[linux-2.6-block.git] / drivers / pci / bus.c

/*
 *	drivers/pci/bus.c
 *
 * From setup-res.c, by:
 *	Dave Rusling (david.rusling@reo.mts.dec.com)
 *	David Mosberger (davidm@cs.arizona.edu)
 *	David Miller (davem@redhat.com)
 *	Ivan Kokshaysky (ink@jurassic.park.msu.ru)
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>

#include "pci.h"

void pci_add_resource_offset(struct list_head *resources, struct resource *res,
			     resource_size_t offset)
{
	struct pci_host_bridge_window *window;

	window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
	if (!window) {
		printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
		return;
	}

	window->res = res;
	window->offset = offset;
	list_add_tail(&window->list, resources);
}
EXPORT_SYMBOL(pci_add_resource_offset);

void pci_add_resource(struct list_head *resources, struct resource *res)
{
	pci_add_resource_offset(resources, res, 0);
}
EXPORT_SYMBOL(pci_add_resource);

void pci_free_resource_list(struct list_head *resources)
{
	struct pci_host_bridge_window *window, *tmp;

	list_for_each_entry_safe(window, tmp, resources, list) {
		list_del(&window->list);
		kfree(window);
	}
}
EXPORT_SYMBOL(pci_free_resource_list);

void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
			  unsigned int flags)
{
	struct pci_bus_resource *bus_res;

	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
	if (!bus_res) {
		dev_err(&bus->dev, "can't add %pR resource\n", res);
		return;
	}

	bus_res->res = res;
	bus_res->flags = flags;
	list_add_tail(&bus_res->list, &bus->resources);
}

struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
{
	struct pci_bus_resource *bus_res;

	if (n < PCI_BRIDGE_RESOURCE_NUM)
		return bus->resource[n];

	n -= PCI_BRIDGE_RESOURCE_NUM;
	list_for_each_entry(bus_res, &bus->resources, list) {
		if (n-- == 0)
			return bus_res->res;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(pci_bus_resource_n);

void pci_bus_remove_resources(struct pci_bus *bus)
{
	int i;
	struct pci_bus_resource *bus_res, *tmp;

	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
		bus->resource[i] = NULL;

	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
		list_del(&bus_res->list);
		kfree(bus_res);
	}
}

static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
static struct pci_bus_region pci_64_bit = {0,
				(dma_addr_t) 0xffffffffffffffffULL};
static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
				(dma_addr_t) 0xffffffffffffffffULL};
#endif

/*
 * @res contains CPU addresses.  Clip it so the corresponding bus addresses
 * on @bus are entirely within @region.  This is used to control the bus
 * addresses of resources we allocate, e.g., we may need a resource that
 * can be mapped by a 32-bit BAR.
 */
static void pci_clip_resource_to_region(struct pci_bus *bus,
					struct resource *res,
					struct pci_bus_region *region)
{
	struct pci_bus_region r;

	pcibios_resource_to_bus(bus, &r, res);
	if (r.start < region->start)
		r.start = region->start;
	if (r.end > region->end)
		r.end = region->end;

	if (r.end < r.start)
		res->end = res->start - 1;
	else
		pcibios_bus_to_resource(bus, res, &r);
}

static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
		resource_size_t size, resource_size_t align,
		resource_size_t min, unsigned long type_mask,
		resource_size_t (*alignf)(void *,
					  const struct resource *,
					  resource_size_t,
					  resource_size_t),
		void *alignf_data,
		struct pci_bus_region *region)
{
	int i, ret;
	struct resource *r, avail;
	resource_size_t max;

	type_mask |= IORESOURCE_TYPE_BITS;

	pci_bus_for_each_resource(bus, r, i) {
		if (!r)
			continue;

		/* type_mask must match */
		if ((res->flags ^ r->flags) & type_mask)
			continue;

