xref: /openbmc/linux/drivers/pci/pci-driver.c (revision 4da722ca)
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 new_id_store(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_WO(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 remove_id_store(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 	size_t 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 = count;
194 			break;
195 		}
196 	}
197 	spin_unlock(&pdrv->dynids.lock);
198 
199 	return retval;
200 }
201 static DRIVER_ATTR_WO(remove_id);
202 
203 static struct attribute *pci_drv_attrs[] = {
204 	&driver_attr_new_id.attr,
205 	&driver_attr_remove_id.attr,
206 	NULL,
207 };
208 ATTRIBUTE_GROUPS(pci_drv);
209 
210 /**
211  * pci_match_id - See if a pci device matches a given pci_id table
212  * @ids: array of PCI device id structures to search in
213  * @dev: the PCI device structure to match against.
214  *
215  * Used by a driver to check whether a PCI device present in the
216  * system is in its list of supported devices.  Returns the matching
217  * pci_device_id structure or %NULL if there is no match.
218  *
219  * Deprecated, don't use this as it will not catch any dynamic ids
220  * that a driver might want to check for.
221  */
222 const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
223 					 struct pci_dev *dev)
224 {
225 	if (ids) {
226 		while (ids->vendor || ids->subvendor || ids->class_mask) {
227 			if (pci_match_one_device(ids, dev))
228 				return ids;
229 			ids++;
230 		}
231 	}
232 	return NULL;
233 }
234 EXPORT_SYMBOL(pci_match_id);
235 
236 static const struct pci_device_id pci_device_id_any = {
237 	.vendor = PCI_ANY_ID,
238 	.device = PCI_ANY_ID,
239 	.subvendor = PCI_ANY_ID,
240 	.subdevice = PCI_ANY_ID,
241 };
242 
243 /**
244  * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
245  * @drv: the PCI driver to match against
246  * @dev: the PCI device structure to match against
247  *
248  * Used by a driver to check whether a PCI device present in the
249  * system is in its list of supported devices.  Returns the matching
250  * pci_device_id structure or %NULL if there is no match.
251  */
252 static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
253 						    struct pci_dev *dev)
254 {
255 	struct pci_dynid *dynid;
256 	const struct pci_device_id *found_id = NULL;
257 
258 	/* When driver_override is set, only bind to the matching driver */
259 	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
260 		return NULL;
261 
262 	/* Look at the dynamic ids first, before the static ones */
263 	spin_lock(&drv->dynids.lock);
264 	list_for_each_entry(dynid, &drv->dynids.list, node) {
265 		if (pci_match_one_device(&dynid->id, dev)) {
266 			found_id = &dynid->id;
267 			break;
268 		}
269 	}
270 	spin_unlock(&drv->dynids.lock);
271 
272 	if (!found_id)
273 		found_id = pci_match_id(drv->id_table, dev);
274 
275 	/* driver_override will always match, send a dummy id */
276 	if (!found_id && dev->driver_override)
277 		found_id = &pci_device_id_any;
278 
279 	return found_id;
280 }
281 
282 struct drv_dev_and_id {
283 	struct pci_driver *drv;
284 	struct pci_dev *dev;
285 	const struct pci_device_id *id;
286 };
287 
288 static long local_pci_probe(void *_ddi)
289 {
290 	struct drv_dev_and_id *ddi = _ddi;
291 	struct pci_dev *pci_dev = ddi->dev;
292 	struct pci_driver *pci_drv = ddi->drv;
293 	struct device *dev = &pci_dev->dev;
294 	int rc;
295 
296 	/*
297 	 * Unbound PCI devices are always put in D0, regardless of
298 	 * runtime PM status.  During probe, the device is set to
299 	 * active and the usage count is incremented.  If the driver
300 	 * supports runtime PM, it should call pm_runtime_put_noidle(),
301 	 * or any other runtime PM helper function decrementing the usage
302 	 * count, in its probe routine and pm_runtime_get_noresume() in
303 	 * its remove routine.
304 	 */
305 	pm_runtime_get_sync(dev);
306 	pci_dev->driver = pci_drv;
307 	rc = pci_drv->probe(pci_dev, ddi->id);
308 	if (!rc)
309 		return rc;
310 	if (rc < 0) {
311 		pci_dev->driver = NULL;
312 		pm_runtime_put_sync(dev);
313 		return rc;
314 	}
315 	/*
316 	 * Probe function should return < 0 for failure, 0 for success
317 	 * Treat values > 0 as success, but warn.
318 	 */
319 	dev_warn(dev, "Driver probe function unexpectedly returned %d\n", rc);
320 	return 0;
321 }
322 
323 static bool pci_physfn_is_probed(struct pci_dev *dev)
324 {
325 #ifdef CONFIG_PCI_IOV
326 	return dev->is_virtfn && dev->physfn->is_probed;
327 #else
328 	return false;
329 #endif
330 }
331 
332 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
333 			  const struct pci_device_id *id)
334 {
335 	int error, node, cpu;
336 	struct drv_dev_and_id ddi = { drv, dev, id };
337 
338 	/*
339 	 * Execute driver initialization on node where the device is
340 	 * attached.  This way the driver likely allocates its local memory
341 	 * on the right node.
