[mirror_ubuntu-bionic-kernel.git] / drivers / pci / slot.c

/*
 * drivers/pci/slot.c
 * 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 DEFINE_MUTEX(pci_slot_mutex);

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 sprintf(buf, "%04x:%02x\n",
				pci_domain_nr(slot->bus),
				slot->bus->number);
	else
		return sprintf(buf, "%04x:%02x:%02x\n",
				pci_domain_nr(slot->bus),
				slot->bus->number,
				slot->number);
}

/* these strings match up with the values in pci_bus_speed */
static const char *pci_bus_speed_strings[] = {
	"33 MHz PCI",		/* 0x00 */
	"66 MHz PCI",		/* 0x01 */
	"66 MHz PCI-X",		/* 0x02 */
	"100 MHz PCI-X",	/* 0x03 */
	"133 MHz PCI-X",	/* 0x04 */
	NULL,			/* 0x05 */
	NULL,			/* 0x06 */
	NULL,			/* 0x07 */
	NULL,			/* 0x08 */
	"66 MHz PCI-X 266",	/* 0x09 */
	"100 MHz PCI-X 266",	/* 0x0a */
	"133 MHz PCI-X 266",	/* 0x0b */
	"Unknown AGP",		/* 0x0c */
	"1x AGP",		/* 0x0d */
	"2x AGP",		/* 0x0e */
	"4x AGP",		/* 0x0f */
	"8x AGP",		/* 0x10 */
	"66 MHz PCI-X 533",	/* 0x11 */
	"100 MHz PCI-X 533",	/* 0x12 */
	"133 MHz PCI-X 533",	/* 0x13 */
	"2.5 GT/s PCIe",	/* 0x14 */
	"5.0 GT/s PCIe",	/* 0x15 */
	"8.0 GT/s PCIe",	/* 0x16 */
};

static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
{
	const char *speed_string;

	if (speed < ARRAY_SIZE(pci_bus_speed_strings))
		speed_string = pci_bus_speed_strings[speed];
	else
		speed_string = "Unknown";

	return sprintf(buf, "%s\n", speed_string);
}

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,
};

static struct kobj_type pci_slot_ktype = {
	.sysfs_ops = &pci_slot_sysfs_ops,
	.release = &pci_slot_release,
	.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(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;
		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);

	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:
	kfree(slot);
	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_link - create symbolic link to the 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->ops->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_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) {
		printk(KERN_ERR "PCI: Slot initialization failure\n");
		return -ENOMEM;
	}
	return 0;
}

