1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
new file mode 100644
index 000000000..a0c67191a
--- /dev/null
+++ b/drivers/pci/slot.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
+ * Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
+ *	Alex Chiang <achiang@hp.com>
+ */
+
+#include <linux/kobject.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/err.h>
+#include "pci.h"
+
+struct kset *pci_slots_kset;
+EXPORT_SYMBOL_GPL(pci_slots_kset);
+
+static ssize_t pci_slot_attr_show(struct kobject *kobj,
+					struct attribute *attr, char *buf)
+{
+	struct pci_slot *slot = to_pci_slot(kobj);
+	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
+	return attribute->show ? attribute->show(slot, buf) : -EIO;
+}
+
+static ssize_t pci_slot_attr_store(struct kobject *kobj,
+			struct attribute *attr, const char *buf, size_t len)
+{
+	struct pci_slot *slot = to_pci_slot(kobj);
+	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
+	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
+}
+
+static const struct sysfs_ops pci_slot_sysfs_ops = {
+	.show = pci_slot_attr_show,
+	.store = pci_slot_attr_store,
+};
+
+static ssize_t address_read_file(struct pci_slot *slot, char *buf)
+{
+	if (slot->number == 0xff)
+		return sysfs_emit(buf, "%04x:%02x\n",
+				  pci_domain_nr(slot->bus),
+				  slot->bus->number);
+
+	return sysfs_emit(buf, "%04x:%02x:%02x\n",
+			  pci_domain_nr(slot->bus),
+			  slot->bus->number,
+			  slot->number);
+}
+
+static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
+{
+	return sysfs_emit(buf, "%s\n", pci_speed_string(speed));
+}
+
+static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
+{
+	return bus_speed_read(slot->bus->max_bus_speed, buf);
+}
+
+static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
+{
+	return bus_speed_read(slot->bus->cur_bus_speed, buf);
+}
+
+static void pci_slot_release(struct kobject *kobj)
+{
+	struct pci_dev *dev;
+	struct pci_slot *slot = to_pci_slot(kobj);
+
+	dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
+		slot->number, pci_slot_name(slot));
+
+	down_read(&pci_bus_sem);
+	list_for_each_entry(dev, &slot->bus->devices, bus_list)
+		if (PCI_SLOT(dev->devfn) == slot->number)
+			dev->slot = NULL;
+	up_read(&pci_bus_sem);
+
+	list_del(&slot->list);
+
+	kfree(slot);
+}
+
+static struct pci_slot_attribute pci_slot_attr_address =
+	__ATTR(address, S_IRUGO, address_read_file, NULL);
+static struct pci_slot_attribute pci_slot_attr_max_speed =
+	__ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
+static struct pci_slot_attribute pci_slot_attr_cur_speed =
+	__ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
+
+static struct attribute *pci_slot_default_attrs[] = {
+	&pci_slot_attr_address.attr,
+	&pci_slot_attr_max_speed.attr,
+	&pci_slot_attr_cur_speed.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pci_slot_default);
+
+static struct kobj_type pci_slot_ktype = {
+	.sysfs_ops = &pci_slot_sysfs_ops,
+	.release = &pci_slot_release,
+	.default_groups = pci_slot_default_groups,
+};
+
+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(pci_slot_name(slot), 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;
+}
+
+void pci_dev_assign_slot(struct pci_dev *dev)
+{
+	struct pci_slot *slot;
+
+	mutex_lock(&pci_slot_mutex);
+	list_for_each_entry(slot, &dev->bus->slots, list)
+		if (PCI_SLOT(dev->devfn) == slot->number)
+			dev->slot = slot;
+	mutex_unlock(&pci_slot_mutex);
+}
+
+static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
+{
+	struct pci_slot *slot;
+
+	/* We already hold pci_slot_mutex */
+	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
+ * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
+ * @name: user visible string presented in /sys/bus/pci/slots/<name>
