xref: /openbmc/linux/drivers/pci/pci-driver.c (revision e8f6f3b4)
1 /*
2  * drivers/pci/pci-driver.c
3  *
4  * (C) Copyright 2002-2004, 2007 Greg Kroah-Hartman <greg@kroah.com>
5  * (C) Copyright 2007 Novell Inc.
6  *
7  * Released under the GPL v2 only.
8  *
9  */
10 
11 #include <linux/pci.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/device.h>
15 #include <linux/mempolicy.h>
16 #include <linux/string.h>
17 #include <linux/slab.h>
18 #include <linux/sched.h>
19 #include <linux/cpu.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/suspend.h>
22 #include <linux/kexec.h>
23 #include "pci.h"
24 
25 struct pci_dynid {
26 	struct list_head node;
27 	struct pci_device_id id;
28 };
29 
30 /**
31  * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
32  * @drv: target pci driver
33  * @vendor: PCI vendor ID
34  * @device: PCI device ID
35  * @subvendor: PCI subvendor ID
36  * @subdevice: PCI subdevice ID
37  * @class: PCI class
38  * @class_mask: PCI class mask
39  * @driver_data: private driver data
40  *
41  * Adds a new dynamic pci device ID to this driver and causes the
42  * driver to probe for all devices again.  @drv must have been
43  * registered prior to calling this function.
44  *
45  * CONTEXT:
46  * Does GFP_KERNEL allocation.
47  *
48  * RETURNS:
49  * 0 on success, -errno on failure.
50  */
51 int pci_add_dynid(struct pci_driver *drv,
52 		  unsigned int vendor, unsigned int device,
53 		  unsigned int subvendor, unsigned int subdevice,
54 		  unsigned int class, unsigned int class_mask,
55 		  unsigned long driver_data)
56 {
57 	struct pci_dynid *dynid;
58 
59 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
60 	if (!dynid)
61 		return -ENOMEM;
62 
63 	dynid->id.vendor = vendor;
64 	dynid->id.device = device;
65 	dynid->id.subvendor = subvendor;
66 	dynid->id.subdevice = subdevice;
67 	dynid->id.class = class;
68 	dynid->id.class_mask = class_mask;
69 	dynid->id.driver_data = driver_data;
70 
71 	spin_lock(&drv->dynids.lock);
72 	list_add_tail(&dynid->node, &drv->dynids.list);
73 	spin_unlock(&drv->dynids.lock);
74 
75 	return driver_attach(&drv->driver);
76 }
77 EXPORT_SYMBOL_GPL(pci_add_dynid);
78 
79 static void pci_free_dynids(struct pci_driver *drv)
80 {
81 	struct pci_dynid *dynid, *n;
82 
83 	spin_lock(&drv->dynids.lock);
84 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
85 		list_del(&dynid->node);
86 		kfree(dynid);
87 	}
88 	spin_unlock(&drv->dynids.lock);
89 }
90 
91 /**
92  * store_new_id - sysfs frontend to pci_add_dynid()
93  * @driver: target device driver
94  * @buf: buffer for scanning device ID data
95  * @count: input size
96  *
97  * Allow PCI IDs to be added to an existing driver via sysfs.
98  */
99 static ssize_t store_new_id(struct device_driver *driver, const char *buf,
100 			    size_t count)
101 {
102 	struct pci_driver *pdrv = to_pci_driver(driver);
103 	const struct pci_device_id *ids = pdrv->id_table;
104 	__u32 vendor, device, subvendor = PCI_ANY_ID,
105 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
106 	unsigned long driver_data = 0;
107 	int fields = 0;
108 	int retval = 0;
109 
110 	fields = sscanf(buf, "%x %x %x %x %x %x %lx",
111 			&vendor, &device, &subvendor, &subdevice,
112 			&class, &class_mask, &driver_data);
113 	if (fields < 2)
114 		return -EINVAL;
115 
116 	if (fields != 7) {
117 		struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
118 		if (!pdev)
119 			return -ENOMEM;
120 
121 		pdev->vendor = vendor;
122 		pdev->device = device;
123 		pdev->subsystem_vendor = subvendor;
124 		pdev->subsystem_device = subdevice;
125 		pdev->class = class;
126 
127 		if (pci_match_id(pdrv->id_table, pdev))
128 			retval = -EEXIST;
129 
130 		kfree(pdev);
131 
132 		if (retval)
133 			return retval;
134 	}
135 
136 	/* Only accept driver_data values that match an existing id_table
137 	   entry */
138 	if (ids) {
139 		retval = -EINVAL;
140 		while (ids->vendor || ids->subvendor || ids->class_mask) {
141 			if (driver_data == ids->driver_data) {
142 				retval = 0;
143 				break;
144 			}
145 			ids++;
146 		}
147 		if (retval)	/* No match */
148 			return retval;
149 	}
150 
151 	retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
152 			       class, class_mask, driver_data);
153 	if (retval)
154 		return retval;
155 	return count;
156 }
157 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
158 
159 /**
160  * store_remove_id - remove a PCI device ID from this driver
161  * @driver: target device driver
162  * @buf: buffer for scanning device ID data
163  * @count: input size
164  *
165  * Removes a dynamic pci device ID to this driver.
