4 files changed, 115 insertions, 82 deletions

diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c
index e7152482518..a6f1f282b68 100644
--- a/drivers/pci/hotplug/pci_hotplug_core.c
+++ b/drivers/pci/hotplug/pci_hotplug_core.c
@@ -569,12 +569,6 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr,
 
 	mutex_lock(&pci_hp_mutex);
 
-	/* Check if we have already registered a slot with the same name. */
-	if (get_slot_from_name(name)) {
-		result = -EEXIST;
-		goto out;
-	}
-
 	/*
 	 * No problems if we call this interface from both ACPI_PCI_SLOT
 	 * driver and call it here again. If we've already created the
@@ -583,27 +577,12 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr,
 	pci_slot = pci_create_slot(bus, slot_nr, name, slot);
 	if (IS_ERR(pci_slot)) {
 		result = PTR_ERR(pci_slot);
-		goto cleanup;
-	}
-
-	if (pci_slot->hotplug) {
-		dbg("%s: already claimed\n", __func__);
-		result = -EBUSY;
-		goto cleanup;
+		goto out;
 	}
 
 	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), name)) {
-		result = kobject_rename(&pci_slot->kobj, name);
-		if (result)
-			goto cleanup;
-	}
-
 	list_add(&slot->slot_list, &pci_hotplug_slot_list);
 
 	result = fs_add_slot(pci_slot);
@@ -612,9 +591,6 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr,
 out:
 	mutex_unlock(&pci_hp_mutex);
 	return result;
-cleanup:
-	pci_destroy_slot(pci_slot);
-	goto out;
 }
 
 /**
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 3ace5e05760..af89d7bd1ed 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -196,7 +196,6 @@ static int init_slots(struct controller *ctrl)
 	struct slot *slot;
 	struct hotplug_slot *hotplug_slot;
 	struct hotplug_slot_info *info;
-	int len, dup = 1;
 	int retval = -ENOMEM;
 
 	list_for_each_entry(slot, &ctrl->slot_list, slot_list) {
@@ -223,25 +222,11 @@ static int init_slots(struct controller *ctrl)
 		ctrl_dbg(ctrl, "Registering bus=%x dev=%x hp_slot=%x sun=%x "
 			 "slot_device_offset=%x\n", slot->bus, slot->device,
 			 slot->hp_slot, slot->number, ctrl->slot_device_offset);
-duplicate_name:
 		retval = pci_hp_register(hotplug_slot,
 					 ctrl->pci_dev->subordinate,
 					 slot->device,
 					 slot->name);
 		if (retval) {
-			/*
-			 * If slot N already exists, we'll try to create
-			 * slot N-1, N-2 ... N-M, until we overflow.
-			 */
-			if (retval == -EEXIST) {
-				len = snprintf(slot->name, SLOT_NAME_SIZE,
-					       "%d-%d", slot->number, dup++);
-				if (len < SLOT_NAME_SIZE)
-					goto duplicate_name;
-				else
-					ctrl_err(ctrl, "duplicate slot name "
-						 "overflow\n");
-			}
 			ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
 				 retval);
 			goto error_info;
diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c
index bf5096612aa..cfdd0796364 100644
--- a/drivers/pci/hotplug/shpchp_core.c
+++ b/drivers/pci/hotplug/shpchp_core.c
@@ -102,7 +102,7 @@ static int init_slots(struct controller *ctrl)
 	struct hotplug_slot *hotplug_slot;
 	struct hotplug_slot_info *info;
 	int retval = -ENOMEM;
-	int i, len, dup = 1;
+	int i;
 
 	for (i = 0; i < ctrl->num_slots; i++) {
 		slot = kzalloc(sizeof(*slot), GFP_KERNEL);
@@ -144,23 +144,10 @@ static int init_slots(struct controller *ctrl)
 		dbg("Registering bus=%x dev=%x hp_slot=%x sun=%x "
 		    "slot_device_offset=%x\n", slot->bus, slot->device,
 		    slot->hp_slot, slot->number, ctrl->slot_device_offset);
-duplicate_name:
 		retval = pci_hp_register(slot->hotplug_slot,
 				ctrl->pci_dev->subordinate, slot->device,
 				hotplug_slot->name);
 		if (retval) {
-			/*
-			 * If slot N already exists, we'll try to create
-			 * slot N-1, N-2 ... N-M, until we overflow.
-			 */
-			if (retval == -EEXIST) {
-				len = snprintf(slot->name, SLOT_NAME_SIZE,
-					       "%d-%d", slot->number, dup++);
-				if (len < SLOT_NAME_SIZE)
-					goto duplicate_name;
-				else
-					err("duplicate slot name overflow\n");
-			}
 			err("pci_hp_register failed with error %d\n", retval);
 			goto error_info;
 		}
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 0e009c3ba5f..b6ee352ae45 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -78,6 +78,77 @@ static struct kobj_type pci_slot_ktype = {
 	.default_attrs = pci_slot_default_attrs,
 };
 
