xref: /openbmc/linux/drivers/pci/pci-driver.c (revision 7587cdef)
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/sched/isolation.h>
16 #include <linux/cpu.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/suspend.h>
19 #include <linux/kexec.h>
20 #include <linux/of_device.h>
21 #include <linux/acpi.h>
22 #include <linux/dma-map-ops.h>
23 #include <linux/iommu.h>
24 #include "pci.h"
25 #include "pcie/portdrv.h"
26 
27 struct pci_dynid {
28 	struct list_head node;
29 	struct pci_device_id id;
30 };
31 
32 /**
33  * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
34  * @drv: target pci driver
35  * @vendor: PCI vendor ID
36  * @device: PCI device ID
37  * @subvendor: PCI subvendor ID
38  * @subdevice: PCI subdevice ID
39  * @class: PCI class
40  * @class_mask: PCI class mask
41  * @driver_data: private driver data
42  *
43  * Adds a new dynamic pci device ID to this driver and causes the
44  * driver to probe for all devices again.  @drv must have been
45  * registered prior to calling this function.
46  *
47  * CONTEXT:
48  * Does GFP_KERNEL allocation.
49  *
50  * RETURNS:
51  * 0 on success, -errno on failure.
52  */
53 int pci_add_dynid(struct pci_driver *drv,
54 		  unsigned int vendor, unsigned int device,
55 		  unsigned int subvendor, unsigned int subdevice,
56 		  unsigned int class, unsigned int class_mask,
57 		  unsigned long driver_data)
58 {
59 	struct pci_dynid *dynid;
60 
61 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
62 	if (!dynid)
63 		return -ENOMEM;
64 
65 	dynid->id.vendor = vendor;
66 	dynid->id.device = device;
67 	dynid->id.subvendor = subvendor;
68 	dynid->id.subdevice = subdevice;
69 	dynid->id.class = class;
70 	dynid->id.class_mask = class_mask;
71 	dynid->id.driver_data = driver_data;
72 
73 	spin_lock(&drv->dynids.lock);
74 	list_add_tail(&dynid->node, &drv->dynids.list);
75 	spin_unlock(&drv->dynids.lock);
76 
77 	return driver_attach(&drv->driver);
78 }
79 EXPORT_SYMBOL_GPL(pci_add_dynid);
80 
81 static void pci_free_dynids(struct pci_driver *drv)
82 {
83 	struct pci_dynid *dynid, *n;
84 
85 	spin_lock(&drv->dynids.lock);
86 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
87 		list_del(&dynid->node);
88 		kfree(dynid);
89 	}
90 	spin_unlock(&drv->dynids.lock);
91 }
92 
93 /**
94  * pci_match_id - See if a PCI device matches a given pci_id table
95  * @ids: array of PCI device ID structures to search in
96  * @dev: the PCI device structure to match against.
97  *
98  * Used by a driver to check whether a PCI device is in its list of
99  * supported devices.  Returns the matching pci_device_id structure or
100  * %NULL if there is no match.
101  *
102  * Deprecated; don't use this as it will not catch any dynamic IDs
103  * that a driver might want to check for.
104  */
105 const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
106 					 struct pci_dev *dev)
107 {
108 	if (ids) {
109 		while (ids->vendor || ids->subvendor || ids->class_mask) {
110 			if (pci_match_one_device(ids, dev))
111 				return ids;
112 			ids++;
113 		}
114 	}
115 	return NULL;
116 }
117 EXPORT_SYMBOL(pci_match_id);
118 
119 static const struct pci_device_id pci_device_id_any = {
120 	.vendor = PCI_ANY_ID,
121 	.device = PCI_ANY_ID,
122 	.subvendor = PCI_ANY_ID,
123 	.subdevice = PCI_ANY_ID,
124 };
125 
126 /**
127  * pci_match_device - See if a device matches a driver's list of IDs
128  * @drv: the PCI driver to match against
129  * @dev: the PCI device structure to match against
130  *
131  * Used by a driver to check whether a PCI device is in its list of
132  * supported devices or in the dynids list, which may have been augmented
133  * via the sysfs "new_id" file.  Returns the matching pci_device_id
134  * structure or %NULL if there is no match.
135  */
136 static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
137 						    struct pci_dev *dev)
138 {
139 	struct pci_dynid *dynid;
140 	const struct pci_device_id *found_id = NULL, *ids;
141 
142 	/* When driver_override is set, only bind to the matching driver */
143 	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
144 		return NULL;
145 
146 	/* Look at the dynamic ids first, before the static ones */
147 	spin_lock(&drv->dynids.lock);
148 	list_for_each_entry(dynid, &drv->dynids.list, node) {
149 		if (pci_match_one_device(&dynid->id, dev)) {
150 			found_id = &dynid->id;
151 			break;
152 		}
153 	}
154 	spin_unlock(&drv->dynids.lock);
155 
156 	if (found_id)
157 		return found_id;
158 
159 	for (ids = drv->id_table; (found_id = pci_match_id(ids, dev));
160 	     ids = found_id + 1) {
161 		/*
162 		 * The match table is split based on driver_override.
163 		 * In case override_only was set, enforce driver_override
164 		 * matching.
165 		 */
166 		if (found_id->override_only) {
167 			if (dev->driver_override)
168 				return found_id;
169 		} else {
170 			return found_id;
171 		}
172 	}
173 
174 	/* driver_override will always match, send a dummy id */
175 	if (dev->driver_override)
176 		return &pci_device_id_any;
177 	return NULL;
178 }
179 
180 /**
181  * new_id_store - sysfs frontend to pci_add_dynid()
182  * @driver: target device driver
183  * @buf: buffer for scanning device ID data
184  * @count: input size
185  *
186  * Allow PCI IDs to be added to an existing driver via sysfs.
187  */
188 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
189 			    size_t count)
190 {
191 	struct pci_driver *pdrv = to_pci_driver(driver);
192 	const struct pci_device_id *ids = pdrv->id_table;
193 	u32 vendor, device, subvendor = PCI_ANY_ID,
194 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
195 	unsigned long driver_data = 0;
196 	int fields = 0;
197 	int retval = 0;
198 
199 	fields = sscanf(buf, "%x %x %x %x %x %x %lx",
200 			&vendor, &device, &subvendor, &subdevice,
201 			&class, &class_mask, &driver_data);
202 	if (fields < 2)
203 		return -EINVAL;
204 
205 	if (fields != 7) {
206 		struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
207 		if (!pdev)
208 			return -ENOMEM;
209 
210 		pdev->vendor = vendor;
211 		pdev->device = device;
212 		pdev->subsystem_vendor = subvendor;
213 		pdev->subsystem_device = subdevice;
214 		pdev->class = class;
215 
216 		if (pci_match_device(pdrv, pdev))
217 			retval = -EEXIST;
218 
219 		kfree(pdev);
220 
221 		if (retval)
222 			return retval;
223 	}
224 
225 	/* Only accept driver_data values that match an existing id_table
226 	   entry */
227 	if (ids) {
228 		retval = -EINVAL;
229 		while (ids->vendor || ids->subvendor || ids->class_mask) {
230 			if (driver_data == ids->driver_data) {
231 				retval = 0;
232 				break;
233 			}
234 			ids++;
235 		}
236 		if (retval)	/* No match */
237 			return retval;
238 	}
239 
240 	retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
241 			       class, class_mask, driver_data);
242 	if (retval)
243 		return retval;
244 	return count;
245 }
246 static DRIVER_ATTR_WO(new_id);
247 
248 /**
249  * remove_id_store - remove a PCI device ID from this driver
250  * @driver: target device driver
251  * @buf: buffer for scanning device ID data
252  * @count: input size
253  *
254  * Removes a dynamic pci device ID to this driver.
