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 "pci.h"
24#include "pcie/portdrv.h"
25
26struct pci_dynid {
27	struct list_head node;
28	struct pci_device_id id;
29};
30
31/**
32 * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
33 * @drv: target pci driver
34 * @vendor: PCI vendor ID
35 * @device: PCI device ID
36 * @subvendor: PCI subvendor ID
37 * @subdevice: PCI subdevice ID
38 * @class: PCI class
39 * @class_mask: PCI class mask
40 * @driver_data: private driver data
41 *
42 * Adds a new dynamic pci device ID to this driver and causes the
43 * driver to probe for all devices again.  @drv must have been
44 * registered prior to calling this function.
45 *
46 * CONTEXT:
47 * Does GFP_KERNEL allocation.
48 *
49 * RETURNS:
50 * 0 on success, -errno on failure.
51 */
52int pci_add_dynid(struct pci_driver *drv,
53		  unsigned int vendor, unsigned int device,
54		  unsigned int subvendor, unsigned int subdevice,
55		  unsigned int class, unsigned int class_mask,
56		  unsigned long driver_data)
57{
58	struct pci_dynid *dynid;
59
60	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
61	if (!dynid)
62		return -ENOMEM;
63
64	dynid->id.vendor = vendor;
65	dynid->id.device = device;
66	dynid->id.subvendor = subvendor;
67	dynid->id.subdevice = subdevice;
68	dynid->id.class = class;
69	dynid->id.class_mask = class_mask;
70	dynid->id.driver_data = driver_data;
71
72	spin_lock(&drv->dynids.lock);
73	list_add_tail(&dynid->node, &drv->dynids.list);
74	spin_unlock(&drv->dynids.lock);
75
76	return driver_attach(&drv->driver);
77}
78EXPORT_SYMBOL_GPL(pci_add_dynid);
79
80static void pci_free_dynids(struct pci_driver *drv)
81{
82	struct pci_dynid *dynid, *n;
83
84	spin_lock(&drv->dynids.lock);
85	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
86		list_del(&dynid->node);
87		kfree(dynid);
88	}
89	spin_unlock(&drv->dynids.lock);
90}
91
92/**
93 * store_new_id - sysfs frontend to pci_add_dynid()
94 * @driver: target device driver
95 * @buf: buffer for scanning device ID data
96 * @count: input size
97 *
98 * Allow PCI IDs to be added to an existing driver via sysfs.
99 */
100static ssize_t new_id_store(struct device_driver *driver, const char *buf,
101			    size_t count)
102{
103	struct pci_driver *pdrv = to_pci_driver(driver);
104	const struct pci_device_id *ids = pdrv->id_table;
105	u32 vendor, device, subvendor = PCI_ANY_ID,
106		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
107	unsigned long driver_data = 0;
108	int fields = 0;
109	int retval = 0;
110
111	fields = sscanf(buf, "%x %x %x %x %x %x %lx",
112			&vendor, &device, &subvendor, &subdevice,
113			&class, &class_mask, &driver_data);
114	if (fields < 2)
115		return -EINVAL;
116
117	if (fields != 7) {
118		struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
119		if (!pdev)
120			return -ENOMEM;
121
122		pdev->vendor = vendor;
123		pdev->device = device;
124		pdev->subsystem_vendor = subvendor;
125		pdev->subsystem_device = subdevice;
126		pdev->class = class;
127
128		if (pci_match_id(pdrv->id_table, pdev))
129			retval = -EEXIST;
130
131		kfree(pdev);
132
133		if (retval)
134			return retval;
135	}
136
137	/* Only accept driver_data values that match an existing id_table
138	   entry */
139	if (ids) {
140		retval = -EINVAL;
141		while (ids->vendor || ids->subvendor || ids->class_mask) {
142			if (driver_data == ids->driver_data) {
143				retval = 0;
144				break;
145			}
146			ids++;
147		}
148		if (retval)	/* No match */
149			return retval;
150	}
151
152	retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
153			       class, class_mask, driver_data);
154	if (retval)
155		return retval;
156	return count;
157}
158static DRIVER_ATTR_WO(new_id);
159
160/**
161 * store_remove_id - remove a PCI device ID from this driver
162 * @driver: target device driver
163 * @buf: buffer for scanning device ID data
164 * @count: input size
165 *
166 * Removes a dynamic pci device ID to this driver.