		/* We cannot allocate a non-prefetching resource
		   from a pre-fetching area */
		if ((r->flags & IORESOURCE_PREFETCH) &&
		    !(res->flags & IORESOURCE_PREFETCH))
			continue;

		avail = *r;
		pci_clip_resource_to_region(bus, &avail, region);

		/*
		 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
		 * protect badly documented motherboard resources, but if
		 * this is an already-configured bridge window, its start
		 * overrides "min".
		 */
		if (avail.start)
			min = avail.start;

		max = avail.end;

		/* Ok, try it out.. */
		ret = allocate_resource(r, res, size, min, max,
					align, alignf, alignf_data);
		if (ret == 0)
			return 0;
	}
	return -ENOMEM;
}

/**
 * pci_bus_alloc_resource - allocate a resource from a parent bus
 * @bus: PCI bus
 * @res: resource to allocate
 * @size: size of resource to allocate
 * @align: alignment of resource to allocate
 * @min: minimum /proc/iomem address to allocate
 * @type_mask: IORESOURCE_* type flags
 * @alignf: resource alignment function
 * @alignf_data: data argument for resource alignment function
 *
 * Given the PCI bus a device resides on, the size, minimum address,
 * alignment and type, try to find an acceptable resource allocation
 * for a specific device resource.
 */
int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
		resource_size_t size, resource_size_t align,
		resource_size_t min, unsigned long type_mask,
		resource_size_t (*alignf)(void *,
					  const struct resource *,
					  resource_size_t,
					  resource_size_t),
		void *alignf_data)
{
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
	int rc;

	if (res->flags & IORESOURCE_MEM_64) {
		rc = pci_bus_alloc_from_region(bus, res, size, align, min,
					       type_mask, alignf, alignf_data,
					       &pci_high);
		if (rc == 0)
			return 0;

		return pci_bus_alloc_from_region(bus, res, size, align, min,
						 type_mask, alignf, alignf_data,
						 &pci_64_bit);
	}
#endif

	return pci_bus_alloc_from_region(bus, res, size, align, min,
					 type_mask, alignf, alignf_data,
					 &pci_32_bit);
}

void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }

/**
 * pci_bus_add_device - start driver for a single device
 * @dev: device to add
 *
 * This adds add sysfs entries and start device drivers
 */
void pci_bus_add_device(struct pci_dev *dev)
{
	int retval;

	/*
	 * Can not put in pci_device_add yet because resources
	 * are not assigned yet for some devices.
	 */
	pci_fixup_device(pci_fixup_final, dev);
	pci_create_sysfs_dev_files(dev);
	pci_proc_attach_device(dev);

	dev->match_driver = true;
	retval = device_attach(&dev->dev);
	WARN_ON(retval < 0);

	dev->is_added = 1;
}

/**
 * pci_bus_add_devices - start driver for PCI devices
 * @bus: bus to check for new devices
 *
 * Start driver for PCI devices and add some sysfs entries.
 */
void pci_bus_add_devices(const struct pci_bus *bus)
{
	struct pci_dev *dev;
	struct pci_bus *child;

	list_for_each_entry(dev, &bus->devices, bus_list) {
		/* Skip already-added devices */
		if (dev->is_added)
			continue;
		pci_bus_add_device(dev);
	}

	list_for_each_entry(dev, &bus->devices, bus_list) {
		BUG_ON(!dev->is_added);
		child = dev->subordinate;
		if (child)
			pci_bus_add_devices(child);
	}
}