342 	 */
343 	node = dev_to_node(&dev->dev);
344 	dev->is_probed = 1;
345 
346 	cpu_hotplug_disable();
347 
348 	/*
349 	 * Prevent nesting work_on_cpu() for the case where a Virtual Function
350 	 * device is probed from work_on_cpu() of the Physical device.
351 	 */
352 	if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
353 	    pci_physfn_is_probed(dev))
354 		cpu = nr_cpu_ids;
355 	else
356 		cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask);
357 
358 	if (cpu < nr_cpu_ids)
359 		error = work_on_cpu(cpu, local_pci_probe, &ddi);
360 	else
361 		error = local_pci_probe(&ddi);
362 
363 	dev->is_probed = 0;
364 	cpu_hotplug_enable();
365 	return error;
366 }
367 
368 /**
369  * __pci_device_probe - check if a driver wants to claim a specific PCI device
370  * @drv: driver to call to check if it wants the PCI device
371  * @pci_dev: PCI device being probed
372  *
373  * returns 0 on success, else error.
374  * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
375  */
376 static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
377 {
378 	const struct pci_device_id *id;
379 	int error = 0;
380 
381 	if (!pci_dev->driver && drv->probe) {
382 		error = -ENODEV;
383 
384 		id = pci_match_device(drv, pci_dev);
385 		if (id)
386 			error = pci_call_probe(drv, pci_dev, id);
387 	}
388 	return error;
389 }
390 
391 int __weak pcibios_alloc_irq(struct pci_dev *dev)
392 {
393 	return 0;
394 }
395 
396 void __weak pcibios_free_irq(struct pci_dev *dev)
397 {
398 }
399 
400 #ifdef CONFIG_PCI_IOV
401 static inline bool pci_device_can_probe(struct pci_dev *pdev)
402 {
403 	return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe);
404 }
405 #else
406 static inline bool pci_device_can_probe(struct pci_dev *pdev)
407 {
408 	return true;
409 }
410 #endif
411 
412 static int pci_device_probe(struct device *dev)
413 {
414 	int error;
415 	struct pci_dev *pci_dev = to_pci_dev(dev);
416 	struct pci_driver *drv = to_pci_driver(dev->driver);
417 
418 	pci_assign_irq(pci_dev);
419 
420 	error = pcibios_alloc_irq(pci_dev);
421 	if (error < 0)
422 		return error;
423 
424 	pci_dev_get(pci_dev);
425 	if (pci_device_can_probe(pci_dev)) {
426 		error = __pci_device_probe(drv, pci_dev);
427 		if (error) {
428 			pcibios_free_irq(pci_dev);
429 			pci_dev_put(pci_dev);
430 		}
431 	}
432 
433 	return error;
434 }
435 
436 static int pci_device_remove(struct device *dev)
437 {
438 	struct pci_dev *pci_dev = to_pci_dev(dev);
439 	struct pci_driver *drv = pci_dev->driver;
440 
441 	if (drv) {
442 		if (drv->remove) {
443 			pm_runtime_get_sync(dev);
444 			drv->remove(pci_dev);
445 			pm_runtime_put_noidle(dev);
446 		}
447 		pcibios_free_irq(pci_dev);
448 		pci_dev->driver = NULL;
449 	}
450 
451 	/* Undo the runtime PM settings in local_pci_probe() */
452 	pm_runtime_put_sync(dev);
453 
454 	/*
455 	 * If the device is still on, set the power state as "unknown",
456 	 * since it might change by the next time we load the driver.
457 	 */
458 	if (pci_dev->current_state == PCI_D0)
459 		pci_dev->current_state = PCI_UNKNOWN;
460 
461 	/*
462 	 * We would love to complain here if pci_dev->is_enabled is set, that
463 	 * the driver should have called pci_disable_device(), but the
464 	 * unfortunate fact is there are too many odd BIOS and bridge setups
465 	 * that don't like drivers doing that all of the time.
466 	 * Oh well, we can dream of sane hardware when we sleep, no matter how
467 	 * horrible the crap we have to deal with is when we are awake...
468 	 */
469 
470 	pci_dev_put(pci_dev);
471 	return 0;
472 }
473 
474 static void pci_device_shutdown(struct device *dev)
475 {
476 	struct pci_dev *pci_dev = to_pci_dev(dev);
477 	struct pci_driver *drv = pci_dev->driver;
478 
479 	pm_runtime_resume(dev);
480 
481 	if (drv && drv->shutdown)
482 		drv->shutdown(pci_dev);
483 
484 	/*
485 	 * If this is a kexec reboot, turn off Bus Master bit on the
486 	 * device to tell it to not continue to do DMA. Don't touch
487 	 * devices in D3cold or unknown states.
488 	 * If it is not a kexec reboot, firmware will hit the PCI
489 	 * devices with big hammer and stop their DMA any way.
490 	 */
491 	if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
492 		pci_clear_master(pci_dev);
493 }
494 
495 #ifdef CONFIG_PM
496 
497 /* Auxiliary functions used for system resume and run-time resume. */
498 
499 /**
500  * pci_restore_standard_config - restore standard config registers of PCI device
501  * @pci_dev: PCI device to handle
502  */
503 static int pci_restore_standard_config(struct pci_dev *pci_dev)
504 {
505 	pci_update_current_state(pci_dev, PCI_UNKNOWN);
506 
507 	if (pci_dev->current_state != PCI_D0) {
508 		int error = pci_set_power_state(pci_dev, PCI_D0);
509 		if (error)
510 			return error;
511 	}
512 
513 	pci_restore_state(pci_dev);
514 	pci_pme_restore(pci_dev);
515 	return 0;
516 }
517 
518 #endif
519 
520 #ifdef CONFIG_PM_SLEEP
521 
522 static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
523 {
524 	pci_power_up(pci_dev);
525 	pci_restore_state(pci_dev);
526 	pci_pme_restore(pci_dev);
527 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
528 }
529 
530 /*
531  * Default "suspend" method for devices that have no driver provided suspend,
532  * or not even a driver at all (second part).
