PCI: ACPI PCI slot detection driver

Detect all physical PCI slots as described by ACPI, and create entries in
/sys/bus/pci/slots/.

Not all physical slots are hotpluggable, and the acpiphp module does not
detect them.  Now we know the physical PCI geography of our system, without
caring about hotplug.

[kaneshige.kenji@jp.fujitsu.com: export-kobject_rename-for-pci_hotplug_core]
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Greg KH <greg@kroah.com>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix build with CONFIG_DMI=n]
Signed-off-by: Alex Chiang <achiang@hp.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Len Brown <len.brown@intel.com>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/acpi/Kconfig

@@ -338,6 +338,15 @@ config ACPI_EC
 	  the battery and thermal drivers.  If you are compiling for a 
 	  mobile system, say Y.
 
+config ACPI_PCI_SLOT
+	tristate "PCI slot detection driver"
+	default n
+	help
+	  This driver will attempt to discover all PCI slots in your system,
+	  and creates entries in /sys/bus/pci/slots/. This feature can
+	  help you correlate PCI bus addresses with the physical geography
+	  of your slots. If you are unsure, say N.
+
 config ACPI_POWER
 	bool
 	default y

drivers/acpi/Makefile

@@ -48,6 +48,7 @@ obj-$(CONFIG_ACPI_DOCK)		+= dock.o
 obj-$(CONFIG_ACPI_BAY)		+= bay.o
 obj-$(CONFIG_ACPI_VIDEO)	+= video.o
 obj-y				+= pci_root.o pci_link.o pci_irq.o pci_bind.o
+obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
 obj-$(CONFIG_ACPI_POWER)	+= power.o
 obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
 obj-$(CONFIG_ACPI_CONTAINER)	+= container.o

drivers/pci/hotplug/pci_hotplug_core.c

@@ -572,6 +572,11 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
 	if (tmp)
 		return -EEXIST;
 
+	/*
+	 * No problems if we call this interface from both ACPI_PCI_SLOT
+	 * driver and call it here again. If we've already created the
+	 * pci_slot, the interface will simply bump the refcount.
+	 */
 	pci_slot = pci_create_slot(bus, slot_nr, slot->name);
 	if (IS_ERR(pci_slot))
 		return PTR_ERR(pci_slot);
@@ -585,6 +590,17 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
 	slot->pci_slot = pci_slot;
 	pci_slot->hotplug = slot;
 
+	/*
+	 * Allow pcihp drivers to override the ACPI_PCI_SLOT name.
+	 */
+	if (strcmp(kobject_name(&pci_slot->kobj), slot->name)) {
+		result = kobject_rename(&pci_slot->kobj, slot->name);
+		if (result) {
+			pci_destroy_slot(pci_slot);
+			return result;
+		}
+	}
+
 	spin_lock(&pci_hotplug_slot_list_lock);
 	list_add(&slot->slot_list, &pci_hotplug_slot_list);
 	spin_unlock(&pci_hotplug_slot_list_lock);

lib/kobject.c

@@ -439,6 +439,7 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
 
 	return error;
 }
+EXPORT_SYMBOL_GPL(kobject_rename);
 
 /**
  * kobject_move - move object to another parent