[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/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 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);
}

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;

	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 attribute *pci_slot_default_attrs[] = {
	&pci_slot_attr_address.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);

	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);

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>
	9	#include <linux/pci.h>
	10	#include <linux/err.h>
	11	#include "pci.h"
	12
	13	struct kset *pci_slots_kset;
	14	EXPORT_SYMBOL_GPL(pci_slots_kset);
	15
	16	static ssize_t pci_slot_attr_show(struct kobject *kobj,
	17	struct attribute attr, char buf)
	18	{
	19	struct pci_slot *slot = to_pci_slot(kobj);
	20	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	21	return attribute->show ? attribute->show(slot, buf) : -EIO;
	22	}
	23
	24	static ssize_t pci_slot_attr_store(struct kobject *kobj,
	25	struct attribute attr, const char buf, size_t len)
	26	{
	27	struct pci_slot *slot = to_pci_slot(kobj);
	28	struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
	29	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
	30	}
	31
	32	static struct sysfs_ops pci_slot_sysfs_ops = {
	33	.show = pci_slot_attr_show,
	34	.store = pci_slot_attr_store,
	35	};
	36
	37	static ssize_t address_read_file(struct pci_slot slot, char buf)
	38	{
	39	if (slot->number == 0xff)
	40	return sprintf(buf, "%04x:%02x\n",
	41	pci_domain_nr(slot->bus),
	42	slot->bus->number);
	43	else
	44	return sprintf(buf, "%04x:%02x:%02x\n",
	45	pci_domain_nr(slot->bus),
	46	slot->bus->number,
	47	slot->number);
	48	}
	49
	50	static void pci_slot_release(struct kobject *kobj)
	51	{
cef354db	52	struct pci_dev *dev;
f46753c5 AC	53	struct pci_slot *slot = to_pci_slot(kobj);
f46753c5 AC	54
62795041 AC	55	dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
62795041 AC	56	slot->number, pci_slot_name(slot));
f46753c5	57
cef354db AC	58	list_for_each_entry(dev, &slot->bus->devices, bus_list)
	59	if (PCI_SLOT(dev->devfn) == slot->number)
	60	dev->slot = NULL;
	61
f46753c5 AC	62	list_del(&slot->list);
	63
	64	kfree(slot);
	65	}
	66
	67	static struct pci_slot_attribute pci_slot_attr_address =
	68	__ATTR(address, (S_IFREG \| S_IRUGO), address_read_file, NULL);
	69
	70	static struct attribute *pci_slot_default_attrs[] = {
	71	&pci_slot_attr_address.attr,
	72	NULL,
	73	};
	74
	75	static struct kobj_type pci_slot_ktype = {
	76	.sysfs_ops = &pci_slot_sysfs_ops,
	77	.release = &pci_slot_release,
	78	.default_attrs = pci_slot_default_attrs,
	79	};
	80
5fe6cc60 AC	81	static char make_slot_name(const char name)
	82	{
	83	char *new_name;
	84	int len, max, dup;
	85
	86	new_name = kstrdup(name, GFP_KERNEL);
	87	if (!new_name)
	88	return NULL;
	89
	90	/*
	91	* Make sure we hit the realloc case the first time through the
	92	* loop. 'len' will be strlen(name) + 3 at that point which is
	93	* enough space for "name-X" and the trailing NUL.
