xref: /linux/drivers/pci/pci-driver.c (revision 307797159ac25fe5a2048bf5c6a5718298edca57)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * (C) Copyright 2002-2004, 2007 Greg Kroah-Hartman <greg@kroah.com>
4  * (C) Copyright 2007 Novell Inc.
5  */
6 
7 #include <linux/pci.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/device.h>
11 #include <linux/mempolicy.h>
12 #include <linux/string.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/cpu.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/suspend.h>
18 #include <linux/kexec.h>
19 #include <linux/of_device.h>
20 #include <linux/acpi.h>
21 #include "pci.h"
22 #include "pcie/portdrv.h"
23 
24 struct pci_dynid {
25 	struct list_head node;
26 	struct pci_device_id id;
27 };
28 
29 /**
30  * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
31  * @drv: target pci driver
32  * @vendor: PCI vendor ID
33  * @device: PCI device ID
34  * @subvendor: PCI subvendor ID
35  * @subdevice: PCI subdevice ID
36  * @class: PCI class
37  * @class_mask: PCI class mask
38  * @driver_data: private driver data
39  *
40  * Adds a new dynamic pci device ID to this driver and causes the
41  * driver to probe for all devices again.  @drv must have been
42  * registered prior to calling this function.
43  *
44  * CONTEXT:
45  * Does GFP_KERNEL allocation.
46  *
47  * RETURNS:
48  * 0 on success, -errno on failure.
49  */
50 int pci_add_dynid(struct pci_driver *drv,
51 		  unsigned int vendor, unsigned int device,
52 		  unsigned int subvendor, unsigned int subdevice,
53 		  unsigned int class, unsigned int class_mask,
54 		  unsigned long driver_data)
55 {
56 	struct pci_dynid *dynid;
57 
58 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
59 	if (!dynid)
60 		return -ENOMEM;
61 
62 	dynid->id.vendor = vendor;
63 	dynid->id.device = device;
64 	dynid->id.subvendor = subvendor;
65 	dynid->id.subdevice = subdevice;
66 	dynid->id.class = class;
67 	dynid->id.class_mask = class_mask;
68 	dynid->id.driver_data = driver_data;
69 
70 	spin_lock(&drv->dynids.lock);
71 	list_add_tail(&dynid->node, &drv->dynids.list);
72 	spin_unlock(&drv->dynids.lock);
73 
74 	return driver_attach(&drv->driver);
75 }
76 EXPORT_SYMBOL_GPL(pci_add_dynid);
77 
78 static void pci_free_dynids(struct pci_driver *drv)
79 {
80 	struct pci_dynid *dynid, *n;
81 
82 	spin_lock(&drv->dynids.lock);
83 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
84 		list_del(&dynid->node);
85 		kfree(dynid);
86 	}
87 	spin_unlock(&drv->dynids.lock);
88 }
89 
90 /**
91  * store_new_id - sysfs frontend to pci_add_dynid()
92  * @driver: target device driver
93  * @buf: buffer for scanning device ID data
94  * @count: input size
95  *
96  * Allow PCI IDs to be added to an existing driver via sysfs.
97  */
98 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
99 			    size_t count)
100 {
101 	struct pci_driver *pdrv = to_pci_driver(driver);
102 	const struct pci_device_id *ids = pdrv->id_table;
103 	__u32 vendor, device, subvendor = PCI_ANY_ID,
104 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
105 	unsigned long driver_data = 0;
106 	int fields = 0;
107 	int retval = 0;
108 
109 	fields = sscanf(buf, "%x %x %x %x %x %x %lx",
110 			&vendor, &device, &subvendor, &subdevice,
111 			&class, &class_mask, &driver_data);
112 	if (fields < 2)
113 		return -EINVAL;
114 
115 	if (fields != 7) {
116 		struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
117 		if (!pdev)
118 			return -ENOMEM;
119 
120 		pdev->vendor = vendor;
121 		pdev->device = device;
122 		pdev->subsystem_vendor = subvendor;
123 		pdev->subsystem_device = subdevice;
124 		pdev->class = class;
125 
126 		if (pci_match_id(pdrv->id_table, pdev))
127 			retval = -EEXIST;
128 
129 		kfree(pdev);
130 
131 		if (retval)
132 			return retval;
133 	}
134 
135 	/* Only accept driver_data values that match an existing id_table
136 	   entry */
137 	if (ids) {
138 		retval = -EINVAL;
139 		while (ids->vendor || ids->subvendor || ids->class_mask) {
140 			if (driver_data == ids->driver_data) {
141 				retval = 0;
142 				break;
143 			}
144 			ids++;
145 		}
146 		if (retval)	/* No match */
147 			return retval;
148 	}
149 
150 	retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
151 			       class, class_mask, driver_data);
152 	if (retval)
153 		return retval;
154 	return count;
155 }
156 static DRIVER_ATTR_WO(new_id);
157 
158 /**
159  * store_remove_id - remove a PCI device ID from this driver
160  * @driver: target device driver
161  * @buf: buffer for scanning device ID data
162  * @count: input size
163  *
164  * Removes a dynamic pci device ID to this driver.
165  */
166 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
167 			       size_t count)
168 {
169 	struct pci_dynid *dynid, *n;
170 	struct pci_driver *pdrv = to_pci_driver(driver);
171 	__u32 vendor, device, subvendor = PCI_ANY_ID,
172 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
173 	int fields = 0;
174 	size_t retval = -ENODEV;
175 
176 	fields = sscanf(buf, "%x %x %x %x %x %x",
177 			&vendor, &device, &subvendor, &subdevice,
178 			&class, &class_mask);
179 	if (fields < 2)
180 		return -EINVAL;
181 
182 	spin_lock(&pdrv->dynids.lock);
183 	list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
184 		struct pci_device_id *id = &dynid->id;
185 		if ((id->vendor == vendor) &&
186 		    (id->device == device) &&
187 		    (subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
188 		    (subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
189 		    !((id->class ^ class) & class_mask)) {
190 			list_del(&dynid->node);
191 			kfree(dynid);
192 			retval = count;
193 			break;
194 		}
195 	}
196 	spin_unlock(&pdrv->dynids.lock);
197 
198 	return retval;
199 }
200 static DRIVER_ATTR_WO(remove_id);
201 
202 static struct attribute *pci_drv_attrs[] = {
203 	&driver_attr_new_id.attr,
204 	&driver_attr_remove_id.attr,
205 	NULL,
206 };
207 ATTRIBUTE_GROUPS(pci_drv);
208 
209 /**
210  * pci_match_id - See if a pci device matches a given pci_id table
211  * @ids: array of PCI device id structures to search in
212  * @dev: the PCI device structure to match against.