167 */
168static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
169			       size_t count)
170{
171	struct pci_dynid *dynid, *n;
172	struct pci_driver *pdrv = to_pci_driver(driver);
173	u32 vendor, device, subvendor = PCI_ANY_ID,
174		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
175	int fields = 0;
176	size_t retval = -ENODEV;
177
178	fields = sscanf(buf, "%x %x %x %x %x %x",
179			&vendor, &device, &subvendor, &subdevice,
180			&class, &class_mask);
181	if (fields < 2)
182		return -EINVAL;
183
184	spin_lock(&pdrv->dynids.lock);
185	list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
186		struct pci_device_id *id = &dynid->id;
187		if ((id->vendor == vendor) &&
188		    (id->device == device) &&
189		    (subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
190		    (subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
191		    !((id->class ^ class) & class_mask)) {
192			list_del(&dynid->node);
193			kfree(dynid);
194			retval = count;
195			break;
196		}
197	}
198	spin_unlock(&pdrv->dynids.lock);
199
200	return retval;
201}
202static DRIVER_ATTR_WO(remove_id);
203
204static struct attribute *pci_drv_attrs[] = {
205	&driver_attr_new_id.attr,
206	&driver_attr_remove_id.attr,
207	NULL,
208};
209ATTRIBUTE_GROUPS(pci_drv);
210
211/**
212 * pci_match_id - See if a pci device matches a given pci_id table
213 * @ids: array of PCI device id structures to search in
214 * @dev: the PCI device structure to match against.
215 *
216 * Used by a driver to check whether a PCI device present in the
217 * system is in its list of supported devices.  Returns the matching
218 * pci_device_id structure or %NULL if there is no match.
219 *
220 * Deprecated, don't use this as it will not catch any dynamic ids
221 * that a driver might want to check for.
222 */
223const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
224					 struct pci_dev *dev)
225{
226	if (ids) {
227		while (ids->vendor || ids->subvendor || ids->class_mask) {
228			if (pci_match_one_device(ids, dev))
229				return ids;
230			ids++;
231		}
232	}
233	return NULL;
234}
235EXPORT_SYMBOL(pci_match_id);
236
237static const struct pci_device_id pci_device_id_any = {
238	.vendor = PCI_ANY_ID,
239	.device = PCI_ANY_ID,
240	.subvendor = PCI_ANY_ID,
241	.subdevice = PCI_ANY_ID,
242};
243
244/**
245 * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
246 * @drv: the PCI driver to match against
247 * @dev: the PCI device structure to match against
248 *
249 * Used by a driver to check whether a PCI device present in the
250 * system is in its list of supported devices.  Returns the matching
251 * pci_device_id structure or %NULL if there is no match.
