[CPCI] Fix potential deadlock on extract found by Rusty Lynch.

Removed cpci_find_slot function that created potential deadlock
condition from the CPCI hotplug API.

drivers/pci/hotplug/cpci_hotplug.h

@@ -75,7 +75,6 @@ extern int cpci_hp_register_controller(struct cpci_hp_controller *controller);
 extern int cpci_hp_unregister_controller(struct cpci_hp_controller *controller);
 extern int cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last);
 extern int cpci_hp_unregister_bus(struct pci_bus *bus);
-extern struct slot *cpci_find_slot(struct pci_bus *bus, unsigned int devfn);
 extern int cpci_hp_start(void);
 extern int cpci_hp_stop(void);
 

drivers/pci/hotplug/cpci_hotplug_core.c

@@ -427,34 +427,6 @@ cpci_hp_unregister_bus(struct pci_bus *bus)
 	return 0;
 }
 
-struct slot *
-cpci_find_slot(struct pci_bus *bus, unsigned int devfn)
-{
-	struct slot *slot;
-	struct slot *found;
-	struct list_head *tmp;
-
-	if(!bus) {
-		return NULL;
-	}
-
-	spin_lock(&list_lock);
-	if(!slots) {
-		spin_unlock(&list_lock);
-		return NULL;
-	}
-	found = NULL;
-	list_for_each(tmp, &slot_list) {
-		slot = list_entry(tmp, struct slot, slot_list);
-		if(slot->bus == bus && slot->devfn == devfn) {
-			found = slot;
-			break;
-		}
-	}
-	spin_unlock(&list_lock);
-	return found;
-}
-
 /* This is the interrupt mode interrupt handler */
 irqreturn_t
 cpci_hp_intr(int irq, void *data, struct pt_regs *regs)
@@ -924,6 +896,5 @@ EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
-EXPORT_SYMBOL_GPL(cpci_find_slot);
 EXPORT_SYMBOL_GPL(cpci_hp_start);
 EXPORT_SYMBOL_GPL(cpci_hp_stop);

drivers/pci/hotplug/cpci_hotplug_pci.c

@@ -448,7 +448,7 @@ static int cpci_configure_bridge(struct pci_bus* bus, struct pci_dev* dev)
 }
 
 static int configure_visit_pci_dev(struct pci_dev_wrapped *wrapped_dev,
-			struct pci_bus_wrapped *wrapped_bus)
+				   struct pci_bus_wrapped *wrapped_bus)
 {
 	int rc;
 	struct pci_dev *dev = wrapped_dev->dev;
@@ -461,8 +461,8 @@ static int configure_visit_pci_dev(struct pci_dev_wrapped *wrapped_dev,
 	 * We need to fix up the hotplug representation with the Linux
 	 * representation.
 	 */
-	slot = cpci_find_slot(dev->bus, dev->devfn);
-	if(slot) {
+	if(wrapped_dev->data) {
+		slot = (struct slot*) wrapped_dev->data;
 		slot->dev = dev;
 	}
 
@@ -504,8 +504,8 @@ static int unconfigure_visit_pci_dev_phase2(struct pci_dev_wrapped *wrapped_dev,
 	/*
 	 * Now remove the hotplug representation.
 	 */
-	slot = cpci_find_slot(dev->bus, dev->devfn);
-	if(slot) {
+	if(wrapped_dev->data) {
+		slot = (struct slot*) wrapped_dev->data;
 		slot->dev = NULL;
 	} else {
 		dbg("No hotplug representation for %02x:%02x.%x",
@@ -603,6 +603,10 @@ int cpci_configure_slot(struct slot* slot)
 				continue;
 			wrapped_dev.dev = dev;
 			wrapped_bus.bus = slot->dev->bus;
+			if(i)
+				wrapped_dev.data = NULL;
+			else
+				wrapped_dev.data = (void*) slot;
 			rc = pci_visit_dev(&configure_functions, &wrapped_dev, &wrapped_bus);
 		}
 	}
@@ -635,9 +639,14 @@ int cpci_unconfigure_slot(struct slot* slot)
 		if(dev) {
 			wrapped_dev.dev = dev;
 			wrapped_bus.bus = dev->bus;
+ 			if(i)
+ 				wrapped_dev.data = NULL;
+ 			else
+ 				wrapped_dev.data = (void*) slot;
 			dbg("%s - unconfigure phase 2", __FUNCTION__);
 			rc = pci_visit_dev(&unconfigure_functions_phase2,
-					   &wrapped_dev, &wrapped_bus);
+					   &wrapped_dev,
+					   &wrapped_bus);
 			if(rc)
 				break;
 		}