/** pci_walk_bus - walk devices on/under bus, calling callback.
 *  @top      bus whose devices should be walked
 *  @cb       callback to be called for each device found
 *  @userdata arbitrary pointer to be passed to callback.
 *
 *  Walk the given bus, including any bridged devices
 *  on buses under this bus.  Call the provided callback
 *  on each device found.
 *
 *  We check the return of @cb each time. If it returns anything
 *  other than 0, we break out.
 *
 */
void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
		  void *userdata)
{
	struct pci_dev *dev;
	struct pci_bus *bus;
	struct list_head *next;
	int retval;

	bus = top;
	down_read(&pci_bus_sem);
	next = top->devices.next;
	for (;;) {
		if (next == &bus->devices) {
			/* end of this bus, go up or finish */
			if (bus == top)
				break;
			next = bus->self->bus_list.next;
			bus = bus->self->bus;
			continue;
		}
		dev = list_entry(next, struct pci_dev, bus_list);
		if (dev->subordinate) {
			/* this is a pci-pci bridge, do its devices next */
			next = dev->subordinate->devices.next;
			bus = dev->subordinate;
		} else
			next = dev->bus_list.next;

		retval = cb(dev, userdata);
		if (retval)
			break;
	}
	up_read(&pci_bus_sem);
}
EXPORT_SYMBOL_GPL(pci_walk_bus);

struct pci_bus *pci_bus_get(struct pci_bus *bus)
{
	if (bus)
		get_device(&bus->dev);
	return bus;
}
EXPORT_SYMBOL(pci_bus_get);

void pci_bus_put(struct pci_bus *bus)
{
	if (bus)
		put_device(&bus->dev);
}
EXPORT_SYMBOL(pci_bus_put);