533  */
534 static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
535 {
536 	/*
537 	 * mark its power state as "unknown", since we don't know if
538 	 * e.g. the BIOS will change its device state when we suspend.
539 	 */
540 	if (pci_dev->current_state == PCI_D0)
541 		pci_dev->current_state = PCI_UNKNOWN;
542 }
543 
544 /*
545  * Default "resume" method for devices that have no driver provided resume,
546  * or not even a driver at all (second part).
547  */
548 static int pci_pm_reenable_device(struct pci_dev *pci_dev)
549 {
550 	int retval;
551 
552 	/* if the device was enabled before suspend, reenable */
553 	retval = pci_reenable_device(pci_dev);
554 	/*
555 	 * if the device was busmaster before the suspend, make it busmaster
556 	 * again
557 	 */
558 	if (pci_dev->is_busmaster)
559 		pci_set_master(pci_dev);
560 
561 	return retval;
562 }
563 
564 static int pci_legacy_suspend(struct device *dev, pm_message_t state)
565 {
566 	struct pci_dev *pci_dev = to_pci_dev(dev);
567 	struct pci_driver *drv = pci_dev->driver;
568 
569 	if (drv && drv->suspend) {
570 		pci_power_t prev = pci_dev->current_state;
571 		int error;
572 
573 		error = drv->suspend(pci_dev, state);
574 		suspend_report_result(drv->suspend, error);
575 		if (error)
576 			return error;
577 
578 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
579 		    && pci_dev->current_state != PCI_UNKNOWN) {
580 			WARN_ONCE(pci_dev->current_state != prev,
581 				"PCI PM: Device state not saved by %pF\n",
582 				drv->suspend);
583 		}
584 	}
585 
586 	pci_fixup_device(pci_fixup_suspend, pci_dev);
587 
588 	return 0;
589 }
590 
591 static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
592 {
593 	struct pci_dev *pci_dev = to_pci_dev(dev);
594 	struct pci_driver *drv = pci_dev->driver;
595 
596 	if (drv && drv->suspend_late) {
597 		pci_power_t prev = pci_dev->current_state;
598 		int error;
599 
600 		error = drv->suspend_late(pci_dev, state);
601 		suspend_report_result(drv->suspend_late, error);
602 		if (error)
603 			return error;
604 
605 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
606 		    && pci_dev->current_state != PCI_UNKNOWN) {
607 			WARN_ONCE(pci_dev->current_state != prev,
608 				"PCI PM: Device state not saved by %pF\n",
609 				drv->suspend_late);
610 			goto Fixup;
611 		}
612 	}
613 
614 	if (!pci_dev->state_saved)
615 		pci_save_state(pci_dev);
616 
617 	pci_pm_set_unknown_state(pci_dev);
618 
619 Fixup:
620 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
621 
622 	return 0;
623 }
624 
625 static int pci_legacy_resume_early(struct device *dev)
626 {
627 	struct pci_dev *pci_dev = to_pci_dev(dev);
628 	struct pci_driver *drv = pci_dev->driver;
629 
630 	return drv && drv->resume_early ?
631 			drv->resume_early(pci_dev) : 0;
632 }
633 
634 static int pci_legacy_resume(struct device *dev)
635 {
636 	struct pci_dev *pci_dev = to_pci_dev(dev);
637 	struct pci_driver *drv = pci_dev->driver;
638 
639 	pci_fixup_device(pci_fixup_resume, pci_dev);
640 
641 	return drv && drv->resume ?
642 			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
643 }
644 
645 /* Auxiliary functions used by the new power management framework */
646 
647 static void pci_pm_default_resume(struct pci_dev *pci_dev)
648 {
649 	pci_fixup_device(pci_fixup_resume, pci_dev);
650 
651 	if (!pci_has_subordinate(pci_dev))
652 		pci_enable_wake(pci_dev, PCI_D0, false);
653 }
654 
655 static void pci_pm_default_suspend(struct pci_dev *pci_dev)
656 {
657 	/* Disable non-bridge devices without PM support */
658 	if (!pci_has_subordinate(pci_dev))
659 		pci_disable_enabled_device(pci_dev);
660 }
661 
662 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
663 {
664 	struct pci_driver *drv = pci_dev->driver;
665 	bool ret = drv && (drv->suspend || drv->suspend_late || drv->resume
666 		|| drv->resume_early);
667 
668 	/*
669 	 * Legacy PM support is used by default, so warn if the new framework is
670 	 * supported as well.  Drivers are supposed to support either the
671 	 * former, or the latter, but not both at the same time.
