[PATCH] PCI Hotplug: rpaphp: Change slot pci reference

The slot structure in the rpaphp module currently references the PCI
contents of the slot using the PCI device of the parent bridge.  This
is unnecessary, since the module is actually interested in the
subordinate bus of the bridge.  The dependency on a PCI bridge device
also prohibits the module from registering hotplug slots that have a
root bridge as a parent, since root bridges on PPC64 don't have PCI
devices.

This patch changes struct slot to reference the PCI subsystem using a
pci_bus rather than a pci_dev.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/hotplug/rpadlpar_core.c

@@ -198,28 +198,6 @@ static struct pci_dev *dlpar_pci_add_bus(struct device_node *dn)
 	return dev;
 }
 
-static int dlpar_pci_remove_bus(struct pci_dev *bridge_dev)
-{
-	struct pci_bus *secondary_bus;
-
-	if (!bridge_dev) {
-		printk(KERN_ERR "%s: unexpected null device\n",
-			__FUNCTION__);
-		return -EINVAL;
-	}
-
-	secondary_bus = bridge_dev->subordinate;
-
-	if (unmap_bus_range(secondary_bus)) {
-		printk(KERN_ERR "%s: failed to unmap bus range\n",
-			__FUNCTION__);
-		return -ERANGE;
-	}
-
-	pci_remove_bus_device(bridge_dev);
-	return 0;
-}
-
 static inline int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
 {
 	struct pci_dev *dev;
@@ -415,14 +393,7 @@ static int dlpar_remove_vio_slot(struct device_node *dn, char *drc_name)
  */
 int dlpar_remove_pci_slot(struct slot *slot, char *drc_name)
 {
-	struct pci_dev *bridge_dev;
-
-	bridge_dev = slot->bridge;
-	if (!bridge_dev) {
-		printk(KERN_ERR "%s: unexpected null bridge device\n",
-			__FUNCTION__);
-		return -EIO;
-	}
+	struct pci_bus *bus = slot->bus;
 
 	/* Remove hotplug slot */
 	if (rpaphp_remove_slot(slot)) {
@@ -431,13 +402,14 @@ int dlpar_remove_pci_slot(struct slot *slot, char *drc_name)
 		return -EIO;
 	}
 
-	/* Remove pci bus */
-
-	if (dlpar_pci_remove_bus(bridge_dev)) {
-		printk(KERN_ERR "%s: unable to remove pci bus %s\n",
-			__FUNCTION__, drc_name);
-		return -EIO;
+	if (unmap_bus_range(bus)) {
+		printk(KERN_ERR "%s: failed to unmap bus range\n",
+			__FUNCTION__);
+		return -ERANGE;
 	}
+
+	BUG_ON(!bus->self);
+	pci_remove_bus_device(bus->self);
 	return 0;
 }
 

drivers/pci/hotplug/rpaphp.h

@@ -80,10 +80,9 @@ struct slot {
 	char *name;
 	char *location;
 	u8 removable;
-	struct device_node *dn;	/* slot's device_node in OFDT */
-				/* dn has phb info */
-	struct pci_dev *bridge;	/* slot's pci_dev in pci_devices */
-	struct list_head *pci_devs; /* pci_devs in PCI slot */
+	struct device_node *dn;
+	struct pci_bus *bus;
+	struct list_head *pci_devs;
 	struct hotplug_slot *hotplug_slot;
 };
 

drivers/pci/hotplug/rpaphp_pci.c

@@ -45,6 +45,32 @@ struct pci_dev *rpaphp_find_pci_dev(struct device_node *dn)
 	return dev;
 }
 
+struct pci_bus *find_bus_among_children(struct pci_bus *bus,
+					struct device_node *dn)
+{
+	struct pci_bus *child = NULL;
+	struct list_head *tmp;
+	struct device_node *busdn;
+
+	busdn = pci_bus_to_OF_node(bus);
+	if (busdn == dn)
+		return bus;
+
+	list_for_each(tmp, &bus->children) {
+		child = find_bus_among_children(pci_bus_b(tmp), dn);
+		if (child)
+			break;
+	}
+	return child;
+}
+
+struct pci_bus *rpaphp_find_pci_bus(struct device_node *dn)
+{
+	BUG_ON(!dn->phb || !dn->phb->bus);
+
+	return find_bus_among_children(dn->phb->bus, dn);
+}
+
 EXPORT_SYMBOL_GPL(rpaphp_find_pci_dev);
 
 int rpaphp_claim_resource(struct pci_dev *dev, int resource)
@@ -69,11 +95,6 @@ int rpaphp_claim_resource(struct pci_dev *dev, int resource)
 
 EXPORT_SYMBOL_GPL(rpaphp_claim_resource);
 
-static struct pci_dev *rpaphp_find_bridge_pdev(struct slot *slot)
-{
-	return rpaphp_find_pci_dev(slot->dn);
-}
-
 static int rpaphp_get_sensor_state(struct slot *slot, int *state)
 {
 	int rc;
@@ -226,20 +247,22 @@ static int rpaphp_pci_config_bridge(struct pci_dev *dev)
 static struct pci_dev *
 rpaphp_pci_config_slot(struct device_node *dn, struct pci_bus *bus)
 {
-	struct device_node *eads_first_child = dn->child;
 	struct pci_dev *dev = NULL;
+	int slotno;
 	int num;
 
 	dbg("Enter %s: dn=%s bus=%s\n", __FUNCTION__, dn->full_name, bus->name);
 