	94	*/
	95	len = strlen(name) + 2;
	96	max = 1;
	97	dup = 1;
	98
	99	for (;;) {
	100	struct kobject *dup_slot;
	101	dup_slot = kset_find_obj(pci_slots_kset, new_name);
	102	if (!dup_slot)
	103	break;
	104	kobject_put(dup_slot);
	105	if (dup == max) {
	106	len++;
	107	max *= 10;
	108	kfree(new_name);
	109	new_name = kmalloc(len, GFP_KERNEL);
	110	if (!new_name)
	111	break;
	112	}
	113	sprintf(new_name, "%s-%d", name, dup++);
	114	}
	115
	116	return new_name;
	117	}
	118
	119	static int rename_slot(struct pci_slot slot, const char name)
	120	{
	121	int result = 0;
	122	char *slot_name;
	123
0ad772ec	124	if (strcmp(pci_slot_name(slot), name) == 0)
5fe6cc60 AC	125	return result;
	126
	127	slot_name = make_slot_name(name);
	128	if (!slot_name)
	129	return -ENOMEM;
	130
	131	result = kobject_rename(&slot->kobj, slot_name);
	132	kfree(slot_name);
	133
	134	return result;
	135	}
	136
	137	static struct pci_slot get_slot(struct pci_bus parent, int slot_nr)
	138	{
	139	struct pci_slot *slot;
	140	/*
	141	* We already hold pci_bus_sem so don't worry
	142	*/
	143	list_for_each_entry(slot, &parent->slots, list)
	144	if (slot->number == slot_nr) {
	145	kobject_get(&slot->kobj);
	146	return slot;
	147	}
	148
	149	return NULL;
	150	}
	151
f46753c5 AC	152	/**
	153	* pci_create_slot - create or increment refcount for physical PCI slot
	154	* @parent: struct pci_bus of parent bridge
	155	* @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
	156	* @name: user visible string presented in /sys/bus/pci/slots/<name>
828f3768	157	* @hotplug: set if caller is hotplug driver, NULL otherwise
f46753c5 AC	158	*
	159	* PCI slots have first class attributes such as address, speed, width,
	160	* and a &struct pci_slot is used to manage them. This interface will
	161	* either return a new &struct pci_slot to the caller, or if the pci_slot
	162	* already exists, its refcount will be incremented.
	163	*
5fe6cc60 AC	164	* Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
	165	*
	166	* There are known platforms with broken firmware that assign the same
	167	* name to multiple slots. Workaround these broken platforms by renaming
	168	* the slots on behalf of the caller. If firmware assigns name N to
	169	* multiple slots:
	170	*
	171	* The first slot is assigned N
	172	* The second slot is assigned N-1
	173	* The third slot is assigned N-2
	174	* etc.
f46753c5 AC	175	*
	176	* Placeholder slots:
	177	* In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
	178	* a slot. There is one notable exception - pSeries (rpaphp), where the
	179	* @slot_nr cannot be determined until a device is actually inserted into
	180	* the slot. In this scenario, the caller may pass -1 for @slot_nr.
	181	*
	182	* The following semantics are imposed when the caller passes @slot_nr ==
5fe6cc60 AC	183	* -1. First, we no longer check for an existing %struct pci_slot, as there
5fe6cc60 AC	184	* may be many slots with @slot_nr of -1. The other change in semantics is
f46753c5 AC	185	* user-visible, which is the 'address' parameter presented in sysfs will
	186	* consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
	187	* %struct pci_bus and bb is the bus number. In other words, the devfn of
	188	* the 'placeholder' slot will not be displayed.
	189	*/
f46753c5	190	struct pci_slot pci_create_slot(struct pci_bus parent, int slot_nr,
828f3768 AC	191	const char *name,
828f3768 AC	192	struct hotplug_slot *hotplug)
f46753c5	193	{
cef354db	194	struct pci_dev *dev;
f46753c5	195	struct pci_slot *slot;
5fe6cc60 AC	196	int err = 0;
5fe6cc60 AC	197	char *slot_name = NULL;
f46753c5 AC	198
	199	down_write(&pci_bus_sem);
	200
	201	if (slot_nr == -1)
	202	goto placeholder;
	203
5fe6cc60 AC	204	/*
	205	* Hotplug drivers are allowed to rename an existing slot,
	206	* but only if not already claimed.
	207	*/
	208	slot = get_slot(parent, slot_nr);
	209	if (slot) {
	210	if (hotplug) {
	211	if ((err = slot->hotplug ? -EBUSY : 0)
	212	\|\| (err = rename_slot(slot, name))) {
	213	kobject_put(&slot->kobj);
	214	slot = NULL;
	215	goto err;
	216	}
f46753c5	217	}
5fe6cc60	218	goto out;
f46753c5 AC	219	}
	220
	221	placeholder:
	222	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
	223	if (!slot) {
5fe6cc60 AC	224	err = -ENOMEM;
5fe6cc60 AC	225	goto err;
f46753c5 AC	226	}
	227
	228	slot->bus = parent;
	229	slot->number = slot_nr;
	230
	231	slot->kobj.kset = pci_slots_kset;
5fe6cc60 AC	232
	233	slot_name = make_slot_name(name);
	234	if (!slot_name) {
	235	err = -ENOMEM;
f46753c5 AC	236	goto err;
	237	}
	238
5fe6cc60 AC	239	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
	240	"%s", slot_name);
	241	if (err)
	242	goto err;
	243
f46753c5 AC	244	INIT_LIST_HEAD(&slot->list);
	245	list_add(&slot->list, &parent->slots);
	246
cef354db AC	247	list_for_each_entry(dev, &parent->devices, bus_list)
	248	if (PCI_SLOT(dev->devfn) == slot_nr)
	249	dev->slot = slot;
	250
62795041 AC	251	dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
62795041 AC	252	slot_nr, pci_slot_name(slot));
f46753c5	253
5fe6cc60	254	out:
3b5dd45e	255	kfree(slot_name);
f46753c5 AC	256	up_write(&pci_bus_sem);
f46753c5 AC	257	return slot;
5fe6cc60	258	err:
f46753c5 AC	259	kfree(slot);
	260	slot = ERR_PTR(err);
	261	goto out;
	262	}
	263	EXPORT_SYMBOL_GPL(pci_create_slot);
	264
	265	/**
d25b7c8d	266	* pci_renumber_slot - update %struct pci_slot -> number
cffb2faf RD	267	* @slot: &struct pci_slot to update
cffb2faf RD	268	* @slot_nr: new number for slot
f46753c5 AC	269	*
	270	* The primary purpose of this interface is to allow callers who earlier
	271	* created a placeholder slot in pci_create_slot() by passing a -1 as
	272	* slot_nr, to update their %struct pci_slot with the correct @slot_nr.
	273	*/
d25b7c8d	274	void pci_renumber_slot(struct pci_slot *slot, int slot_nr)
f46753c5	275	{
f46753c5 AC	276	struct pci_slot *tmp;
	277
	278	down_write(&pci_bus_sem);
	279
	280	list_for_each_entry(tmp, &slot->bus->slots, list) {
	281	WARN_ON(tmp->number == slot_nr);
d25b7c8d	282	goto out;
f46753c5 AC	283	}
f46753c5 AC	284
f46753c5	285	slot->number = slot_nr;
d25b7c8d	286	out:
f46753c5 AC	287	up_write(&pci_bus_sem);
f46753c5 AC	288	}
d25b7c8d	289	EXPORT_SYMBOL_GPL(pci_renumber_slot);
f46753c5 AC	290
	291	/**
	292	* pci_destroy_slot - decrement refcount for physical PCI slot
	293	* @slot: struct pci_slot to decrement
	294	*
	295	* %struct pci_slot is refcounted, so destroying them is really easy; we
	296	* just call kobject_put on its kobj and let our release methods do the
	297	* rest.
	298	*/
f46753c5 AC	299	void pci_destroy_slot(struct pci_slot *slot)
f46753c5 AC	300	{
62795041 AC	301	dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
62795041 AC	302	slot->number, atomic_read(&slot->kobj.kref.refcount) - 1);
f46753c5 AC	303
	304	down_write(&pci_bus_sem);
	305	kobject_put(&slot->kobj);
	306	up_write(&pci_bus_sem);
	307	}
	308	EXPORT_SYMBOL_GPL(pci_destroy_slot);
	309
	310	static int pci_slot_init(void)
	311	{
	312	struct kset *pci_bus_kset;
	313
	314	pci_bus_kset = bus_get_kset(&pci_bus_type);
	315	pci_slots_kset = kset_create_and_add("slots", NULL,
	316	&pci_bus_kset->kobj);
	317	if (!pci_slots_kset) {
	318	printk(KERN_ERR "PCI: Slot initialization failure\n");
	319	return -ENOMEM;
	320	}
	321	return 0;
	322	}
	323
	324	subsys_initcall(pci_slot_init);