+ * @hotplug: set if caller is hotplug driver, NULL otherwise
+ *
+ * PCI slots have first class attributes such as address, speed, width,
+ * and a &struct pci_slot is used to manage them. This interface will
+ * 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 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
+ * a slot. There is one notable exception - pSeries (rpaphp), where the
+ * @slot_nr cannot be determined until a device is actually inserted into
+ * 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, 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 = 0;
+	char *slot_name = NULL;
+
+	mutex_lock(&pci_slot_mutex);
+
+	if (slot_nr == -1)
+		goto placeholder;
+
+	/*
+	 * 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) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	slot->bus = parent;
+	slot->number = slot_nr;
+
+	slot->kobj.kset = pci_slots_kset;
+
+	slot_name = make_slot_name(name);
+	if (!slot_name) {
+		err = -ENOMEM;
+		kfree(slot);
+		goto err;
+	}
+
+	INIT_LIST_HEAD(&slot->list);
+	list_add(&slot->list, &parent->slots);
+
+	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
+				   "%s", slot_name);
+	if (err) {
+		kobject_put(&slot->kobj);
+		goto err;
+	}
+
+	down_read(&pci_bus_sem);
+	list_for_each_entry(dev, &parent->devices, bus_list)
+		if (PCI_SLOT(dev->devfn) == slot_nr)
+			dev->slot = slot;
+	up_read(&pci_bus_sem);
+
+	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
+		slot_nr, pci_slot_name(slot));
+
+out:
+	kfree(slot_name);
+	mutex_unlock(&pci_slot_mutex);
+	return slot;
+err:
+	slot = ERR_PTR(err);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(pci_create_slot);
+
+/**
+ * pci_destroy_slot - decrement refcount for physical PCI slot
+ * @slot: struct pci_slot to decrement
+ *
+ * %struct pci_slot is refcounted, so destroying them is really easy; we
+ * just call kobject_put on its kobj and let our release methods do the
+ * rest.
+ */
+void pci_destroy_slot(struct pci_slot *slot)
+{
+	dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
+		slot->number, kref_read(&slot->kobj.kref) - 1);
+
+	mutex_lock(&pci_slot_mutex);
+	kobject_put(&slot->kobj);
+	mutex_unlock(&pci_slot_mutex);
+}
+EXPORT_SYMBOL_GPL(pci_destroy_slot);
+
+#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
+#include <linux/pci_hotplug.h>
+/**
+ * pci_hp_create_module_link - create symbolic link to hotplug driver module
+ * @pci_slot: struct pci_slot
+ *
+ * Helper function for pci_hotplug_core.c to create symbolic link to
+ * the hotplug driver module.
+ */
+void pci_hp_create_module_link(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+	struct kobject *kobj = NULL;
+	int ret;
+
+	if (!slot || !slot->ops)
+		return;
+	kobj = kset_find_obj(module_kset, slot->mod_name);
+	if (!kobj)
+		return;
+	ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
+	if (ret)
+		dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
+			ret);
+	kobject_put(kobj);
+}
+EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
+
+/**
+ * pci_hp_remove_module_link - remove symbolic link to the hotplug driver
+ * 	module.
+ * @pci_slot: struct pci_slot
+ *
+ * Helper function for pci_hotplug_core.c to remove symbolic link to
+ * the hotplug driver module.
+ */
+void pci_hp_remove_module_link(struct pci_slot *pci_slot)
+{
+	sysfs_remove_link(&pci_slot->kobj, "module");
+}
+EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
+#endif
+
+static int pci_slot_init(void)
+{
+	struct kset *pci_bus_kset;
+
+	pci_bus_kset = bus_get_kset(&pci_bus_type);
+	pci_slots_kset = kset_create_and_add("slots", NULL,
+						&pci_bus_kset->kobj);
+	if (!pci_slots_kset) {
+		pr_err("PCI: Slot initialization failure\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+subsys_initcall(pci_slot_init);