255  */
256 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
257 			       size_t count)
258 {
259 	struct pci_dynid *dynid, *n;
260 	struct pci_driver *pdrv = to_pci_driver(driver);
261 	u32 vendor, device, subvendor = PCI_ANY_ID,
262 		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
263 	int fields = 0;
264 	size_t retval = -ENODEV;
265 
266 	fields = sscanf(buf, "%x %x %x %x %x %x",
267 			&vendor, &device, &subvendor, &subdevice,
268 			&class, &class_mask);
269 	if (fields < 2)
270 		return -EINVAL;
271 
272 	spin_lock(&pdrv->dynids.lock);
273 	list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
274 		struct pci_device_id *id = &dynid->id;
275 		if ((id->vendor == vendor) &&
276 		    (id->device == device) &&
277 		    (subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
278 		    (subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
279 		    !((id->class ^ class) & class_mask)) {
280 			list_del(&dynid->node);
281 			kfree(dynid);
282 			retval = count;
283 			break;
284 		}
285 	}
286 	spin_unlock(&pdrv->dynids.lock);
287 
288 	return retval;
289 }
290 static DRIVER_ATTR_WO(remove_id);
291 
292 static struct attribute *pci_drv_attrs[] = {
293 	&driver_attr_new_id.attr,
294 	&driver_attr_remove_id.attr,
295 	NULL,
296 };
297 ATTRIBUTE_GROUPS(pci_drv);
298 
299 struct drv_dev_and_id {
300 	struct pci_driver *drv;
301 	struct pci_dev *dev;
302 	const struct pci_device_id *id;
303 };
304 
305 static long local_pci_probe(void *_ddi)
306 {
307 	struct drv_dev_and_id *ddi = _ddi;
308 	struct pci_dev *pci_dev = ddi->dev;
309 	struct pci_driver *pci_drv = ddi->drv;
310 	struct device *dev = &pci_dev->dev;
311 	int rc;
312 
313 	/*
314 	 * Unbound PCI devices are always put in D0, regardless of
315 	 * runtime PM status.  During probe, the device is set to
316 	 * active and the usage count is incremented.  If the driver
317 	 * supports runtime PM, it should call pm_runtime_put_noidle(),
318 	 * or any other runtime PM helper function decrementing the usage
319 	 * count, in its probe routine and pm_runtime_get_noresume() in
320 	 * its remove routine.
321 	 */
322 	pm_runtime_get_sync(dev);
323 	pci_dev->driver = pci_drv;
324 	rc = pci_drv->probe(pci_dev, ddi->id);
325 	if (!rc)
326 		return rc;
327 	if (rc < 0) {
328 		pci_dev->driver = NULL;
329 		pm_runtime_put_sync(dev);
330 		return rc;
331 	}
332 	/*
333 	 * Probe function should return < 0 for failure, 0 for success
334 	 * Treat values > 0 as success, but warn.
335 	 */
336 	pci_warn(pci_dev, "Driver probe function unexpectedly returned %d\n",
337 		 rc);
338 	return 0;
339 }
340 
341 static bool pci_physfn_is_probed(struct pci_dev *dev)
342 {
343 #ifdef CONFIG_PCI_IOV
344 	return dev->is_virtfn && dev->physfn->is_probed;
345 #else
346 	return false;
347 #endif
348 }
349 
350 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
351 			  const struct pci_device_id *id)
352 {
353 	int error, node, cpu;
354 	struct drv_dev_and_id ddi = { drv, dev, id };
355 
356 	/*
357 	 * Execute driver initialization on node where the device is
358 	 * attached.  This way the driver likely allocates its local memory
359 	 * on the right node.
360 	 */
361 	node = dev_to_node(&dev->dev);
362 	dev->is_probed = 1;
363 
364 	cpu_hotplug_disable();
365 
366 	/*
367 	 * Prevent nesting work_on_cpu() for the case where a Virtual Function
368 	 * device is probed from work_on_cpu() of the Physical device.
369 	 */
370 	if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
371 	    pci_physfn_is_probed(dev)) {
372 		cpu = nr_cpu_ids;
373 	} else {
374 		cpumask_var_t wq_domain_mask;
375 
376 		if (!zalloc_cpumask_var(&wq_domain_mask, GFP_KERNEL)) {
377 			error = -ENOMEM;
378 			goto out;
379 		}
380 		cpumask_and(wq_domain_mask,
381 			    housekeeping_cpumask(HK_TYPE_WQ),
382 			    housekeeping_cpumask(HK_TYPE_DOMAIN));
383 
384 		cpu = cpumask_any_and(cpumask_of_node(node),
385 				      wq_domain_mask);
386 		free_cpumask_var(wq_domain_mask);
387 	}
388 
389 	if (cpu < nr_cpu_ids)
390 		error = work_on_cpu(cpu, local_pci_probe, &ddi);
391 	else
392 		error = local_pci_probe(&ddi);
393 out:
394 	dev->is_probed = 0;
395 	cpu_hotplug_enable();
396 	return error;
397 }
398 
399 /**
400  * __pci_device_probe - check if a driver wants to claim a specific PCI device
401  * @drv: driver to call to check if it wants the PCI device
402  * @pci_dev: PCI device being probed
403  *
404  * returns 0 on success, else error.