672 	 */
673 	WARN(ret && drv->driver.pm, "driver %s device %04x:%04x\n",
674 		drv->name, pci_dev->vendor, pci_dev->device);
675 
676 	return ret;
677 }
678 
679 /* New power management framework */
680 
681 static int pci_pm_prepare(struct device *dev)
682 {
683 	struct device_driver *drv = dev->driver;
684 
685 	/*
686 	 * Devices having power.ignore_children set may still be necessary for
687 	 * suspending their children in the next phase of device suspend.
688 	 */
689 	if (dev->power.ignore_children)
690 		pm_runtime_resume(dev);
691 
692 	if (drv && drv->pm && drv->pm->prepare) {
693 		int error = drv->pm->prepare(dev);
694 		if (error)
695 			return error;
696 	}
697 	return pci_dev_keep_suspended(to_pci_dev(dev));
698 }
699 
700 static void pci_pm_complete(struct device *dev)
701 {
702 	struct pci_dev *pci_dev = to_pci_dev(dev);
703 
704 	pci_dev_complete_resume(pci_dev);
705 	pm_generic_complete(dev);
706 
707 	/* Resume device if platform firmware has put it in reset-power-on */
708 	if (dev->power.direct_complete && pm_resume_via_firmware()) {
709 		pci_power_t pre_sleep_state = pci_dev->current_state;
710 
711 		pci_update_current_state(pci_dev, pci_dev->current_state);
712 		if (pci_dev->current_state < pre_sleep_state)
713 			pm_request_resume(dev);
714 	}
715 }
716 
717 #else /* !CONFIG_PM_SLEEP */
718 
719 #define pci_pm_prepare	NULL
720 #define pci_pm_complete	NULL
721 
722 #endif /* !CONFIG_PM_SLEEP */
723 
724 #ifdef CONFIG_SUSPEND
725 
726 static int pci_pm_suspend(struct device *dev)
727 {
728 	struct pci_dev *pci_dev = to_pci_dev(dev);
729 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
730 
731 	if (pci_has_legacy_pm_support(pci_dev))
732 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
733 
734 	if (!pm) {
735 		pci_pm_default_suspend(pci_dev);
736 		goto Fixup;
737 	}
738 
739 	/*
740 	 * PCI devices suspended at run time need to be resumed at this point,
741 	 * because in general it is necessary to reconfigure them for system
742 	 * suspend.  Namely, if the device is supposed to wake up the system
743 	 * from the sleep state, we may need to reconfigure it for this purpose.
744 	 * In turn, if the device is not supposed to wake up the system from the
745 	 * sleep state, we'll have to prevent it from signaling wake-up.
746 	 */
747 	pm_runtime_resume(dev);
748 
749 	pci_dev->state_saved = false;
750 	if (pm->suspend) {
751 		pci_power_t prev = pci_dev->current_state;
752 		int error;
753 
754 		error = pm->suspend(dev);
755 		suspend_report_result(pm->suspend, error);
756 		if (error)
757 			return error;
758 
759 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
760 		    && pci_dev->current_state != PCI_UNKNOWN) {
761 			WARN_ONCE(pci_dev->current_state != prev,
762 				"PCI PM: State of device not saved by %pF\n",
763 				pm->suspend);
764 		}
765 	}
766 
767  Fixup:
768 	pci_fixup_device(pci_fixup_suspend, pci_dev);
769 
770 	return 0;
771 }
772 
773 static int pci_pm_suspend_noirq(struct device *dev)
774 {
775 	struct pci_dev *pci_dev = to_pci_dev(dev);
776 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
777 
778 	if (pci_has_legacy_pm_support(pci_dev))
779 		return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
780 
781 	if (!pm) {
782 		pci_save_state(pci_dev);
783 		goto Fixup;
784 	}
785 
786 	if (pm->suspend_noirq) {
787 		pci_power_t prev = pci_dev->current_state;
788 		int error;
789 
790 		error = pm->suspend_noirq(dev);
791 		suspend_report_result(pm->suspend_noirq, error);
792 		if (error)
793 			return error;
794 
795 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
796 		    && pci_dev->current_state != PCI_UNKNOWN) {
797 			WARN_ONCE(pci_dev->current_state != prev,
798 				"PCI PM: State of device not saved by %pF\n",
799 				pm->suspend_noirq);
800 			goto Fixup;
801 		}
802 	}
803 
804 	if (!pci_dev->state_saved) {
805 		pci_save_state(pci_dev);
806 		if (pci_power_manageable(pci_dev))
807 			pci_prepare_to_sleep(pci_dev);
808 	}
809 
810 	pci_pm_set_unknown_state(pci_dev);
811 
812 	/*
813 	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
814 	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
815 	 * hasn't been quiesced and tries to turn it off.  If the controller
816 	 * is already in D3, this can hang or cause memory corruption.
817 	 *
818 	 * Since the value of the COMMAND register doesn't matter once the
819 	 * device has been suspended, we can safely set it to 0 here.
820 	 */
821 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
822 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
823 
824 Fixup:
825 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
826 
827 	return 0;
828 }
829 
830 static int pci_pm_resume_noirq(struct device *dev)
831 {
832 	struct pci_dev *pci_dev = to_pci_dev(dev);
833 	struct device_driver *drv = dev->driver;
834 	int error = 0;
835 
836 	pci_pm_default_resume_early(pci_dev);
837 
838 	if (pci_has_legacy_pm_support(pci_dev))
839 		return pci_legacy_resume_early(dev);
840 
841 	if (drv && drv->pm && drv->pm->resume_noirq)
842 		error = drv->pm->resume_noirq(dev);
843 
844 	return error;
845 }
846 
847 static int pci_pm_resume(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 	int error = 0;
852 
853 	/*
854 	 * This is necessary for the suspend error path in which resume is
855 	 * called without restoring the standard config registers of the device.