subsys_initcall(pci_slot_init);
Commit	Line	Data
f46753c5 AC	1	/*
	2	* drivers/pci/slot.c
	3	* Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
62795041 AC	4	* Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
62795041 AC	5	* Alex Chiang <achiang@hp.com>
f46753c5 AC	6	*/
	7
	8	#include <linux/kobject.h>
5a0e3ad6	9	#include <linux/slab.h>
eefa9cfc	10	#include <linux/module.h>
f46753c5 AC	11	#include <linux/pci.h>
	12	#include <linux/err.h>
	13	#include "pci.h"
	14
	15	struct kset *pci_slots_kset;
	16	EXPORT_SYMBOL_GPL(pci_slots_kset);
67546762	17	static DEFINE_MUTEX(pci_slot_mutex);
f46753c5 AC	18
	19	static ssize_t pci_slot_attr_show(struct kobject *kobj,
	20	struct attribute attr, char buf)
	21	{
	22	struct pci_slot *slot = to_pci_slot(kobj);
	23	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	24	return attribute->show ? attribute->show(slot, buf) : -EIO;
	25	}
	26
	27	static ssize_t pci_slot_attr_store(struct kobject *kobj,
	28	struct attribute attr, const char buf, size_t len)
	29	{
	30	struct pci_slot *slot = to_pci_slot(kobj);
	31	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	32	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
	33	}
	34
52cf25d0	35	static const struct sysfs_ops pci_slot_sysfs_ops = {
f46753c5 AC	36	.show = pci_slot_attr_show,
	37	.store = pci_slot_attr_store,
	38	};
	39
	40	static ssize_t address_read_file(struct pci_slot slot, char buf)
	41	{
	42	if (slot->number == 0xff)
	43	return sprintf(buf, "%04x:%02x\n",
	44	pci_domain_nr(slot->bus),
	45	slot->bus->number);
	46	else
	47	return sprintf(buf, "%04x:%02x:%02x\n",
	48	pci_domain_nr(slot->bus),
	49	slot->bus->number,
	50	slot->number);
	51	}
	52
3749c51a	53	/* these strings match up with the values in pci_bus_speed */
17134d96	54	static const char *pci_bus_speed_strings[] = {
3749c51a MW	55	"33 MHz PCI", /* 0x00 */
3749c51a MW	56	"66 MHz PCI", /* 0x01 */
f7625980	57	"66 MHz PCI-X", /* 0x02 */
3749c51a MW	58	"100 MHz PCI-X", /* 0x03 */
	59	"133 MHz PCI-X", /* 0x04 */
	60	NULL, /* 0x05 */
	61	NULL, /* 0x06 */
	62	NULL, /* 0x07 */
	63	NULL, /* 0x08 */
	64	"66 MHz PCI-X 266", /* 0x09 */
	65	"100 MHz PCI-X 266", /* 0x0a */
	66	"133 MHz PCI-X 266", /* 0x0b */
45b4cdd5 MW	67	"Unknown AGP", /* 0x0c */
	68	"1x AGP", /* 0x0d */
	69	"2x AGP", /* 0x0e */
	70	"4x AGP", /* 0x0f */
	71	"8x AGP", /* 0x10 */
3749c51a MW	72	"66 MHz PCI-X 533", /* 0x11 */
	73	"100 MHz PCI-X 533", /* 0x12 */
	74	"133 MHz PCI-X 533", /* 0x13 */
	75	"2.5 GT/s PCIe", /* 0x14 */
	76	"5.0 GT/s PCIe", /* 0x15 */
9dfd97fe	77	"8.0 GT/s PCIe", /* 0x16 */
3749c51a MW	78	};
	79
	80	static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
	81	{
	82	const char *speed_string;
	83
	84	if (speed < ARRAY_SIZE(pci_bus_speed_strings))
	85	speed_string = pci_bus_speed_strings[speed];
	86	else
	87	speed_string = "Unknown";
	88
	89	return sprintf(buf, "%s\n", speed_string);
	90	}
	91
	92	static ssize_t max_speed_read_file(struct pci_slot slot, char buf)
	93	{
	94	return bus_speed_read(slot->bus->max_bus_speed, buf);
	95	}
	96
	97	static ssize_t cur_speed_read_file(struct pci_slot slot, char buf)
	98	{
	99	return bus_speed_read(slot->bus->cur_bus_speed, buf);
	100	}
	101
f46753c5 AC	102	static void pci_slot_release(struct kobject *kobj)
f46753c5 AC	103	{
cef354db	104	struct pci_dev *dev;
f46753c5 AC	105	struct pci_slot *slot = to_pci_slot(kobj);
