[deliverable/linux.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;
}

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, atomic_read(&slot->kobj.kref.refcount) - 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
	197	static struct pci_slot get_slot(struct pci_bus parent, int slot_nr)
	198	{
	199	struct pci_slot *slot;
67546762 YW	200
67546762 YW	201	/* We already hold pci_slot_mutex */
5fe6cc60 AC	202	list_for_each_entry(slot, &parent->slots, list)
	203	if (slot->number == slot_nr) {
	204	kobject_get(&slot->kobj);
	205	return slot;
	206	}
	207
	208	return NULL;
	209	}
	210
f46753c5 AC	211	/**
	212	* pci_create_slot - create or increment refcount for physical PCI slot
	213	* @parent: struct pci_bus of parent bridge
	214	* @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
	215	* @name: user visible string presented in /sys/bus/pci/slots/<name>
828f3768	216	* @hotplug: set if caller is hotplug driver, NULL otherwise
f46753c5 AC	217	*
	218	* PCI slots have first class attributes such as address, speed, width,
	219	* and a &struct pci_slot is used to manage them. This interface will
	220	* either return a new &struct pci_slot to the caller, or if the pci_slot
	221	* already exists, its refcount will be incremented.
	222	*
5fe6cc60 AC	223	* Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
	224	*
	225	* There are known platforms with broken firmware that assign the same
	226	* name to multiple slots. Workaround these broken platforms by renaming
	227	* the slots on behalf of the caller. If firmware assigns name N to
	228	* multiple slots:
	229	*
	230	* The first slot is assigned N
	231	* The second slot is assigned N-1
	232	* The third slot is assigned N-2
	233	* etc.
f46753c5 AC	234	*
	235	* Placeholder slots:
	236	* In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
	237	* a slot. There is one notable exception - pSeries (rpaphp), where the
	238	* @slot_nr cannot be determined until a device is actually inserted into
	239	* the slot. In this scenario, the caller may pass -1 for @slot_nr.
	240	*
	241	* The following semantics are imposed when the caller passes @slot_nr ==
5fe6cc60 AC	242	* -1. First, we no longer check for an existing %struct pci_slot, as there
5fe6cc60 AC	243	* may be many slots with @slot_nr of -1. The other change in semantics is
f46753c5 AC	244	* user-visible, which is the 'address' parameter presented in sysfs will
	245	* consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
	246	* %struct pci_bus and bb is the bus number. In other words, the devfn of
	247	* the 'placeholder' slot will not be displayed.
	248	*/
f46753c5	249	struct pci_slot pci_create_slot(struct pci_bus parent, int slot_nr,
828f3768 AC	250	const char *name,
828f3768 AC	251	struct hotplug_slot *hotplug)
f46753c5	252	{
cef354db	253	struct pci_dev *dev;
f46753c5	254	struct pci_slot *slot;
5fe6cc60 AC	255	int err = 0;
5fe6cc60 AC	256	char *slot_name = NULL;
f46753c5	257
67546762	258	mutex_lock(&pci_slot_mutex);
f46753c5 AC	259
	260	if (slot_nr == -1)
	261	goto placeholder;
	262
5fe6cc60 AC	263	/*
	264	* Hotplug drivers are allowed to rename an existing slot,
	265	* but only if not already claimed.