405  * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
406  */
407 static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
408 {
409 	const struct pci_device_id *id;
410 	int error = 0;
411 
412 	if (drv->probe) {
413 		error = -ENODEV;
414 
415 		id = pci_match_device(drv, pci_dev);
416 		if (id)
417 			error = pci_call_probe(drv, pci_dev, id);
418 	}
419 	return error;
420 }
421 
422 int __weak pcibios_alloc_irq(struct pci_dev *dev)
423 {
424 	return 0;
425 }
426 
427 void __weak pcibios_free_irq(struct pci_dev *dev)
428 {
429 }
430 
431 #ifdef CONFIG_PCI_IOV
432 static inline bool pci_device_can_probe(struct pci_dev *pdev)
433 {
434 	return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe ||
435 		pdev->driver_override);
436 }
437 #else
438 static inline bool pci_device_can_probe(struct pci_dev *pdev)
439 {
440 	return true;
441 }
442 #endif
443 
444 static int pci_device_probe(struct device *dev)
445 {
446 	int error;
447 	struct pci_dev *pci_dev = to_pci_dev(dev);
448 	struct pci_driver *drv = to_pci_driver(dev->driver);
449 
450 	if (!pci_device_can_probe(pci_dev))
451 		return -ENODEV;
452 
453 	pci_assign_irq(pci_dev);
454 
455 	error = pcibios_alloc_irq(pci_dev);
456 	if (error < 0)
457 		return error;
458 
459 	pci_dev_get(pci_dev);
460 	error = __pci_device_probe(drv, pci_dev);
461 	if (error) {
462 		pcibios_free_irq(pci_dev);
463 		pci_dev_put(pci_dev);
464 	}
465 
466 	return error;
467 }
468 
469 static void pci_device_remove(struct device *dev)
470 {
471 	struct pci_dev *pci_dev = to_pci_dev(dev);
472 	struct pci_driver *drv = pci_dev->driver;
473 
474 	if (drv->remove) {
475 		pm_runtime_get_sync(dev);
476 		drv->remove(pci_dev);
477 		pm_runtime_put_noidle(dev);
478 	}
479 	pcibios_free_irq(pci_dev);
480 	pci_dev->driver = NULL;
481 	pci_iov_remove(pci_dev);
482 
483 	/* Undo the runtime PM settings in local_pci_probe() */
484 	pm_runtime_put_sync(dev);
485 
486 	/*
487 	 * If the device is still on, set the power state as "unknown",
488 	 * since it might change by the next time we load the driver.
489 	 */
490 	if (pci_dev->current_state == PCI_D0)
491 		pci_dev->current_state = PCI_UNKNOWN;
492 
493 	/*
494 	 * We would love to complain here if pci_dev->is_enabled is set, that
495 	 * the driver should have called pci_disable_device(), but the
496 	 * unfortunate fact is there are too many odd BIOS and bridge setups
497 	 * that don't like drivers doing that all of the time.
498 	 * Oh well, we can dream of sane hardware when we sleep, no matter how
499 	 * horrible the crap we have to deal with is when we are awake...
500 	 */
501 
502 	pci_dev_put(pci_dev);
503 }
504 
505 static void pci_device_shutdown(struct device *dev)
506 {
507 	struct pci_dev *pci_dev = to_pci_dev(dev);
508 	struct pci_driver *drv = pci_dev->driver;
509 
510 	pm_runtime_resume(dev);
511 
512 	if (drv && drv->shutdown)
513 		drv->shutdown(pci_dev);
514 
515 	/*
516 	 * If this is a kexec reboot, turn off Bus Master bit on the
517 	 * device to tell it to not continue to do DMA. Don't touch
518 	 * devices in D3cold or unknown states.
519 	 * If it is not a kexec reboot, firmware will hit the PCI
520 	 * devices with big hammer and stop their DMA any way.
521 	 */
522 	if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
523 		pci_clear_master(pci_dev);
524 }
525 
526 #ifdef CONFIG_PM_SLEEP
527 
528 /* Auxiliary functions used for system resume */
529 
530 /**
531  * pci_restore_standard_config - restore standard config registers of PCI device
532  * @pci_dev: PCI device to handle
533  */
534 static int pci_restore_standard_config(struct pci_dev *pci_dev)
535 {
536 	pci_update_current_state(pci_dev, PCI_UNKNOWN);
537 
538 	if (pci_dev->current_state != PCI_D0) {
539 		int error = pci_set_power_state(pci_dev, PCI_D0);
540 		if (error)
541 			return error;
542 	}
543 
544 	pci_restore_state(pci_dev);
545 	pci_pme_restore(pci_dev);
546 	return 0;
547 }
548 #endif /* CONFIG_PM_SLEEP */
549 
550 #ifdef CONFIG_PM
551 
552 /* Auxiliary functions used for system resume and run-time resume */
553 
554 static void pci_pm_default_resume(struct pci_dev *pci_dev)
555 {
556 	pci_fixup_device(pci_fixup_resume, pci_dev);
557 	pci_enable_wake(pci_dev, PCI_D0, false);
558 }
559 
560 static void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
561 {
562 	pci_power_up(pci_dev);
563 	pci_update_current_state(pci_dev, PCI_D0);
564 }
565 
566 static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
567 {
568 	pci_pm_power_up_and_verify_state(pci_dev);
569 	pci_restore_state(pci_dev);
570 	pci_pme_restore(pci_dev);
571 }
572 
573 static void pci_pm_bridge_power_up_actions(struct pci_dev *pci_dev)
574 {
575 	pci_bridge_wait_for_secondary_bus(pci_dev);
576 	/*
577 	 * When powering on a bridge from D3cold, the whole hierarchy may be
578 	 * powered on into D0uninitialized state, resume them to give them a
579 	 * chance to suspend again
580 	 */
581 	pci_resume_bus(pci_dev->subordinate);
582 }
583 
584 #endif /* CONFIG_PM */
585 
586 #ifdef CONFIG_PM_SLEEP
587 
588 /*
589  * Default "suspend" method for devices that have no driver provided suspend,
590  * or not even a driver at all (second part).
591  */
592 static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
593 {
594 	/*
595 	 * mark its power state as "unknown", since we don't know if
596 	 * e.g. the BIOS will change its device state when we suspend.
597 	 */
598 	if (pci_dev->current_state == PCI_D0)
599 		pci_dev->current_state = PCI_UNKNOWN;
600 }
601 
602 /*
603  * Default "resume" method for devices that have no driver provided resume,
604  * or not even a driver at all (second part).
605  */
606 static int pci_pm_reenable_device(struct pci_dev *pci_dev)
607 {
608 	int retval;
609 
610 	/* if the device was enabled before suspend, re-enable */
611 	retval = pci_reenable_device(pci_dev);
612 	/*
613 	 * if the device was busmaster before the suspend, make it busmaster
614 	 * again
615 	 */
616 	if (pci_dev->is_busmaster)
617 		pci_set_master(pci_dev);
618 
619 	return retval;
620 }
621 
622 static int pci_legacy_suspend(struct device *dev, pm_message_t state)
623 {
624 	struct pci_dev *pci_dev = to_pci_dev(dev);
625 	struct pci_driver *drv = pci_dev->driver;
626 
627 	if (drv && drv->suspend) {
628 		pci_power_t prev = pci_dev->current_state;
629 		int error;
630 
631 		error = drv->suspend(pci_dev, state);
632 		suspend_report_result(dev, drv->suspend, error);
633 		if (error)
634 			return error;
635 
636 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
637 		    && pci_dev->current_state != PCI_UNKNOWN) {
638 			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
639 				      "PCI PM: Device state not saved by %pS\n",
640 				      drv->suspend);
641 		}
642 	}
643 
644 	pci_fixup_device(pci_fixup_suspend, pci_dev);
645 
646 	return 0;
647 }
648 
649 static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
650 {
651 	struct pci_dev *pci_dev = to_pci_dev(dev);
652 
653 	if (!pci_dev->state_saved)
654 		pci_save_state(pci_dev);
655 
656 	pci_pm_set_unknown_state(pci_dev);
657 
658 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
659 
660 	return 0;
661 }
662 
663 static int pci_legacy_resume(struct device *dev)
664 {
665 	struct pci_dev *pci_dev = to_pci_dev(dev);
666 	struct pci_driver *drv = pci_dev->driver;
667 
668 	pci_fixup_device(pci_fixup_resume, pci_dev);
669 
670 	return drv && drv->resume ?