f46753c5 AC	106
62795041 AC	107	dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
62795041 AC	108	slot->number, pci_slot_name(slot));
f46753c5	109
67546762	110	down_read(&pci_bus_sem);
cef354db AC	111	list_for_each_entry(dev, &slot->bus->devices, bus_list)
	112	if (PCI_SLOT(dev->devfn) == slot->number)
	113	dev->slot = NULL;
67546762	114	up_read(&pci_bus_sem);
cef354db	115
f46753c5 AC	116	list_del(&slot->list);
	117
	118	kfree(slot);
	119	}
	120
	121	static struct pci_slot_attribute pci_slot_attr_address =
58f86cc8	122	__ATTR(address, S_IRUGO, address_read_file, NULL);
3749c51a	123	static struct pci_slot_attribute pci_slot_attr_max_speed =
58f86cc8	124	__ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
3749c51a	125	static struct pci_slot_attribute pci_slot_attr_cur_speed =
58f86cc8	126	__ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
f46753c5 AC	127
	128	static struct attribute *pci_slot_default_attrs[] = {
	129	&pci_slot_attr_address.attr,
3749c51a MW	130	&pci_slot_attr_max_speed.attr,
3749c51a MW	131	&pci_slot_attr_cur_speed.attr,
f46753c5 AC	132	NULL,
	133	};
	134
	135	static struct kobj_type pci_slot_ktype = {
	136	.sysfs_ops = &pci_slot_sysfs_ops,
	137	.release = &pci_slot_release,
	138	.default_attrs = pci_slot_default_attrs,
	139	};
	140
5fe6cc60 AC	141	static char make_slot_name(const char name)
	142	{
	143	char *new_name;
	144	int len, max, dup;
	145
	146	new_name = kstrdup(name, GFP_KERNEL);
	147	if (!new_name)
	148	return NULL;
	149
	150	/*
	151	* Make sure we hit the realloc case the first time through the
	152	* loop. 'len' will be strlen(name) + 3 at that point which is
	153	* enough space for "name-X" and the trailing NUL.
	154	*/
	155	len = strlen(name) + 2;
	156	max = 1;
	157	dup = 1;
	158
	159	for (;;) {
	160	struct kobject *dup_slot;
	161	dup_slot = kset_find_obj(pci_slots_kset, new_name);
	162	if (!dup_slot)
	163	break;
	164	kobject_put(dup_slot);
	165	if (dup == max) {
	166	len++;
	167	max *= 10;
	168	kfree(new_name);
	169	new_name = kmalloc(len, GFP_KERNEL);
	170	if (!new_name)
	171	break;
	172	}
	173	sprintf(new_name, "%s-%d", name, dup++);
	174	}
	175
	176	return new_name;
	177	}
	178
	179	static int rename_slot(struct pci_slot slot, const char name)
	180	{
	181	int result = 0;
	182	char *slot_name;
	183
0ad772ec	184	if (strcmp(pci_slot_name(slot), name) == 0)
5fe6cc60 AC	185	return result;
	186
	187	slot_name = make_slot_name(name);
	188	if (!slot_name)
	189	return -ENOMEM;
	190
	191	result = kobject_rename(&slot->kobj, slot_name);
	192	kfree(slot_name);
	193
	194	return result;
	195	}
	196
017ffe64 YW	197	void pci_dev_assign_slot(struct pci_dev *dev)
	198	{
	199	struct pci_slot *slot;
	200
	201	mutex_lock(&pci_slot_mutex);
	202	list_for_each_entry(slot, &dev->bus->slots, list)
	203	if (PCI_SLOT(dev->devfn) == slot->number)
	204	dev->slot = slot;
	205	mutex_unlock(&pci_slot_mutex);
	206	}
	207
5fe6cc60 AC	208	static struct pci_slot get_slot(struct pci_bus parent, int slot_nr)
	209	{
	210	struct pci_slot *slot;
67546762 YW	211
67546762 YW	212	/* We already hold pci_slot_mutex */
5fe6cc60 AC	213	list_for_each_entry(slot, &parent->slots, list)
	214	if (slot->number == slot_nr) {
	215	kobject_get(&slot->kobj);
	216	return slot;
	217	}
	218
	219	return NULL;
	220	}
	221
f46753c5 AC	222	/**