856 	 */
857 	if (pci_dev->state_saved)
858 		pci_restore_standard_config(pci_dev);
859 
860 	if (pci_has_legacy_pm_support(pci_dev))
861 		return pci_legacy_resume(dev);
862 
863 	pci_pm_default_resume(pci_dev);
864 
865 	if (pm) {
866 		if (pm->resume)
867 			error = pm->resume(dev);
868 	} else {
869 		pci_pm_reenable_device(pci_dev);
870 	}
871 
872 	return error;
873 }
874 
875 #else /* !CONFIG_SUSPEND */
876 
877 #define pci_pm_suspend		NULL
878 #define pci_pm_suspend_noirq	NULL
879 #define pci_pm_resume		NULL
880 #define pci_pm_resume_noirq	NULL
881 
882 #endif /* !CONFIG_SUSPEND */
883 
884 #ifdef CONFIG_HIBERNATE_CALLBACKS
885 
886 
887 /*
888  * pcibios_pm_ops - provide arch-specific hooks when a PCI device is doing
889  * a hibernate transition
890  */
891 struct dev_pm_ops __weak pcibios_pm_ops;
892 
893 static int pci_pm_freeze(struct device *dev)
894 {
895 	struct pci_dev *pci_dev = to_pci_dev(dev);
896 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
897 
898 	if (pci_has_legacy_pm_support(pci_dev))
899 		return pci_legacy_suspend(dev, PMSG_FREEZE);
900 
901 	if (!pm) {
902 		pci_pm_default_suspend(pci_dev);
903 		return 0;
904 	}
905 
906 	/*
907 	 * This used to be done in pci_pm_prepare() for all devices and some
908 	 * drivers may depend on it, so do it here.  Ideally, runtime-suspended
909 	 * devices should not be touched during freeze/thaw transitions,
910 	 * however.
911 	 */
912 	pm_runtime_resume(dev);
913 
914 	pci_dev->state_saved = false;
915 	if (pm->freeze) {
916 		int error;
917 
918 		error = pm->freeze(dev);
919 		suspend_report_result(pm->freeze, error);
920 		if (error)
921 			return error;
922 	}
923 
924 	if (pcibios_pm_ops.freeze)
925 		return pcibios_pm_ops.freeze(dev);
926 
927 	return 0;
928 }
929 
930 static int pci_pm_freeze_noirq(struct device *dev)
931 {
932 	struct pci_dev *pci_dev = to_pci_dev(dev);
933 	struct device_driver *drv = dev->driver;
934 
935 	if (pci_has_legacy_pm_support(pci_dev))
936 		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
937 
938 	if (drv && drv->pm && drv->pm->freeze_noirq) {
939 		int error;
940 
941 		error = drv->pm->freeze_noirq(dev);
942 		suspend_report_result(drv->pm->freeze_noirq, error);
943 		if (error)
944 			return error;
945 	}
946 
947 	if (!pci_dev->state_saved)
948 		pci_save_state(pci_dev);
949 
950 	pci_pm_set_unknown_state(pci_dev);
951 
952 	if (pcibios_pm_ops.freeze_noirq)
953 		return pcibios_pm_ops.freeze_noirq(dev);
954 
955 	return 0;
956 }
957 
958 static int pci_pm_thaw_noirq(struct device *dev)
959 {
960 	struct pci_dev *pci_dev = to_pci_dev(dev);
961 	struct device_driver *drv = dev->driver;
962 	int error = 0;
963 
964 	if (pcibios_pm_ops.thaw_noirq) {
965 		error = pcibios_pm_ops.thaw_noirq(dev);
966 		if (error)
967 			return error;
968 	}
969 
970 	if (pci_has_legacy_pm_support(pci_dev))
971 		return pci_legacy_resume_early(dev);
972 
973 	pci_update_current_state(pci_dev, PCI_D0);
974 	pci_restore_state(pci_dev);
975 
976 	if (drv && drv->pm && drv->pm->thaw_noirq)
977 		error = drv->pm->thaw_noirq(dev);
978 
979 	return error;
980 }
981 
982 static int pci_pm_thaw(struct device *dev)
983 {
984 	struct pci_dev *pci_dev = to_pci_dev(dev);
985 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
986 	int error = 0;
987 
988 	if (pcibios_pm_ops.thaw) {
989 		error = pcibios_pm_ops.thaw(dev);
990 		if (error)
991 			return error;
992 	}
993 
994 	if (pci_has_legacy_pm_support(pci_dev))
995 		return pci_legacy_resume(dev);
996 
997 	if (pm) {
998 		if (pm->thaw)
999 			error = pm->thaw(dev);
1000 	} else {
1001 		pci_pm_reenable_device(pci_dev);
1002 	}
1003 
1004 	pci_dev->state_saved = false;
1005 
1006 	return error;
1007 }
1008 
1009 static int pci_pm_poweroff(struct device *dev)
1010 {
1011 	struct pci_dev *pci_dev = to_pci_dev(dev);
1012 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1013 
1014 	if (pci_has_legacy_pm_support(pci_dev))
1015 		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
1016 
1017 	if (!pm) {
1018 		pci_pm_default_suspend(pci_dev);
1019 		goto Fixup;
1020 	}
1021 
1022 	/* The reason to do that is the same as in pci_pm_suspend(). */
1023 	pm_runtime_resume(dev);
1024 
1025 	pci_dev->state_saved = false;
1026 	if (pm->poweroff) {