213  *
214  * Used by a driver to check whether a PCI device present in the
215  * system is in its list of supported devices.  Returns the matching
216  * pci_device_id structure or %NULL if there is no match.
217  *
218  * Deprecated, don't use this as it will not catch any dynamic ids
219  * that a driver might want to check for.
220  */
221 const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
222 					 struct pci_dev *dev)
223 {
224 	if (ids) {
225 		while (ids->vendor || ids->subvendor || ids->class_mask) {
226 			if (pci_match_one_device(ids, dev))
227 				return ids;
228 			ids++;
229 		}
230 	}
231 	return NULL;
232 }
233 EXPORT_SYMBOL(pci_match_id);
234 
235 static const struct pci_device_id pci_device_id_any = {
236 	.vendor = PCI_ANY_ID,
237 	.device = PCI_ANY_ID,
238 	.subvendor = PCI_ANY_ID,
239 	.subdevice = PCI_ANY_ID,
240 };
241 
242 /**
243  * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
244  * @drv: the PCI driver to match against
245  * @dev: the PCI device structure to match against
246  *
247  * Used by a driver to check whether a PCI device present in the
248  * system is in its list of supported devices.  Returns the matching
249  * pci_device_id structure or %NULL if there is no match.
250  */
251 static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
252 						    struct pci_dev *dev)
253 {
254 	struct pci_dynid *dynid;
255 	const struct pci_device_id *found_id = NULL;
256 
257 	/* When driver_override is set, only bind to the matching driver */
258 	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
259 		return NULL;
260 
261 	/* Look at the dynamic ids first, before the static ones */
262 	spin_lock(&drv->dynids.lock);
263 	list_for_each_entry(dynid, &drv->dynids.list, node) {
264 		if (pci_match_one_device(&dynid->id, dev)) {
265 			found_id = &dynid->id;
266 			break;
267 		}
268 	}
269 	spin_unlock(&drv->dynids.lock);
270 
271 	if (!found_id)
272 		found_id = pci_match_id(drv->id_table, dev);
273 
274 	/* driver_override will always match, send a dummy id */
275 	if (!found_id && dev->driver_override)
276 		found_id = &pci_device_id_any;
277 
278 	return found_id;
279 }
280 
281 struct drv_dev_and_id {
282 	struct pci_driver *drv;
283 	struct pci_dev *dev;
284 	const struct pci_device_id *id;
285 };
286 
287 static long local_pci_probe(void *_ddi)
288 {
289 	struct drv_dev_and_id *ddi = _ddi;
290 	struct pci_dev *pci_dev = ddi->dev;
291 	struct pci_driver *pci_drv = ddi->drv;
292 	struct device *dev = &pci_dev->dev;
293 	int rc;
294 
295 	/*
296 	 * Unbound PCI devices are always put in D0, regardless of
297 	 * runtime PM status.  During probe, the device is set to
298 	 * active and the usage count is incremented.  If the driver
299 	 * supports runtime PM, it should call pm_runtime_put_noidle(),
300 	 * or any other runtime PM helper function decrementing the usage
301 	 * count, in its probe routine and pm_runtime_get_noresume() in
302 	 * its remove routine.
303 	 */
304 	pm_runtime_get_sync(dev);
305 	pci_dev->driver = pci_drv;
306 	rc = pci_drv->probe(pci_dev, ddi->id);
307 	if (!rc)
308 		return rc;
309 	if (rc < 0) {
310 		pci_dev->driver = NULL;
311 		pm_runtime_put_sync(dev);
312 		return rc;
313 	}
314 	/*
315 	 * Probe function should return < 0 for failure, 0 for success
316 	 * Treat values > 0 as success, but warn.
317 	 */
318 	dev_warn(dev, "Driver probe function unexpectedly returned %d\n", rc);
319 	return 0;
320 }
321 
322 static bool pci_physfn_is_probed(struct pci_dev *dev)
323 {
324 #ifdef CONFIG_PCI_IOV
325 	return dev->is_virtfn && dev->physfn->is_probed;
326 #else
327 	return false;
328 #endif
329 }
330 
331 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
332 			  const struct pci_device_id *id)
333 {
334 	int error, node, cpu;
335 	struct drv_dev_and_id ddi = { drv, dev, id };
336 
337 	/*
338 	 * Execute driver initialization on node where the device is
339 	 * attached.  This way the driver likely allocates its local memory
340 	 * on the right node.
341 	 */
342 	node = dev_to_node(&dev->dev);
343 	dev->is_probed = 1;
344 
345 	cpu_hotplug_disable();
346 
347 	/*
348 	 * Prevent nesting work_on_cpu() for the case where a Virtual Function
349 	 * device is probed from work_on_cpu() of the Physical device.
350 	 */
351 	if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
352 	    pci_physfn_is_probed(dev))
353 		cpu = nr_cpu_ids;
354 	else
355 		cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask);
356 
357 	if (cpu < nr_cpu_ids)
358 		error = work_on_cpu(cpu, local_pci_probe, &ddi);
359 	else
360 		error = local_pci_probe(&ddi);
361 
362 	dev->is_probed = 0;
363 	cpu_hotplug_enable();
364 	return error;
365 }
366 
367 /**
368  * __pci_device_probe - check if a driver wants to claim a specific PCI device
369  * @drv: driver to call to check if it wants the PCI device
370  * @pci_dev: PCI device being probed
371  *
372  * returns 0 on success, else error.