166  */
167 static ssize_t store_remove_id(struct device_driver *driver, const char *buf,
168 			       size_t count)
169 {
170 	struct pci_dynid *dynid, *n;
171 	struct pci_driver *pdrv = to_pci_driver(driver);
172 	__u32 vendor, device, subvendor = PCI_ANY_ID,
173 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
174 	int fields = 0;
175 	int retval = -ENODEV;
176 
177 	fields = sscanf(buf, "%x %x %x %x %x %x",
178 			&vendor, &device, &subvendor, &subdevice,
179 			&class, &class_mask);
180 	if (fields < 2)
181 		return -EINVAL;
182 
183 	spin_lock(&pdrv->dynids.lock);
184 	list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
185 		struct pci_device_id *id = &dynid->id;
186 		if ((id->vendor == vendor) &&
187 		    (id->device == device) &&
188 		    (subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
189 		    (subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
190 		    !((id->class ^ class) & class_mask)) {
191 			list_del(&dynid->node);
192 			kfree(dynid);
193 			retval = 0;
194 			break;
195 		}
196 	}
197 	spin_unlock(&pdrv->dynids.lock);
198 
199 	if (retval)
200 		return retval;
201 	return count;
202 }
203 static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id);
204 
205 static struct attribute *pci_drv_attrs[] = {
206 	&driver_attr_new_id.attr,
207 	&driver_attr_remove_id.attr,
208 	NULL,
209 };
210 ATTRIBUTE_GROUPS(pci_drv);
211 
212 /**
213  * pci_match_id - See if a pci device matches a given pci_id table
214  * @ids: array of PCI device id structures to search in
215  * @dev: the PCI device structure to match against.
216  *
217  * Used by a driver to check whether a PCI device present in the
218  * system is in its list of supported devices.  Returns the matching
219  * pci_device_id structure or %NULL if there is no match.
220  *
221  * Deprecated, don't use this as it will not catch any dynamic ids
222  * that a driver might want to check for.
223  */
224 const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
225 					 struct pci_dev *dev)
226 {
227 	if (ids) {
228 		while (ids->vendor || ids->subvendor || ids->class_mask) {
229 			if (pci_match_one_device(ids, dev))
230 				return ids;
231 			ids++;
232 		}
233 	}
234 	return NULL;
235 }
236 EXPORT_SYMBOL(pci_match_id);
237 
238 static const struct pci_device_id pci_device_id_any = {
239 	.vendor = PCI_ANY_ID,
240 	.device = PCI_ANY_ID,
241 	.subvendor = PCI_ANY_ID,
242 	.subdevice = PCI_ANY_ID,
243 };
244 
245 /**
246  * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
247  * @drv: the PCI driver to match against
248  * @dev: the PCI device structure to match against
249  *
250  * Used by a driver to check whether a PCI device present in the
251  * system is in its list of supported devices.  Returns the matching
252  * pci_device_id structure or %NULL if there is no match.
253  */
254 static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
255 						    struct pci_dev *dev)
256 {
257 	struct pci_dynid *dynid;
258 	const struct pci_device_id *found_id = NULL;
259 
260 	/* When driver_override is set, only bind to the matching driver */
261 	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
262 		return NULL;
263 
264 	/* Look at the dynamic ids first, before the static ones */
265 	spin_lock(&drv->dynids.lock);
266 	list_for_each_entry(dynid, &drv->dynids.list, node) {
267 		if (pci_match_one_device(&dynid->id, dev)) {
268 			found_id = &dynid->id;
269 			break;
270 		}
271 	}
272 	spin_unlock(&drv->dynids.lock);
273 
274 	if (!found_id)
275 		found_id = pci_match_id(drv->id_table, dev);
276 
277 	/* driver_override will always match, send a dummy id */
278 	if (!found_id && dev->driver_override)
279 		found_id = &pci_device_id_any;
280 
281 	return found_id;
282 }
283 
284 struct drv_dev_and_id {
285 	struct pci_driver *drv;
286 	struct pci_dev *dev;
287 	const struct pci_device_id *id;
288 };
289 
290 static long local_pci_probe(void *_ddi)
291 {
292 	struct drv_dev_and_id *ddi = _ddi;
293 	struct pci_dev *pci_dev = ddi->dev;
294 	struct pci_driver *pci_drv = ddi->drv;
295 	struct device *dev = &pci_dev->dev;
296 	int rc;
297 
298 	/*
299 	 * Unbound PCI devices are always put in D0, regardless of
300 	 * runtime PM status.  During probe, the device is set to
301 	 * active and the usage count is incremented.  If the driver
302 	 * supports runtime PM, it should call pm_runtime_put_noidle()
303 	 * in its probe routine and pm_runtime_get_noresume() in its
304 	 * remove routine.
305 	 */
306 	pm_runtime_get_sync(dev);
307 	pci_dev->driver = pci_drv;
308 	rc = pci_drv->probe(pci_dev, ddi->id);
309 	if (!rc)
310 		return rc;
311 	if (rc < 0) {
312 		pci_dev->driver = NULL;
313 		pm_runtime_put_sync(dev);
314 		return rc;
315 	}
316 	/*
317 	 * Probe function should return < 0 for failure, 0 for success
318 	 * Treat values > 0 as success, but warn.
319 	 */
320 	dev_warn(dev, "Driver probe function unexpectedly returned %d\n", rc);
321 	return 0;
322 }
323 
324 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
325 			  const struct pci_device_id *id)
326 {
327 	int error, node;
328 	struct drv_dev_and_id ddi = { drv, dev, id };
329 
330 	/*
331 	 * Execute driver initialization on node where the device is
332 	 * attached.  This way the driver likely allocates its local memory
333 	 * on the right node.
334 	 */
335 	node = dev_to_node(&dev->dev);
336 
337 	/*
338 	 * On NUMA systems, we are likely to call a PF probe function using
339 	 * work_on_cpu().  If that probe calls pci_enable_sriov() (which
340 	 * adds the VF devices via pci_bus_add_device()), we may re-enter
341 	 * this function to call the VF probe function.  Calling
342 	 * work_on_cpu() again will cause a lockdep warning.  Since VFs are
343 	 * always on the same node as the PF, we can work around this by
344 	 * avoiding work_on_cpu() when we're already on the correct node.
345 	 *
346 	 * Preemption is enabled, so it's theoretically unsafe to use
347 	 * numa_node_id(), but even if we run the probe function on the
348 	 * wrong node, it should be functionally correct.
