PCI: shpchp: Iterate over all devices in slot, not functions 0-7

Iterate through devices in a slot by using the upstream bridge's
"bus->devices" list instead of assuming they are functions 0-7.  It's
possible there are several slots on the same pci_bus, so restrict it to
only devices matching this slot's device number.

ARI (which allows functions 0-255) is a PCIe-only feature, and this is
a PCI hotplug driver, so we shouldn't find anything other than functions
0-7, but it's better to iterate the same way as other hotplug drivers.

[bhelgaas: changelog, check PCI_SLOT, fix shpchp_unconfigure_device()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/hotplug/shpchp_pci.c

@@ -40,7 +40,7 @@ int __ref shpchp_configure_device(struct slot *p_slot)
 	struct controller *ctrl = p_slot->ctrl;
 	struct pci_dev *bridge = ctrl->pci_dev;
 	struct pci_bus *parent = bridge->subordinate;
-	int num, fn;
+	int num;
 
 	dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, 0));
 	if (dev) {
@@ -57,24 +57,20 @@ int __ref shpchp_configure_device(struct slot *p_slot)
 		return -ENODEV;
 	}
 
-	for (fn = 0; fn < 8; fn++) {
-		dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, fn));
-		if (!dev)
+	list_for_each_entry(dev, &parent->devices, bus_list) {
+		if (PCI_SLOT(dev->devfn) != p_slot->device)
 			continue;
 		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
 		    (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
 			pci_hp_add_bridge(dev);
-		pci_dev_put(dev);
 	}
 
 	pci_assign_unassigned_bridge_resources(bridge);
 
-	for (fn = 0; fn < 8; fn++) {
-		dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, fn));
-		if (!dev)
+	list_for_each_entry(dev, &parent->devices, bus_list) {
+		if (PCI_SLOT(dev->devfn) != p_slot->device)
 			continue;
 		pci_configure_slot(dev);
-		pci_dev_put(dev);
 	}
 
 	pci_bus_add_devices(parent);
@@ -85,32 +81,32 @@ int __ref shpchp_configure_device(struct slot *p_slot)
 int shpchp_unconfigure_device(struct slot *p_slot)
 {
 	int rc = 0;
-	int j;
 	u8 bctl = 0;
 	struct pci_bus *parent = p_slot->ctrl->pci_dev->subordinate;
+	struct pci_dev *dev, *temp;
 	struct controller *ctrl = p_slot->ctrl;
 
 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:%02x\n",
 		 __func__, pci_domain_nr(parent), p_slot->bus, p_slot->device);
 
-	for (j = 0; j < 8 ; j++) {
-		struct pci_dev *temp = pci_get_slot(parent,
-				(p_slot->device << 3) | j);
-		if (!temp)
+	list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {
+		if (PCI_SLOT(dev->devfn) != p_slot->device)
 			continue;
-		if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
-			pci_read_config_byte(temp, PCI_BRIDGE_CONTROL, &bctl);
+
+		pci_dev_get(dev);
+		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+			pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);
 			if (bctl & PCI_BRIDGE_CTL_VGA) {
 				ctrl_err(ctrl,
 					 "Cannot remove display device %s\n",
-					 pci_name(temp));
-				pci_dev_put(temp);
+					 pci_name(dev));
+				pci_dev_put(dev);
 				rc = -EINVAL;
 				break;
 			}
 		}
-		pci_stop_and_remove_bus_device(temp);
-		pci_dev_put(temp);
+		pci_stop_and_remove_bus_device(dev);
+		pci_dev_put(dev);
 	}
 	return rc;
 }