252 */
253static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
254						    struct pci_dev *dev)
255{
256	struct pci_dynid *dynid;
257	const struct pci_device_id *found_id = NULL;
258
259	/* When driver_override is set, only bind to the matching driver */
260	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
261		return NULL;
262
263	/* Look at the dynamic ids first, before the static ones */
264	spin_lock(&drv->dynids.lock);
265	list_for_each_entry(dynid, &drv->dynids.list, node) {
266		if (pci_match_one_device(&dynid->id, dev)) {
267			found_id = &dynid->id;
268			break;
269		}
270	}
271	spin_unlock(&drv->dynids.lock);
272
273	if (!found_id)
274		found_id = pci_match_id(drv->id_table, dev);
275
276	/* driver_override will always match, send a dummy id */
277	if (!found_id && dev->driver_override)
278		found_id = &pci_device_id_any;
279
280	return found_id;
281}
282
283struct drv_dev_and_id {
284	struct pci_driver *drv;
285	struct pci_dev *dev;
286	const struct pci_device_id *id;
287};
288
289static long local_pci_probe(void *_ddi)
290{
291	struct drv_dev_and_id *ddi = _ddi;
292	struct pci_dev *pci_dev = ddi->dev;
293	struct pci_driver *pci_drv = ddi->drv;
294	struct device *dev = &pci_dev->dev;
295	int rc;
296
297	/*
298	 * Unbound PCI devices are always put in D0, regardless of
299	 * runtime PM status.  During probe, the device is set to
300	 * active and the usage count is incremented.  If the driver
301	 * supports runtime PM, it should call pm_runtime_put_noidle(),
302	 * or any other runtime PM helper function decrementing the usage
303	 * count, in its probe routine and pm_runtime_get_noresume() in
304	 * its remove routine.
305	 */
306	pm_runtime_get_sync(dev);
307	pci_dev->driver = pci_drv;
308	rc = pci_drv->probe(pci_dev, ddi->id);
309	if (!rc)
310		return rc;
311	if (rc < 0) {
312		pci_dev->driver = NULL;
313		pm_runtime_put_sync(dev);
314		return rc;
315	}
316	/*
317	 * Probe function should return < 0 for failure, 0 for success
318	 * Treat values > 0 as success, but warn.
319	 */
320	pci_warn(pci_dev, "Driver probe function unexpectedly returned %d\n",
321		 rc);
322	return 0;
323}
324
325static bool pci_physfn_is_probed(struct pci_dev *dev)
326{
327#ifdef CONFIG_PCI_IOV
328	return dev->is_virtfn && dev->physfn->is_probed;
329#else
330	return false;
331#endif
332}
333
334static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
335			  const struct pci_device_id *id)
336{
337	int error, node, cpu;
338	int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ;
339	struct drv_dev_and_id ddi = { drv, dev, id };
340
341	/*
342	 * Execute driver initialization on node where the device is
343	 * attached.  This way the driver likely allocates its local memory
344	 * on the right node.
345	 */
346	node = dev_to_node(&dev->dev);
347	dev->is_probed = 1;
348
349	cpu_hotplug_disable();
350
351	/*
352	 * Prevent nesting work_on_cpu() for the case where a Virtual Function
353	 * device is probed from work_on_cpu() of the Physical device.
354	 */
355	if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
356	    pci_physfn_is_probed(dev))
357		cpu = nr_cpu_ids;
358	else
359		cpu = cpumask_any_and(cpumask_of_node(node),
360				      housekeeping_cpumask(hk_flags));
361
362	if (cpu < nr_cpu_ids)
363		error = work_on_cpu(cpu, local_pci_probe, &ddi);
364	else
365		error = local_pci_probe(&ddi);
366
367	dev->is_probed = 0;
368	cpu_hotplug_enable();
369	return error;
370}
371
372/**
373 * __pci_device_probe - check if a driver wants to claim a specific PCI device
374 * @drv: driver to call to check if it wants the PCI device
375 * @pci_dev: PCI device being probed
376 *
377 * returns 0 on success, else error.