349 	 */
350 	if (node >= 0 && node != numa_node_id()) {
351 		int cpu;
352 
353 		get_online_cpus();
354 		cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask);
355 		if (cpu < nr_cpu_ids)
356 			error = work_on_cpu(cpu, local_pci_probe, &ddi);
357 		else
358 			error = local_pci_probe(&ddi);
359 		put_online_cpus();
360 	} else
361 		error = local_pci_probe(&ddi);
362 
363 	return error;
364 }
365 
366 /**
367  * __pci_device_probe - check if a driver wants to claim a specific PCI device
368  * @drv: driver to call to check if it wants the PCI device
369  * @pci_dev: PCI device being probed
370  *
371  * returns 0 on success, else error.
372  * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
373  */
374 static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
375 {
376 	const struct pci_device_id *id;
377 	int error = 0;
378 
379 	if (!pci_dev->driver && drv->probe) {
380 		error = -ENODEV;
381 
382 		id = pci_match_device(drv, pci_dev);
383 		if (id)
384 			error = pci_call_probe(drv, pci_dev, id);
385 		if (error >= 0)
386 			error = 0;
387 	}
388 	return error;
389 }
390 
391 static int pci_device_probe(struct device *dev)
392 {
393 	int error = 0;
394 	struct pci_driver *drv;
395 	struct pci_dev *pci_dev;
396 
397 	drv = to_pci_driver(dev->driver);
398 	pci_dev = to_pci_dev(dev);
399 	pci_dev_get(pci_dev);
400 	error = __pci_device_probe(drv, pci_dev);
401 	if (error)
402 		pci_dev_put(pci_dev);
403 
404 	return error;
405 }
406 
407 static int pci_device_remove(struct device *dev)
408 {
409 	struct pci_dev *pci_dev = to_pci_dev(dev);
410 	struct pci_driver *drv = pci_dev->driver;
411 
412 	if (drv) {
413 		if (drv->remove) {
414 			pm_runtime_get_sync(dev);
415 			drv->remove(pci_dev);
416 			pm_runtime_put_noidle(dev);
417 		}
418 		pci_dev->driver = NULL;
419 	}
420 
421 	/* Undo the runtime PM settings in local_pci_probe() */
422 	pm_runtime_put_sync(dev);
423 
424 	/*
425 	 * If the device is still on, set the power state as "unknown",
426 	 * since it might change by the next time we load the driver.
427 	 */
428 	if (pci_dev->current_state == PCI_D0)
429 		pci_dev->current_state = PCI_UNKNOWN;
430 
431 	/*
432 	 * We would love to complain here if pci_dev->is_enabled is set, that
433 	 * the driver should have called pci_disable_device(), but the
434 	 * unfortunate fact is there are too many odd BIOS and bridge setups
435 	 * that don't like drivers doing that all of the time.
436 	 * Oh well, we can dream of sane hardware when we sleep, no matter how
437 	 * horrible the crap we have to deal with is when we are awake...
438 	 */
439 
440 	pci_dev_put(pci_dev);
441 	return 0;
442 }
443 
444 static void pci_device_shutdown(struct device *dev)
445 {
446 	struct pci_dev *pci_dev = to_pci_dev(dev);
447 	struct pci_driver *drv = pci_dev->driver;
448 
449 	pm_runtime_resume(dev);
450 
451 	if (drv && drv->shutdown)
452 		drv->shutdown(pci_dev);
453 	pci_msi_shutdown(pci_dev);
454 	pci_msix_shutdown(pci_dev);
455 
456 #ifdef CONFIG_KEXEC
457 	/*
458 	 * If this is a kexec reboot, turn off Bus Master bit on the
459 	 * device to tell it to not continue to do DMA. Don't touch
460 	 * devices in D3cold or unknown states.
461 	 * If it is not a kexec reboot, firmware will hit the PCI
462 	 * devices with big hammer and stop their DMA any way.
463 	 */
464 	if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
465 		pci_clear_master(pci_dev);
466 #endif
467 }
468 
469 #ifdef CONFIG_PM
470 
471 /* Auxiliary functions used for system resume and run-time resume. */
472 
473 /**
474  * pci_restore_standard_config - restore standard config registers of PCI device
475  * @pci_dev: PCI device to handle
476  */
477 static int pci_restore_standard_config(struct pci_dev *pci_dev)
478 {
479 	pci_update_current_state(pci_dev, PCI_UNKNOWN);
480 
481 	if (pci_dev->current_state != PCI_D0) {
482 		int error = pci_set_power_state(pci_dev, PCI_D0);
483 		if (error)
484 			return error;
485 	}
486 
487 	pci_restore_state(pci_dev);
488 	return 0;
489 }
490 
491 #endif
492 
493 #ifdef CONFIG_PM_SLEEP
494 
495 static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
496 {
497 	pci_power_up(pci_dev);
498 	pci_restore_state(pci_dev);
499 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
500 }
501 
502 /*
503  * Default "suspend" method for devices that have no driver provided suspend,
504  * or not even a driver at all (second part).
505  */
506 static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
507 {
508 	/*
509 	 * mark its power state as "unknown", since we don't know if
510 	 * e.g. the BIOS will change its device state when we suspend.
511 	 */
512 	if (pci_dev->current_state == PCI_D0)
513 		pci_dev->current_state = PCI_UNKNOWN;
514 }
515 
516 /*
517  * Default "resume" method for devices that have no driver provided resume,
518  * or not even a driver at all (second part).