373  * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
374  */
375 static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
376 {
377 	const struct pci_device_id *id;
378 	int error = 0;
379 
380 	if (!pci_dev->driver && drv->probe) {
381 		error = -ENODEV;
382 
383 		id = pci_match_device(drv, pci_dev);
384 		if (id)
385 			error = pci_call_probe(drv, pci_dev, id);
386 	}
387 	return error;
388 }
389 
390 int __weak pcibios_alloc_irq(struct pci_dev *dev)
391 {
392 	return 0;
393 }
394 
395 void __weak pcibios_free_irq(struct pci_dev *dev)
396 {
397 }
398 
399 #ifdef CONFIG_PCI_IOV
400 static inline bool pci_device_can_probe(struct pci_dev *pdev)
401 {
402 	return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe);
403 }
404 #else
405 static inline bool pci_device_can_probe(struct pci_dev *pdev)
406 {
407 	return true;
408 }
409 #endif
410 
411 static int pci_device_probe(struct device *dev)
412 {
413 	int error;
414 	struct pci_dev *pci_dev = to_pci_dev(dev);
415 	struct pci_driver *drv = to_pci_driver(dev->driver);
416 
417 	pci_assign_irq(pci_dev);
418 
419 	error = pcibios_alloc_irq(pci_dev);
420 	if (error < 0)
421 		return error;
422 
423 	pci_dev_get(pci_dev);
424 	if (pci_device_can_probe(pci_dev)) {
425 		error = __pci_device_probe(drv, pci_dev);
426 		if (error) {
427 			pcibios_free_irq(pci_dev);
428 			pci_dev_put(pci_dev);
429 		}
430 	}
431 
432 	return error;
433 }
434 
435 static int pci_device_remove(struct device *dev)
436 {
437 	struct pci_dev *pci_dev = to_pci_dev(dev);
438 	struct pci_driver *drv = pci_dev->driver;
439 
440 	if (drv) {
441 		if (drv->remove) {
442 			pm_runtime_get_sync(dev);
443 			drv->remove(pci_dev);
444 			pm_runtime_put_noidle(dev);
445 		}
446 		pcibios_free_irq(pci_dev);
447 		pci_dev->driver = NULL;
448 		pci_iov_remove(pci_dev);
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 	pci_enable_wake(pci_dev, PCI_D0, false);
651 }
652 
653 static void pci_pm_default_suspend(struct pci_dev *pci_dev)
654 {
655 	/* Disable non-bridge devices without PM support */
656 	if (!pci_has_subordinate(pci_dev))
657 		pci_disable_enabled_device(pci_dev);
658 }
659 
660 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
661 {
662 	struct pci_driver *drv = pci_dev->driver;
663 	bool ret = drv && (drv->suspend || drv->suspend_late || drv->resume
664 		|| drv->resume_early);
665 
666 	/*
667 	 * Legacy PM support is used by default, so warn if the new framework is
668 	 * supported as well.  Drivers are supposed to support either the
669 	 * former, or the latter, but not both at the same time.
670 	 */
671 	WARN(ret && drv->driver.pm, "driver %s device %04x:%04x\n",
672 		drv->name, pci_dev->vendor, pci_dev->device);
673 
674 	return ret;
675 }
676 
677 /* New power management framework */
678 
679 static int pci_pm_prepare(struct device *dev)
680 {
681 	struct device_driver *drv = dev->driver;
682 
683 	if (drv && drv->pm && drv->pm->prepare) {
684 		int error = drv->pm->prepare(dev);
685 		if (error < 0)
686 			return error;
687 
688 		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
689 			return 0;
690 	}
691 	return pci_dev_keep_suspended(to_pci_dev(dev));
692 }
693 
694 static void pci_pm_complete(struct device *dev)
695 {
696 	struct pci_dev *pci_dev = to_pci_dev(dev);
697 
698 	pci_dev_complete_resume(pci_dev);
699 	pm_generic_complete(dev);
700 
701 	/* Resume device if platform firmware has put it in reset-power-on */
702 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
703 		pci_power_t pre_sleep_state = pci_dev->current_state;
704 
705 		pci_update_current_state(pci_dev, pci_dev->current_state);
706 		if (pci_dev->current_state < pre_sleep_state)
707 			pm_request_resume(dev);
708 	}
709 }
710 
711 #else /* !CONFIG_PM_SLEEP */
712 
713 #define pci_pm_prepare	NULL
714 #define pci_pm_complete	NULL
715 
716 #endif /* !CONFIG_PM_SLEEP */
717 
718 #ifdef CONFIG_SUSPEND
719 static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
720 {
721 	/*
722 	 * Some BIOSes forget to clear Root PME Status bits after system
723 	 * wakeup, which breaks ACPI-based runtime wakeup on PCI Express.
724 	 * Clear those bits now just in case (shouldn't hurt).
725 	 */
726 	if (pci_is_pcie(pci_dev) &&
727 	    (pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT ||
728 	     pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
729 		pcie_clear_root_pme_status(pci_dev);
730 }
731 
732 static int pci_pm_suspend(struct device *dev)
733 {
734 	struct pci_dev *pci_dev = to_pci_dev(dev);
735 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
736 
737 	if (pci_has_legacy_pm_support(pci_dev))
738 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
739 
740 	if (!pm) {
741 		pci_pm_default_suspend(pci_dev);
742 		return 0;
743 	}
744 
745 	/*
746 	 * PCI devices suspended at run time may need to be resumed at this
747 	 * point, because in general it may be necessary to reconfigure them for
748 	 * system suspend.  Namely, if the device is expected to wake up the
749 	 * system from the sleep state, it may have to be reconfigured for this
750 	 * purpose, or if the device is not expected to wake up the system from
751 	 * the sleep state, it should be prevented from signaling wakeup events
752 	 * going forward.
753 	 *
754 	 * Also if the driver of the device does not indicate that its system
755 	 * suspend callbacks can cope with runtime-suspended devices, it is
756 	 * better to resume the device from runtime suspend here.
