[net-next-2.6.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/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 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 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 remove_sysfs_files(struct pci_slot *slot)
{
	char func[10];
	struct list_head *tmp;

	list_for_each(tmp, &slot->bus->devices) {
		struct pci_dev *dev = pci_dev_b(tmp);
		if (PCI_SLOT(dev->devfn) != slot->number)
			continue;
		sysfs_remove_link(&dev->dev.kobj, "slot");

		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
		sysfs_remove_link(&slot->kobj, func);
	}
}

static int create_sysfs_files(struct pci_slot *slot)
{
	int result;
	char func[10];
	struct list_head *tmp;

	list_for_each(tmp, &slot->bus->devices) {
		struct pci_dev *dev = pci_dev_b(tmp);
		if (PCI_SLOT(dev->devfn) != slot->number)
			continue;

		result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
		if (result)
			goto fail;

		snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
		result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
		if (result)
			goto fail;
	}

	return 0;

fail:
	remove_sysfs_files(slot);
	return result;
}

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));

	list_for_each_entry(dev, &slot->bus->devices, bus_list)
		if (PCI_SLOT(dev->devfn) == slot->number)
			dev->slot = NULL;

	remove_sysfs_files(slot);

	list_del(&slot->list);

	kfree(slot);
}

static struct pci_slot_attribute pci_slot_attr_address =
	__ATTR(address, (S_IFREG | S_IRUGO), address_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_max_speed =
	__ATTR(max_bus_speed, (S_IFREG | S_IRUGO), max_speed_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_cur_speed =
	__ATTR(cur_bus_speed, (S_IFREG | 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_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
 * @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;

	down_write(&pci_bus_sem);

	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);

	create_sysfs_files(slot);

	list_for_each_entry(dev, &parent->devices, bus_list)
		if (PCI_SLOT(dev->devfn) == slot_nr)
			dev->slot = slot;

	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
		slot_nr, pci_slot_name(slot));

out:
	kfree(slot_name);
	up_write(&pci_bus_sem);
	return slot;
err:
	kfree(slot);
	slot = ERR_PTR(err);
	goto out;
}
EXPORT_SYMBOL_GPL(pci_create_slot);

/**
 * pci_renumber_slot - update %struct pci_slot -> number
 * @slot: &struct pci_slot to update
 * @slot_nr: new number for slot
 *
 * The primary purpose of this interface is to allow callers who earlier
 * created a placeholder slot in pci_create_slot() by passing a -1 as
 * slot_nr, to update their %struct pci_slot with the correct @slot_nr.
 */
void pci_renumber_slot(struct pci_slot *slot, int slot_nr)
{
	struct pci_slot *tmp;

	down_write(&pci_bus_sem);

	list_for_each_entry(tmp, &slot->bus->slots, list) {
		WARN_ON(tmp->number == slot_nr);
		goto out;
	}

	slot->number = slot_nr;
out:
	up_write(&pci_bus_sem);
}
EXPORT_SYMBOL_GPL(pci_renumber_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);

	down_write(&pci_bus_sem);
	kobject_put(&slot->kobj);
	up_write(&pci_bus_sem);
}
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 no_warn;