378 * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
379 */
380static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
381{
382	const struct pci_device_id *id;
383	int error = 0;
384
385	if (!pci_dev->driver && drv->probe) {
386		error = -ENODEV;
387
388		id = pci_match_device(drv, pci_dev);
389		if (id)
390			error = pci_call_probe(drv, pci_dev, id);
391	}
392	return error;
393}
394
395int __weak pcibios_alloc_irq(struct pci_dev *dev)
396{
397	return 0;
398}
399
400void __weak pcibios_free_irq(struct pci_dev *dev)
401{
402}
403
404#ifdef CONFIG_PCI_IOV
405static inline bool pci_device_can_probe(struct pci_dev *pdev)
406{
407	return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe ||
408		pdev->driver_override);
409}
410#else
411static inline bool pci_device_can_probe(struct pci_dev *pdev)
412{
413	return true;
414}
415#endif
416
417static int pci_device_probe(struct device *dev)
418{
419	int error;
420	struct pci_dev *pci_dev = to_pci_dev(dev);
421	struct pci_driver *drv = to_pci_driver(dev->driver);
422
423	if (!pci_device_can_probe(pci_dev))
424		return -ENODEV;
425
426	pci_assign_irq(pci_dev);
427
428	error = pcibios_alloc_irq(pci_dev);
429	if (error < 0)
430		return error;
431
432	pci_dev_get(pci_dev);
433	error = __pci_device_probe(drv, pci_dev);
434	if (error) {
435		pcibios_free_irq(pci_dev);
436		pci_dev_put(pci_dev);
437	}
438
439	return error;
440}
441
442static int pci_device_remove(struct device *dev)
443{
444	struct pci_dev *pci_dev = to_pci_dev(dev);
445	struct pci_driver *drv = pci_dev->driver;
446
447	if (drv->remove) {
448		pm_runtime_get_sync(dev);
449		/*
450		 * If the driver provides a .runtime_idle() callback and it has
451		 * started to run already, it may continue to run in parallel
452		 * with the code below, so wait until all of the runtime PM
453		 * activity has completed.
454		 */
455		pm_runtime_barrier(dev);
456		drv->remove(pci_dev);
457		pm_runtime_put_noidle(dev);
458	}
459	pcibios_free_irq(pci_dev);
460	pci_dev->driver = NULL;
461	pci_iov_remove(pci_dev);
462
463	/* Undo the runtime PM settings in local_pci_probe() */
464	pm_runtime_put_sync(dev);
465
466	/*
467	 * If the device is still on, set the power state as "unknown",
468	 * since it might change by the next time we load the driver.
469	 */
470	if (pci_dev->current_state == PCI_D0)
471		pci_dev->current_state = PCI_UNKNOWN;
472
473	/*
474	 * We would love to complain here if pci_dev->is_enabled is set, that
475	 * the driver should have called pci_disable_device(), but the
476	 * unfortunate fact is there are too many odd BIOS and bridge setups
477	 * that don't like drivers doing that all of the time.
478	 * Oh well, we can dream of sane hardware when we sleep, no matter how
479	 * horrible the crap we have to deal with is when we are awake...
480	 */
481
482	pci_dev_put(pci_dev);
483	return 0;
484}
485
486static void pci_device_shutdown(struct device *dev)
487{
488	struct pci_dev *pci_dev = to_pci_dev(dev);
489	struct pci_driver *drv = pci_dev->driver;
490
491	pm_runtime_resume(dev);
492
493	if (drv && drv->shutdown)
494		drv->shutdown(pci_dev);
495
496	/*
497	 * If this is a kexec reboot, turn off Bus Master bit on the
498	 * device to tell it to not continue to do DMA. Don't touch
499	 * devices in D3cold or unknown states.
500	 * If it is not a kexec reboot, firmware will hit the PCI
501	 * devices with big hammer and stop their DMA any way.