EXPORT_SYMBOL(pci_bus_alloc_resource);
EXPORT_SYMBOL_GPL(pci_bus_add_device);
EXPORT_SYMBOL(pci_bus_add_devices);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/pci/bus.c
	3	*
	4	* From setup-res.c, by:
	5	* Dave Rusling (david.rusling@reo.mts.dec.com)
	6	* David Mosberger (davidm@cs.arizona.edu)
	7	* David Miller (davem@redhat.com)
	8	* Ivan Kokshaysky (ink@jurassic.park.msu.ru)
	9	*/
	10	#include <linux/module.h>
	11	#include <linux/kernel.h>
	12	#include <linux/pci.h>
	13	#include <linux/errno.h>
	14	#include <linux/ioport.h>
	15	#include <linux/proc_fs.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4 LT	17
	18	#include "pci.h"
	19
0efd5aab BH	20	void pci_add_resource_offset(struct list_head resources, struct resource res,
0efd5aab BH	21	resource_size_t offset)
45ca9e97	22	{
0efd5aab	23	struct pci_host_bridge_window *window;
45ca9e97	24
0efd5aab BH	25	window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
	26	if (!window) {
	27	printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
45ca9e97 BH	28	return;
	29	}
	30
0efd5aab BH	31	window->res = res;
	32	window->offset = offset;
	33	list_add_tail(&window->list, resources);
	34	}
	35	EXPORT_SYMBOL(pci_add_resource_offset);
	36
	37	void pci_add_resource(struct list_head resources, struct resource res)
	38	{
	39	pci_add_resource_offset(resources, res, 0);
45ca9e97 BH	40	}
	41	EXPORT_SYMBOL(pci_add_resource);
	42
	43	void pci_free_resource_list(struct list_head *resources)
	44	{
0efd5aab	45	struct pci_host_bridge_window window, tmp;
45ca9e97	46
0efd5aab BH	47	list_for_each_entry_safe(window, tmp, resources, list) {
	48	list_del(&window->list);
	49	kfree(window);
45ca9e97 BH	50	}
	51	}
	52	EXPORT_SYMBOL(pci_free_resource_list);
	53
2fe2abf8 BH	54	void pci_bus_add_resource(struct pci_bus bus, struct resource res,
	55	unsigned int flags)
	56	{
	57	struct pci_bus_resource *bus_res;
	58
	59	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
	60	if (!bus_res) {
	61	dev_err(&bus->dev, "can't add %pR resource\n", res);
	62	return;
	63	}
	64
	65	bus_res->res = res;
	66	bus_res->flags = flags;
	67	list_add_tail(&bus_res->list, &bus->resources);
	68	}
	69
	70	struct resource pci_bus_resource_n(const struct pci_bus bus, int n)
	71	{
	72	struct pci_bus_resource *bus_res;
	73
	74	if (n < PCI_BRIDGE_RESOURCE_NUM)
	75	return bus->resource[n];
	76
	77	n -= PCI_BRIDGE_RESOURCE_NUM;
	78	list_for_each_entry(bus_res, &bus->resources, list) {
	79	if (n-- == 0)
	80	return bus_res->res;
	81	}
	82	return NULL;
	83	}
	84	EXPORT_SYMBOL_GPL(pci_bus_resource_n);
	85
	86	void pci_bus_remove_resources(struct pci_bus *bus)
	87	{
2fe2abf8	88	int i;
817a2685	89	struct pci_bus_resource bus_res, tmp;
2fe2abf8 BH	90
2fe2abf8 BH	91	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
7736a05a	92	bus->resource[i] = NULL;
2fe2abf8	93
817a2685 YL	94	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
	95	list_del(&bus_res->list);
	96	kfree(bus_res);
	97	}
2fe2abf8 BH	98	}
2fe2abf8 BH	99
f75b99d5 YL	100	static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
	101	#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
	102	static struct pci_bus_region pci_64_bit = {0,
	103	(dma_addr_t) 0xffffffffffffffffULL};
d56dbf5b YL	104	static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
d56dbf5b YL	105	(dma_addr_t) 0xffffffffffffffffULL};
f75b99d5 YL	106	#endif
	107
	108	/*
	109	* @res contains CPU addresses. Clip it so the corresponding bus addresses
	110	* on @bus are entirely within @region. This is used to control the bus
	111	* addresses of resources we allocate, e.g., we may need a resource that
	112	* can be mapped by a 32-bit BAR.
1da177e4	113	*/
f75b99d5 YL	114	static void pci_clip_resource_to_region(struct pci_bus *bus,
	115	struct resource *res,