519  */
520 static int pci_pm_reenable_device(struct pci_dev *pci_dev)
521 {
522 	int retval;
523 
524 	/* if the device was enabled before suspend, reenable */
525 	retval = pci_reenable_device(pci_dev);
526 	/*
527 	 * if the device was busmaster before the suspend, make it busmaster
528 	 * again
529 	 */
530 	if (pci_dev->is_busmaster)
531 		pci_set_master(pci_dev);
532 
533 	return retval;
534 }
535 
536 static int pci_legacy_suspend(struct device *dev, pm_message_t state)
537 {
538 	struct pci_dev *pci_dev = to_pci_dev(dev);
539 	struct pci_driver *drv = pci_dev->driver;
540 
541 	if (drv && drv->suspend) {
542 		pci_power_t prev = pci_dev->current_state;
543 		int error;
544 
545 		error = drv->suspend(pci_dev, state);
546 		suspend_report_result(drv->suspend, error);
547 		if (error)
548 			return error;
549 
550 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
551 		    && pci_dev->current_state != PCI_UNKNOWN) {
552 			WARN_ONCE(pci_dev->current_state != prev,
553 				"PCI PM: Device state not saved by %pF\n",
554 				drv->suspend);
555 		}
556 	}
557 
558 	pci_fixup_device(pci_fixup_suspend, pci_dev);
559 
560 	return 0;
561 }
562 
563 static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
564 {
565 	struct pci_dev *pci_dev = to_pci_dev(dev);
566 	struct pci_driver *drv = pci_dev->driver;
567 
568 	if (drv && drv->suspend_late) {
569 		pci_power_t prev = pci_dev->current_state;
570 		int error;
571 
572 		error = drv->suspend_late(pci_dev, state);
573 		suspend_report_result(drv->suspend_late, error);
574 		if (error)
575 			return error;
576 
577 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
578 		    && pci_dev->current_state != PCI_UNKNOWN) {
579 			WARN_ONCE(pci_dev->current_state != prev,
580 				"PCI PM: Device state not saved by %pF\n",
581 				drv->suspend_late);
582 			goto Fixup;
583 		}
584 	}
585 
586 	if (!pci_dev->state_saved)
587 		pci_save_state(pci_dev);
588 
589 	pci_pm_set_unknown_state(pci_dev);
590 
591 Fixup:
592 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
593 
594 	return 0;
595 }
596 
597 static int pci_legacy_resume_early(struct device *dev)
598 {
599 	struct pci_dev *pci_dev = to_pci_dev(dev);
600 	struct pci_driver *drv = pci_dev->driver;
601 
602 	return drv && drv->resume_early ?
603 			drv->resume_early(pci_dev) : 0;
604 }
605 
606 static int pci_legacy_resume(struct device *dev)
607 {
608 	struct pci_dev *pci_dev = to_pci_dev(dev);
609 	struct pci_driver *drv = pci_dev->driver;
610 
611 	pci_fixup_device(pci_fixup_resume, pci_dev);
612 
613 	return drv && drv->resume ?
614 			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
615 }
616 
617 /* Auxiliary functions used by the new power management framework */
618 
619 static void pci_pm_default_resume(struct pci_dev *pci_dev)
620 {
621 	pci_fixup_device(pci_fixup_resume, pci_dev);
622 
623 	if (!pci_has_subordinate(pci_dev))
624 		pci_enable_wake(pci_dev, PCI_D0, false);
625 }
626 
627 static void pci_pm_default_suspend(struct pci_dev *pci_dev)
628 {
629 	/* Disable non-bridge devices without PM support */
630 	if (!pci_has_subordinate(pci_dev))
631 		pci_disable_enabled_device(pci_dev);
632 }
633 
634 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
635 {
636 	struct pci_driver *drv = pci_dev->driver;
637 	bool ret = drv && (drv->suspend || drv->suspend_late || drv->resume
638 		|| drv->resume_early);
639 
640 	/*
641 	 * Legacy PM support is used by default, so warn if the new framework is
642 	 * supported as well.  Drivers are supposed to support either the
643 	 * former, or the latter, but not both at the same time.
644 	 */
645 	WARN(ret && drv->driver.pm, "driver %s device %04x:%04x\n",
646 		drv->name, pci_dev->vendor, pci_dev->device);
647 
648 	return ret;
649 }
650 
651 /* New power management framework */
652 
653 static int pci_pm_prepare(struct device *dev)
654 {
655 	struct device_driver *drv = dev->driver;
656 	int error = 0;
657 
658 	/*
659 	 * Devices having power.ignore_children set may still be necessary for
660 	 * suspending their children in the next phase of device suspend.
661 	 */
662 	if (dev->power.ignore_children)
663 		pm_runtime_resume(dev);
664 
665 	if (drv && drv->pm && drv->pm->prepare)
666 		error = drv->pm->prepare(dev);
667 
668 	return error;
669 }
670 
671 
672 #else /* !CONFIG_PM_SLEEP */
673 
674 #define pci_pm_prepare	NULL
675 
676 #endif /* !CONFIG_PM_SLEEP */
677 
678 #ifdef CONFIG_SUSPEND
679 
680 static int pci_pm_suspend(struct device *dev)
681 {
682 	struct pci_dev *pci_dev = to_pci_dev(dev);
683 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
684 
685 	if (pci_has_legacy_pm_support(pci_dev))
686 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
687 
688 	if (!pm) {
689 		pci_pm_default_suspend(pci_dev);
690 		goto Fixup;
691 	}
692 
693 	/*
694 	 * PCI devices suspended at run time need to be resumed at this point,
695 	 * because in general it is necessary to reconfigure them for system
696 	 * suspend.  Namely, if the device is supposed to wake up the system
697 	 * from the sleep state, we may need to reconfigure it for this purpose.
698 	 * In turn, if the device is not supposed to wake up the system from the
699 	 * sleep state, we'll have to prevent it from signaling wake-up.