502	 */
503	if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
504		pci_clear_master(pci_dev);
505}
506
507#ifdef CONFIG_PM
508
509/* Auxiliary functions used for system resume and run-time resume. */
510
511/**
512 * pci_restore_standard_config - restore standard config registers of PCI device
513 * @pci_dev: PCI device to handle
514 */
515static int pci_restore_standard_config(struct pci_dev *pci_dev)
516{
517	pci_update_current_state(pci_dev, PCI_UNKNOWN);
518
519	if (pci_dev->current_state != PCI_D0) {
520		int error = pci_set_power_state(pci_dev, PCI_D0);
521		if (error)
522			return error;
523	}
524
525	pci_restore_state(pci_dev);
526	pci_pme_restore(pci_dev);
527	return 0;
528}
529
530static void pci_pm_default_resume(struct pci_dev *pci_dev)
531{
532	pci_fixup_device(pci_fixup_resume, pci_dev);
533	pci_enable_wake(pci_dev, PCI_D0, false);
534}
535
536#endif
537
538#ifdef CONFIG_PM_SLEEP
539
540static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
541{
542	pci_power_up(pci_dev);
543	pci_update_current_state(pci_dev, PCI_D0);
544	pci_restore_state(pci_dev);
545	pci_pme_restore(pci_dev);
546}
547
548/*
549 * Default "suspend" method for devices that have no driver provided suspend,
550 * or not even a driver at all (second part).
551 */
552static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
553{
554	/*
555	 * mark its power state as "unknown", since we don't know if
556	 * e.g. the BIOS will change its device state when we suspend.
557	 */
558	if (pci_dev->current_state == PCI_D0)
559		pci_dev->current_state = PCI_UNKNOWN;
560}
561
562/*
563 * Default "resume" method for devices that have no driver provided resume,
564 * or not even a driver at all (second part).
565 */
566static int pci_pm_reenable_device(struct pci_dev *pci_dev)
567{
568	int retval;
569
570	/* if the device was enabled before suspend, reenable */
571	retval = pci_reenable_device(pci_dev);
572	/*
573	 * if the device was busmaster before the suspend, make it busmaster
574	 * again
575	 */
576	if (pci_dev->is_busmaster)
577		pci_set_master(pci_dev);
578
579	return retval;
580}
581
582static int pci_legacy_suspend(struct device *dev, pm_message_t state)
583{
584	struct pci_dev *pci_dev = to_pci_dev(dev);
585	struct pci_driver *drv = pci_dev->driver;
586
587	if (drv && drv->suspend) {
588		pci_power_t prev = pci_dev->current_state;
589		int error;
590
591		error = drv->suspend(pci_dev, state);
592		suspend_report_result(drv->suspend, error);
593		if (error)
594			return error;
595
596		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
597		    && pci_dev->current_state != PCI_UNKNOWN) {
598			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
599				      "PCI PM: Device state not saved by %pS\n",
600				      drv->suspend);
601		}
602	}
603
604	pci_fixup_device(pci_fixup_suspend, pci_dev);
605
606	return 0;
607}
608
609static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
610{
611	struct pci_dev *pci_dev = to_pci_dev(dev);
612
613	if (!pci_dev->state_saved)
614		pci_save_state(pci_dev);
615
616	pci_pm_set_unknown_state(pci_dev);
617
618	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
619
620	return 0;
621}
622
623static int pci_legacy_resume(struct device *dev)
624{
625	struct pci_dev *pci_dev = to_pci_dev(dev);
626	struct pci_driver *drv = pci_dev->driver;
627
628	pci_fixup_device(pci_fixup_resume, pci_dev);
629
630	return drv && drv->resume ?
631			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
632}
633
634/* Auxiliary functions used by the new power management framework */
635
636static void pci_pm_default_suspend(struct pci_dev *pci_dev)
637{
638	/* Disable non-bridge devices without PM support */
639	if (!pci_has_subordinate(pci_dev))
640		pci_disable_enabled_device(pci_dev);
641}
642
643static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
644{
645	struct pci_driver *drv = pci_dev->driver;
646	bool ret = drv && (drv->suspend || drv->resume);
647
648	/*
649	 * Legacy PM support is used by default, so warn if the new framework is
650	 * supported as well.  Drivers are supposed to support either the
651	 * former, or the latter, but not both at the same time.