	116	struct pci_bus_region *region)
	117	{
	118	struct pci_bus_region r;
	119
	120	pcibios_resource_to_bus(bus, &r, res);
	121	if (r.start < region->start)
	122	r.start = region->start;
	123	if (r.end > region->end)
	124	r.end = region->end;
	125
	126	if (r.end < r.start)
	127	res->end = res->start - 1;
	128	else
	129	pcibios_bus_to_resource(bus, res, &r);
	130	}
	131
	132	static int pci_bus_alloc_from_region(struct pci_bus bus, struct resource res,
e31dd6e4	133	resource_size_t size, resource_size_t align,
664c2848	134	resource_size_t min, unsigned long type_mask,
b26b2d49	135	resource_size_t (alignf)(void ,
3b7a17fc	136	const struct resource *,
b26b2d49 DB	137	resource_size_t,
b26b2d49 DB	138	resource_size_t),
f75b99d5 YL	139	void *alignf_data,
f75b99d5 YL	140	struct pci_bus_region *region)
1da177e4	141	{
f75b99d5 YL	142	int i, ret;
	143	struct resource *r, avail;
	144	resource_size_t max;
1da177e4	145
aa11fc58	146	type_mask \|= IORESOURCE_TYPE_BITS;
1da177e4	147
6db45b76 BH	148	pci_bus_for_each_resource(bus, r, i) {
	149	if (!r)
	150	continue;
	151
1da177e4 LT	152	/* type_mask must match */
	153	if ((res->flags ^ r->flags) & type_mask)
	154	continue;
	155
	156	/* We cannot allocate a non-prefetching resource
	157	from a pre-fetching area */
	158	if ((r->flags & IORESOURCE_PREFETCH) &&
	159	!(res->flags & IORESOURCE_PREFETCH))
	160	continue;
	161
f75b99d5 YL	162	avail = *r;
f75b99d5 YL	163	pci_clip_resource_to_region(bus, &avail, region);
f75b99d5	164
36e097a8 BH	165	/*
	166	* "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
	167	* protect badly documented motherboard resources, but if
	168	* this is an already-configured bridge window, its start
	169	* overrides "min".
	170	*/
f75b99d5 YL	171	if (avail.start)
	172	min = avail.start;
	173
	174	max = avail.end;
36e097a8	175
1da177e4	176	/* Ok, try it out.. */
36e097a8 BH	177	ret = allocate_resource(r, res, size, min, max,
36e097a8 BH	178	align, alignf, alignf_data);
1da177e4	179	if (ret == 0)
f75b99d5	180	return 0;
1da177e4	181	}
f75b99d5 YL	182	return -ENOMEM;
	183	}
	184
	185	/**
	186	* pci_bus_alloc_resource - allocate a resource from a parent bus
	187	* @bus: PCI bus
	188	* @res: resource to allocate
	189	* @size: size of resource to allocate
	190	* @align: alignment of resource to allocate
	191	* @min: minimum /proc/iomem address to allocate
	192	* @type_mask: IORESOURCE_* type flags
	193	* @alignf: resource alignment function
	194	* @alignf_data: data argument for resource alignment function
	195	*
	196	* Given the PCI bus a device resides on, the size, minimum address,
	197	* alignment and type, try to find an acceptable resource allocation
	198	* for a specific device resource.
	199	*/
d56dbf5b	200	int pci_bus_alloc_resource(struct pci_bus bus, struct resource res,
f75b99d5	201	resource_size_t size, resource_size_t align,
664c2848	202	resource_size_t min, unsigned long type_mask,
f75b99d5 YL	203	resource_size_t (alignf)(void ,
	204	const struct resource *,
	205	resource_size_t,
	206	resource_size_t),
	207	void *alignf_data)
	208	{
	209	#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
d56dbf5b YL	210	int rc;
	211
	212	if (res->flags & IORESOURCE_MEM_64) {
	213	rc = pci_bus_alloc_from_region(bus, res, size, align, min,
	214	type_mask, alignf, alignf_data,
	215	&pci_high);
	216	if (rc == 0)
	217	return 0;
	218
f75b99d5 YL	219	return pci_bus_alloc_from_region(bus, res, size, align, min,
	220	type_mask, alignf, alignf_data,
	221	&pci_64_bit);
1da177e4	222	}
f75b99d5 YL	223	#endif
	224
	225	return pci_bus_alloc_from_region(bus, res, size, align, min,
	226	type_mask, alignf, alignf_data,
	227	&pci_32_bit);
1da177e4 LT	228	}
1da177e4 LT	229
3c449ed0 YL	230	void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