671 			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
672 }
673 
674 /* Auxiliary functions used by the new power management framework */
675 
676 static void pci_pm_default_suspend(struct pci_dev *pci_dev)
677 {
678 	/* Disable non-bridge devices without PM support */
679 	if (!pci_has_subordinate(pci_dev))
680 		pci_disable_enabled_device(pci_dev);
681 }
682 
683 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
684 {
685 	struct pci_driver *drv = pci_dev->driver;
686 	bool ret = drv && (drv->suspend || drv->resume);
687 
688 	/*
689 	 * Legacy PM support is used by default, so warn if the new framework is
690 	 * supported as well.  Drivers are supposed to support either the
691 	 * former, or the latter, but not both at the same time.
692 	 */
693 	pci_WARN(pci_dev, ret && drv->driver.pm, "device %04x:%04x\n",
694 		 pci_dev->vendor, pci_dev->device);
695 
696 	return ret;
697 }
698 
699 /* New power management framework */
700 
701 static int pci_pm_prepare(struct device *dev)
702 {
703 	struct pci_dev *pci_dev = to_pci_dev(dev);
704 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
705 
706 	if (pm && pm->prepare) {
707 		int error = pm->prepare(dev);
708 		if (error < 0)
709 			return error;
710 
711 		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
712 			return 0;
713 	}
714 	if (pci_dev_need_resume(pci_dev))
715 		return 0;
716 
717 	/*
718 	 * The PME setting needs to be adjusted here in case the direct-complete
719 	 * optimization is used with respect to this device.
720 	 */
721 	pci_dev_adjust_pme(pci_dev);
722 	return 1;
723 }
724 
725 static void pci_pm_complete(struct device *dev)
726 {
727 	struct pci_dev *pci_dev = to_pci_dev(dev);
728 
729 	pci_dev_complete_resume(pci_dev);
730 	pm_generic_complete(dev);
731 
732 	/* Resume device if platform firmware has put it in reset-power-on */
733 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
734 		pci_power_t pre_sleep_state = pci_dev->current_state;
735 
736 		pci_refresh_power_state(pci_dev);
737 		/*
738 		 * On platforms with ACPI this check may also trigger for
739 		 * devices sharing power resources if one of those power
740 		 * resources has been activated as a result of a change of the
741 		 * power state of another device sharing it.  However, in that
742 		 * case it is also better to resume the device, in general.
743 		 */
744 		if (pci_dev->current_state < pre_sleep_state)
745 			pm_request_resume(dev);
746 	}
747 }
748 
749 #else /* !CONFIG_PM_SLEEP */
750 
751 #define pci_pm_prepare	NULL
752 #define pci_pm_complete	NULL
753 
754 #endif /* !CONFIG_PM_SLEEP */
755 
756 #ifdef CONFIG_SUSPEND
757 static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
758 {
759 	/*
760 	 * Some BIOSes forget to clear Root PME Status bits after system
761 	 * wakeup, which breaks ACPI-based runtime wakeup on PCI Express.
762 	 * Clear those bits now just in case (shouldn't hurt).
763 	 */
764 	if (pci_is_pcie(pci_dev) &&
765 	    (pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT ||
766 	     pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
767 		pcie_clear_root_pme_status(pci_dev);
768 }
769 
770 static int pci_pm_suspend(struct device *dev)
771 {
772 	struct pci_dev *pci_dev = to_pci_dev(dev);
773 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
774 
775 	pci_dev->skip_bus_pm = false;
776 
777 	/*
778 	 * Disabling PTM allows some systems, e.g., Intel mobile chips
779 	 * since Coffee Lake, to enter a lower-power PM state.
780 	 */
781 	pci_suspend_ptm(pci_dev);
782 
783 	if (pci_has_legacy_pm_support(pci_dev))
784 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
785 
786 	if (!pm) {
787 		pci_pm_default_suspend(pci_dev);
788 		return 0;
789 	}
790 
791 	/*
792 	 * PCI devices suspended at run time may need to be resumed at this
793 	 * point, because in general it may be necessary to reconfigure them for
794 	 * system suspend.  Namely, if the device is expected to wake up the
795 	 * system from the sleep state, it may have to be reconfigured for this
796 	 * purpose, or if the device is not expected to wake up the system from
797 	 * the sleep state, it should be prevented from signaling wakeup events
798 	 * going forward.
799 	 *
800 	 * Also if the driver of the device does not indicate that its system
801 	 * suspend callbacks can cope with runtime-suspended devices, it is
802 	 * better to resume the device from runtime suspend here.
803 	 */
804 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
805 	    pci_dev_need_resume(pci_dev)) {
806 		pm_runtime_resume(dev);
807 		pci_dev->state_saved = false;
808 	} else {
809 		pci_dev_adjust_pme(pci_dev);
810 	}
811 
812 	if (pm->suspend) {
813 		pci_power_t prev = pci_dev->current_state;
814 		int error;
815 
816 		error = pm->suspend(dev);
817 		suspend_report_result(dev, pm->suspend, 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 			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
824 				      "PCI PM: State of device not saved by %pS\n",
825 				      pm->suspend);
826 		}
827 	}
828 
829 	return 0;
830 }
831 
832 static int pci_pm_suspend_late(struct device *dev)
833 {
834 	if (dev_pm_skip_suspend(dev))
835 		return 0;
836 
837 	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
838 
839 	return pm_generic_suspend_late(dev);
840 }
841 
842 static int pci_pm_suspend_noirq(struct device *dev)
843 {
844 	struct pci_dev *pci_dev = to_pci_dev(dev);
845 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
846 
847 	if (dev_pm_skip_suspend(dev))
848 		return 0;
849 
850 	if (pci_has_legacy_pm_support(pci_dev))
851 		return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
852 
853 	if (!pm) {
854 		pci_save_state(pci_dev);
855 		goto Fixup;
856 	}
857 
858 	if (pm->suspend_noirq) {
859 		pci_power_t prev = pci_dev->current_state;
860 		int error;
861 
862 		error = pm->suspend_noirq(dev);
863 		suspend_report_result(dev, pm->suspend_noirq, error);
864 		if (error)
865 			return error;
866 
867 		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
868 		    && pci_dev->current_state != PCI_UNKNOWN) {
869 			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
870 				      "PCI PM: State of device not saved by %pS\n",
871 				      pm->suspend_noirq);
872 			goto Fixup;
873 		}
874 	}
875 
876 	if (!pci_dev->state_saved) {
877 		pci_save_state(pci_dev);
878 
879 		/*
880 		 * If the device is a bridge with a child in D0 below it,
881 		 * it needs to stay in D0, so check skip_bus_pm to avoid
882 		 * putting it into a low-power state in that case.
883 		 */
884 		if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
885 			pci_prepare_to_sleep(pci_dev);
886 	}
887 
888 	pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
889 		pci_power_name(pci_dev->current_state));
890 
891 	if (pci_dev->current_state == PCI_D0) {
892 		pci_dev->skip_bus_pm = true;
893 		/*
894 		 * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
895 		 * downstream device is in D0, so avoid changing the power state
896 		 * of the parent bridge by setting the skip_bus_pm flag for it.