	223	* pci_create_slot - create or increment refcount for physical PCI slot
	224	* @parent: struct pci_bus of parent bridge
	225	* @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
	226	* @name: user visible string presented in /sys/bus/pci/slots/<name>
828f3768	227	* @hotplug: set if caller is hotplug driver, NULL otherwise
f46753c5 AC	228	*
	229	* PCI slots have first class attributes such as address, speed, width,
	230	* and a &struct pci_slot is used to manage them. This interface will
	231	* either return a new &struct pci_slot to the caller, or if the pci_slot
	232	* already exists, its refcount will be incremented.
	233	*
5fe6cc60 AC	234	* Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
	235	*
	236	* There are known platforms with broken firmware that assign the same
	237	* name to multiple slots. Workaround these broken platforms by renaming
	238	* the slots on behalf of the caller. If firmware assigns name N to
	239	* multiple slots:
	240	*
	241	* The first slot is assigned N
	242	* The second slot is assigned N-1
	243	* The third slot is assigned N-2
	244	* etc.
f46753c5 AC	245	*
	246	* Placeholder slots:
	247	* In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
	248	* a slot. There is one notable exception - pSeries (rpaphp), where the
	249	* @slot_nr cannot be determined until a device is actually inserted into
	250	* the slot. In this scenario, the caller may pass -1 for @slot_nr.
	251	*
	252	* The following semantics are imposed when the caller passes @slot_nr ==
5fe6cc60 AC	253	* -1. First, we no longer check for an existing %struct pci_slot, as there
5fe6cc60 AC	254	* may be many slots with @slot_nr of -1. The other change in semantics is
f46753c5 AC	255	* user-visible, which is the 'address' parameter presented in sysfs will
	256	* consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
	257	* %struct pci_bus and bb is the bus number. In other words, the devfn of
	258	* the 'placeholder' slot will not be displayed.
	259	*/
f46753c5	260	struct pci_slot pci_create_slot(struct pci_bus parent, int slot_nr,
828f3768 AC	261	const char *name,
828f3768 AC	262	struct hotplug_slot *hotplug)
f46753c5	263	{
cef354db	264	struct pci_dev *dev;
f46753c5	265	struct pci_slot *slot;
5fe6cc60 AC	266	int err = 0;
5fe6cc60 AC	267	char *slot_name = NULL;
f46753c5	268
67546762	269	mutex_lock(&pci_slot_mutex);
f46753c5 AC	270
	271	if (slot_nr == -1)
	272	goto placeholder;
	273
5fe6cc60 AC	274	/*
	275	* Hotplug drivers are allowed to rename an existing slot,
	276	* but only if not already claimed.
	277	*/
	278	slot = get_slot(parent, slot_nr);
	279	if (slot) {
	280	if (hotplug) {
	281	if ((err = slot->hotplug ? -EBUSY : 0)
	282	\|\| (err = rename_slot(slot, name))) {
	283	kobject_put(&slot->kobj);
	284	slot = NULL;
	285	goto err;
	286	}
f46753c5	287	}
5fe6cc60	288	goto out;
f46753c5 AC	289	}
	290
	291	placeholder:
	292	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
	293	if (!slot) {
5fe6cc60 AC	294	err = -ENOMEM;
5fe6cc60 AC	295	goto err;
f46753c5 AC	296	}
	297
	298	slot->bus = parent;
	299	slot->number = slot_nr;
	300
	301	slot->kobj.kset = pci_slots_kset;
5fe6cc60 AC	302
	303	slot_name = make_slot_name(name);
	304	if (!slot_name) {
	305	err = -ENOMEM;
f46753c5 AC	306	goto err;
	307	}
	308
5fe6cc60 AC	309	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