757 	 */
758 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
759 	    !pci_dev_keep_suspended(pci_dev)) {
760 		pm_runtime_resume(dev);
761 		pci_dev->state_saved = false;
762 	}
763 
764 	if (pm->suspend) {
765 		pci_power_t prev = pci_dev->current_state;
766 		int error;
767 
768 		error = pm->suspend(dev);
769 		suspend_report_result(pm->suspend, error);
770 		if (error)
771 			return error;
772 
773 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
774 		    && pci_dev->current_state != PCI_UNKNOWN) {
775 			WARN_ONCE(pci_dev->current_state != prev,
776 				"PCI PM: State of device not saved by %pF\n",
777 				pm->suspend);
778 		}
779 	}
780 
781 	return 0;
782 }
783 
784 static int pci_pm_suspend_late(struct device *dev)
785 {
786 	if (dev_pm_smart_suspend_and_suspended(dev))
787 		return 0;
788 
789 	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
790 
791 	return pm_generic_suspend_late(dev);
792 }
793 
794 static int pci_pm_suspend_noirq(struct device *dev)
795 {
796 	struct pci_dev *pci_dev = to_pci_dev(dev);
797 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
798 
799 	if (dev_pm_smart_suspend_and_suspended(dev)) {
800 		dev->power.may_skip_resume = true;
801 		return 0;
802 	}
803 
804 	if (pci_has_legacy_pm_support(pci_dev))
805 		return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
806 
807 	if (!pm) {
808 		pci_save_state(pci_dev);
809 		goto Fixup;
810 	}
811 
812 	if (pm->suspend_noirq) {
813 		pci_power_t prev = pci_dev->current_state;
814 		int error;
815 
816 		error = pm->suspend_noirq(dev);
817 		suspend_report_result(pm->suspend_noirq, error);
818 		if (error)
819 			return error;
820 
821 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
822 		    && pci_dev->current_state != PCI_UNKNOWN) {
823 			WARN_ONCE(pci_dev->current_state != prev,
824 				"PCI PM: State of device not saved by %pF\n",
825 				pm->suspend_noirq);
826 			goto Fixup;
827 		}
828 	}
829 
830 	if (!pci_dev->state_saved) {
831 		pci_save_state(pci_dev);
832 		if (pci_power_manageable(pci_dev))
833 			pci_prepare_to_sleep(pci_dev);
834 	}
835 
836 	dev_dbg(dev, "PCI PM: Suspend power state: %s\n",
837 		pci_power_name(pci_dev->current_state));
838 
839 	pci_pm_set_unknown_state(pci_dev);
840 
841 	/*
842 	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
843 	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
844 	 * hasn't been quiesced and tries to turn it off.  If the controller
845 	 * is already in D3, this can hang or cause memory corruption.
846 	 *
847 	 * Since the value of the COMMAND register doesn't matter once the
848 	 * device has been suspended, we can safely set it to 0 here.
849 	 */
850 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
851 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
852 
853 Fixup:
854 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
855 
856 	/*
857 	 * If the target system sleep state is suspend-to-idle, it is sufficient
858 	 * to check whether or not the device's wakeup settings are good for
859 	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
860 	 * pci_pm_complete() to take care of fixing up the device's state
861 	 * anyway, if need be.
862 	 */
863 	dev->power.may_skip_resume = device_may_wakeup(dev) ||
864 					!device_can_wakeup(dev);
865 
866 	return 0;
867 }
868 
869 static int pci_pm_resume_noirq(struct device *dev)
870 {
871 	struct pci_dev *pci_dev = to_pci_dev(dev);
872 	struct device_driver *drv = dev->driver;
873 	int error = 0;
874 
875 	if (dev_pm_may_skip_resume(dev))
876 		return 0;
877 
878 	/*
879 	 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
880 	 * during system suspend, so update their runtime PM status to "active"
881 	 * as they are going to be put into D0 shortly.
882 	 */
883 	if (dev_pm_smart_suspend_and_suspended(dev))
884 		pm_runtime_set_active(dev);
885 
886 	pci_pm_default_resume_early(pci_dev);
887 
888 	if (pci_has_legacy_pm_support(pci_dev))
889 		return pci_legacy_resume_early(dev);
890 
891 	pcie_pme_root_status_cleanup(pci_dev);
892 
893 	if (drv && drv->pm && drv->pm->resume_noirq)
894 		error = drv->pm->resume_noirq(dev);
895 
896 	return error;
897 }
898 
899 static int pci_pm_resume(struct device *dev)
900 {
901 	struct pci_dev *pci_dev = to_pci_dev(dev);
902 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
903 	int error = 0;
904 
905 	/*
906 	 * This is necessary for the suspend error path in which resume is
907 	 * called without restoring the standard config registers of the device.
908 	 */
909 	if (pci_dev->state_saved)
910 		pci_restore_standard_config(pci_dev);
911 
912 	if (pci_has_legacy_pm_support(pci_dev))
913 		return pci_legacy_resume(dev);
914 
915 	pci_pm_default_resume(pci_dev);
916 
917 	if (pm) {
918 		if (pm->resume)
919 			error = pm->resume(dev);
920 	} else {
921 		pci_pm_reenable_device(pci_dev);
922 	}
923 
924 	return error;
925 }
926 
927 #else /* !CONFIG_SUSPEND */
928 
929 #define pci_pm_suspend		NULL
930 #define pci_pm_suspend_late	NULL
931 #define pci_pm_suspend_noirq	NULL
932 #define pci_pm_resume		NULL
933 #define pci_pm_resume_noirq	NULL
934 
935 #endif /* !CONFIG_SUSPEND */
936 
937 #ifdef CONFIG_HIBERNATE_CALLBACKS
938 
939 
940 /*
941  * pcibios_pm_ops - provide arch-specific hooks when a PCI device is doing
942  * a hibernate transition
943  */
944 struct dev_pm_ops __weak pcibios_pm_ops;
945 
946 static int pci_pm_freeze(struct device *dev)
947 {
948 	struct pci_dev *pci_dev = to_pci_dev(dev);
949 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
950 
951 	if (pci_has_legacy_pm_support(pci_dev))
952 		return pci_legacy_suspend(dev, PMSG_FREEZE);
953 
954 	if (!pm) {
955 		pci_pm_default_suspend(pci_dev);
956 		return 0;
957 	}
958 
959 	/*
960 	 * This used to be done in pci_pm_prepare() for all devices and some
961 	 * drivers may depend on it, so do it here.  Ideally, runtime-suspended
962 	 * devices should not be touched during freeze/thaw transitions,
963 	 * however.