897 		 */
898 		if (pci_dev->bus->self)
899 			pci_dev->bus->self->skip_bus_pm = true;
900 	}
901 
902 	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
903 		pci_dbg(pci_dev, "PCI PM: Skipped\n");
904 		goto Fixup;
905 	}
906 
907 	pci_pm_set_unknown_state(pci_dev);
908 
909 	/*
910 	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
911 	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
912 	 * hasn't been quiesced and tries to turn it off.  If the controller
913 	 * is already in D3, this can hang or cause memory corruption.
914 	 *
915 	 * Since the value of the COMMAND register doesn't matter once the
916 	 * device has been suspended, we can safely set it to 0 here.
917 	 */
918 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
919 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
920 
921 Fixup:
922 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
923 
924 	/*
925 	 * If the target system sleep state is suspend-to-idle, it is sufficient
926 	 * to check whether or not the device's wakeup settings are good for
927 	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
928 	 * pci_pm_complete() to take care of fixing up the device's state
929 	 * anyway, if need be.
930 	 */
931 	if (device_can_wakeup(dev) && !device_may_wakeup(dev))
932 		dev->power.may_skip_resume = false;
933 
934 	return 0;
935 }
936 
937 static int pci_pm_resume_noirq(struct device *dev)
938 {
939 	struct pci_dev *pci_dev = to_pci_dev(dev);
940 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
941 	pci_power_t prev_state = pci_dev->current_state;
942 	bool skip_bus_pm = pci_dev->skip_bus_pm;
943 
944 	if (dev_pm_skip_resume(dev))
945 		return 0;
946 
947 	/*
948 	 * In the suspend-to-idle case, devices left in D0 during suspend will
949 	 * stay in D0, so it is not necessary to restore or update their
950 	 * configuration here and attempting to put them into D0 again is
951 	 * pointless, so avoid doing that.
952 	 */
953 	if (!(skip_bus_pm && pm_suspend_no_platform()))
954 		pci_pm_default_resume_early(pci_dev);
955 
956 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
957 	pcie_pme_root_status_cleanup(pci_dev);
958 
959 	if (!skip_bus_pm && prev_state == PCI_D3cold)
960 		pci_pm_bridge_power_up_actions(pci_dev);
961 
962 	if (pci_has_legacy_pm_support(pci_dev))
963 		return 0;
964 
965 	if (pm && pm->resume_noirq)
966 		return pm->resume_noirq(dev);
967 
968 	return 0;
969 }
970 
971 static int pci_pm_resume_early(struct device *dev)
972 {
973 	if (dev_pm_skip_resume(dev))
974 		return 0;
975 
976 	return pm_generic_resume_early(dev);
977 }
978 
979 static int pci_pm_resume(struct device *dev)
980 {
981 	struct pci_dev *pci_dev = to_pci_dev(dev);
982 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
983 
984 	/*
985 	 * This is necessary for the suspend error path in which resume is
986 	 * called without restoring the standard config registers of the device.
987 	 */
988 	if (pci_dev->state_saved)
989 		pci_restore_standard_config(pci_dev);
990 
991 	pci_resume_ptm(pci_dev);
992 
993 	if (pci_has_legacy_pm_support(pci_dev))
994 		return pci_legacy_resume(dev);
995 
996 	pci_pm_default_resume(pci_dev);
997 
998 	if (pm) {
999 		if (pm->resume)
1000 			return pm->resume(dev);
1001 	} else {
1002 		pci_pm_reenable_device(pci_dev);
1003 	}
1004 
1005 	return 0;
1006 }
1007 
1008 #else /* !CONFIG_SUSPEND */
1009 
1010 #define pci_pm_suspend		NULL
1011 #define pci_pm_suspend_late	NULL
1012 #define pci_pm_suspend_noirq	NULL
1013 #define pci_pm_resume		NULL
1014 #define pci_pm_resume_early	NULL
1015 #define pci_pm_resume_noirq	NULL
1016 
1017 #endif /* !CONFIG_SUSPEND */
1018 
1019 #ifdef CONFIG_HIBERNATE_CALLBACKS
1020 
1021 static int pci_pm_freeze(struct device *dev)
1022 {
1023 	struct pci_dev *pci_dev = to_pci_dev(dev);
1024 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1025 
1026 	if (pci_has_legacy_pm_support(pci_dev))
1027 		return pci_legacy_suspend(dev, PMSG_FREEZE);
1028 
1029 	if (!pm) {
1030 		pci_pm_default_suspend(pci_dev);
1031 		return 0;
1032 	}
1033 
1034 	/*
1035 	 * Resume all runtime-suspended devices before creating a snapshot
1036 	 * image of system memory, because the restore kernel generally cannot
1037 	 * be expected to always handle them consistently and they need to be
1038 	 * put into the runtime-active metastate during system resume anyway,
1039 	 * so it is better to ensure that the state saved in the image will be
1040 	 * always consistent with that.
1041 	 */
1042 	pm_runtime_resume(dev);
1043 	pci_dev->state_saved = false;
1044 
1045 	if (pm->freeze) {
1046 		int error;
1047 
1048 		error = pm->freeze(dev);
1049 		suspend_report_result(dev, pm->freeze, error);
1050 		if (error)
1051 			return error;
1052 	}
1053 
1054 	return 0;
1055 }
1056 
1057 static int pci_pm_freeze_noirq(struct device *dev)
1058 {
1059 	struct pci_dev *pci_dev = to_pci_dev(dev);
1060 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1061 
1062 	if (pci_has_legacy_pm_support(pci_dev))
1063 		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
1064 
1065 	if (pm && pm->freeze_noirq) {
1066 		int error;
1067 
1068 		error = pm->freeze_noirq(dev);
1069 		suspend_report_result(dev, pm->freeze_noirq, error);
1070 		if (error)
1071 			return error;
1072 	}
1073 
1074 	if (!pci_dev->state_saved)
1075 		pci_save_state(pci_dev);
1076 
1077 	pci_pm_set_unknown_state(pci_dev);
1078 
1079 	return 0;
1080 }
1081 
1082 static int pci_pm_thaw_noirq(struct device *dev)
1083 {
1084 	struct pci_dev *pci_dev = to_pci_dev(dev);
1085 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1086 
1087 	/*
1088 	 * The pm->thaw_noirq() callback assumes the device has been
1089 	 * returned to D0 and its config state has been restored.
1090 	 *
1091 	 * In addition, pci_restore_state() restores MSI-X state in MMIO
1092 	 * space, which requires the device to be in D0, so return it to D0
1093 	 * in case the driver's "freeze" callbacks put it into a low-power
1094 	 * state.