1027 		int error;
1028 
1029 		error = pm->poweroff(dev);
1030 		suspend_report_result(pm->poweroff, error);
1031 		if (error)
1032 			return error;
1033 	}
1034 
1035  Fixup:
1036 	pci_fixup_device(pci_fixup_suspend, pci_dev);
1037 
1038 	if (pcibios_pm_ops.poweroff)
1039 		return pcibios_pm_ops.poweroff(dev);
1040 
1041 	return 0;
1042 }
1043 
1044 static int pci_pm_poweroff_noirq(struct device *dev)
1045 {
1046 	struct pci_dev *pci_dev = to_pci_dev(dev);
1047 	struct device_driver *drv = dev->driver;
1048 
1049 	if (pci_has_legacy_pm_support(to_pci_dev(dev)))
1050 		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
1051 
1052 	if (!drv || !drv->pm) {
1053 		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1054 		return 0;
1055 	}
1056 
1057 	if (drv->pm->poweroff_noirq) {
1058 		int error;
1059 
1060 		error = drv->pm->poweroff_noirq(dev);
1061 		suspend_report_result(drv->pm->poweroff_noirq, error);
1062 		if (error)
1063 			return error;
1064 	}
1065 
1066 	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
1067 		pci_prepare_to_sleep(pci_dev);
1068 
1069 	/*
1070 	 * The reason for doing this here is the same as for the analogous code
1071 	 * in pci_pm_suspend_noirq().
1072 	 */
1073 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
1074 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
1075 
1076 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1077 
1078 	if (pcibios_pm_ops.poweroff_noirq)
1079 		return pcibios_pm_ops.poweroff_noirq(dev);
1080 
1081 	return 0;
1082 }
1083 
1084 static int pci_pm_restore_noirq(struct device *dev)
1085 {
1086 	struct pci_dev *pci_dev = to_pci_dev(dev);
1087 	struct device_driver *drv = dev->driver;
1088 	int error = 0;
1089 
1090 	if (pcibios_pm_ops.restore_noirq) {
1091 		error = pcibios_pm_ops.restore_noirq(dev);
1092 		if (error)
1093 			return error;
1094 	}
1095 
1096 	pci_pm_default_resume_early(pci_dev);
1097 
1098 	if (pci_has_legacy_pm_support(pci_dev))
1099 		return pci_legacy_resume_early(dev);
1100 
1101 	if (drv && drv->pm && drv->pm->restore_noirq)
1102 		error = drv->pm->restore_noirq(dev);
1103 
1104 	return error;
1105 }
1106 
1107 static int pci_pm_restore(struct device *dev)
1108 {
1109 	struct pci_dev *pci_dev = to_pci_dev(dev);
1110 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1111 	int error = 0;
1112 
1113 	if (pcibios_pm_ops.restore) {
1114 		error = pcibios_pm_ops.restore(dev);
1115 		if (error)
1116 			return error;
1117 	}
1118 
1119 	/*
1120 	 * This is necessary for the hibernation error path in which restore is
1121 	 * called without restoring the standard config registers of the device.
1122 	 */
1123 	if (pci_dev->state_saved)
1124 		pci_restore_standard_config(pci_dev);
1125 
1126 	if (pci_has_legacy_pm_support(pci_dev))
1127 		return pci_legacy_resume(dev);
1128 
1129 	pci_pm_default_resume(pci_dev);
1130 
1131 	if (pm) {
1132 		if (pm->restore)
1133 			error = pm->restore(dev);
1134 	} else {
1135 		pci_pm_reenable_device(pci_dev);
1136 	}
1137 
1138 	return error;
1139 }
1140 
1141 #else /* !CONFIG_HIBERNATE_CALLBACKS */
1142 
1143 #define pci_pm_freeze		NULL
1144 #define pci_pm_freeze_noirq	NULL
1145 #define pci_pm_thaw		NULL
1146 #define pci_pm_thaw_noirq	NULL
1147 #define pci_pm_poweroff		NULL
1148 #define pci_pm_poweroff_noirq	NULL
1149 #define pci_pm_restore		NULL
1150 #define pci_pm_restore_noirq	NULL
1151 
1152 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
1153 
1154 #ifdef CONFIG_PM
1155 
1156 static int pci_pm_runtime_suspend(struct device *dev)
1157 {
1158 	struct pci_dev *pci_dev = to_pci_dev(dev);
1159 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1160 	pci_power_t prev = pci_dev->current_state;
1161 	int error;
1162 
1163 	/*
1164 	 * If pci_dev->driver is not set (unbound), the device should
1165 	 * always remain in D0 regardless of the runtime PM status
1166 	 */
1167 	if (!pci_dev->driver)
1168 		return 0;
1169 
1170 	if (!pm || !pm->runtime_suspend)
1171 		return -ENOSYS;
1172 
1173 	pci_dev->state_saved = false;
1174 	error = pm->runtime_suspend(dev);
1175 	if (error) {
1176 		/*
1177 		 * -EBUSY and -EAGAIN is used to request the runtime PM core
1178 		 * to schedule a new suspend, so log the event only with debug
1179 		 * log level.
