6 +138,7 @@ struct eeh_dev {
 	struct list_head list;		/* Form link list in the PE	*/
 	struct pci_controller *phb;	/* Associated PHB		*/
 	struct device_node *dn;		/* Associated device node	*/
+	struct pci_dn *pdn;		/* Associated PCI device node	*/
 	struct pci_dev *pdev;		/* Associated PCI device	*/
 	struct pci_bus *bus;		/* PCI bus for partial hotplug	*/
 };
@@ -146,6 +148,11 @@ static inline struct device_node *eeh_dev_to_of_node(struct eeh_dev *edev)
 	return edev ? edev->dn : NULL;
 }
 
+static inline struct pci_dn *eeh_dev_to_pdn(struct eeh_dev *edev)
+{
+	return edev ? edev->pdn : NULL;
+}
+
 static inline struct pci_dev *eeh_dev_to_pci_dev(struct eeh_dev *edev)
 {
 	return edev ? edev->pdev : NULL;
@@ -272,7 +279,7 @@ void eeh_pe_restore_bars(struct eeh_pe *pe);
 const char *eeh_pe_loc_get(struct eeh_pe *pe);
 struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);
 
-void *eeh_dev_init(struct device_node *dn, void *data);
+void *eeh_dev_init(struct pci_dn *pdn, void *data);
 void eeh_dev_phb_init_dynamic(struct pci_controller *phb);
 int eeh_init(void);
 int __init eeh_ops_register(struct eeh_ops *ops);
@@ -323,7 +330,7 @@ static inline int eeh_init(void)
 	return 0;
 }
 
-static inline void *eeh_dev_init(struct device_node *dn, void *data)
+static inline void *eeh_dev_init(struct pci_dn *pdn, void *data)
 {
 	return NULL;
 }

arch/powerpc/include/asm/pci-bridge.h

@@ -213,8 +213,14 @@ static inline struct eeh_dev *of_node_to_eeh_dev(struct device_node *dn)
 
 	return PCI_DN(dn)->edev;
 }
+
+static inline struct eeh_dev *pdn_to_eeh_dev(struct pci_dn *pdn)
+{
+	return pdn ? pdn->edev : NULL;
+}
 #else
 #define of_node_to_eeh_dev(x)	(NULL)
+#define pdn_to_eeh_dev(x)	(NULL)
 #endif
 
 /** Find the bus corresponding to the indicated device node */

arch/powerpc/include/asm/ppc-pci.h

@@ -33,9 +33,14 @@ extern struct pci_dev *isa_bridge_pcidev;	/* may be NULL if no ISA bus */
 
 /* PCI device_node operations */
 struct device_node;
+struct pci_dn;
+
 typedef void *(*traverse_func)(struct device_node *me, void *data);
 void *traverse_pci_devices(struct device_node *start, traverse_func pre,
 		void *data);
+void *traverse_pci_dn(struct pci_dn *root,
+		      void *(*fn)(struct pci_dn *, void *),
+		      void *data);
 
 extern void pci_devs_phb_init(void);
 extern void pci_devs_phb_init_dynamic(struct pci_controller *phb);

arch/powerpc/kernel/eeh_dev.c

@@ -43,13 +43,13 @@
 
 /**
  * eeh_dev_init - Create EEH device according to OF node
- * @dn: device node
+ * @pdn: PCI device node
  * @data: PHB
  *
  * It will create EEH device according to the given OF node. The function
  * might be called by PCI emunation, DR, PHB hotplug.
  */
-void *eeh_dev_init(struct device_node *dn, void *data)
+void *eeh_dev_init(struct pci_dn *pdn, void *data)
 {
 	struct pci_controller *phb = data;
 	struct eeh_dev *edev;
@@ -63,8 +63,8 @@ void *eeh_dev_init(struct device_node *dn, void *data)
 	}
 
 	/* Associate EEH device with OF node */
-	PCI_DN(dn)->edev = edev;
-	edev->dn  = dn;
+	pdn->edev = edev;
+	edev->pdn = pdn;
 	edev->phb = phb;
 	INIT_LIST_HEAD(&edev->list);
 
@@ -80,16 +80,16 @@ void *eeh_dev_init(struct device_node *dn, void *data)
  */
 void eeh_dev_phb_init_dynamic(struct pci_controller *phb)
 {
-	struct device_node *dn = phb->dn;
+	struct pci_dn *root = phb->pci_data;
 
 	/* EEH PE for PHB */
 	eeh_phb_pe_create(phb);
 
 	/* EEH device for PHB */
-	eeh_dev_init(dn, phb);
+	eeh_dev_init(root, phb);
 
 	/* EEH devices for children OF nodes */
-	traverse_pci_devices(dn, eeh_dev_init, phb);
+	traverse_pci_dn(root, eeh_dev_init, phb);
 }
 
 /**

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)

arch/powerpc/platforms/pseries/setup.c

@@ -265,7 +265,7 @@ static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long act
 			update_dn_pci_info(np, pci->phb);
 
 			/* Create EEH device for the OF node */
-			eeh_dev_init(np, pci->phb);
+			eeh_dev_init(PCI_DN(np), pci->phb);
 		}
 		break;
 	default: