[deliverable/linux.git] / drivers / pci / search.c

/*
 *	PCI searching functions.
 *
 *	Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
 *					David Mosberger-Tang
 *	Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
 *	Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
 */

#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include "pci.h"

DECLARE_RWSEM(pci_bus_sem);
EXPORT_SYMBOL_GPL(pci_bus_sem);

/*
 * pci_for_each_dma_alias - Iterate over DMA aliases for a device
 * @pdev: starting downstream device
 * @fn: function to call for each alias
 * @data: opaque data to pass to @fn
 *
 * Starting @pdev, walk up the bus calling @fn for each possible alias
 * of @pdev at the root bus.
 */
int pci_for_each_dma_alias(struct pci_dev *pdev,
			   int (*fn)(struct pci_dev *pdev,
				     u16 alias, void *data), void *data)
{
	struct pci_bus *bus;
	int ret;

	ret = fn(pdev, PCI_DEVID(pdev->bus->number, pdev->devfn), data);
	if (ret)
		return ret;

	/*
	 * If the device is broken and uses an alias requester ID for
	 * DMA, iterate over that too.
	 */
	if (unlikely(pdev->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN)) {
		ret = fn(pdev, PCI_DEVID(pdev->bus->number,
					 pdev->dma_alias_devfn), data);
		if (ret)
			return ret;
	}

	for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
		struct pci_dev *tmp;

		/* Skip virtual buses */
		if (!bus->self)
			continue;

		tmp = bus->self;

		/*
		 * PCIe-to-PCI/X bridges alias transactions from downstream
		 * devices using the subordinate bus number (PCI Express to
		 * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3).  For all cases
		 * where the upstream bus is PCI/X we alias to the bridge
		 * (there are various conditions in the previous reference
		 * where the bridge may take ownership of transactions, even
		 * when the secondary interface is PCI-X).
		 */
		if (pci_is_pcie(tmp)) {
			switch (pci_pcie_type(tmp)) {
			case PCI_EXP_TYPE_ROOT_PORT:
			case PCI_EXP_TYPE_UPSTREAM:
			case PCI_EXP_TYPE_DOWNSTREAM:
				continue;
			case PCI_EXP_TYPE_PCI_BRIDGE:
				ret = fn(tmp,
					 PCI_DEVID(tmp->subordinate->number,
						   PCI_DEVFN(0, 0)), data);
				if (ret)
					return ret;
				continue;
			case PCI_EXP_TYPE_PCIE_BRIDGE:
				ret = fn(tmp,
					 PCI_DEVID(tmp->bus->number,
						   tmp->devfn), data);
				if (ret)
					return ret;
				continue;
			}
		} else {
			if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
				ret = fn(tmp,
					 PCI_DEVID(tmp->subordinate->number,
						   PCI_DEVFN(0, 0)), data);
			else
				ret = fn(tmp,
					 PCI_DEVID(tmp->bus->number,
						   tmp->devfn), data);
			if (ret)
				return ret;
		}
	}

	return ret;
}

/*
 * find the upstream PCIe-to-PCI bridge of a PCI device
 * if the device is PCIE, return NULL
 * if the device isn't connected to a PCIe bridge (that is its parent is a
 * legacy PCI bridge and the bridge is directly connected to bus 0), return its
 * parent
 */
struct pci_dev *
pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
{
	struct pci_dev *tmp = NULL;

	if (pci_is_pcie(pdev))
		return NULL;
	while (1) {
		if (pci_is_root_bus(pdev->bus))
			break;
		pdev = pdev->bus->self;
		/* a p2p bridge */
		if (!pci_is_pcie(pdev)) {
			tmp = pdev;
			continue;
		}
		/* PCI device should connect to a PCIe bridge */
		if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) {
			/* Busted hardware? */
			WARN_ON_ONCE(1);
			return NULL;
		}
		return pdev;
	}

	return tmp;
}

static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
{
	struct pci_bus *child;
	struct pci_bus *tmp;

	if(bus->number == busnr)
		return bus;

	list_for_each_entry(tmp, &bus->children, node) {
		child = pci_do_find_bus(tmp, busnr);
		if(child)
			return child;
	}
	return NULL;
}

/**
 * pci_find_bus - locate PCI bus from a given domain and bus number
 * @domain: number of PCI domain to search
 * @busnr: number of desired PCI bus
 *
 * Given a PCI bus number and domain number, the desired PCI bus is located
 * in the global list of PCI buses.  If the bus is found, a pointer to its
 * data structure is returned.  If no bus is found, %NULL is returned.
 */
struct pci_bus * pci_find_bus(int domain, int busnr)
{
	struct pci_bus *bus = NULL;
	struct pci_bus *tmp_bus;

	while ((bus = pci_find_next_bus(bus)) != NULL)  {
		if (pci_domain_nr(bus) != domain)
			continue;
		tmp_bus = pci_do_find_bus(bus, busnr);
		if (tmp_bus)
			return tmp_bus;
	}
	return NULL;
}

/**
 * pci_find_next_bus - begin or continue searching for a PCI bus
 * @from: Previous PCI bus found, or %NULL for new search.
 *
 * Iterates through the list of known PCI buses.  A new search is
 * initiated by passing %NULL as the @from argument.  Otherwise if
 * @from is not %NULL, searches continue from next device on the
 * global list.
 */
struct pci_bus *
pci_find_next_bus(const struct pci_bus *from)
{
	struct list_head *n;
	struct pci_bus *b = NULL;

	WARN_ON(in_interrupt());
	down_read(&pci_bus_sem);
	n = from ? from->node.next : pci_root_buses.next;
	if (n != &pci_root_buses)
		b = list_entry(n, struct pci_bus, node);
	up_read(&pci_bus_sem);
	return b;
}

/**
 * pci_get_slot - locate PCI device for a given PCI slot
 * @bus: PCI bus on which desired PCI device resides
 * @devfn: encodes number of PCI slot in which the desired PCI
 * device resides and the logical device number within that slot
 * in case of multi-function devices.
 *
 * Given a PCI bus and slot/function number, the desired PCI device
 * is located in the list of PCI devices.
 * If the device is found, its reference count is increased and this
 * function returns a pointer to its data structure.  The caller must
 * decrement the reference count by calling pci_dev_put().
 * If no device is found, %NULL is returned.
 */
struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
{
	struct pci_dev *dev;

	WARN_ON(in_interrupt());
	down_read(&pci_bus_sem);

	list_for_each_entry(dev, &bus->devices, bus_list) {
		if (dev->devfn == devfn)
			goto out;
	}

	dev = NULL;
 out:
	pci_dev_get(dev);
	up_read(&pci_bus_sem);
	return dev;
}

/**
 * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
 * @domain: PCI domain/segment on which the PCI device resides.
 * @bus: PCI bus on which desired PCI device resides
 * @devfn: encodes number of PCI slot in which the desired PCI device
 * resides and the logical device number within that slot in case of
 * multi-function devices.
 *
 * Given a PCI domain, bus, and slot/function number, the desired PCI
 * device is located in the list of PCI devices. If the device is
 * found, its reference count is increased and this function returns a
 * pointer to its data structure.  The caller must decrement the
 * reference count by calling pci_dev_put().  If no device is found,
 * %NULL is returned.
 */
struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
					    unsigned int devfn)
{
	struct pci_dev *dev = NULL;

	for_each_pci_dev(dev) {
		if (pci_domain_nr(dev->bus) == domain &&
		    (dev->bus->number == bus && dev->devfn == devfn))
			return dev;
	}
	return NULL;
}
EXPORT_SYMBOL(pci_get_domain_bus_and_slot);

static int match_pci_dev_by_id(struct device *dev, void *data)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	struct pci_device_id *id = data;

	if (pci_match_one_device(id, pdev))
		return 1;
	return 0;
}

/*
 * pci_get_dev_by_id - begin or continue searching for a PCI device by id
 * @id: pointer to struct pci_device_id to match for the device
 * @from: Previous PCI device found in search, or %NULL for new search.
 *
 * Iterates through the list of known PCI devices.  If a PCI device is found
 * with a matching id a pointer to its device structure is returned, and the
 * reference count to the device is incremented.  Otherwise, %NULL is returned.
 * A new search is initiated by passing %NULL as the @from argument.  Otherwise
 * if @from is not %NULL, searches continue from next device on the global
 * list.  The reference count for @from is always decremented if it is not
 * %NULL.
 *
 * This is an internal function for use by the other search functions in
 * this file.
 */
static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
					 struct pci_dev *from)
{
	struct device *dev;
	struct device *dev_start = NULL;
	struct pci_dev *pdev = NULL;

	WARN_ON(in_interrupt());
	if (from)
		dev_start = &from->dev;
	dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
			      match_pci_dev_by_id);
	if (dev)
		pdev = to_pci_dev(dev);
	if (from)
		pci_dev_put(from);
	return pdev;
}

/**
 * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 * @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
 * @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
 * @from: Previous PCI device found in search, or %NULL for new search.
 *
 * Iterates through the list of known PCI devices.  If a PCI device is found
 * with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
 * device structure is returned, and the reference count to the device is
 * incremented.  Otherwise, %NULL is returned.  A new search is initiated by
 * passing %NULL as the @from argument.  Otherwise if @from is not %NULL,
 * searches continue from next device on the global list.
 * The reference count for @from is always decremented if it is not %NULL.
 */
struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
			       unsigned int ss_vendor, unsigned int ss_device,
			       struct pci_dev *from)
{
	struct pci_device_id id = {
		.vendor = vendor,
		.device = device,
		.subvendor = ss_vendor,
		.subdevice = ss_device,
	};

	return pci_get_dev_by_id(&id, from);
}

/**
 * pci_get_device - begin or continue searching for a PCI device by vendor/device id
 * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
 * @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
 * @from: Previous PCI device found in search, or %NULL for new search.
 *
 * Iterates through the list of known PCI devices.  If a PCI device is
 * found with a matching @vendor and @device, the reference count to the
 * device is incremented and a pointer to its device structure is returned.
 * Otherwise, %NULL is returned.  A new search is initiated by passing %NULL
 * as the @from argument.  Otherwise if @from is not %NULL, searches continue
 * from next device on the global list.  The reference count for @from is
 * always decremented if it is not %NULL.
 */
struct pci_dev *
pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
{
	return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
}

/**
 * pci_get_class - begin or continue searching for a PCI device by class
 * @class: search for a PCI device with this class designation
 * @from: Previous PCI device found in search, or %NULL for new search.
 *
 * Iterates through the list of known PCI devices.  If a PCI device is
 * found with a matching @class, the reference count to the device is
 * incremented and a pointer to its device structure is returned.
 * Otherwise, %NULL is returned.
 * A new search is initiated by passing %NULL as the @from argument.
 * Otherwise if @from is not %NULL, searches continue from next device
 * on the global list.  The reference count for @from is always decremented
 * if it is not %NULL.
 */
struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
{
	struct pci_device_id id = {
		.vendor = PCI_ANY_ID,
		.device = PCI_ANY_ID,
		.subvendor = PCI_ANY_ID,
		.subdevice = PCI_ANY_ID,
		.class_mask = PCI_ANY_ID,
		.class = class,
	};

	return pci_get_dev_by_id(&id, from);
}

/**
 * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
 * @ids: A pointer to a null terminated list of struct pci_device_id structures
 * that describe the type of PCI device the caller is trying to find.
 *
 * Obvious fact: You do not have a reference to any device that might be found
 * by this function, so if that device is removed from the system right after
 * this function is finished, the value will be stale.  Use this function to
 * find devices that are usually built into a system, or for a general hint as
 * to if another device happens to be present at this specific moment in time.
 */
int pci_dev_present(const struct pci_device_id *ids)
{
	struct pci_dev *found = NULL;

	WARN_ON(in_interrupt());
	while (ids->vendor || ids->subvendor || ids->class_mask) {
		found = pci_get_dev_by_id(ids, NULL);
		if (found) {
			pci_dev_put(found);
			return 1;
		}
		ids++;
	}

	return 0;
}
EXPORT_SYMBOL(pci_dev_present);

/* For boot time work */
EXPORT_SYMBOL(pci_find_bus);
EXPORT_SYMBOL(pci_find_next_bus);
/* For everyone */
EXPORT_SYMBOL(pci_get_device);
EXPORT_SYMBOL(pci_get_subsys);
EXPORT_SYMBOL(pci_get_slot);
EXPORT_SYMBOL(pci_get_class);
Commit	Line	Data
1da177e4	1	/*
f7625980	2	* PCI searching functions.
1da177e4 LT	3	*
	4	* Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
	5	* David Mosberger-Tang
	6	* Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
	7	* Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
	8	*/
	9
1da177e4	10	#include <linux/pci.h>
5a0e3ad6	11	#include <linux/slab.h>
1da177e4 LT	12	#include <linux/module.h>
	13	#include <linux/interrupt.h>
	14	#include "pci.h"
	15
d71374da	16	DECLARE_RWSEM(pci_bus_sem);
ce29ca3e AK	17	EXPORT_SYMBOL_GPL(pci_bus_sem);
ce29ca3e AK	18
c25dc828 AW	19	/*
	20	* pci_for_each_dma_alias - Iterate over DMA aliases for a device
	21	* @pdev: starting downstream device
	22	* @fn: function to call for each alias
	23	* @data: opaque data to pass to @fn
	24	*
	25	* Starting @pdev, walk up the bus calling @fn for each possible alias
	26	* of @pdev at the root bus.
	27	*/
	28	int pci_for_each_dma_alias(struct pci_dev *pdev,
	29	int (fn)(struct pci_dev pdev,
	30	u16 alias, void data), void data)
	31	{
	32	struct pci_bus *bus;
	33	int ret;
	34
	35	ret = fn(pdev, PCI_DEVID(pdev->bus->number, pdev->devfn), data);
	36	if (ret)
	37	return ret;
	38
31c2b815 AW	39	/*
	40	* If the device is broken and uses an alias requester ID for
	41	* DMA, iterate over that too.
	42	*/
	43	if (unlikely(pdev->dev_flags & PCI_DEV_FLAGS_DMA_ALIAS_DEVFN)) {
	44	ret = fn(pdev, PCI_DEVID(pdev->bus->number,
	45	pdev->dma_alias_devfn), data);
	46	if (ret)
	47	return ret;
	48	}
	49
c25dc828 AW	50	for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
	51	struct pci_dev *tmp;
	52
	53	/* Skip virtual buses */
	54	if (!bus->self)
	55	continue;
	56
	57	tmp = bus->self;
	58
	59	/*
	60	* PCIe-to-PCI/X bridges alias transactions from downstream
	61	* devices using the subordinate bus number (PCI Express to
	62	* PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
	63	* where the upstream bus is PCI/X we alias to the bridge
	64	* (there are various conditions in the previous reference
	65	* where the bridge may take ownership of transactions, even
	66	* when the secondary interface is PCI-X).
	67	*/
	68	if (pci_is_pcie(tmp)) {
	69	switch (pci_pcie_type(tmp)) {
	70	case PCI_EXP_TYPE_ROOT_PORT:
	71	case PCI_EXP_TYPE_UPSTREAM:
	72	case PCI_EXP_TYPE_DOWNSTREAM:
	73	continue;
	74	case PCI_EXP_TYPE_PCI_BRIDGE:
	75	ret = fn(tmp,
	76	PCI_DEVID(tmp->subordinate->number,
	77	PCI_DEVFN(0, 0)), data);
	78	if (ret)
	79	return ret;
	80	continue;
	81	case PCI_EXP_TYPE_PCIE_BRIDGE:
	82	ret = fn(tmp,
	83	PCI_DEVID(tmp->bus->number,
	84	tmp->devfn), data);
	85	if (ret)
	86	return ret;
	87	continue;
	88	}
	89	} else {
c8fe16e3 AW	90	if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
	91	ret = fn(tmp,
	92	PCI_DEVID(tmp->subordinate->number,
	93	PCI_DEVFN(0, 0)), data);
	94	else
	95	ret = fn(tmp,
	96	PCI_DEVID(tmp->bus->number,
	97	tmp->devfn), data);
c25dc828 AW	98	if (ret)
	99	return ret;
	100	}
	101	}
	102
	103	return ret;
	104	}
	105
994a65e2	106	/*
45e829ea	107	* find the upstream PCIe-to-PCI bridge of a PCI device
994a65e2	108	* if the device is PCIE, return NULL
45e829ea	109	* if the device isn't connected to a PCIe bridge (that is its parent is a
994a65e2 KA	110	* legacy PCI bridge and the bridge is directly connected to bus 0), return its
	111	* parent
	112	*/
	113	struct pci_dev *
	114	pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
	115	{
	116	struct pci_dev *tmp = NULL;
	117
5f4d91a1	118	if (pci_is_pcie(pdev))
994a65e2 KA	119	return NULL;
994a65e2 KA	120	while (1) {
6e3f36df	121	if (pci_is_root_bus(pdev->bus))
994a65e2 KA	122	break;
	123	pdev = pdev->bus->self;
	124	/* a p2p bridge */
5f4d91a1	125	if (!pci_is_pcie(pdev)) {
994a65e2 KA	126	tmp = pdev;
	127	continue;
	128	}
45e829ea	129	/* PCI device should connect to a PCIe bridge */
62f87c0e	130	if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) {
994a65e2 KA	131	/* Busted hardware? */
	132	WARN_ON_ONCE(1);
	133	return NULL;
	134	}
	135	return pdev;
	136	}
	137
	138	return tmp;
	139	}
1da177e4	140
96bde06a	141	static struct pci_bus pci_do_find_bus(struct pci_bus bus, unsigned char busnr)
1da177e4	142	{
94e6a9b9 YW	143	struct pci_bus *child;
94e6a9b9 YW	144	struct pci_bus *tmp;
1da177e4 LT	145
	146	if(bus->number == busnr)
	147	return bus;
	148
94e6a9b9 YW	149	list_for_each_entry(tmp, &bus->children, node) {
94e6a9b9 YW	150	child = pci_do_find_bus(tmp, busnr);
1da177e4 LT	151	if(child)
	152	return child;
	153	}
	154	return NULL;
	155	}
	156
	157	/**
	158	* pci_find_bus - locate PCI bus from a given domain and bus number
	159	* @domain: number of PCI domain to search
	160	* @busnr: number of desired PCI bus
	161	*
	162	* Given a PCI bus number and domain number, the desired PCI bus is located
	163	* in the global list of PCI buses. If the bus is found, a pointer to its
	164	* data structure is returned. If no bus is found, %NULL is returned.
	165	*/
c8439cfc	166	struct pci_bus * pci_find_bus(int domain, int busnr)
1da177e4 LT	167	{
	168	struct pci_bus *bus = NULL;
	169	struct pci_bus *tmp_bus;
	170
	171	while ((bus = pci_find_next_bus(bus)) != NULL) {
	172	if (pci_domain_nr(bus) != domain)
	173	continue;
	174	tmp_bus = pci_do_find_bus(bus, busnr);
	175	if (tmp_bus)
	176	return tmp_bus;
	177	}
	178	return NULL;
	179	}
	180
	181	/**
	182	* pci_find_next_bus - begin or continue searching for a PCI bus
	183	* @from: Previous PCI bus found, or %NULL for new search.
	184	*
f7625980	185	* Iterates through the list of known PCI buses. A new search is
d75763d2	186	* initiated by passing %NULL as the @from argument. Otherwise if
1da177e4 LT	187	* @from is not %NULL, searches continue from next device on the
	188	* global list.
	189	*/
f7625980	190	struct pci_bus *
1da177e4 LT	191	pci_find_next_bus(const struct pci_bus *from)
	192	{
	193	struct list_head *n;
	194	struct pci_bus *b = NULL;
	195
	196	WARN_ON(in_interrupt());
d71374da	197	down_read(&pci_bus_sem);
1da177e4 LT	198	n = from ? from->node.next : pci_root_buses.next;
1da177e4 LT	199	if (n != &pci_root_buses)
94e6a9b9	200	b = list_entry(n, struct pci_bus, node);
d71374da	201	up_read(&pci_bus_sem);
1da177e4 LT	202	return b;
	203	}
	204
1da177e4 LT	205	/**
	206	* pci_get_slot - locate PCI device for a given PCI slot
	207	* @bus: PCI bus on which desired PCI device resides
f7625980 BH	208	* @devfn: encodes number of PCI slot in which the desired PCI
f7625980 BH	209	* device resides and the logical device number within that slot
1da177e4 LT	210	* in case of multi-function devices.
1da177e4 LT	211	*
f7625980	212	* Given a PCI bus and slot/function number, the desired PCI device
1da177e4 LT	213	* is located in the list of PCI devices.
	214	* If the device is found, its reference count is increased and this
	215	* function returns a pointer to its data structure. The caller must
	216	* decrement the reference count by calling pci_dev_put().
	217	* If no device is found, %NULL is returned.
	218	*/
66455f54	219	struct pci_dev pci_get_slot(struct pci_bus bus, unsigned int devfn)
1da177e4	220	{
1da177e4 LT	221	struct pci_dev *dev;
	222
	223	WARN_ON(in_interrupt());
d71374da	224	down_read(&pci_bus_sem);
1da177e4	225
66455f54	226	list_for_each_entry(dev, &bus->devices, bus_list) {
1da177e4 LT	227	if (dev->devfn == devfn)
	228	goto out;
	229	}
	230
	231	dev = NULL;
	232	out:
	233	pci_dev_get(dev);
d71374da	234	up_read(&pci_bus_sem);
1da177e4 LT	235	return dev;
	236	}
	237
29f3eb64	238	/**
3c299dc2 AP	239	* pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
	240	* @domain: PCI domain/segment on which the PCI device resides.
	241	* @bus: PCI bus on which desired PCI device resides
	242	* @devfn: encodes number of PCI slot in which the desired PCI device
	243	* resides and the logical device number within that slot in case of
	244	* multi-function devices.
5463d9f0	245	*
3c299dc2 AP	246	* Given a PCI domain, bus, and slot/function number, the desired PCI
	247	* device is located in the list of PCI devices. If the device is
	248	* found, its reference count is increased and this function returns a
	249	* pointer to its data structure. The caller must decrement the
	250	* reference count by calling pci_dev_put(). If no device is found,
	251	* %NULL is returned.
29f3eb64	252	*/
3c299dc2 AP	253	struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
3c299dc2 AP	254	unsigned int devfn)
29f3eb64 AC	255	{
	256	struct pci_dev *dev = NULL;
	257
4e344b1c	258	for_each_pci_dev(dev) {
3c299dc2 AP	259	if (pci_domain_nr(dev->bus) == domain &&
3c299dc2 AP	260	(dev->bus->number == bus && dev->devfn == devfn))
29f3eb64 AC	261	return dev;
	262	}
	263	return NULL;
	264	}
3c299dc2	265	EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
29f3eb64	266
95247b57	267	static int match_pci_dev_by_id(struct device dev, void data)
1da177e4	268	{
95247b57 GKH	269	struct pci_dev *pdev = to_pci_dev(dev);
95247b57 GKH	270	struct pci_device_id *id = data;
1da177e4	271
95247b57 GKH	272	if (pci_match_one_device(id, pdev))
	273	return 1;
	274	return 0;
1da177e4 LT	275	}
1da177e4 LT	276
95247b57 GKH	277	/*
	278	* pci_get_dev_by_id - begin or continue searching for a PCI device by id
	279	* @id: pointer to struct pci_device_id to match for the device
1da177e4 LT	280	* @from: Previous PCI device found in search, or %NULL for new search.
1da177e4 LT	281	*
d75763d2	282	* Iterates through the list of known PCI devices. If a PCI device is found
95247b57 GKH	283	* with a matching id a pointer to its device structure is returned, and the
	284	* reference count to the device is incremented. Otherwise, %NULL is returned.
	285	* A new search is initiated by passing %NULL as the @from argument. Otherwise
	286	* if @from is not %NULL, searches continue from next device on the global
	287	* list. The reference count for @from is always decremented if it is not
	288	* %NULL.
	289	*
	290	* This is an internal function for use by the other search functions in
	291	* this file.
1da177e4	292	*/
95247b57	293	static struct pci_dev pci_get_dev_by_id(const struct pci_device_id id,
b08508c4	294	struct pci_dev *from)
1da177e4	295	{
95247b57 GKH	296	struct device *dev;
	297	struct device *dev_start = NULL;
	298	struct pci_dev *pdev = NULL;
	299
	300	WARN_ON(in_interrupt());
c4ed02fa MW	301	if (from)
c4ed02fa MW	302	dev_start = &from->dev;
95247b57 GKH	303	dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
	304	match_pci_dev_by_id);
	305	if (dev)
	306	pdev = to_pci_dev(dev);
ebca4f1b GK	307	if (from)
ebca4f1b GK	308	pci_dev_put(from);
95247b57	309	return pdev;
1da177e4 LT	310	}
	311
	312	/**
	313	* pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
	314	* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
	315	* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
	316	* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
	317	* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
	318	* @from: Previous PCI device found in search, or %NULL for new search.
	319	*
d75763d2 RD	320	* Iterates through the list of known PCI devices. If a PCI device is found
d75763d2 RD	321	* with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
1da177e4 LT	322	* device structure is returned, and the reference count to the device is
1da177e4 LT	323	* incremented. Otherwise, %NULL is returned. A new search is initiated by
d75763d2	324	* passing %NULL as the @from argument. Otherwise if @from is not %NULL,
1da177e4 LT	325	* searches continue from next device on the global list.
	326	* The reference count for @from is always decremented if it is not %NULL.
	327	*/
95247b57 GKH	328	struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
95247b57 GKH	329	unsigned int ss_vendor, unsigned int ss_device,
b08508c4	330	struct pci_dev *from)
1da177e4	331	{
b9443f40 FT	332	struct pci_device_id id = {
	333	.vendor = vendor,
	334	.device = device,
	335	.subvendor = ss_vendor,
	336	.subdevice = ss_device,
	337	};
6ae4adf5	338
b9443f40	339	return pci_get_dev_by_id(&id, from);
1da177e4 LT	340	}
	341
	342	/**
	343	* pci_get_device - begin or continue searching for a PCI device by vendor/device id
	344	* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
	345	* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
	346	* @from: Previous PCI device found in search, or %NULL for new search.
	347	*
	348	* Iterates through the list of known PCI devices. If a PCI device is
	349	* found with a matching @vendor and @device, the reference count to the
	350	* device is incremented and a pointer to its device structure is returned.
	351	* Otherwise, %NULL is returned. A new search is initiated by passing %NULL
d75763d2	352	* as the @from argument. Otherwise if @from is not %NULL, searches continue
1da177e4 LT	353	* from next device on the global list. The reference count for @from is
	354	* always decremented if it is not %NULL.
	355	*/
	356	struct pci_dev *
	357	pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
	358	{
	359	return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
	360	}
	361
1da177e4 LT	362	/**
	363	* pci_get_class - begin or continue searching for a PCI device by class
	364	* @class: search for a PCI device with this class designation
	365	* @from: Previous PCI device found in search, or %NULL for new search.
	366	*
	367	* Iterates through the list of known PCI devices. If a PCI device is
	368	* found with a matching @class, the reference count to the device is
	369	* incremented and a pointer to its device structure is returned.
	370	* Otherwise, %NULL is returned.
d75763d2	371	* A new search is initiated by passing %NULL as the @from argument.
1da177e4 LT	372	* Otherwise if @from is not %NULL, searches continue from next device
	373	* on the global list. The reference count for @from is always decremented
	374	* if it is not %NULL.
	375	*/
	376	struct pci_dev pci_get_class(unsigned int class, struct pci_dev from)
	377	{
b9443f40 FT	378	struct pci_device_id id = {
	379	.vendor = PCI_ANY_ID,
	380	.device = PCI_ANY_ID,
	381	.subvendor = PCI_ANY_ID,
	382	.subdevice = PCI_ANY_ID,
	383	.class_mask = PCI_ANY_ID,
	384	.class = class,
	385	};
	386
	387	return pci_get_dev_by_id(&id, from);
1da177e4 LT	388	}
1da177e4 LT	389
448432c4 GKH	390	/**
	391	* pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
	392	* @ids: A pointer to a null terminated list of struct pci_device_id structures
	393	* that describe the type of PCI device the caller is trying to find.
	394	*
	395	* Obvious fact: You do not have a reference to any device that might be found
	396	* by this function, so if that device is removed from the system right after
	397	* this function is finished, the value will be stale. Use this function to
	398	* find devices that are usually built into a system, or for a general hint as
	399	* to if another device happens to be present at this specific moment in time.
	400	*/
	401	int pci_dev_present(const struct pci_device_id *ids)
d86f90f9	402	{
95247b57	403	struct pci_dev *found = NULL;
d86f90f9 AC	404
d86f90f9 AC	405	WARN_ON(in_interrupt());
d86f90f9	406	while (ids->vendor \|\| ids->subvendor \|\| ids->class_mask) {
95247b57	407	found = pci_get_dev_by_id(ids, NULL);
d5af7d98 JL	408	if (found) {
	409	pci_dev_put(found);
	410	return 1;
	411	}
d86f90f9 AC	412	ids++;
d86f90f9 AC	413	}
d5af7d98	414
448432c4	415	return 0;
1da177e4 LT	416	}
	417	EXPORT_SYMBOL(pci_dev_present);
	418
29f3eb64 AC	419	/* For boot time work */
	420	EXPORT_SYMBOL(pci_find_bus);
	421	EXPORT_SYMBOL(pci_find_next_bus);
	422	/* For everyone */
1da177e4 LT	423	EXPORT_SYMBOL(pci_get_device);
	424	EXPORT_SYMBOL(pci_get_subsys);
	425	EXPORT_SYMBOL(pci_get_slot);
	426	EXPORT_SYMBOL(pci_get_class);