	if (!slot || !slot->ops)
		return;
	kobj = kset_find_obj(module_kset, slot->ops->mod_name);
	if (!kobj)
		return;
	no_warn = sysfs_create_link(&pci_slot->kobj, kobj, "module");
	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>
f46753c5 AC	10	#include <linux/pci.h>
	11	#include <linux/err.h>
	12	#include "pci.h"
	13
	14	struct kset *pci_slots_kset;
	15	EXPORT_SYMBOL_GPL(pci_slots_kset);
	16
	17	static ssize_t pci_slot_attr_show(struct kobject *kobj,
	18	struct attribute attr, char buf)
	19	{
	20	struct pci_slot *slot = to_pci_slot(kobj);
	21	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	22	return attribute->show ? attribute->show(slot, buf) : -EIO;
	23	}
	24
	25	static ssize_t pci_slot_attr_store(struct kobject *kobj,
	26	struct attribute attr, const char buf, size_t len)
	27	{
	28	struct pci_slot *slot = to_pci_slot(kobj);
	29	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	30	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
	31	}
	32
52cf25d0	33	static const struct sysfs_ops pci_slot_sysfs_ops = {
f46753c5 AC	34	.show = pci_slot_attr_show,
	35	.store = pci_slot_attr_store,
	36	};
	37
	38	static ssize_t address_read_file(struct pci_slot slot, char buf)
	39	{
	40	if (slot->number == 0xff)
	41	return sprintf(buf, "%04x:%02x\n",
	42	pci_domain_nr(slot->bus),
	43	slot->bus->number);
	44	else
	45	return sprintf(buf, "%04x:%02x:%02x\n",
	46	pci_domain_nr(slot->bus),
	47	slot->bus->number,
	48	slot->number);
	49	}
	50
3749c51a MW	51	/* these strings match up with the values in pci_bus_speed */
	52	static char *pci_bus_speed_strings[] = {
	53	"33 MHz PCI", /* 0x00 */
	54	"66 MHz PCI", /* 0x01 */
	55	"66 MHz PCI-X", /* 0x02 */
	56	"100 MHz PCI-X", /* 0x03 */
	57	"133 MHz PCI-X", /* 0x04 */
	58	NULL, /* 0x05 */
	59	NULL, /* 0x06 */
	60	NULL, /* 0x07 */
	61	NULL, /* 0x08 */
	62	"66 MHz PCI-X 266", /* 0x09 */
	63	"100 MHz PCI-X 266", /* 0x0a */
	64	"133 MHz PCI-X 266", /* 0x0b */
45b4cdd5 MW	65	"Unknown AGP", /* 0x0c */
	66	"1x AGP", /* 0x0d */
	67	"2x AGP", /* 0x0e */
	68	"4x AGP", /* 0x0f */
	69	"8x AGP", /* 0x10 */
3749c51a MW	70	"66 MHz PCI-X 533", /* 0x11 */
	71	"100 MHz PCI-X 533", /* 0x12 */
	72	"133 MHz PCI-X 533", /* 0x13 */
	73	"2.5 GT/s PCIe", /* 0x14 */
	74	"5.0 GT/s PCIe", /* 0x15 */
9dfd97fe	75	"8.0 GT/s PCIe", /* 0x16 */
3749c51a MW	76	};
	77
	78	static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
	79	{
	80	const char *speed_string;
	81
	82	if (speed < ARRAY_SIZE(pci_bus_speed_strings))
	83	speed_string = pci_bus_speed_strings[speed];
	84	else
	85	speed_string = "Unknown";
	86
	87	return sprintf(buf, "%s\n", speed_string);
	88	}
	89
	90	static ssize_t max_speed_read_file(struct pci_slot slot, char buf)
	91	{
	92	return bus_speed_read(slot->bus->max_bus_speed, buf);
	93	}
	94
	95	static ssize_t cur_speed_read_file(struct pci_slot slot, char buf)
	96	{
	97	return bus_speed_read(slot->bus->cur_bus_speed, buf);
	98	}
	99
75568f80 AC	100	static void remove_sysfs_files(struct pci_slot *slot)
	101	{
	102	char func[10];
	103	struct list_head *tmp;
	104
	105	list_for_each(tmp, &slot->bus->devices) {
	106	struct pci_dev *dev = pci_dev_b(tmp);
	107	if (PCI_SLOT(dev->devfn) != slot->number)
	108	continue;
	109	sysfs_remove_link(&dev->dev.kobj, "slot");
	110
	111	snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
	112	sysfs_remove_link(&slot->kobj, func);
	113	}
	114	}
	115
	116	static int create_sysfs_files(struct pci_slot *slot)
	117	{
	118	int result;
	119	char func[10];
	120	struct list_head *tmp;
	121
	122	list_for_each(tmp, &slot->bus->devices) {
	123	struct pci_dev *dev = pci_dev_b(tmp);
	124	if (PCI_SLOT(dev->devfn) != slot->number)