700 	 */
701 	pm_runtime_resume(dev);
702 
703 	pci_dev->state_saved = false;
704 	if (pm->suspend) {
705 		pci_power_t prev = pci_dev->current_state;
706 		int error;
707 
708 		error = pm->suspend(dev);
709 		suspend_report_result(pm->suspend, error);
710 		if (error)
711 			return error;
712 
713 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
714 		    && pci_dev->current_state != PCI_UNKNOWN) {
715 			WARN_ONCE(pci_dev->current_state != prev,
716 				"PCI PM: State of device not saved by %pF\n",
717 				pm->suspend);
718 		}
719 	}
720 
721  Fixup:
722 	pci_fixup_device(pci_fixup_suspend, pci_dev);
723 
724 	return 0;
725 }
726 
727 static int pci_pm_suspend_noirq(struct device *dev)
728 {
729 	struct pci_dev *pci_dev = to_pci_dev(dev);
730 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
731 
732 	if (pci_has_legacy_pm_support(pci_dev))
733 		return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
734 
735 	if (!pm) {
736 		pci_save_state(pci_dev);
737 		goto Fixup;
738 	}
739 
740 	if (pm->suspend_noirq) {
741 		pci_power_t prev = pci_dev->current_state;
742 		int error;
743 
744 		error = pm->suspend_noirq(dev);
745 		suspend_report_result(pm->suspend_noirq, error);
746 		if (error)
747 			return error;
748 
749 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
750 		    && pci_dev->current_state != PCI_UNKNOWN) {
751 			WARN_ONCE(pci_dev->current_state != prev,
752 				"PCI PM: State of device not saved by %pF\n",
753 				pm->suspend_noirq);
754 			goto Fixup;
755 		}
756 	}
757 
758 	if (!pci_dev->state_saved) {
759 		pci_save_state(pci_dev);
760 		if (!pci_has_subordinate(pci_dev))
761 			pci_prepare_to_sleep(pci_dev);
762 	}
763 
764 	pci_pm_set_unknown_state(pci_dev);
765 
766 	/*
767 	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
768 	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
769 	 * hasn't been quiesced and tries to turn it off.  If the controller
770 	 * is already in D3, this can hang or cause memory corruption.
771 	 *
772 	 * Since the value of the COMMAND register doesn't matter once the
773 	 * device has been suspended, we can safely set it to 0 here.
774 	 */
775 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
776 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
777 
778 Fixup:
779 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
780 
781 	return 0;
782 }
783 
784 static int pci_pm_resume_noirq(struct device *dev)
785 {
786 	struct pci_dev *pci_dev = to_pci_dev(dev);
787 	struct device_driver *drv = dev->driver;
788 	int error = 0;
789 
790 	pci_pm_default_resume_early(pci_dev);
791 
792 	if (pci_has_legacy_pm_support(pci_dev))
793 		return pci_legacy_resume_early(dev);
794 
795 	if (drv && drv->pm && drv->pm->resume_noirq)
796 		error = drv->pm->resume_noirq(dev);
797 
798 	return error;
799 }
800 
801 static int pci_pm_resume(struct device *dev)
802 {
803 	struct pci_dev *pci_dev = to_pci_dev(dev);
804 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
805 	int error = 0;
806 
807 	/*
808 	 * This is necessary for the suspend error path in which resume is
809 	 * called without restoring the standard config registers of the device.
810 	 */
811 	if (pci_dev->state_saved)
812 		pci_restore_standard_config(pci_dev);
813 
814 	if (pci_has_legacy_pm_support(pci_dev))
815 		return pci_legacy_resume(dev);
816 
817 	pci_pm_default_resume(pci_dev);
818 
819 	if (pm) {
820 		if (pm->resume)
821 			error = pm->resume(dev);
822 	} else {
823 		pci_pm_reenable_device(pci_dev);
824 	}
825 
826 	return error;
827 }
828 
829 #else /* !CONFIG_SUSPEND */
830 
831 #define pci_pm_suspend		NULL
832 #define pci_pm_suspend_noirq	NULL
833 #define pci_pm_resume		NULL
834 #define pci_pm_resume_noirq	NULL
835 
836 #endif /* !CONFIG_SUSPEND */
837 
838 #ifdef CONFIG_HIBERNATE_CALLBACKS
839 
840 
841 /*
842  * pcibios_pm_ops - provide arch-specific hooks when a PCI device is doing
843  * a hibernate transition
844  */
845 struct dev_pm_ops __weak pcibios_pm_ops;
846 
847 static int pci_pm_freeze(struct device *dev)
848 {
849 	struct pci_dev *pci_dev = to_pci_dev(dev);
850 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
851 
852 	if (pci_has_legacy_pm_support(pci_dev))
853 		return pci_legacy_suspend(dev, PMSG_FREEZE);
854 
855 	if (!pm) {
856 		pci_pm_default_suspend(pci_dev);
857 		return 0;
858 	}
859 
860 	/*
861 	 * This used to be done in pci_pm_prepare() for all devices and some
862 	 * drivers may depend on it, so do it here.  Ideally, runtime-suspended
863 	 * devices should not be touched during freeze/thaw transitions,
864 	 * however.