	310	"%s", slot_name);
	311	if (err)
	312	goto err;
	313
f46753c5 AC	314	INIT_LIST_HEAD(&slot->list);
	315	list_add(&slot->list, &parent->slots);
	316
67546762	317	down_read(&pci_bus_sem);
cef354db AC	318	list_for_each_entry(dev, &parent->devices, bus_list)
	319	if (PCI_SLOT(dev->devfn) == slot_nr)
	320	dev->slot = slot;
67546762	321	up_read(&pci_bus_sem);
cef354db	322
62795041 AC	323	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
62795041 AC	324	slot_nr, pci_slot_name(slot));
f46753c5	325
5fe6cc60	326	out:
3b5dd45e	327	kfree(slot_name);
67546762	328	mutex_unlock(&pci_slot_mutex);
f46753c5	329	return slot;
5fe6cc60	330	err:
f46753c5 AC	331	kfree(slot);
	332	slot = ERR_PTR(err);
	333	goto out;
	334	}
	335	EXPORT_SYMBOL_GPL(pci_create_slot);
	336
f46753c5 AC	337	/**
	338	* pci_destroy_slot - decrement refcount for physical PCI slot
	339	* @slot: struct pci_slot to decrement
	340	*
	341	* %struct pci_slot is refcounted, so destroying them is really easy; we
	342	* just call kobject_put on its kobj and let our release methods do the
	343	* rest.
	344	*/
f46753c5 AC	345	void pci_destroy_slot(struct pci_slot *slot)
f46753c5 AC	346	{
62795041	347	dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
2c935bc5	348	slot->number, kref_read(&slot->kobj.kref) - 1);
f46753c5	349
67546762	350	mutex_lock(&pci_slot_mutex);
f46753c5	351	kobject_put(&slot->kobj);
67546762	352	mutex_unlock(&pci_slot_mutex);
f46753c5 AC	353	}
	354	EXPORT_SYMBOL_GPL(pci_destroy_slot);
	355
c825bc94 KK	356	#if defined(CONFIG_HOTPLUG_PCI) \|\| defined(CONFIG_HOTPLUG_PCI_MODULE)
	357	#include <linux/pci_hotplug.h>
	358	/**
	359	* pci_hp_create_link - create symbolic link to the hotplug driver module.
503998ca	360	* @pci_slot: struct pci_slot
c825bc94 KK	361	*
	362	* Helper function for pci_hotplug_core.c to create symbolic link to
	363	* the hotplug driver module.
	364	*/
	365	void pci_hp_create_module_link(struct pci_slot *pci_slot)
	366	{
	367	struct hotplug_slot *slot = pci_slot->hotplug;
	368	struct kobject *kobj = NULL;
9fc9eea0	369	int ret;
c825bc94 KK	370
	371	if (!slot \|\| !slot->ops)
	372	return;
	373	kobj = kset_find_obj(module_kset, slot->ops->mod_name);
	374	if (!kobj)
	375	return;
9fc9eea0 BH	376	ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
	377	if (ret)
	378	dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
	379	ret);
c825bc94 KK	380	kobject_put(kobj);
	381	}
	382	EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
	383
	384	/**
	385	* pci_hp_remove_link - remove symbolic link to the hotplug driver module.
503998ca	386	* @pci_slot: struct pci_slot
c825bc94 KK	387	*
	388	* Helper function for pci_hotplug_core.c to remove symbolic link to
	389	* the hotplug driver module.
	390	*/
	391	void pci_hp_remove_module_link(struct pci_slot *pci_slot)
	392	{
	393	sysfs_remove_link(&pci_slot->kobj, "module");
	394	}
	395	EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
	396	#endif
	397
f46753c5 AC	398	static int pci_slot_init(void)
	399	{
	400	struct kset *pci_bus_kset;
	401
	402	pci_bus_kset = bus_get_kset(&pci_bus_type);
	403	pci_slots_kset = kset_create_and_add("slots", NULL,
	404	&pci_bus_kset->kobj);
	405	if (!pci_slots_kset) {
	406	printk(KERN_ERR "PCI: Slot initialization failure\n");
	407	return -ENOMEM;
	408	}
	409	return 0;
	410	}
	411
	412	subsys_initcall(pci_slot_init);