+static char *make_slot_name(const char *name)
+{
+	char *new_name;
+	int len, max, dup;
+
+	new_name = kstrdup(name, GFP_KERNEL);
+	if (!new_name)
+		return NULL;
+
+	/*
+	 * Make sure we hit the realloc case the first time through the
+	 * loop.  'len' will be strlen(name) + 3 at that point which is
+	 * enough space for "name-X" and the trailing NUL.
+	 */
+	len = strlen(name) + 2;
+	max = 1;
+	dup = 1;
+
+	for (;;) {
+		struct kobject *dup_slot;
+		dup_slot = kset_find_obj(pci_slots_kset, new_name);
+		if (!dup_slot)
+			break;
+		kobject_put(dup_slot);
+		if (dup == max) {
+			len++;
+			max *= 10;
+			kfree(new_name);
+			new_name = kmalloc(len, GFP_KERNEL);
+			if (!new_name)
+				break;
+		}
+		sprintf(new_name, "%s-%d", name, dup++);
+	}
+
+	return new_name;
+}
+
+static int rename_slot(struct pci_slot *slot, const char *name)
+{
+	int result = 0;
+	char *slot_name;
+
+	if (strcmp(kobject_name(&slot->kobj), name) == 0)
+		return result;
+
+	slot_name = make_slot_name(name);
+	if (!slot_name)
+		return -ENOMEM;
+
+	result = kobject_rename(&slot->kobj, slot_name);
+	kfree(slot_name);
+
+	return result;
+}
+
+static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
+{
+	struct pci_slot *slot;
+	/*
+	 * We already hold pci_bus_sem so don't worry
+	 */
+	list_for_each_entry(slot, &parent->slots, list)
+		if (slot->number == slot_nr) {
+			kobject_get(&slot->kobj);
+			return slot;
+		}
+
+	return NULL;
+}
+
 /**
  * pci_create_slot - create or increment refcount for physical PCI slot
  * @parent: struct pci_bus of parent bridge
@@ -90,7 +161,17 @@ static struct kobj_type pci_slot_ktype = {
  * either return a new &struct pci_slot to the caller, or if the pci_slot
  * already exists, its refcount will be incremented.
  *
- * Slots are uniquely identified by a @pci_bus, @slot_nr, @name tuple.
+ * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
+ *
+ * There are known platforms with broken firmware that assign the same
+ * name to multiple slots. Workaround these broken platforms by renaming
+ * the slots on behalf of the caller. If firmware assigns name N to
+ * multiple slots:
+ *
+ * The first slot is assigned N
+ * The second slot is assigned N-1
+ * The third slot is assigned N-2
+ * etc.
  *
  * Placeholder slots:
  * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
@@ -99,62 +180,67 @@ static struct kobj_type pci_slot_ktype = {
  * the slot. In this scenario, the caller may pass -1 for @slot_nr.
  *
  * The following semantics are imposed when the caller passes @slot_nr ==
- * -1. First, the check for existing %struct pci_slot is skipped, as the
- * caller may know about several unpopulated slots on a given %struct
- * pci_bus, and each slot would have a @slot_nr of -1.  Uniqueness for
- * these slots is then determined by the @name parameter. We expect
- * kobject_init_and_add() to warn us if the caller attempts to create
- * multiple slots with the same name. The other change in semantics is
+ * -1. First, we no longer check for an existing %struct pci_slot, as there
+ * may be many slots with @slot_nr of -1.  The other change in semantics is
  * user-visible, which is the 'address' parameter presented in sysfs will
  * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
  * %struct pci_bus and bb is the bus number. In other words, the devfn of
  * the 'placeholder' slot will not be displayed.
  */
-
 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name,
 				 struct hotplug_slot *hotplug)
 {
 	struct pci_dev *dev;
 	struct pci_slot *slot;
-	int err;
+	int err = 0;
+	char *slot_name = NULL;
 
 	down_write(&pci_bus_sem);
 
 	if (slot_nr == -1)
 		goto placeholder;
 
-	/* If we've already created this slot, bump refcount and return. */
-	list_for_each_entry(slot, &parent->slots, list) {
-		if (slot->number == slot_nr) {
-			kobject_get(&slot->kobj);
-			pr_debug("%s: inc refcount to %d on %04x:%02x:%02x\n",
-				 __func__,
-				 atomic_read(&slot->kobj.kref.refcount),
-				 pci_domain_nr(parent), parent->number,
-				 slot_nr);
-			goto out;
+	/*
+	 * Hotplug drivers are allowed to rename an existing slot,
+	 * but only if not already claimed.
+	 */
+	slot = get_slot(parent, slot_nr);
+	if (slot) {
+		if (hotplug) {
+			if ((err = slot->hotplug ? -EBUSY : 0)
+			     || (err = rename_slot(slot, name))) {
+				kobject_put(&slot->kobj);
+				slot = NULL;
+				goto err;
+			}
 		}
+		goto out;
 	}
 
 placeholder:
 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 	if (!slot) {
-		slot = ERR_PTR(-ENOMEM);
-		goto out;
+		err = -ENOMEM;
+		goto err;
 	}
 
 	slot->bus = parent;
 	slot->number = slot_nr;
 
 	slot->kobj.kset = pci_slots_kset;
-	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
-				   "%s", name);
-	if (err) {
-		printk(KERN_ERR "Unable to register kobject %s\n", name);
+
+	slot_name = make_slot_name(name);
+	if (!slot_name) {
+		err = -ENOMEM;
 		goto err;
 	}
 
+	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
+				   "%s", slot_name);
+	if (err)
+		goto err;
+
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
 
@@ -166,10 +252,10 @@ placeholder:
 	pr_debug("%s: created pci_slot on %04x:%02x:%02x\n",
 		 __func__, pci_domain_nr(parent), parent->number, slot_nr);
 
- out:
+out:
 	up_write(&pci_bus_sem);
 	return slot;
- err:
+err:
 	kfree(slot);
 	slot = ERR_PTR(err);
 	goto out;
@@ -210,7 +296,6 @@ EXPORT_SYMBOL_GPL(pci_renumber_slot);
  * just call kobject_put on its kobj and let our release methods do the
  * rest.
  */
-
 void pci_destroy_slot(struct pci_slot *slot)
 {
 	pr_debug("%s: dec refcount to %d on %04x:%02x:%02x\n", __func__,