powerpc/pseries: Cleanup on pci_dn_reconfig_notifier()

This applies cleanup on pci_dn_reconfig_notifier(), no functional
changes:

   * Rename variable "pci" to "pdn" to indicate its purpose clearly.
   * The parent node can be released at any time. So it should be
     hold with of_get_parent() before accessing it.
   * The device node doesn't have to have parent node in theory.
     More check on this.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 13 insertions, 11 deletions

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index e6e8b241d717..39a74fad3e04 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -254,24 +254,26 @@ static void __init pseries_discover_pic(void)
 static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *data)
 {
         struct of_reconfig_data *rd = data;
-        struct device_node *np = rd->dn;
-        struct pci_dn *pci = NULL;
+        struct device_node *parent, *np = rd->dn;
+        struct pci_dn *pdn;
         int err = NOTIFY_OK;
 
         switch (action) {
         case OF_RECONFIG_ATTACH_NODE:
-                pci = np->parent->data;
-                if (pci) {
-                        update_dn_pci_info(np, pci->phb);
-
-                        /* Create EEH device for the OF node */
-                        eeh_dev_init(PCI_DN(np), pci->phb);
+                parent = of_get_parent(np);
+                pdn = parent ? PCI_DN(parent) : NULL;
+                if (pdn) {
+                        /* Create pdn and EEH device */
+                        update_dn_pci_info(np, pdn->phb);
+                        eeh_dev_init(PCI_DN(np), pdn->phb);
                 }
+
+                of_node_put(parent);
                 break;
         case OF_RECONFIG_DETACH_NODE:
-                pci = PCI_DN(np);
-                if (pci)
-                        list_del(&pci->list);
+                pdn = PCI_DN(np);
+                if (pdn)
+                        list_del(&pdn->list);
                 break;
         default:
                 err = NOTIFY_DONE;