964 	 */
965 	if (!dev_pm_smart_suspend_and_suspended(dev)) {
966 		pm_runtime_resume(dev);
967 		pci_dev->state_saved = false;
968 	}
969 
970 	if (pm->freeze) {
971 		int error;
972 
973 		error = pm->freeze(dev);
974 		suspend_report_result(pm->freeze, error);
975 		if (error)
976 			return error;
977 	}
978 
979 	return 0;
980 }
981 
982 static int pci_pm_freeze_late(struct device *dev)
983 {
984 	if (dev_pm_smart_suspend_and_suspended(dev))
985 		return 0;
986 
987 	return pm_generic_freeze_late(dev);
988 }
989 
990 static int pci_pm_freeze_noirq(struct device *dev)
991 {
992 	struct pci_dev *pci_dev = to_pci_dev(dev);
993 	struct device_driver *drv = dev->driver;
994 
995 	if (dev_pm_smart_suspend_and_suspended(dev))
996 		return 0;
997 
998 	if (pci_has_legacy_pm_support(pci_dev))
999 		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
1000 
1001 	if (drv && drv->pm && drv->pm->freeze_noirq) {
1002 		int error;
1003 
1004 		error = drv->pm->freeze_noirq(dev);
1005 		suspend_report_result(drv->pm->freeze_noirq, error);
1006 		if (error)
1007 			return error;
1008 	}
1009 
1010 	if (!pci_dev->state_saved)
1011 		pci_save_state(pci_dev);
1012 
1013 	pci_pm_set_unknown_state(pci_dev);
1014 
1015 	if (pcibios_pm_ops.freeze_noirq)
1016 		return pcibios_pm_ops.freeze_noirq(dev);
1017 
1018 	return 0;
1019 }
1020 
1021 static int pci_pm_thaw_noirq(struct device *dev)
1022 {
1023 	struct pci_dev *pci_dev = to_pci_dev(dev);
1024 	struct device_driver *drv = dev->driver;
1025 	int error = 0;
1026 
1027 	/*
1028 	 * If the device is in runtime suspend, the code below may not work
1029 	 * correctly with it, so skip that code and make the PM core skip all of
1030 	 * the subsequent "thaw" callbacks for the device.
1031 	 */
1032 	if (dev_pm_smart_suspend_and_suspended(dev)) {
1033 		dev_pm_skip_next_resume_phases(dev);
1034 		return 0;
1035 	}
1036 
1037 	if (pcibios_pm_ops.thaw_noirq) {
1038 		error = pcibios_pm_ops.thaw_noirq(dev);
1039 		if (error)
1040 			return error;
1041 	}
1042 
1043 	if (pci_has_legacy_pm_support(pci_dev))
1044 		return pci_legacy_resume_early(dev);
1045 
1046 	/*
1047 	 * pci_restore_state() requires the device to be in D0 (because of MSI
1048 	 * restoration among other things), so force it into D0 in case the
1049 	 * driver's "freeze" callbacks put it into a low-power state directly.
1050 	 */
1051 	pci_set_power_state(pci_dev, PCI_D0);
1052 	pci_restore_state(pci_dev);
1053 
1054 	if (drv && drv->pm && drv->pm->thaw_noirq)
1055 		error = drv->pm->thaw_noirq(dev);
1056 
1057 	return error;
1058 }
1059 
1060 static int pci_pm_thaw(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 (pci_has_legacy_pm_support(pci_dev))
1067 		return pci_legacy_resume(dev);
1068 
1069 	if (pm) {
1070 		if (pm->thaw)
1071 			error = pm->thaw(dev);
1072 	} else {
1073 		pci_pm_reenable_device(pci_dev);
1074 	}
1075 
1076 	pci_dev->state_saved = false;
1077 
1078 	return error;
1079 }
1080 
1081 static int pci_pm_poweroff(struct device *dev)
1082 {
1083 	struct pci_dev *pci_dev = to_pci_dev(dev);
1084 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1085 
1086 	if (pci_has_legacy_pm_support(pci_dev))
1087 		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
1088 
1089 	if (!pm) {
1090 		pci_pm_default_suspend(pci_dev);
1091 		return 0;
1092 	}
1093 
1094 	/* The reason to do that is the same as in pci_pm_suspend(). */
1095 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1096 	    !pci_dev_keep_suspended(pci_dev))
1097 		pm_runtime_resume(dev);
1098 
1099 	pci_dev->state_saved = false;
1100 	if (pm->poweroff) {
1101 		int error;
1102 
1103 		error = pm->poweroff(dev);
1104 		suspend_report_result(pm->poweroff, error);
1105 		if (error)
1106 			return error;
1107 	}
1108 
1109 	return 0;
1110 }
1111 
1112 static int pci_pm_poweroff_late(struct device *dev)
1113 {
1114 	if (dev_pm_smart_suspend_and_suspended(dev))
1115 		return 0;
1116 
1117 	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
1118 
1119 	return pm_generic_poweroff_late(dev);
1120 }
1121 
1122 static int pci_pm_poweroff_noirq(struct device *dev)
1123 {
1124 	struct pci_dev *pci_dev = to_pci_dev(dev);
1125 	struct device_driver *drv = dev->driver;
1126 
1127 	if (dev_pm_smart_suspend_and_suspended(dev))
1128 		return 0;
1129 
1130 	if (pci_has_legacy_pm_support(to_pci_dev(dev)))
1131 		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
1132 
1133 	if (!drv || !drv->pm) {
1134 		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1135 		return 0;
1136 	}
1137 
1138 	if (drv->pm->poweroff_noirq) {
1139 		int error;
1140 
1141 		error = drv->pm->poweroff_noirq(dev);
1142 		suspend_report_result(drv->pm->poweroff_noirq, error);
1143 		if (error)
1144 			return error;
1145 	}
1146 
1147 	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
1148 		pci_prepare_to_sleep(pci_dev);
1149 
1150 	/*
1151 	 * The reason for doing this here is the same as for the analogous code
1152 	 * in pci_pm_suspend_noirq().