	266	*/
	267	slot = get_slot(parent, slot_nr);
	268	if (slot) {
	269	if (hotplug) {
	270	if ((err = slot->hotplug ? -EBUSY : 0)
	271	\|\| (err = rename_slot(slot, name))) {
	272	kobject_put(&slot->kobj);
	273	slot = NULL;
	274	goto err;
	275	}
f46753c5	276	}
5fe6cc60	277	goto out;
f46753c5 AC	278	}
	279
	280	placeholder:
	281	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
	282	if (!slot) {
5fe6cc60 AC	283	err = -ENOMEM;
5fe6cc60 AC	284	goto err;
f46753c5 AC	285	}
	286
	287	slot->bus = parent;
	288	slot->number = slot_nr;
	289
	290	slot->kobj.kset = pci_slots_kset;
5fe6cc60 AC	291
	292	slot_name = make_slot_name(name);
	293	if (!slot_name) {
	294	err = -ENOMEM;
f46753c5 AC	295	goto err;
	296	}
	297
5fe6cc60 AC	298	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
	299	"%s", slot_name);
	300	if (err)
	301	goto err;
	302
f46753c5 AC	303	INIT_LIST_HEAD(&slot->list);
	304	list_add(&slot->list, &parent->slots);
	305
67546762	306	down_read(&pci_bus_sem);
cef354db AC	307	list_for_each_entry(dev, &parent->devices, bus_list)
	308	if (PCI_SLOT(dev->devfn) == slot_nr)
	309	dev->slot = slot;
67546762	310	up_read(&pci_bus_sem);
cef354db	311
62795041 AC	312	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
62795041 AC	313	slot_nr, pci_slot_name(slot));
f46753c5	314
5fe6cc60	315	out:
3b5dd45e	316	kfree(slot_name);
67546762	317	mutex_unlock(&pci_slot_mutex);
f46753c5	318	return slot;
5fe6cc60	319	err:
f46753c5 AC	320	kfree(slot);
	321	slot = ERR_PTR(err);
	322	goto out;
	323	}
	324	EXPORT_SYMBOL_GPL(pci_create_slot);
	325
f46753c5 AC	326	/**
	327	* pci_destroy_slot - decrement refcount for physical PCI slot
	328	* @slot: struct pci_slot to decrement
	329	*
	330	* %struct pci_slot is refcounted, so destroying them is really easy; we
	331	* just call kobject_put on its kobj and let our release methods do the
	332	* rest.
	333	*/
f46753c5 AC	334	void pci_destroy_slot(struct pci_slot *slot)
f46753c5 AC	335	{
62795041 AC	336	dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
62795041 AC	337	slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
f46753c5	338
67546762	339	mutex_lock(&pci_slot_mutex);
f46753c5	340	kobject_put(&slot->kobj);
67546762	341	mutex_unlock(&pci_slot_mutex);
f46753c5 AC	342	}
	343	EXPORT_SYMBOL_GPL(pci_destroy_slot);
	344
c825bc94 KK	345	#if defined(CONFIG_HOTPLUG_PCI) \|\| defined(CONFIG_HOTPLUG_PCI_MODULE)
	346	#include <linux/pci_hotplug.h>
	347	/**
	348	* pci_hp_create_link - create symbolic link to the hotplug driver module.
503998ca	349	* @pci_slot: struct pci_slot
c825bc94 KK	350	*
	351	* Helper function for pci_hotplug_core.c to create symbolic link to
	352	* the hotplug driver module.
	353	*/
	354	void pci_hp_create_module_link(struct pci_slot *pci_slot)
	355	{
	356	struct hotplug_slot *slot = pci_slot->hotplug;
	357	struct kobject *kobj = NULL;
9fc9eea0	358	int ret;
c825bc94 KK	359
	360	if (!slot \|\| !slot->ops)
	361	return;
	362	kobj = kset_find_obj(module_kset, slot->ops->mod_name);
	363	if (!kobj)
	364	return;
9fc9eea0 BH	365	ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
	366	if (ret)
	367	dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
	368	ret);
c825bc94 KK	369	kobject_put(kobj);
	370	}
	371	EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
	372
	373	/**
	374	* pci_hp_remove_link - remove symbolic link to the hotplug driver module.
503998ca	375	* @pci_slot: struct pci_slot
c825bc94 KK	376	*
	377	* Helper function for pci_hotplug_core.c to remove symbolic link to
	378	* the hotplug driver module.
	379	*/
	380	void pci_hp_remove_module_link(struct pci_slot *pci_slot)
	381	{
	382	sysfs_remove_link(&pci_slot->kobj, "module");
	383	}
	384	EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
	385	#endif
	386
f46753c5 AC	387	static int pci_slot_init(void)
	388	{
	389	struct kset *pci_bus_kset;
	390
	391	pci_bus_kset = bus_get_kset(&pci_bus_type);
	392	pci_slots_kset = kset_create_and_add("slots", NULL,
	393	&pci_bus_kset->kobj);
	394	if (!pci_slots_kset) {
	395	printk(KERN_ERR "PCI: Slot initialization failure\n");
	396	return -ENOMEM;
	397	}
	398	return 0;
	399	}
	400
	401	subsys_initcall(pci_slot_init);