1095 	 */
1096 	pci_pm_power_up_and_verify_state(pci_dev);
1097 	pci_restore_state(pci_dev);
1098 
1099 	if (pci_has_legacy_pm_support(pci_dev))
1100 		return 0;
1101 
1102 	if (pm && pm->thaw_noirq)
1103 		return pm->thaw_noirq(dev);
1104 
1105 	return 0;
1106 }
1107 
1108 static int pci_pm_thaw(struct device *dev)
1109 {
1110 	struct pci_dev *pci_dev = to_pci_dev(dev);
1111 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1112 	int error = 0;
1113 
1114 	if (pci_has_legacy_pm_support(pci_dev))
1115 		return pci_legacy_resume(dev);
1116 
1117 	if (pm) {
1118 		if (pm->thaw)
1119 			error = pm->thaw(dev);
1120 	} else {
1121 		pci_pm_reenable_device(pci_dev);
1122 	}
1123 
1124 	pci_dev->state_saved = false;
1125 
1126 	return error;
1127 }
1128 
1129 static int pci_pm_poweroff(struct device *dev)
1130 {
1131 	struct pci_dev *pci_dev = to_pci_dev(dev);
1132 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1133 
1134 	if (pci_has_legacy_pm_support(pci_dev))
1135 		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
1136 
1137 	if (!pm) {
1138 		pci_pm_default_suspend(pci_dev);
1139 		return 0;
1140 	}
1141 
1142 	/* The reason to do that is the same as in pci_pm_suspend(). */
1143 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1144 	    pci_dev_need_resume(pci_dev)) {
1145 		pm_runtime_resume(dev);
1146 		pci_dev->state_saved = false;
1147 	} else {
1148 		pci_dev_adjust_pme(pci_dev);
1149 	}
1150 
1151 	if (pm->poweroff) {
1152 		int error;
1153 
1154 		error = pm->poweroff(dev);
1155 		suspend_report_result(dev, pm->poweroff, error);
1156 		if (error)
1157 			return error;
1158 	}
1159 
1160 	return 0;
1161 }
1162 
1163 static int pci_pm_poweroff_late(struct device *dev)
1164 {
1165 	if (dev_pm_skip_suspend(dev))
1166 		return 0;
1167 
1168 	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
1169 
1170 	return pm_generic_poweroff_late(dev);
1171 }
1172 
1173 static int pci_pm_poweroff_noirq(struct device *dev)
1174 {
1175 	struct pci_dev *pci_dev = to_pci_dev(dev);
1176 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1177 
1178 	if (dev_pm_skip_suspend(dev))
1179 		return 0;
1180 
1181 	if (pci_has_legacy_pm_support(pci_dev))
1182 		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
1183 
1184 	if (!pm) {
1185 		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1186 		return 0;
1187 	}
1188 
1189 	if (pm->poweroff_noirq) {
1190 		int error;
1191 
1192 		error = pm->poweroff_noirq(dev);
1193 		suspend_report_result(dev, pm->poweroff_noirq, error);
1194 		if (error)
1195 			return error;
1196 	}
1197 
1198 	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
1199 		pci_prepare_to_sleep(pci_dev);
1200 
1201 	/*
1202 	 * The reason for doing this here is the same as for the analogous code
1203 	 * in pci_pm_suspend_noirq().
1204 	 */
1205 	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
1206 		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
1207 
1208 	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1209 
1210 	return 0;
1211 }
1212 
1213 static int pci_pm_restore_noirq(struct device *dev)
1214 {
1215 	struct pci_dev *pci_dev = to_pci_dev(dev);
1216 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1217 
1218 	pci_pm_default_resume_early(pci_dev);
1219 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1220 
1221 	if (pci_has_legacy_pm_support(pci_dev))
1222 		return 0;
1223 
1224 	if (pm && pm->restore_noirq)
1225 		return pm->restore_noirq(dev);
1226 
1227 	return 0;
1228 }
1229 
1230 static int pci_pm_restore(struct device *dev)
1231 {
1232 	struct pci_dev *pci_dev = to_pci_dev(dev);
1233 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1234 
1235 	/*
1236 	 * This is necessary for the hibernation error path in which restore is
1237 	 * called without restoring the standard config registers of the device.
1238 	 */
1239 	if (pci_dev->state_saved)
1240 		pci_restore_standard_config(pci_dev);
1241 
1242 	if (pci_has_legacy_pm_support(pci_dev))
1243 		return pci_legacy_resume(dev);
1244 
1245 	pci_pm_default_resume(pci_dev);
1246 
1247 	if (pm) {
1248 		if (pm->restore)
1249 			return pm->restore(dev);
1250 	} else {
1251 		pci_pm_reenable_device(pci_dev);
1252 	}
1253 
1254 	return 0;
1255 }
1256 
1257 #else /* !CONFIG_HIBERNATE_CALLBACKS */
1258 
1259 #define pci_pm_freeze		NULL
1260 #define pci_pm_freeze_noirq	NULL
1261 #define pci_pm_thaw		NULL
1262 #define pci_pm_thaw_noirq	NULL
1263 #define pci_pm_poweroff		NULL
1264 #define pci_pm_poweroff_late	NULL
1265 #define pci_pm_poweroff_noirq	NULL
1266 #define pci_pm_restore		NULL
1267 #define pci_pm_restore_noirq	NULL
1268 
1269 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
1270 
1271 #ifdef CONFIG_PM
1272 
1273 static int pci_pm_runtime_suspend(struct device *dev)
1274 {
1275 	struct pci_dev *pci_dev = to_pci_dev(dev);
1276 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1277 	pci_power_t prev = pci_dev->current_state;
1278 	int error;
1279 
1280 	pci_suspend_ptm(pci_dev);
1281 
1282 	/*
1283 	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
1284 	 * but it may go to D3cold when the bridge above it runtime suspends.
1285 	 * Save its config space in case that happens.
1286 	 */
1287 	if (!pci_dev->driver) {
1288 		pci_save_state(pci_dev);
1289 		return 0;
1290 	}
1291 
1292 	pci_dev->state_saved = false;
1293 	if (pm && pm->runtime_suspend) {
1294 		error = pm->runtime_suspend(dev);
1295 		/*
1296 		 * -EBUSY and -EAGAIN is used to request the runtime PM core
1297 		 * to schedule a new suspend, so log the event only with debug
1298 		 * log level.
1299 		 */
1300 		if (error == -EBUSY || error == -EAGAIN) {
1301 			pci_dbg(pci_dev, "can't suspend now (%ps returned %d)\n",
1302 				pm->runtime_suspend, error);
1303 			return error;
1304 		} else if (error) {
1305 			pci_err(pci_dev, "can't suspend (%ps returned %d)\n",
1306 				pm->runtime_suspend, error);
1307 			return error;
1308 		}
1309 	}
1310 
1311 	pci_fixup_device(pci_fixup_suspend, pci_dev);
1312 
1313 	if (pm && pm->runtime_suspend
1314 	    && !pci_dev->state_saved && pci_dev->current_state != PCI_D0
1315 	    && pci_dev->current_state != PCI_UNKNOWN) {
1316 		pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
1317 			      "PCI PM: State of device not saved by %pS\n",
1318 			      pm->runtime_suspend);
1319 		return 0;
1320 	}
1321 
1322 	if (!pci_dev->state_saved) {
1323 		pci_save_state(pci_dev);
1324 		pci_finish_runtime_suspend(pci_dev);
1325 	}
1326 
1327 	return 0;
1328 }
1329 
1330 static int pci_pm_runtime_resume(struct device *dev)
1331 {
1332 	struct pci_dev *pci_dev = to_pci_dev(dev);
1333 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1334 	pci_power_t prev_state = pci_dev->current_state;
1335 	int error = 0;
1336 
1337 	/*
1338 	 * Restoring config space is necessary even if the device is not bound
1339 	 * to a driver because although we left it in D0, it may have gone to
1340 	 * D3cold when the bridge above it runtime suspended.