1153 	 */
1154 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
1155 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
1156 
1157 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1158 
1159 	if (pcibios_pm_ops.poweroff_noirq)
1160 		return pcibios_pm_ops.poweroff_noirq(dev);
1161 
1162 	return 0;
1163 }
1164 
1165 static int pci_pm_restore_noirq(struct device *dev)
1166 {
1167 	struct pci_dev *pci_dev = to_pci_dev(dev);
1168 	struct device_driver *drv = dev->driver;
1169 	int error = 0;
1170 
1171 	/* This is analogous to the pci_pm_resume_noirq() case. */
1172 	if (dev_pm_smart_suspend_and_suspended(dev))
1173 		pm_runtime_set_active(dev);
1174 
1175 	if (pcibios_pm_ops.restore_noirq) {
1176 		error = pcibios_pm_ops.restore_noirq(dev);
1177 		if (error)
1178 			return error;
1179 	}
1180 
1181 	pci_pm_default_resume_early(pci_dev);
1182 
1183 	if (pci_has_legacy_pm_support(pci_dev))
1184 		return pci_legacy_resume_early(dev);
1185 
1186 	if (drv && drv->pm && drv->pm->restore_noirq)
1187 		error = drv->pm->restore_noirq(dev);
1188 
1189 	return error;
1190 }
1191 
1192 static int pci_pm_restore(struct device *dev)
1193 {
1194 	struct pci_dev *pci_dev = to_pci_dev(dev);
1195 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1196 	int error = 0;
1197 
1198 	/*
1199 	 * This is necessary for the hibernation error path in which restore is
1200 	 * called without restoring the standard config registers of the device.
1201 	 */
1202 	if (pci_dev->state_saved)
1203 		pci_restore_standard_config(pci_dev);
1204 
1205 	if (pci_has_legacy_pm_support(pci_dev))
1206 		return pci_legacy_resume(dev);
1207 
1208 	pci_pm_default_resume(pci_dev);
1209 
1210 	if (pm) {
1211 		if (pm->restore)
1212 			error = pm->restore(dev);
1213 	} else {
1214 		pci_pm_reenable_device(pci_dev);
1215 	}
1216 
1217 	return error;
1218 }
1219 
1220 #else /* !CONFIG_HIBERNATE_CALLBACKS */
1221 
1222 #define pci_pm_freeze		NULL
1223 #define pci_pm_freeze_late	NULL
1224 #define pci_pm_freeze_noirq	NULL
1225 #define pci_pm_thaw		NULL
1226 #define pci_pm_thaw_noirq	NULL
1227 #define pci_pm_poweroff		NULL
1228 #define pci_pm_poweroff_late	NULL
1229 #define pci_pm_poweroff_noirq	NULL
1230 #define pci_pm_restore		NULL
1231 #define pci_pm_restore_noirq	NULL
1232 
1233 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
1234 
1235 #ifdef CONFIG_PM
1236 
1237 static int pci_pm_runtime_suspend(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 	pci_power_t prev = pci_dev->current_state;
1242 	int error;
1243 
1244 	/*
1245 	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
1246 	 * but it may go to D3cold when the bridge above it runtime suspends.
1247 	 * Save its config space in case that happens.
1248 	 */
1249 	if (!pci_dev->driver) {
1250 		pci_save_state(pci_dev);
1251 		return 0;
1252 	}
1253 
1254 	if (!pm || !pm->runtime_suspend)
1255 		return -ENOSYS;
1256 
1257 	pci_dev->state_saved = false;
1258 	error = pm->runtime_suspend(dev);
1259 	if (error) {
1260 		/*
1261 		 * -EBUSY and -EAGAIN is used to request the runtime PM core
1262 		 * to schedule a new suspend, so log the event only with debug
1263 		 * log level.
1264 		 */
1265 		if (error == -EBUSY || error == -EAGAIN)
1266 			dev_dbg(dev, "can't suspend now (%pf returned %d)\n",
1267 				pm->runtime_suspend, error);
1268 		else
1269 			dev_err(dev, "can't suspend (%pf returned %d)\n",
1270 				pm->runtime_suspend, error);
1271 
1272 		return error;
1273 	}
1274 
1275 	pci_fixup_device(pci_fixup_suspend, pci_dev);
1276 
1277 	if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
1278 	    && pci_dev->current_state != PCI_UNKNOWN) {
1279 		WARN_ONCE(pci_dev->current_state != prev,
1280 			"PCI PM: State of device not saved by %pF\n",
1281 			pm->runtime_suspend);
1282 		return 0;
1283 	}
1284 
1285 	if (!pci_dev->state_saved) {
1286 		pci_save_state(pci_dev);
1287 		pci_finish_runtime_suspend(pci_dev);
1288 	}
1289 
1290 	return 0;
1291 }
1292 
1293 static int pci_pm_runtime_resume(struct device *dev)
1294 {
1295 	int rc;
1296 	struct pci_dev *pci_dev = to_pci_dev(dev);
1297 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1298 
1299 	/*
1300 	 * Restoring config space is necessary even if the device is not bound
1301 	 * to a driver because although we left it in D0, it may have gone to
1302 	 * D3cold when the bridge above it runtime suspended.