	125	continue;
	126
	127	result = sysfs_create_link(&dev->dev.kobj, &slot->kobj, "slot");
	128	if (result)
	129	goto fail;
	130
	131	snprintf(func, 10, "function%d", PCI_FUNC(dev->devfn));
	132	result = sysfs_create_link(&slot->kobj, &dev->dev.kobj, func);
	133	if (result)
	134	goto fail;
	135	}
	136
	137	return 0;
	138
	139	fail:
	140	remove_sysfs_files(slot);
	141	return result;
	142	}
	143
f46753c5 AC	144	static void pci_slot_release(struct kobject *kobj)
f46753c5 AC	145	{
cef354db	146	struct pci_dev *dev;
f46753c5 AC	147	struct pci_slot *slot = to_pci_slot(kobj);
f46753c5 AC	148
62795041 AC	149	dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
62795041 AC	150	slot->number, pci_slot_name(slot));
f46753c5	151
cef354db AC	152	list_for_each_entry(dev, &slot->bus->devices, bus_list)
	153	if (PCI_SLOT(dev->devfn) == slot->number)
	154	dev->slot = NULL;
	155
75568f80 AC	156	remove_sysfs_files(slot);
75568f80 AC	157
f46753c5 AC	158	list_del(&slot->list);
	159
	160	kfree(slot);
	161	}
	162
	163	static struct pci_slot_attribute pci_slot_attr_address =
	164	__ATTR(address, (S_IFREG \| S_IRUGO), address_read_file, NULL);
3749c51a MW	165	static struct pci_slot_attribute pci_slot_attr_max_speed =
	166	__ATTR(max_bus_speed, (S_IFREG \| S_IRUGO), max_speed_read_file, NULL);
	167	static struct pci_slot_attribute pci_slot_attr_cur_speed =
	168	__ATTR(cur_bus_speed, (S_IFREG \| S_IRUGO), cur_speed_read_file, NULL);
f46753c5 AC	169
	170	static struct attribute *pci_slot_default_attrs[] = {
	171	&pci_slot_attr_address.attr,
3749c51a MW	172	&pci_slot_attr_max_speed.attr,
3749c51a MW	173	&pci_slot_attr_cur_speed.attr,
f46753c5 AC	174	NULL,
	175	};
	176
	177	static struct kobj_type pci_slot_ktype = {
	178	.sysfs_ops = &pci_slot_sysfs_ops,
	179	.release = &pci_slot_release,
	180	.default_attrs = pci_slot_default_attrs,
	181	};
	182
5fe6cc60 AC	183	static char make_slot_name(const char name)
	184	{
	185	char *new_name;
	186	int len, max, dup;
	187
	188	new_name = kstrdup(name, GFP_KERNEL);
	189	if (!new_name)
	190	return NULL;
	191
	192	/*
	193	* Make sure we hit the realloc case the first time through the
	194	* loop. 'len' will be strlen(name) + 3 at that point which is
	195	* enough space for "name-X" and the trailing NUL.
	196	*/
	197	len = strlen(name) + 2;
	198	max = 1;
	199	dup = 1;
	200
	201	for (;;) {
	202	struct kobject *dup_slot;
	203	dup_slot = kset_find_obj(pci_slots_kset, new_name);
	204	if (!dup_slot)
	205	break;
	206	kobject_put(dup_slot);
	207	if (dup == max) {
	208	len++;
	209	max *= 10;
	210	kfree(new_name);
	211	new_name = kmalloc(len, GFP_KERNEL);
	212	if (!new_name)
	213	break;
	214	}
	215	sprintf(new_name, "%s-%d", name, dup++);
	216	}
	217
	218	return new_name;
	219	}
	220
	221	static int rename_slot(struct pci_slot slot, const char name)
	222	{
	223	int result = 0;
	224	char *slot_name;
	225
0ad772ec	226	if (strcmp(pci_slot_name(slot), name) == 0)
5fe6cc60 AC	227	return result;
	228
	229	slot_name = make_slot_name(name);
	230	if (!slot_name)
	231	return -ENOMEM;
	232
	233	result = kobject_rename(&slot->kobj, slot_name);
	234	kfree(slot_name);
	235
	236	return result;
	237	}
	238
	239	static struct pci_slot get_slot(struct pci_bus parent, int slot_nr)
	240	{
	241	struct pci_slot *slot;
	242	/*
	243	* We already hold pci_bus_sem so don't worry
	244	*/
	245	list_for_each_entry(slot, &parent->slots, list)
	246	if (slot->number == slot_nr) {
	247	kobject_get(&slot->kobj);
	248	return slot;
	249	}
	250
	251	return NULL;
	252	}
	253
f46753c5 AC	254	/**
	255	* pci_create_slot - create or increment refcount for physical PCI slot
	256	* @parent: struct pci_bus of parent bridge