865 	 */
866 	pm_runtime_resume(dev);
867 
868 	pci_dev->state_saved = false;
869 	if (pm->freeze) {
870 		int error;
871 
872 		error = pm->freeze(dev);
873 		suspend_report_result(pm->freeze, error);
874 		if (error)
875 			return error;
876 	}
877 
878 	if (pcibios_pm_ops.freeze)
879 		return pcibios_pm_ops.freeze(dev);
880 
881 	return 0;
882 }
883 
884 static int pci_pm_freeze_noirq(struct device *dev)
885 {
886 	struct pci_dev *pci_dev = to_pci_dev(dev);
887 	struct device_driver *drv = dev->driver;
888 
889 	if (pci_has_legacy_pm_support(pci_dev))
890 		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
891 
892 	if (drv && drv->pm && drv->pm->freeze_noirq) {
893 		int error;
894 
895 		error = drv->pm->freeze_noirq(dev);
896 		suspend_report_result(drv->pm->freeze_noirq, error);
897 		if (error)
898 			return error;
899 	}
900 
901 	if (!pci_dev->state_saved)
902 		pci_save_state(pci_dev);
903 
904 	pci_pm_set_unknown_state(pci_dev);
905 
906 	if (pcibios_pm_ops.freeze_noirq)
907 		return pcibios_pm_ops.freeze_noirq(dev);
908 
909 	return 0;
910 }
911 
912 static int pci_pm_thaw_noirq(struct device *dev)
913 {
914 	struct pci_dev *pci_dev = to_pci_dev(dev);
915 	struct device_driver *drv = dev->driver;
916 	int error = 0;
917 
918 	if (pcibios_pm_ops.thaw_noirq) {
919 		error = pcibios_pm_ops.thaw_noirq(dev);
920 		if (error)
921 			return error;
922 	}
923 
924 	if (pci_has_legacy_pm_support(pci_dev))
925 		return pci_legacy_resume_early(dev);
926 
927 	pci_update_current_state(pci_dev, PCI_D0);
928 
929 	if (drv && drv->pm && drv->pm->thaw_noirq)
930 		error = drv->pm->thaw_noirq(dev);
931 
932 	return error;
933 }
934 
935 static int pci_pm_thaw(struct device *dev)
936 {
937 	struct pci_dev *pci_dev = to_pci_dev(dev);
938 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
939 	int error = 0;
940 
941 	if (pcibios_pm_ops.thaw) {
942 		error = pcibios_pm_ops.thaw(dev);
943 		if (error)
944 			return error;
945 	}
946 
947 	if (pci_has_legacy_pm_support(pci_dev))
948 		return pci_legacy_resume(dev);
949 
950 	if (pm) {
951 		if (pm->thaw)
952 			error = pm->thaw(dev);
953 	} else {
954 		pci_pm_reenable_device(pci_dev);
955 	}
956 
957 	pci_dev->state_saved = false;
958 
959 	return error;
960 }
961 
962 static int pci_pm_poweroff(struct device *dev)
963 {
964 	struct pci_dev *pci_dev = to_pci_dev(dev);
965 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
966 
967 	if (pci_has_legacy_pm_support(pci_dev))
968 		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
969 
970 	if (!pm) {
971 		pci_pm_default_suspend(pci_dev);
972 		goto Fixup;
973 	}
974 
975 	/* The reason to do that is the same as in pci_pm_suspend(). */
976 	pm_runtime_resume(dev);
977 
978 	pci_dev->state_saved = false;
979 	if (pm->poweroff) {
980 		int error;
981 
982 		error = pm->poweroff(dev);
983 		suspend_report_result(pm->poweroff, error);
984 		if (error)
985 			return error;
986 	}
987 
988  Fixup:
989 	pci_fixup_device(pci_fixup_suspend, pci_dev);
990 
991 	if (pcibios_pm_ops.poweroff)
992 		return pcibios_pm_ops.poweroff(dev);
993 
994 	return 0;
995 }
996 
997 static int pci_pm_poweroff_noirq(struct device *dev)
998 {
999 	struct pci_dev *pci_dev = to_pci_dev(dev);
1000 	struct device_driver *drv = dev->driver;
1001 
1002 	if (pci_has_legacy_pm_support(to_pci_dev(dev)))
1003 		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
1004 
1005 	if (!drv || !drv->pm) {
1006 		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1007 		return 0;
1008 	}
1009 
1010 	if (drv->pm->poweroff_noirq) {
1011 		int error;
1012 
1013 		error = drv->pm->poweroff_noirq(dev);
1014 		suspend_report_result(drv->pm->poweroff_noirq, error);
1015 		if (error)
1016 			return error;
1017 	}
1018 
1019 	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
1020 		pci_prepare_to_sleep(pci_dev);
1021 
1022 	/*
1023 	 * The reason for doing this here is the same as for the analogous code
1024 	 * in pci_pm_suspend_noirq().
1025 	 */
1026 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
1027 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
1028 
1029 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1030 
1031 	if (pcibios_pm_ops.poweroff_noirq)
1032 		return pcibios_pm_ops.poweroff_noirq(dev);
1033 
1034 	return 0;
1035 }
1036 
1037 static int pci_pm_restore_noirq(struct device *dev)
1038 {
1039 	struct pci_dev *pci_dev = to_pci_dev(dev);
1040 	struct device_driver *drv = dev->driver;
1041 	int error = 0;
1042 
1043 	if (pcibios_pm_ops.restore_noirq) {
1044 		error = pcibios_pm_ops.restore_noirq(dev);
1045 		if (error)
1046 			return error;
1047 	}
1048 
1049 	pci_pm_default_resume_early(pci_dev);
1050 
1051 	if (pci_has_legacy_pm_support(pci_dev))
1052 		return pci_legacy_resume_early(dev);
1053 
1054 	if (drv && drv->pm && drv->pm->restore_noirq)
1055 		error = drv->pm->restore_noirq(dev);
1056 
1057 	return error;
1058 }
1059 
1060 static int pci_pm_restore(struct device *dev)
1061 {
1062 	struct pci_dev *pci_dev = to_pci_dev(dev);
1063 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1064 	int error = 0;
1065 
1066 	if (pcibios_pm_ops.restore) {
1067 		error = pcibios_pm_ops.restore(dev);
1068 		if (error)
1069 			return error;
1070 	}
1071 
1072 	/*
1073 	 * This is necessary for the hibernation error path in which restore is
1074 	 * called without restoring the standard config registers of the device.