1341 	 */
1342 	pci_pm_default_resume_early(pci_dev);
1343 	pci_resume_ptm(pci_dev);
1344 
1345 	if (!pci_dev->driver)
1346 		return 0;
1347 
1348 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1349 	pci_pm_default_resume(pci_dev);
1350 
1351 	if (prev_state == PCI_D3cold)
1352 		pci_pm_bridge_power_up_actions(pci_dev);
1353 
1354 	if (pm && pm->runtime_resume)
1355 		error = pm->runtime_resume(dev);
1356 
1357 	return error;
1358 }
1359 
1360 static int pci_pm_runtime_idle(struct device *dev)
1361 {
1362 	struct pci_dev *pci_dev = to_pci_dev(dev);
1363 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1364 
1365 	/*
1366 	 * If pci_dev->driver is not set (unbound), the device should
1367 	 * always remain in D0 regardless of the runtime PM status
1368 	 */
1369 	if (!pci_dev->driver)
1370 		return 0;
1371 
1372 	if (!pm)
1373 		return -ENOSYS;
1374 
1375 	if (pm->runtime_idle)
1376 		return pm->runtime_idle(dev);
1377 
1378 	return 0;
1379 }
1380 
1381 static const struct dev_pm_ops pci_dev_pm_ops = {
1382 	.prepare = pci_pm_prepare,
1383 	.complete = pci_pm_complete,
1384 	.suspend = pci_pm_suspend,
1385 	.suspend_late = pci_pm_suspend_late,
1386 	.resume = pci_pm_resume,
1387 	.resume_early = pci_pm_resume_early,
1388 	.freeze = pci_pm_freeze,
1389 	.thaw = pci_pm_thaw,
1390 	.poweroff = pci_pm_poweroff,
1391 	.poweroff_late = pci_pm_poweroff_late,
1392 	.restore = pci_pm_restore,
1393 	.suspend_noirq = pci_pm_suspend_noirq,
1394 	.resume_noirq = pci_pm_resume_noirq,
1395 	.freeze_noirq = pci_pm_freeze_noirq,
1396 	.thaw_noirq = pci_pm_thaw_noirq,
1397 	.poweroff_noirq = pci_pm_poweroff_noirq,
1398 	.restore_noirq = pci_pm_restore_noirq,
1399 	.runtime_suspend = pci_pm_runtime_suspend,
1400 	.runtime_resume = pci_pm_runtime_resume,
1401 	.runtime_idle = pci_pm_runtime_idle,
1402 };
1403 
1404 #define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
1405 
1406 #else /* !CONFIG_PM */
1407 
1408 #define pci_pm_runtime_suspend	NULL
1409 #define pci_pm_runtime_resume	NULL
1410 #define pci_pm_runtime_idle	NULL
1411 
1412 #define PCI_PM_OPS_PTR	NULL
1413 
1414 #endif /* !CONFIG_PM */
1415 
1416 /**
1417  * __pci_register_driver - register a new pci driver
1418  * @drv: the driver structure to register
1419  * @owner: owner module of drv
1420  * @mod_name: module name string
1421  *
1422  * Adds the driver structure to the list of registered drivers.
1423  * Returns a negative value on error, otherwise 0.
1424  * If no error occurred, the driver remains registered even if
1425  * no device was claimed during registration.
1426  */
1427 int __pci_register_driver(struct pci_driver *drv, struct module *owner,
1428 			  const char *mod_name)
1429 {
1430 	/* initialize common driver fields */
1431 	drv->driver.name = drv->name;
1432 	drv->driver.bus = &pci_bus_type;
1433 	drv->driver.owner = owner;
1434 	drv->driver.mod_name = mod_name;
1435 	drv->driver.groups = drv->groups;
1436 	drv->driver.dev_groups = drv->dev_groups;
1437 
1438 	spin_lock_init(&drv->dynids.lock);
1439 	INIT_LIST_HEAD(&drv->dynids.list);
1440 
1441 	/* register with core */
1442 	return driver_register(&drv->driver);
1443 }
1444 EXPORT_SYMBOL(__pci_register_driver);
1445 
1446 /**
1447  * pci_unregister_driver - unregister a pci driver
1448  * @drv: the driver structure to unregister
1449  *
1450  * Deletes the driver structure from the list of registered PCI drivers,
1451  * gives it a chance to clean up by calling its remove() function for
1452  * each device it was responsible for, and marks those devices as
1453  * driverless.
1454  */
1455 
1456 void pci_unregister_driver(struct pci_driver *drv)
1457 {
1458 	driver_unregister(&drv->driver);
1459 	pci_free_dynids(drv);
1460 }
1461 EXPORT_SYMBOL(pci_unregister_driver);
1462 
1463 static struct pci_driver pci_compat_driver = {
1464 	.name = "compat"
1465 };
1466 
1467 /**
1468  * pci_dev_driver - get the pci_driver of a device
1469  * @dev: the device to query
1470  *
1471  * Returns the appropriate pci_driver structure or %NULL if there is no
1472  * registered driver for the device.
1473  */
1474 struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
1475 {
1476 	if (dev->driver)
1477 		return dev->driver;
1478 	else {
1479 		int i;
1480 		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1481 			if (dev->resource[i].flags & IORESOURCE_BUSY)
1482 				return &pci_compat_driver;
1483 	}
1484 	return NULL;
1485 }
1486 EXPORT_SYMBOL(pci_dev_driver);
1487 
1488 /**
1489  * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
1490  * @dev: the PCI device structure to match against
1491  * @drv: the device driver to search for matching PCI device id structures
1492  *
1493  * Used by a driver to check whether a PCI device present in the
1494  * system is in its list of supported devices. Returns the matching
1495  * pci_device_id structure or %NULL if there is no match.
1496  */
1497 static int pci_bus_match(struct device *dev, struct device_driver *drv)
1498 {
1499 	struct pci_dev *pci_dev = to_pci_dev(dev);
1500 	struct pci_driver *pci_drv;
1501 	const struct pci_device_id *found_id;
1502 
1503 	if (!pci_dev->match_driver)
1504 		return 0;
1505 
1506 	pci_drv = to_pci_driver(drv);
1507 	found_id = pci_match_device(pci_drv, pci_dev);
1508 	if (found_id)
1509 		return 1;
1510 
1511 	return 0;
1512 }
1513 
1514 /**
1515  * pci_dev_get - increments the reference count of the pci device structure
1516  * @dev: the device being referenced
1517  *
1518  * Each live reference to a device should be refcounted.