	257	* @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
	258	* @name: user visible string presented in /sys/bus/pci/slots/<name>
828f3768	259	* @hotplug: set if caller is hotplug driver, NULL otherwise
f46753c5 AC	260	*
	261	* PCI slots have first class attributes such as address, speed, width,
	262	* and a &struct pci_slot is used to manage them. This interface will
	263	* either return a new &struct pci_slot to the caller, or if the pci_slot
	264	* already exists, its refcount will be incremented.
	265	*
5fe6cc60 AC	266	* Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
	267	*
	268	* There are known platforms with broken firmware that assign the same
	269	* name to multiple slots. Workaround these broken platforms by renaming
	270	* the slots on behalf of the caller. If firmware assigns name N to
	271	* multiple slots:
	272	*
	273	* The first slot is assigned N
	274	* The second slot is assigned N-1
	275	* The third slot is assigned N-2
	276	* etc.
f46753c5 AC	277	*
	278	* Placeholder slots:
	279	* In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
	280	* a slot. There is one notable exception - pSeries (rpaphp), where the
	281	* @slot_nr cannot be determined until a device is actually inserted into
	282	* the slot. In this scenario, the caller may pass -1 for @slot_nr.
	283	*
	284	* The following semantics are imposed when the caller passes @slot_nr ==
5fe6cc60 AC	285	* -1. First, we no longer check for an existing %struct pci_slot, as there
5fe6cc60 AC	286	* may be many slots with @slot_nr of -1. The other change in semantics is
f46753c5 AC	287	* user-visible, which is the 'address' parameter presented in sysfs will
	288	* consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
	289	* %struct pci_bus and bb is the bus number. In other words, the devfn of
	290	* the 'placeholder' slot will not be displayed.
	291	*/
f46753c5	292	struct pci_slot pci_create_slot(struct pci_bus parent, int slot_nr,
828f3768 AC	293	const char *name,
828f3768 AC	294	struct hotplug_slot *hotplug)
f46753c5	295	{
cef354db	296	struct pci_dev *dev;
f46753c5	297	struct pci_slot *slot;
5fe6cc60 AC	298	int err = 0;
5fe6cc60 AC	299	char *slot_name = NULL;
f46753c5 AC	300
	301	down_write(&pci_bus_sem);
	302
	303	if (slot_nr == -1)
	304	goto placeholder;
	305
5fe6cc60 AC	306	/*
	307	* Hotplug drivers are allowed to rename an existing slot,
	308	* but only if not already claimed.
	309	*/
	310	slot = get_slot(parent, slot_nr);
	311	if (slot) {
	312	if (hotplug) {
	313	if ((err = slot->hotplug ? -EBUSY : 0)
	314	\|\| (err = rename_slot(slot, name))) {
	315	kobject_put(&slot->kobj);
	316	slot = NULL;
	317	goto err;
	318	}
f46753c5	319	}
5fe6cc60	320	goto out;
f46753c5 AC	321	}
	322
	323	placeholder:
	324	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
	325	if (!slot) {
5fe6cc60 AC	326	err = -ENOMEM;
5fe6cc60 AC	327	goto err;
f46753c5 AC	328	}
	329
	330	slot->bus = parent;
	331	slot->number = slot_nr;
	332
	333	slot->kobj.kset = pci_slots_kset;
5fe6cc60 AC	334
	335	slot_name = make_slot_name(name);
	336	if (!slot_name) {
	337	err = -ENOMEM;
f46753c5 AC	338	goto err;
	339	}
	340
5fe6cc60 AC	341	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
	342	"%s", slot_name);
	343	if (err)
	344	goto err;
	345
f46753c5 AC	346	INIT_LIST_HEAD(&slot->list);
	347	list_add(&slot->list, &parent->slots);
	348
75568f80 AC	349	create_sysfs_files(slot);
75568f80 AC	350
cef354db AC	351	list_for_each_entry(dev, &parent->devices, bus_list)
	352	if (PCI_SLOT(dev->devfn) == slot_nr)
	353	dev->slot = slot;
	354
62795041 AC	355	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
62795041 AC	356	slot_nr, pci_slot_name(slot));