1075 	 */
1076 	if (pci_dev->state_saved)
1077 		pci_restore_standard_config(pci_dev);
1078 
1079 	if (pci_has_legacy_pm_support(pci_dev))
1080 		return pci_legacy_resume(dev);
1081 
1082 	pci_pm_default_resume(pci_dev);
1083 
1084 	if (pm) {
1085 		if (pm->restore)
1086 			error = pm->restore(dev);
1087 	} else {
1088 		pci_pm_reenable_device(pci_dev);
1089 	}
1090 
1091 	return error;
1092 }
1093 
1094 #else /* !CONFIG_HIBERNATE_CALLBACKS */
1095 
1096 #define pci_pm_freeze		NULL
1097 #define pci_pm_freeze_noirq	NULL
1098 #define pci_pm_thaw		NULL
1099 #define pci_pm_thaw_noirq	NULL
1100 #define pci_pm_poweroff		NULL
1101 #define pci_pm_poweroff_noirq	NULL
1102 #define pci_pm_restore		NULL
1103 #define pci_pm_restore_noirq	NULL
1104 
1105 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
1106 
1107 #ifdef CONFIG_PM
1108 
1109 static int pci_pm_runtime_suspend(struct device *dev)
1110 {
1111 	struct pci_dev *pci_dev = to_pci_dev(dev);
1112 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1113 	pci_power_t prev = pci_dev->current_state;
1114 	int error;
1115 
1116 	/*
1117 	 * If pci_dev->driver is not set (unbound), the device should
1118 	 * always remain in D0 regardless of the runtime PM status
1119 	 */
1120 	if (!pci_dev->driver)
1121 		return 0;
1122 
1123 	if (!pm || !pm->runtime_suspend)
1124 		return -ENOSYS;
1125 
1126 	pci_dev->state_saved = false;
1127 	pci_dev->no_d3cold = false;
1128 	error = pm->runtime_suspend(dev);
1129 	suspend_report_result(pm->runtime_suspend, error);
1130 	if (error)
1131 		return error;
1132 	if (!pci_dev->d3cold_allowed)
1133 		pci_dev->no_d3cold = true;
1134 
1135 	pci_fixup_device(pci_fixup_suspend, pci_dev);
1136 
1137 	if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
1138 	    && pci_dev->current_state != PCI_UNKNOWN) {
1139 		WARN_ONCE(pci_dev->current_state != prev,
1140 			"PCI PM: State of device not saved by %pF\n",
1141 			pm->runtime_suspend);
1142 		return 0;
1143 	}
1144 
1145 	if (!pci_dev->state_saved) {
1146 		pci_save_state(pci_dev);
1147 		pci_finish_runtime_suspend(pci_dev);
1148 	}
1149 
1150 	return 0;
1151 }
1152 
1153 static int pci_pm_runtime_resume(struct device *dev)
1154 {
1155 	int rc;
1156 	struct pci_dev *pci_dev = to_pci_dev(dev);
1157 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1158 
1159 	/*
1160 	 * If pci_dev->driver is not set (unbound), the device should
1161 	 * always remain in D0 regardless of the runtime PM status
1162 	 */
1163 	if (!pci_dev->driver)
1164 		return 0;
1165 
1166 	if (!pm || !pm->runtime_resume)
1167 		return -ENOSYS;
1168 
1169 	pci_restore_standard_config(pci_dev);
1170 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1171 	__pci_enable_wake(pci_dev, PCI_D0, true, false);
1172 	pci_fixup_device(pci_fixup_resume, pci_dev);
1173 
1174 	rc = pm->runtime_resume(dev);
1175 
1176 	pci_dev->runtime_d3cold = false;
1177 
1178 	return rc;
1179 }
1180 
1181 static int pci_pm_runtime_idle(struct device *dev)
1182 {
1183 	struct pci_dev *pci_dev = to_pci_dev(dev);
1184 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1185 	int ret = 0;
1186 
1187 	/*
1188 	 * If pci_dev->driver is not set (unbound), the device should
1189 	 * always remain in D0 regardless of the runtime PM status
1190 	 */
1191 	if (!pci_dev->driver)
1192 		return 0;
1193 
1194 	if (!pm)
1195 		return -ENOSYS;
1196 
1197 	if (pm->runtime_idle)
1198 		ret = pm->runtime_idle(dev);
1199 
1200 	return ret;
1201 }
1202 
1203 static const struct dev_pm_ops pci_dev_pm_ops = {
1204 	.prepare = pci_pm_prepare,
1205 	.suspend = pci_pm_suspend,
1206 	.resume = pci_pm_resume,
1207 	.freeze = pci_pm_freeze,
1208 	.thaw = pci_pm_thaw,
1209 	.poweroff = pci_pm_poweroff,
1210 	.restore = pci_pm_restore,
1211 	.suspend_noirq = pci_pm_suspend_noirq,
1212 	.resume_noirq = pci_pm_resume_noirq,
1213 	.freeze_noirq = pci_pm_freeze_noirq,
1214 	.thaw_noirq = pci_pm_thaw_noirq,
1215 	.poweroff_noirq = pci_pm_poweroff_noirq,
1216 	.restore_noirq = pci_pm_restore_noirq,
1217 	.runtime_suspend = pci_pm_runtime_suspend,
1218 	.runtime_resume = pci_pm_runtime_resume,
1219 	.runtime_idle = pci_pm_runtime_idle,
1220 };
1221 
1222 #define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
1223 
1224 #else /* !CONFIG_PM */
1225 
1226 #define pci_pm_runtime_suspend	NULL
1227 #define pci_pm_runtime_resume	NULL
1228 #define pci_pm_runtime_idle	NULL
1229 
1230 #define PCI_PM_OPS_PTR	NULL
1231 
1232 #endif /* !CONFIG_PM */
1233 
1234 /**
1235  * __pci_register_driver - register a new pci driver
1236  * @drv: the driver structure to register
1237  * @owner: owner module of drv
1238  * @mod_name: module name string
1239  *
1240  * Adds the driver structure to the list of registered drivers.
1241  * Returns a negative value on error, otherwise 0.