-	if (eads_first_child) {
-		/* pci_scan_slot should find all children of EADs */
-		num = pci_scan_slot(bus, PCI_DEVFN(PCI_SLOT(eads_first_child->devfn), 0));
+	if (dn->child) {
+		slotno = PCI_SLOT(dn->child->devfn);
+
+		/* pci_scan_slot should find all children */
+		num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
 		if (num) {
 			rpaphp_fixup_new_pci_devices(bus, 1);
 			pci_bus_add_devices(bus);
 		}
-		dev = rpaphp_find_pci_dev(eads_first_child);
+		dev = rpaphp_find_pci_dev(dn->child);
 		if (!dev) {
 			err("No new device found\n");
 			return NULL;
@@ -273,31 +296,19 @@ static void print_slot_pci_funcs(struct slot *slot)
 
 static int rpaphp_config_pci_adapter(struct slot *slot)
 {
-	struct pci_bus *pci_bus;
 	struct pci_dev *dev;
 	int rc = -ENODEV;
 
 	dbg("Entry %s: slot[%s]\n", __FUNCTION__, slot->name);
 
-	if (slot->bridge) {
-
-		pci_bus = slot->bridge->subordinate;
-		if (!pci_bus) {
-			err("%s: can't find bus structure\n", __FUNCTION__);
-			goto exit;
-		}
-		enable_eeh(slot->dn);
-		dev = rpaphp_pci_config_slot(slot->dn, pci_bus);
-		if (!dev) {
-			err("%s: can't find any devices.\n", __FUNCTION__);
-			goto exit;
-		}
-		print_slot_pci_funcs(slot);
-		rc = 0;
-	} else {
-		/* slot is not enabled */
-		err("slot doesn't have pci_dev structure\n");
+	enable_eeh(slot->dn);
+	dev = rpaphp_pci_config_slot(slot->dn, slot->bus);
+	if (!dev) {
+		err("%s: can't find any devices.\n", __FUNCTION__);
+		goto exit;
 	}
+	print_slot_pci_funcs(slot);
+	rc = 0;
 exit:
 	dbg("Exit %s:  rc=%d\n", __FUNCTION__, rc);
 	return rc;
@@ -323,13 +334,14 @@ static void rpaphp_eeh_remove_bus_device(struct pci_dev *dev)
 
 int rpaphp_unconfig_pci_adapter(struct slot *slot)
 {
-	struct pci_dev *dev;
+	struct pci_dev *dev, *tmp;
 	int retval = 0;
 
-	list_for_each_entry(dev, slot->pci_devs, bus_list)
+	list_for_each_entry_safe(dev, tmp, slot->pci_devs, bus_list) {
 		rpaphp_eeh_remove_bus_device(dev);
+		pci_remove_bus_device(dev);
+	}
 
-	pci_remove_behind_bridge(slot->bridge);
 	slot->state = NOT_CONFIGURED;
 	info("%s: devices in slot[%s] unconfigured.\n", __FUNCTION__,
 	     slot->name);
@@ -352,66 +364,41 @@ static int setup_pci_hotplug_slot_info(struct slot *slot)
 	return 0;
 }
 
-static int set_phb_slot_name(struct slot *slot)
+static void set_slot_name(struct slot *slot)
 {
-	struct device_node *dn;
-	struct pci_controller *phb;
-	struct pci_bus *bus;
-
-	dn = slot->dn;
-	if (!dn) {
-		return -EINVAL;
-	}
-	phb = dn->phb;
-	if (!phb) {
-		return -EINVAL;
-	}
-	bus = phb->bus;
-	if (!bus) {
-		return -EINVAL;
-	}
+	struct pci_bus *bus = slot->bus;
+	struct pci_dev *bridge;
 
-	sprintf(slot->name, "%04x:%02x:%02x.%x", pci_domain_nr(bus),
-			bus->number, 0, 0);
-	return 0;
+	bridge = bus->self;
+	if (bridge)
+		strcpy(slot->name, pci_name(bridge));
+	else
+		sprintf(slot->name, "%04x:%02x:00.0", pci_domain_nr(bus),
+			bus->number);
 }
 
 static int setup_pci_slot(struct slot *slot)
 {
+	struct device_node *dn = slot->dn;
 	struct pci_bus *bus;
-	int rc;
 
-	if (slot->type == PHB) {
-		rc = set_phb_slot_name(slot);
-		if (rc < 0) {
-			err("%s: failed to set phb slot name\n", __FUNCTION__);
-			goto exit_rc;
-		}
-	} else {
-		slot->bridge = rpaphp_find_bridge_pdev(slot);
-		if (!slot->bridge) {
-			/* slot being added doesn't have pci_dev yet */
-			err("%s: no pci_dev for bridge dn %s\n",
-					__FUNCTION__, slot->name);
-			goto exit_rc;
-		}
-
-		bus = slot->bridge->subordinate;
-		if (!bus)
-			goto exit_rc;
-		slot->pci_devs = &bus->devices;
-
-		dbg("%s set slot->name to %s\n",  __FUNCTION__,
-				pci_name(slot->bridge));
-		strcpy(slot->name, pci_name(slot->bridge));
+	BUG_ON(!dn);
+	bus = rpaphp_find_pci_bus(dn);
+	if (!bus) {
+		err("%s: no pci_bus for dn %s\n", __FUNCTION__, dn->full_name);
+		goto exit_rc;
 	}
 
+	slot->bus = bus;
+	slot->pci_devs = &bus->devices;
+	set_slot_name(slot);
+
 	/* find slot's pci_dev if it's not empty */
 	if (slot->hotplug_slot->info->adapter_status == EMPTY) {
 		slot->state = EMPTY;	/* slot is empty */
 	} else {
 		/* slot is occupied */
-		if (!(slot->dn->child)) {
+		if (!dn->child) {
 			/* non-empty slot has to have child */
 			err("%s: slot[%s]'s device_node doesn't have child for adapter\n", 
 				__FUNCTION__, slot->name);