PCI: connect struct pci_dev to struct pci_slot

The introduction of struct pci_slot (f46753c5)
added a struct pci_slot pointer to struct pci_dev, but we forgot to
associate the two.

Connect the two structs together; the interesting portions of the object
lifetimes are:

	- when a new pci_slot is created, connect it to the appropriate
	  pci_dev's. A single pci_slot may be associated with multiple
	  pci_dev's, e.g. any multi-function PCI device.

	- when a pci_slot is released, look for all the pci_dev's it was
	  associated with, and set their pci_slot pointers to NULL

	- when a pci_dev is created, look for slots to associate with.

Note -- when a pci_dev is released, we don't need to do any bookkeeping,
since pci_slot's do not have pointers to pci_dev's.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/probe.c

@@ -949,6 +949,7 @@ EXPORT_SYMBOL(alloc_pci_dev);
 static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 {
 	struct pci_dev *dev;
+	struct pci_slot *slot;
 	u32 l;
 	u8 hdr_type;
 	int delay = 1;
@@ -997,6 +998,10 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	dev->error_state = pci_channel_io_normal;
 	set_pcie_port_type(dev);
 
+	list_for_each_entry(slot, &bus->slots, list)
+		if (PCI_SLOT(devfn) == slot->number)
+			dev->slot = slot;
+
 	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
 	   set this higher, assuming the system even supports it.  */
 	dev->dma_mask = 0xffffffff;

drivers/pci/slot.c

@@ -49,11 +49,16 @@ static ssize_t address_read_file(struct pci_slot *slot, char *buf)
 
 static void pci_slot_release(struct kobject *kobj)
 {
+	struct pci_dev *dev;
 	struct pci_slot *slot = to_pci_slot(kobj);
 
 	pr_debug("%s: releasing pci_slot on %x:%d\n", __func__,
 		 slot->bus->number, slot->number);
 
+	list_for_each_entry(dev, &slot->bus->devices, bus_list)
+		if (PCI_SLOT(dev->devfn) == slot->number)
+			dev->slot = NULL;
+
 	list_del(&slot->list);
 
 	kfree(slot);
@@ -108,6 +113,7 @@ static struct kobj_type pci_slot_ktype = {
 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name)
 {
+	struct pci_dev *dev;
 	struct pci_slot *slot;
 	int err;
 
@@ -150,6 +156,10 @@ placeholder:
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
 
+	list_for_each_entry(dev, &parent->devices, bus_list)
+		if (PCI_SLOT(dev->devfn) == slot_nr)
+			dev->slot = slot;
+
 	/* Don't care if debug printk has a -1 for slot_nr */
 	pr_debug("%s: created pci_slot on %04x:%02x:%02x\n",
 		 __func__, pci_domain_nr(parent), parent->number, slot_nr);