1519  *
1520  * Drivers for PCI devices should normally record such references in
1521  * their probe() methods, when they bind to a device, and release
1522  * them by calling pci_dev_put(), in their disconnect() methods.
1523  *
1524  * A pointer to the device with the incremented reference counter is returned.
1525  */
1526 struct pci_dev *pci_dev_get(struct pci_dev *dev)
1527 {
1528 	if (dev)
1529 		get_device(&dev->dev);
1530 	return dev;
1531 }
1532 EXPORT_SYMBOL(pci_dev_get);
1533 
1534 /**
1535  * pci_dev_put - release a use of the pci device structure
1536  * @dev: device that's been disconnected
1537  *
1538  * Must be called when a user of a device is finished with it.  When the last
1539  * user of the device calls this function, the memory of the device is freed.
1540  */
1541 void pci_dev_put(struct pci_dev *dev)
1542 {
1543 	if (dev)
1544 		put_device(&dev->dev);
1545 }
1546 EXPORT_SYMBOL(pci_dev_put);
1547 
1548 static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
1549 {
1550 	struct pci_dev *pdev;
1551 
1552 	if (!dev)
1553 		return -ENODEV;
1554 
1555 	pdev = to_pci_dev(dev);
1556 
1557 	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
1558 		return -ENOMEM;
1559 
1560 	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
1561 		return -ENOMEM;
1562 
1563 	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
1564 			   pdev->subsystem_device))
1565 		return -ENOMEM;
1566 
1567 	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
1568 		return -ENOMEM;
1569 
1570 	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
1571 			   pdev->vendor, pdev->device,
1572 			   pdev->subsystem_vendor, pdev->subsystem_device,
1573 			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
1574 			   (u8)(pdev->class)))
1575 		return -ENOMEM;
1576 
1577 	return 0;
1578 }
1579 
1580 #if defined(CONFIG_PCIEAER) || defined(CONFIG_EEH)
1581 /**
1582  * pci_uevent_ers - emit a uevent during recovery path of PCI device
1583  * @pdev: PCI device undergoing error recovery
1584  * @err_type: type of error event
1585  */
1586 void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type)
1587 {
1588 	int idx = 0;
1589 	char *envp[3];
1590 
1591 	switch (err_type) {
1592 	case PCI_ERS_RESULT_NONE:
1593 	case PCI_ERS_RESULT_CAN_RECOVER:
1594 		envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
1595 		envp[idx++] = "DEVICE_ONLINE=0";
1596 		break;
1597 	case PCI_ERS_RESULT_RECOVERED:
1598 		envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
1599 		envp[idx++] = "DEVICE_ONLINE=1";
1600 		break;
1601 	case PCI_ERS_RESULT_DISCONNECT:
1602 		envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
1603 		envp[idx++] = "DEVICE_ONLINE=0";
1604 		break;
1605 	default:
1606 		break;
1607 	}
1608 
1609 	if (idx > 0) {
1610 		envp[idx++] = NULL;
1611 		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
1612 	}
1613 }
1614 #endif
1615 
1616 static int pci_bus_num_vf(struct device *dev)
1617 {
1618 	return pci_num_vf(to_pci_dev(dev));
1619 }
1620 
1621 /**
1622  * pci_dma_configure - Setup DMA configuration
1623  * @dev: ptr to dev structure
1624  *
1625  * Function to update PCI devices's DMA configuration using the same
1626  * info from the OF node or ACPI node of host bridge's parent (if any).
1627  */
1628 static int pci_dma_configure(struct device *dev)
1629 {
1630 	struct pci_driver *driver = to_pci_driver(dev->driver);
1631 	struct device *bridge;
1632 	int ret = 0;
1633 
1634 	bridge = pci_get_host_bridge_device(to_pci_dev(dev));
1635 
1636 	if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
1637 	    bridge->parent->of_node) {
1638 		ret = of_dma_configure(dev, bridge->parent->of_node, true);
1639 	} else if (has_acpi_companion(bridge)) {
1640 		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
1641 
1642 		ret = acpi_dma_configure(dev, acpi_get_dma_attr(adev));
1643 	}
1644 
1645 	pci_put_host_bridge_device(bridge);
1646 
1647 	if (!ret && !driver->driver_managed_dma) {
1648 		ret = iommu_device_use_default_domain(dev);
1649 		if (ret)
1650 			arch_teardown_dma_ops(dev);
1651 	}
1652 
1653 	return ret;
1654 }
1655 
1656 static void pci_dma_cleanup(struct device *dev)
1657 {
1658 	struct pci_driver *driver = to_pci_driver(dev->driver);
1659 
1660 	if (!driver->driver_managed_dma)
1661 		iommu_device_unuse_default_domain(dev);
1662 }
1663 
1664 struct bus_type pci_bus_type = {
1665 	.name		= "pci",
1666 	.match		= pci_bus_match,
1667 	.uevent		= pci_uevent,
1668 	.probe		= pci_device_probe,
1669 	.remove		= pci_device_remove,
1670 	.shutdown	= pci_device_shutdown,
1671 	.dev_groups	= pci_dev_groups,
1672 	.bus_groups	= pci_bus_groups,
1673 	.drv_groups	= pci_drv_groups,
1674 	.pm		= PCI_PM_OPS_PTR,
1675 	.num_vf		= pci_bus_num_vf,
1676 	.dma_configure	= pci_dma_configure,
1677 	.dma_cleanup	= pci_dma_cleanup,
1678 };
1679 EXPORT_SYMBOL(pci_bus_type);
1680 
1681 #ifdef CONFIG_PCIEPORTBUS
1682 static int pcie_port_bus_match(struct device *dev, struct device_driver *drv)
1683 {
1684 	struct pcie_device *pciedev;
1685 	struct pcie_port_service_driver *driver;
1686 
1687 	if (drv->bus != &pcie_port_bus_type || dev->bus != &pcie_port_bus_type)
1688 		return 0;
1689 
1690 	pciedev = to_pcie_device(dev);
1691 	driver = to_service_driver(drv);
1692 
1693 	if (driver->service != pciedev->service)
1694 		return 0;
1695 
1696 	if (driver->port_type != PCIE_ANY_PORT &&
1697 	    driver->port_type != pci_pcie_type(pciedev->port))
1698 		return 0;
1699 
1700 	return 1;
1701 }
1702 
1703 struct bus_type pcie_port_bus_type = {
1704 	.name		= "pci_express",
1705 	.match		= pcie_port_bus_match,
1706 };
1707 EXPORT_SYMBOL_GPL(pcie_port_bus_type);
1708 #endif
1709 
1710 static int __init pci_driver_init(void)
1711 {
1712 	int ret;
1713 
1714 	ret = bus_register(&pci_bus_type);
1715 	if (ret)
1716 		return ret;
1717 
1718 #ifdef CONFIG_PCIEPORTBUS
1719 	ret = bus_register(&pcie_port_bus_type);
1720 	if (ret)
1721 		return ret;
1722 #endif
1723 	dma_debug_add_bus(&pci_bus_type);
1724 	return 0;
1725 }
1726 postcore_initcall(pci_driver_init);
1727