1180 		 */
1181 		if (error == -EBUSY || error == -EAGAIN)
1182 			dev_dbg(dev, "can't suspend now (%pf returned %d)\n",
1183 				pm->runtime_suspend, error);
1184 		else
1185 			dev_err(dev, "can't suspend (%pf returned %d)\n",
1186 				pm->runtime_suspend, error);
1187 
1188 		return error;
1189 	}
1190 
1191 	pci_fixup_device(pci_fixup_suspend, pci_dev);
1192 
1193 	if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
1194 	    && pci_dev->current_state != PCI_UNKNOWN) {
1195 		WARN_ONCE(pci_dev->current_state != prev,
1196 			"PCI PM: State of device not saved by %pF\n",
1197 			pm->runtime_suspend);
1198 		return 0;
1199 	}
1200 
1201 	if (!pci_dev->state_saved) {
1202 		pci_save_state(pci_dev);
1203 		pci_finish_runtime_suspend(pci_dev);
1204 	}
1205 
1206 	return 0;
1207 }
1208 
1209 static int pci_pm_runtime_resume(struct device *dev)
1210 {
1211 	int rc;
1212 	struct pci_dev *pci_dev = to_pci_dev(dev);
1213 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1214 
1215 	/*
1216 	 * If pci_dev->driver is not set (unbound), the device should
1217 	 * always remain in D0 regardless of the runtime PM status
1218 	 */
1219 	if (!pci_dev->driver)
1220 		return 0;
1221 
1222 	if (!pm || !pm->runtime_resume)
1223 		return -ENOSYS;
1224 
1225 	pci_restore_standard_config(pci_dev);
1226 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1227 	pci_enable_wake(pci_dev, PCI_D0, false);
1228 	pci_fixup_device(pci_fixup_resume, pci_dev);
1229 
1230 	rc = pm->runtime_resume(dev);
1231 
1232 	pci_dev->runtime_d3cold = false;
1233 
1234 	return rc;
1235 }
1236 
1237 static int pci_pm_runtime_idle(struct device *dev)
1238 {
1239 	struct pci_dev *pci_dev = to_pci_dev(dev);
1240 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1241 	int ret = 0;
1242 
1243 	/*
1244 	 * If pci_dev->driver is not set (unbound), the device should
1245 	 * always remain in D0 regardless of the runtime PM status
1246 	 */
1247 	if (!pci_dev->driver)
1248 		return 0;
1249 
1250 	if (!pm)
1251 		return -ENOSYS;
1252 
1253 	if (pm->runtime_idle)
1254 		ret = pm->runtime_idle(dev);
1255 
1256 	return ret;
1257 }
1258 
1259 static const struct dev_pm_ops pci_dev_pm_ops = {
1260 	.prepare = pci_pm_prepare,
1261 	.complete = pci_pm_complete,
1262 	.suspend = pci_pm_suspend,
1263 	.resume = pci_pm_resume,
1264 	.freeze = pci_pm_freeze,
1265 	.thaw = pci_pm_thaw,
1266 	.poweroff = pci_pm_poweroff,
1267 	.restore = pci_pm_restore,
1268 	.suspend_noirq = pci_pm_suspend_noirq,
1269 	.resume_noirq = pci_pm_resume_noirq,
1270 	.freeze_noirq = pci_pm_freeze_noirq,
1271 	.thaw_noirq = pci_pm_thaw_noirq,
1272 	.poweroff_noirq = pci_pm_poweroff_noirq,
1273 	.restore_noirq = pci_pm_restore_noirq,
1274 	.runtime_suspend = pci_pm_runtime_suspend,
1275 	.runtime_resume = pci_pm_runtime_resume,
1276 	.runtime_idle = pci_pm_runtime_idle,
1277 };
1278 
1279 #define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
1280 
1281 #else /* !CONFIG_PM */
1282 
1283 #define pci_pm_runtime_suspend	NULL
1284 #define pci_pm_runtime_resume	NULL
1285 #define pci_pm_runtime_idle	NULL
1286 
1287 #define PCI_PM_OPS_PTR	NULL
1288 
1289 #endif /* !CONFIG_PM */
1290 
1291 /**
1292  * __pci_register_driver - register a new pci driver
1293  * @drv: the driver structure to register
1294  * @owner: owner module of drv
1295  * @mod_name: module name string
1296  *
1297  * Adds the driver structure to the list of registered drivers.
1298  * Returns a negative value on error, otherwise 0.
1299  * If no error occurred, the driver remains registered even if
1300  * no device was claimed during registration.
1301  */
1302 int __pci_register_driver(struct pci_driver *drv, struct module *owner,
1303 			  const char *mod_name)
1304 {
1305 	/* initialize common driver fields */
1306 	drv->driver.name = drv->name;
1307 	drv->driver.bus = &pci_bus_type;
1308 	drv->driver.owner = owner;
1309 	drv->driver.mod_name = mod_name;
1310 
1311 	spin_lock_init(&drv->dynids.lock);
1312 	INIT_LIST_HEAD(&drv->dynids.list);
1313 
1314 	/* register with core */
1315 	return driver_register(&drv->driver);
1316 }
1317 EXPORT_SYMBOL(__pci_register_driver);
1318 
1319 /**
1320  * pci_unregister_driver - unregister a pci driver
1321  * @drv: the driver structure to unregister
1322  *
1323  * Deletes the driver structure from the list of registered PCI drivers,
1324  * gives it a chance to clean up by calling its remove() function for
1325  * each device it was responsible for, and marks those devices as
1326  * driverless.