f46753c5	357
5fe6cc60	358	out:
3b5dd45e	359	kfree(slot_name);
f46753c5 AC	360	up_write(&pci_bus_sem);
f46753c5 AC	361	return slot;
5fe6cc60	362	err:
f46753c5 AC	363	kfree(slot);
	364	slot = ERR_PTR(err);
	365	goto out;
	366	}
	367	EXPORT_SYMBOL_GPL(pci_create_slot);
	368
	369	/**
d25b7c8d	370	* pci_renumber_slot - update %struct pci_slot -> number
cffb2faf RD	371	* @slot: &struct pci_slot to update
cffb2faf RD	372	* @slot_nr: new number for slot
f46753c5 AC	373	*
	374	* The primary purpose of this interface is to allow callers who earlier
	375	* created a placeholder slot in pci_create_slot() by passing a -1 as
	376	* slot_nr, to update their %struct pci_slot with the correct @slot_nr.
	377	*/
d25b7c8d	378	void pci_renumber_slot(struct pci_slot *slot, int slot_nr)
f46753c5	379	{
f46753c5 AC	380	struct pci_slot *tmp;
	381
	382	down_write(&pci_bus_sem);
	383
	384	list_for_each_entry(tmp, &slot->bus->slots, list) {
	385	WARN_ON(tmp->number == slot_nr);
d25b7c8d	386	goto out;
f46753c5 AC	387	}
f46753c5 AC	388
f46753c5	389	slot->number = slot_nr;
d25b7c8d	390	out:
f46753c5 AC	391	up_write(&pci_bus_sem);
f46753c5 AC	392	}
d25b7c8d	393	EXPORT_SYMBOL_GPL(pci_renumber_slot);
f46753c5 AC	394
	395	/**
	396	* pci_destroy_slot - decrement refcount for physical PCI slot
	397	* @slot: struct pci_slot to decrement
	398	*
	399	* %struct pci_slot is refcounted, so destroying them is really easy; we
	400	* just call kobject_put on its kobj and let our release methods do the
	401	* rest.
	402	*/
f46753c5 AC	403	void pci_destroy_slot(struct pci_slot *slot)
f46753c5 AC	404	{
62795041 AC	405	dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
62795041 AC	406	slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
f46753c5 AC	407
	408	down_write(&pci_bus_sem);
	409	kobject_put(&slot->kobj);
	410	up_write(&pci_bus_sem);
	411	}
	412	EXPORT_SYMBOL_GPL(pci_destroy_slot);
	413
c825bc94 KK	414	#if defined(CONFIG_HOTPLUG_PCI) \|\| defined(CONFIG_HOTPLUG_PCI_MODULE)
	415	#include <linux/pci_hotplug.h>
	416	/**
	417	* pci_hp_create_link - create symbolic link to the hotplug driver module.
503998ca	418	* @pci_slot: struct pci_slot
c825bc94 KK	419	*
	420	* Helper function for pci_hotplug_core.c to create symbolic link to
	421	* the hotplug driver module.
	422	*/
	423	void pci_hp_create_module_link(struct pci_slot *pci_slot)
	424	{
	425	struct hotplug_slot *slot = pci_slot->hotplug;
	426	struct kobject *kobj = NULL;
	427	int no_warn;
	428
	429	if (!slot \|\| !slot->ops)
	430	return;
	431	kobj = kset_find_obj(module_kset, slot->ops->mod_name);
	432	if (!kobj)
	433	return;
	434	no_warn = sysfs_create_link(&pci_slot->kobj, kobj, "module");
	435	kobject_put(kobj);
	436	}
	437	EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
	438
	439	/**
	440	* pci_hp_remove_link - remove symbolic link to the hotplug driver module.
503998ca	441	* @pci_slot: struct pci_slot
c825bc94 KK	442	*
	443	* Helper function for pci_hotplug_core.c to remove symbolic link to
	444	* the hotplug driver module.
	445	*/
	446	void pci_hp_remove_module_link(struct pci_slot *pci_slot)
	447	{
	448	sysfs_remove_link(&pci_slot->kobj, "module");
	449	}
	450	EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
	451	#endif
	452
f46753c5 AC	453	static int pci_slot_init(void)
	454	{
	455	struct kset *pci_bus_kset;
	456
	457	pci_bus_kset = bus_get_kset(&pci_bus_type);
	458	pci_slots_kset = kset_create_and_add("slots", NULL,
	459	&pci_bus_kset->kobj);
	460	if (!pci_slots_kset) {
	461	printk(KERN_ERR "PCI: Slot initialization failure\n");
	462	return -ENOMEM;
	463	}
	464	return 0;
	465	}
	466
	467	subsys_initcall(pci_slot_init);