1303 	 */
1304 	pci_restore_standard_config(pci_dev);
1305 
1306 	if (!pci_dev->driver)
1307 		return 0;
1308 
1309 	if (!pm || !pm->runtime_resume)
1310 		return -ENOSYS;
1311 
1312 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1313 	pci_enable_wake(pci_dev, PCI_D0, false);
1314 	pci_fixup_device(pci_fixup_resume, pci_dev);
1315 
1316 	rc = pm->runtime_resume(dev);
1317 
1318 	pci_dev->runtime_d3cold = false;
1319 
1320 	return rc;
1321 }
1322 
1323 static int pci_pm_runtime_idle(struct device *dev)
1324 {
1325 	struct pci_dev *pci_dev = to_pci_dev(dev);
1326 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1327 	int ret = 0;
1328 
1329 	/*
1330 	 * If pci_dev->driver is not set (unbound), the device should
1331 	 * always remain in D0 regardless of the runtime PM status
1332 	 */
1333 	if (!pci_dev->driver)
1334 		return 0;
1335 
1336 	if (!pm)
1337 		return -ENOSYS;
1338 
1339 	if (pm->runtime_idle)
1340 		ret = pm->runtime_idle(dev);
1341 
1342 	return ret;
1343 }
1344 
1345 static const struct dev_pm_ops pci_dev_pm_ops = {
1346 	.prepare = pci_pm_prepare,
1347 	.complete = pci_pm_complete,
1348 	.suspend = pci_pm_suspend,
1349 	.suspend_late = pci_pm_suspend_late,
1350 	.resume = pci_pm_resume,
1351 	.freeze = pci_pm_freeze,
1352 	.freeze_late = pci_pm_freeze_late,
1353 	.thaw = pci_pm_thaw,
1354 	.poweroff = pci_pm_poweroff,
1355 	.poweroff_late = pci_pm_poweroff_late,
1356 	.restore = pci_pm_restore,
1357 	.suspend_noirq = pci_pm_suspend_noirq,
1358 	.resume_noirq = pci_pm_resume_noirq,
1359 	.freeze_noirq = pci_pm_freeze_noirq,
1360 	.thaw_noirq = pci_pm_thaw_noirq,
1361 	.poweroff_noirq = pci_pm_poweroff_noirq,
1362 	.restore_noirq = pci_pm_restore_noirq,
1363 	.runtime_suspend = pci_pm_runtime_suspend,
1364 	.runtime_resume = pci_pm_runtime_resume,
1365 	.runtime_idle = pci_pm_runtime_idle,
1366 };
1367 
1368 #define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
1369 
1370 #else /* !CONFIG_PM */
1371 
1372 #define pci_pm_runtime_suspend	NULL
1373 #define pci_pm_runtime_resume	NULL
1374 #define pci_pm_runtime_idle	NULL
1375 
1376 #define PCI_PM_OPS_PTR	NULL
1377 
1378 #endif /* !CONFIG_PM */
1379 
1380 /**
1381  * __pci_register_driver - register a new pci driver
1382  * @drv: the driver structure to register
1383  * @owner: owner module of drv
1384  * @mod_name: module name string
1385  *
1386  * Adds the driver structure to the list of registered drivers.
1387  * Returns a negative value on error, otherwise 0.
1388  * If no error occurred, the driver remains registered even if
1389  * no device was claimed during registration.
1390  */
1391 int __pci_register_driver(struct pci_driver *drv, struct module *owner,
1392 			  const char *mod_name)
1393 {
1394 	/* initialize common driver fields */
1395 	drv->driver.name = drv->name;
1396 	drv->driver.bus = &pci_bus_type;
1397 	drv->driver.owner = owner;
1398 	drv->driver.mod_name = mod_name;
1399 	drv->driver.groups = drv->groups;
1400 
1401 	spin_lock_init(&drv->dynids.lock);
1402 	INIT_LIST_HEAD(&drv->dynids.list);
1403 
1404 	/* register with core */
1405 	return driver_register(&drv->driver);
1406 }
1407 EXPORT_SYMBOL(__pci_register_driver);
1408 
1409 /**
1410  * pci_unregister_driver - unregister a pci driver
1411  * @drv: the driver structure to unregister
1412  *
1413  * Deletes the driver structure from the list of registered PCI drivers,
1414  * gives it a chance to clean up by calling its remove() function for
1415  * each device it was responsible for, and marks those devices as
1416  * driverless.
1417  */
1418 
1419 void pci_unregister_driver(struct pci_driver *drv)
1420 {
1421 	driver_unregister(&drv->driver);
1422 	pci_free_dynids(drv);
1423 }
1424 EXPORT_SYMBOL(pci_unregister_driver);
1425 
1426 static struct pci_driver pci_compat_driver = {
1427 	.name = "compat"
1428 };
1429 
1430 /**
1431  * pci_dev_driver - get the pci_driver of a device
1432  * @dev: the device to query
1433  *
1434  * Returns the appropriate pci_driver structure or %NULL if there is no
1435  * registered driver for the device.
1436  */
1437 struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
1438 {
1439 	if (dev->driver)
1440 		return dev->driver;
1441 	else {
1442 		int i;
1443 		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1444 			if (dev->resource[i].flags & IORESOURCE_BUSY)
1445 				return &pci_compat_driver;
1446 	}
1447 	return NULL;
1448 }
1449 EXPORT_SYMBOL(pci_dev_driver);
1450 
1451 /**
1452  * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
1453  * @dev: the PCI device structure to match against
1454  * @drv: the device driver to search for matching PCI device id structures
1455  *
1456  * Used by a driver to check whether a PCI device present in the
1457  * system is in its list of supported devices. Returns the matching
1458  * pci_device_id structure or %NULL if there is no match.
1459  */
1460 static int pci_bus_match(struct device *dev, struct device_driver *drv)
1461 {
1462 	struct pci_dev *pci_dev = to_pci_dev(dev);
1463 	struct pci_driver *pci_drv;
1464 	const struct pci_device_id *found_id;
1465 
1466 	if (!pci_dev->match_driver)
1467 		return 0;
1468 
1469 	pci_drv = to_pci_driver(drv);
1470 	found_id = pci_match_device(pci_drv, pci_dev);
1471 	if (found_id)
1472 		return 1;
1473 
1474 	return 0;
1475 }
1476 
1477 /**
1478  * pci_dev_get - increments the reference count of the pci device structure
1479  * @dev: the device being referenced
1480  *
1481  * Each live reference to a device should be refcounted.
1482  *
1483  * Drivers for PCI devices should normally record such references in
1484  * their probe() methods, when they bind to a device, and release
1485  * them by calling pci_dev_put(), in their disconnect() methods.
1486  *
1487  * A pointer to the device with the incremented reference counter is returned.