3c449ed0 YL	231
1da177e4	232	/**
4f535093	233	* pci_bus_add_device - start driver for a single device
1da177e4 LT	234	* @dev: device to add
1da177e4 LT	235	*
4f535093	236	* This adds add sysfs entries and start device drivers
1da177e4	237	*/
c893d133	238	void pci_bus_add_device(struct pci_dev *dev)
1da177e4	239	{
b19441af	240	int retval;
735bff10	241
4f535093 YL	242	/*
	243	* Can not put in pci_device_add yet because resources
	244	* are not assigned yet for some devices.
	245	*/
e253aaf0	246	pci_fixup_device(pci_fixup_final, dev);
4f535093	247	pci_create_sysfs_dev_files(dev);
ef37702e	248	pci_proc_attach_device(dev);
1da177e4	249
58d9a38f YL	250	dev->match_driver = true;
	251	retval = device_attach(&dev->dev);
	252	WARN_ON(retval < 0);
	253
8a1bc901	254	dev->is_added = 1;
876e501a YZ	255	}
876e501a YZ	256
1da177e4	257	/**
4f535093	258	* pci_bus_add_devices - start driver for PCI devices
1da177e4 LT	259	* @bus: bus to check for new devices
1da177e4 LT	260	*
4f535093	261	* Start driver for PCI devices and add some sysfs entries.
1da177e4	262	*/
c48f1670	263	void pci_bus_add_devices(const struct pci_bus *bus)
1da177e4 LT	264	{
1da177e4 LT	265	struct pci_dev *dev;
3fa16fdb	266	struct pci_bus *child;
1da177e4 LT	267
1da177e4 LT	268	list_for_each_entry(dev, &bus->devices, bus_list) {
8a1bc901 GKH	269	/* Skip already-added devices */
8a1bc901 GKH	270	if (dev->is_added)
1da177e4	271	continue;
c893d133	272	pci_bus_add_device(dev);
1da177e4 LT	273	}
	274
	275	list_for_each_entry(dev, &bus->devices, bus_list) {
8a1bc901	276	BUG_ON(!dev->is_added);
3fa16fdb	277	child = dev->subordinate;
981cf9ea JL	278	if (child)
981cf9ea JL	279	pci_bus_add_devices(child);
1da177e4 LT	280	}
	281	}
	282
cecf4864 PM	283	/** pci_walk_bus - walk devices on/under bus, calling callback.
	284	* @top bus whose devices should be walked
	285	* @cb callback to be called for each device found
	286	* @userdata arbitrary pointer to be passed to callback.
	287	*
	288	* Walk the given bus, including any bridged devices
	289	* on buses under this bus. Call the provided callback
	290	* on each device found.
70298c6e ZY	291	*
	292	* We check the return of @cb each time. If it returns anything
	293	* other than 0, we break out.
	294	*
cecf4864	295	*/
70298c6e	296	void pci_walk_bus(struct pci_bus top, int (cb)(struct pci_dev , void ),
cecf4864 PM	297	void *userdata)
	298	{
	299	struct pci_dev *dev;
	300	struct pci_bus *bus;
	301	struct list_head *next;
70298c6e	302	int retval;
cecf4864 PM	303
cecf4864 PM	304	bus = top;
d71374da	305	down_read(&pci_bus_sem);
cecf4864 PM	306	next = top->devices.next;
	307	for (;;) {
	308	if (next == &bus->devices) {
	309	/* end of this bus, go up or finish */
	310	if (bus == top)
	311	break;
	312	next = bus->self->bus_list.next;
	313	bus = bus->self->bus;
	314	continue;
	315	}
	316	dev = list_entry(next, struct pci_dev, bus_list);
cecf4864 PM	317	if (dev->subordinate) {
	318	/* this is a pci-pci bridge, do its devices next */
	319	next = dev->subordinate->devices.next;
	320	bus = dev->subordinate;
	321	} else
	322	next = dev->bus_list.next;
cecf4864	323
70298c6e	324	retval = cb(dev, userdata);
70298c6e ZY	325	if (retval)
70298c6e ZY	326	break;
cecf4864	327	}
d71374da	328	up_read(&pci_bus_sem);
cecf4864	329	}
7c94def8	330	EXPORT_SYMBOL_GPL(pci_walk_bus);
cecf4864	331
fe830ef6 JL	332	struct pci_bus pci_bus_get(struct pci_bus bus)
	333	{
	334	if (bus)
	335	get_device(&bus->dev);
	336	return bus;
	337	}
	338	EXPORT_SYMBOL(pci_bus_get);
	339
	340	void pci_bus_put(struct pci_bus *bus)
	341	{
	342	if (bus)
	343	put_device(&bus->dev);
	344	}
	345	EXPORT_SYMBOL(pci_bus_put);
	346
1da177e4 LT	347	EXPORT_SYMBOL(pci_bus_alloc_resource);
	348	EXPORT_SYMBOL_GPL(pci_bus_add_device);
	349	EXPORT_SYMBOL(pci_bus_add_devices);