1242  * If no error occurred, the driver remains registered even if
1243  * no device was claimed during registration.
1244  */
1245 int __pci_register_driver(struct pci_driver *drv, struct module *owner,
1246 			  const char *mod_name)
1247 {
1248 	/* initialize common driver fields */
1249 	drv->driver.name = drv->name;
1250 	drv->driver.bus = &pci_bus_type;
1251 	drv->driver.owner = owner;
1252 	drv->driver.mod_name = mod_name;
1253 
1254 	spin_lock_init(&drv->dynids.lock);
1255 	INIT_LIST_HEAD(&drv->dynids.list);
1256 
1257 	/* register with core */
1258 	return driver_register(&drv->driver);
1259 }
1260 EXPORT_SYMBOL(__pci_register_driver);
1261 
1262 /**
1263  * pci_unregister_driver - unregister a pci driver
1264  * @drv: the driver structure to unregister
1265  *
1266  * Deletes the driver structure from the list of registered PCI drivers,
1267  * gives it a chance to clean up by calling its remove() function for
1268  * each device it was responsible for, and marks those devices as
1269  * driverless.
1270  */
1271 
1272 void pci_unregister_driver(struct pci_driver *drv)
1273 {
1274 	driver_unregister(&drv->driver);
1275 	pci_free_dynids(drv);
1276 }
1277 EXPORT_SYMBOL(pci_unregister_driver);
1278 
1279 static struct pci_driver pci_compat_driver = {
1280 	.name = "compat"
1281 };
1282 
1283 /**
1284  * pci_dev_driver - get the pci_driver of a device
1285  * @dev: the device to query
1286  *
1287  * Returns the appropriate pci_driver structure or %NULL if there is no
1288  * registered driver for the device.
1289  */
1290 struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
1291 {
1292 	if (dev->driver)
1293 		return dev->driver;
1294 	else {
1295 		int i;
1296 		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1297 			if (dev->resource[i].flags & IORESOURCE_BUSY)
1298 				return &pci_compat_driver;
1299 	}
1300 	return NULL;
1301 }
1302 EXPORT_SYMBOL(pci_dev_driver);
1303 
1304 /**
1305  * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
1306  * @dev: the PCI device structure to match against
1307  * @drv: the device driver to search for matching PCI device id structures
1308  *
1309  * Used by a driver to check whether a PCI device present in the
1310  * system is in its list of supported devices. Returns the matching
1311  * pci_device_id structure or %NULL if there is no match.
1312  */
1313 static int pci_bus_match(struct device *dev, struct device_driver *drv)
1314 {
1315 	struct pci_dev *pci_dev = to_pci_dev(dev);
1316 	struct pci_driver *pci_drv;
1317 	const struct pci_device_id *found_id;
1318 
1319 	if (!pci_dev->match_driver)
1320 		return 0;
1321 
1322 	pci_drv = to_pci_driver(drv);
1323 	found_id = pci_match_device(pci_drv, pci_dev);
1324 	if (found_id)
1325 		return 1;
1326 
1327 	return 0;
1328 }
1329 
1330 /**
1331  * pci_dev_get - increments the reference count of the pci device structure
1332  * @dev: the device being referenced
1333  *
1334  * Each live reference to a device should be refcounted.
1335  *
1336  * Drivers for PCI devices should normally record such references in
1337  * their probe() methods, when they bind to a device, and release
1338  * them by calling pci_dev_put(), in their disconnect() methods.
1339  *
1340  * A pointer to the device with the incremented reference counter is returned.
1341  */
1342 struct pci_dev *pci_dev_get(struct pci_dev *dev)
1343 {
1344 	if (dev)
1345 		get_device(&dev->dev);
1346 	return dev;
1347 }
1348 EXPORT_SYMBOL(pci_dev_get);
1349 
1350 /**
1351  * pci_dev_put - release a use of the pci device structure
1352  * @dev: device that's been disconnected
1353  *
1354  * Must be called when a user of a device is finished with it.  When the last
1355  * user of the device calls this function, the memory of the device is freed.
1356  */
1357 void pci_dev_put(struct pci_dev *dev)
1358 {
1359 	if (dev)
1360 		put_device(&dev->dev);
1361 }
1362 EXPORT_SYMBOL(pci_dev_put);
1363 
1364 static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
1365 {
1366 	struct pci_dev *pdev;
1367 
1368 	if (!dev)
1369 		return -ENODEV;
1370 
1371 	pdev = to_pci_dev(dev);
1372 
1373 	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
1374 		return -ENOMEM;
1375 
1376 	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
1377 		return -ENOMEM;
1378 
1379 	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
1380 			   pdev->subsystem_device))
1381 		return -ENOMEM;
1382 
1383 	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
1384 		return -ENOMEM;
1385 
1386 	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x",
1387 			   pdev->vendor, pdev->device,
1388 			   pdev->subsystem_vendor, pdev->subsystem_device,
1389 			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
1390 			   (u8)(pdev->class)))
1391 		return -ENOMEM;
1392 
1393 	return 0;
1394 }
1395 
1396 struct bus_type pci_bus_type = {
1397 	.name		= "pci",
1398 	.match		= pci_bus_match,
1399 	.uevent		= pci_uevent,
1400 	.probe		= pci_device_probe,
1401 	.remove		= pci_device_remove,
1402 	.shutdown	= pci_device_shutdown,
1403 	.dev_groups	= pci_dev_groups,
1404 	.bus_groups	= pci_bus_groups,
1405 	.drv_groups	= pci_drv_groups,
1406 	.pm		= PCI_PM_OPS_PTR,
1407 };
1408 EXPORT_SYMBOL(pci_bus_type);
1409 
1410 static int __init pci_driver_init(void)
1411 {
1412 	return bus_register(&pci_bus_type);
1413 }
1414 postcore_initcall(pci_driver_init);
1415