1327  */
1328 
1329 void pci_unregister_driver(struct pci_driver *drv)
1330 {
1331 	driver_unregister(&drv->driver);
1332 	pci_free_dynids(drv);
1333 }
1334 EXPORT_SYMBOL(pci_unregister_driver);
1335 
1336 static struct pci_driver pci_compat_driver = {
1337 	.name = "compat"
1338 };
1339 
1340 /**
1341  * pci_dev_driver - get the pci_driver of a device
1342  * @dev: the device to query
1343  *
1344  * Returns the appropriate pci_driver structure or %NULL if there is no
1345  * registered driver for the device.
1346  */
1347 struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
1348 {
1349 	if (dev->driver)
1350 		return dev->driver;
1351 	else {
1352 		int i;
1353 		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1354 			if (dev->resource[i].flags & IORESOURCE_BUSY)
1355 				return &pci_compat_driver;
1356 	}
1357 	return NULL;
1358 }
1359 EXPORT_SYMBOL(pci_dev_driver);
1360 
1361 /**
1362  * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
1363  * @dev: the PCI device structure to match against
1364  * @drv: the device driver to search for matching PCI device id structures
1365  *
1366  * Used by a driver to check whether a PCI device present in the
1367  * system is in its list of supported devices. Returns the matching
1368  * pci_device_id structure or %NULL if there is no match.
1369  */
1370 static int pci_bus_match(struct device *dev, struct device_driver *drv)
1371 {
1372 	struct pci_dev *pci_dev = to_pci_dev(dev);
1373 	struct pci_driver *pci_drv;
1374 	const struct pci_device_id *found_id;
1375 
1376 	if (!pci_dev->match_driver)
1377 		return 0;
1378 
1379 	pci_drv = to_pci_driver(drv);
1380 	found_id = pci_match_device(pci_drv, pci_dev);
1381 	if (found_id)
1382 		return 1;
1383 
1384 	return 0;
1385 }
1386 
1387 /**
1388  * pci_dev_get - increments the reference count of the pci device structure
1389  * @dev: the device being referenced
1390  *
1391  * Each live reference to a device should be refcounted.
1392  *
1393  * Drivers for PCI devices should normally record such references in
1394  * their probe() methods, when they bind to a device, and release
1395  * them by calling pci_dev_put(), in their disconnect() methods.
1396  *
1397  * A pointer to the device with the incremented reference counter is returned.
1398  */
1399 struct pci_dev *pci_dev_get(struct pci_dev *dev)
1400 {
1401 	if (dev)
1402 		get_device(&dev->dev);
1403 	return dev;
1404 }
1405 EXPORT_SYMBOL(pci_dev_get);
1406 
1407 /**
1408  * pci_dev_put - release a use of the pci device structure
1409  * @dev: device that's been disconnected
1410  *
1411  * Must be called when a user of a device is finished with it.  When the last
1412  * user of the device calls this function, the memory of the device is freed.
1413  */
1414 void pci_dev_put(struct pci_dev *dev)
1415 {
1416 	if (dev)
1417 		put_device(&dev->dev);
1418 }
1419 EXPORT_SYMBOL(pci_dev_put);
1420 
1421 static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
1422 {
1423 	struct pci_dev *pdev;
1424 
1425 	if (!dev)
1426 		return -ENODEV;
1427 
1428 	pdev = to_pci_dev(dev);
1429 
1430 	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
1431 		return -ENOMEM;
1432 
1433 	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
1434 		return -ENOMEM;
1435 
1436 	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
1437 			   pdev->subsystem_device))
1438 		return -ENOMEM;
1439 
1440 	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
1441 		return -ENOMEM;
1442 
1443 	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
1444 			   pdev->vendor, pdev->device,
1445 			   pdev->subsystem_vendor, pdev->subsystem_device,
1446 			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
1447 			   (u8)(pdev->class)))
1448 		return -ENOMEM;
1449 
1450 	return 0;
1451 }
1452 
1453 static int pci_bus_num_vf(struct device *dev)
1454 {
1455 	return pci_num_vf(to_pci_dev(dev));
1456 }
1457 
1458 struct bus_type pci_bus_type = {
1459 	.name		= "pci",
1460 	.match		= pci_bus_match,
1461 	.uevent		= pci_uevent,
1462 	.probe		= pci_device_probe,
1463 	.remove		= pci_device_remove,
1464 	.shutdown	= pci_device_shutdown,
1465 	.dev_groups	= pci_dev_groups,
1466 	.bus_groups	= pci_bus_groups,
1467 	.drv_groups	= pci_drv_groups,
1468 	.pm		= PCI_PM_OPS_PTR,
1469 	.num_vf		= pci_bus_num_vf,
1470 };
1471 EXPORT_SYMBOL(pci_bus_type);
1472 
1473 static int __init pci_driver_init(void)
1474 {
1475 	return bus_register(&pci_bus_type);
1476 }
1477 postcore_initcall(pci_driver_init);
1478