1488  */
1489 struct pci_dev *pci_dev_get(struct pci_dev *dev)
1490 {
1491 	if (dev)
1492 		get_device(&dev->dev);
1493 	return dev;
1494 }
1495 EXPORT_SYMBOL(pci_dev_get);
1496 
1497 /**
1498  * pci_dev_put - release a use of the pci device structure
1499  * @dev: device that's been disconnected
1500  *
1501  * Must be called when a user of a device is finished with it.  When the last
1502  * user of the device calls this function, the memory of the device is freed.
1503  */
1504 void pci_dev_put(struct pci_dev *dev)
1505 {
1506 	if (dev)
1507 		put_device(&dev->dev);
1508 }
1509 EXPORT_SYMBOL(pci_dev_put);
1510 
1511 static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
1512 {
1513 	struct pci_dev *pdev;
1514 
1515 	if (!dev)
1516 		return -ENODEV;
1517 
1518 	pdev = to_pci_dev(dev);
1519 
1520 	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
1521 		return -ENOMEM;
1522 
1523 	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
1524 		return -ENOMEM;
1525 
1526 	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
1527 			   pdev->subsystem_device))
1528 		return -ENOMEM;
1529 
1530 	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
1531 		return -ENOMEM;
1532 
1533 	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
1534 			   pdev->vendor, pdev->device,
1535 			   pdev->subsystem_vendor, pdev->subsystem_device,
1536 			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
1537 			   (u8)(pdev->class)))
1538 		return -ENOMEM;
1539 
1540 	return 0;
1541 }
1542 
1543 #if defined(CONFIG_PCIEPORTBUS) || defined(CONFIG_EEH)
1544 /**
1545  * pci_uevent_ers - emit a uevent during recovery path of PCI device
1546  * @pdev: PCI device undergoing error recovery
1547  * @err_type: type of error event
1548  */
1549 void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type)
1550 {
1551 	int idx = 0;
1552 	char *envp[3];
1553 
1554 	switch (err_type) {
1555 	case PCI_ERS_RESULT_NONE:
1556 	case PCI_ERS_RESULT_CAN_RECOVER:
1557 		envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
1558 		envp[idx++] = "DEVICE_ONLINE=0";
1559 		break;
1560 	case PCI_ERS_RESULT_RECOVERED:
1561 		envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
1562 		envp[idx++] = "DEVICE_ONLINE=1";
1563 		break;
1564 	case PCI_ERS_RESULT_DISCONNECT:
1565 		envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
1566 		envp[idx++] = "DEVICE_ONLINE=0";
1567 		break;
1568 	default:
1569 		break;
1570 	}
1571 
1572 	if (idx > 0) {
1573 		envp[idx++] = NULL;
1574 		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
1575 	}
1576 }
1577 #endif
1578 
1579 static int pci_bus_num_vf(struct device *dev)
1580 {
1581 	return pci_num_vf(to_pci_dev(dev));
1582 }
1583 
1584 /**
1585  * pci_dma_configure - Setup DMA configuration
1586  * @dev: ptr to dev structure
1587  *
1588  * Function to update PCI devices's DMA configuration using the same
1589  * info from the OF node or ACPI node of host bridge's parent (if any).
1590  */
1591 static int pci_dma_configure(struct device *dev)
1592 {
1593 	struct device *bridge;
1594 	int ret = 0;
1595 
1596 	bridge = pci_get_host_bridge_device(to_pci_dev(dev));
1597 
1598 	if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
1599 	    bridge->parent->of_node) {
1600 		ret = of_dma_configure(dev, bridge->parent->of_node, true);
1601 	} else if (has_acpi_companion(bridge)) {
1602 		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
1603 		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
1604 
1605 		if (attr != DEV_DMA_NOT_SUPPORTED)
1606 			ret = acpi_dma_configure(dev, attr);
1607 	}
1608 
1609 	pci_put_host_bridge_device(bridge);
1610 	return ret;
1611 }
1612 
1613 struct bus_type pci_bus_type = {
1614 	.name		= "pci",
1615 	.match		= pci_bus_match,
1616 	.uevent		= pci_uevent,
1617 	.probe		= pci_device_probe,
1618 	.remove		= pci_device_remove,
1619 	.shutdown	= pci_device_shutdown,
1620 	.dev_groups	= pci_dev_groups,
1621 	.bus_groups	= pci_bus_groups,
1622 	.drv_groups	= pci_drv_groups,
1623 	.pm		= PCI_PM_OPS_PTR,
1624 	.num_vf		= pci_bus_num_vf,
1625 	.dma_configure	= pci_dma_configure,
1626 };
1627 EXPORT_SYMBOL(pci_bus_type);
1628 
1629 #ifdef CONFIG_PCIEPORTBUS
1630 static int pcie_port_bus_match(struct device *dev, struct device_driver *drv)
1631 {
1632 	struct pcie_device *pciedev;
1633 	struct pcie_port_service_driver *driver;
1634 
1635 	if (drv->bus != &pcie_port_bus_type || dev->bus != &pcie_port_bus_type)
1636 		return 0;
1637 
1638 	pciedev = to_pcie_device(dev);
1639 	driver = to_service_driver(drv);
1640 
1641 	if (driver->service != pciedev->service)
1642 		return 0;
1643 
1644 	if (driver->port_type != PCIE_ANY_PORT &&
1645 	    driver->port_type != pci_pcie_type(pciedev->port))
1646 		return 0;
1647 
1648 	return 1;
1649 }
1650 
1651 struct bus_type pcie_port_bus_type = {
1652 	.name		= "pci_express",
1653 	.match		= pcie_port_bus_match,
1654 };
1655 EXPORT_SYMBOL_GPL(pcie_port_bus_type);
1656 #endif
1657 
1658 static int __init pci_driver_init(void)
1659 {
1660 	int ret;
1661 
1662 	ret = bus_register(&pci_bus_type);
1663 	if (ret)
1664 		return ret;
1665 
1666 #ifdef CONFIG_PCIEPORTBUS
1667 	ret = bus_register(&pcie_port_bus_type);
1668 	if (ret)
1669 		return ret;
1670 #endif
1671 	dma_debug_add_bus(&pci_bus_type);
1672 	return 0;
1673 }
1674 postcore_initcall(pci_driver_init);
1675