652	 */
653	pci_WARN(pci_dev, ret && drv->driver.pm, "device %04x:%04x\n",
654		 pci_dev->vendor, pci_dev->device);
655
656	return ret;
657}
658
659/* New power management framework */
660
661static int pci_pm_prepare(struct device *dev)
662{
663	struct pci_dev *pci_dev = to_pci_dev(dev);
664	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
665
666	if (pm && pm->prepare) {
667		int error = pm->prepare(dev);
668		if (error < 0)
669			return error;
670
671		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
672			return 0;
673	}
674	if (pci_dev_need_resume(pci_dev))
675		return 0;
676
677	/*
678	 * The PME setting needs to be adjusted here in case the direct-complete
679	 * optimization is used with respect to this device.
680	 */
681	pci_dev_adjust_pme(pci_dev);
682	return 1;
683}
684
685static void pci_pm_complete(struct device *dev)
686{
687	struct pci_dev *pci_dev = to_pci_dev(dev);
688
689	pci_dev_complete_resume(pci_dev);
690	pm_generic_complete(dev);
691
692	/* Resume device if platform firmware has put it in reset-power-on */
693	if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
694		pci_power_t pre_sleep_state = pci_dev->current_state;
695
696		pci_refresh_power_state(pci_dev);
697		/*
698		 * On platforms with ACPI this check may also trigger for
699		 * devices sharing power resources if one of those power
700		 * resources has been activated as a result of a change of the
701		 * power state of another device sharing it.  However, in that
702		 * case it is also better to resume the device, in general.
703		 */
704		if (pci_dev->current_state < pre_sleep_state)
705			pm_request_resume(dev);
706	}
707}
708
709#else /* !CONFIG_PM_SLEEP */
710
711#define pci_pm_prepare	NULL
712#define pci_pm_complete	NULL
713
714#endif /* !CONFIG_PM_SLEEP */
715
716#ifdef CONFIG_SUSPEND
717static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
718{
719	/*
720	 * Some BIOSes forget to clear Root PME Status bits after system
721	 * wakeup, which breaks ACPI-based runtime wakeup on PCI Express.
722	 * Clear those bits now just in case (shouldn't hurt).
723	 */
724	if (pci_is_pcie(pci_dev) &&
725	    (pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT ||
726	     pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
727		pcie_clear_root_pme_status(pci_dev);
728}
729
730static int pci_pm_suspend(struct device *dev)
731{
732	struct pci_dev *pci_dev = to_pci_dev(dev);
733	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
734
735	pci_dev->skip_bus_pm = false;
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_need_resume(pci_dev)) {
760		pm_runtime_resume(dev);
761		pci_dev->state_saved = false;
762	} else {
763		pci_dev_adjust_pme(pci_dev);
764	}
765
766	if (pm->suspend) {
767		pci_power_t prev = pci_dev->current_state;
768		int error;
769
770		error = pm->suspend(dev);
771		suspend_report_result(pm->suspend, error);
772		if (error)
773			return error;
774
775		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
776		    && pci_dev->current_state != PCI_UNKNOWN) {
777			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
778				      "PCI PM: State of device not saved by %pS\n",
779				      pm->suspend);
780		}
781	}
782
783	return 0;
784}
785
786static int pci_pm_suspend_late(struct device *dev)
787{
788	if (dev_pm_skip_suspend(dev))
789		return 0;
790
791	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
792
793	return pm_generic_suspend_late(dev);
794}
795
796static int pci_pm_suspend_noirq(struct device *dev)
797{
798	struct pci_dev *pci_dev = to_pci_dev(dev);
799	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
800
801	if (dev_pm_skip_suspend(dev))
802		return 0;
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			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
824				      "PCI PM: State of device not saved by %pS\n",
825				      pm->suspend_noirq);
826			goto Fixup;
827		}
828	}
829
830	if (pci_dev->skip_bus_pm) {
831		/*
832		 * Either the device is a bridge with a child in D0 below it, or
833		 * the function is running for the second time in a row without
834		 * going through full resume, which is possible only during
835		 * suspend-to-idle in a spurious wakeup case.  The device should
836		 * be in D0 at this point, but if it is a bridge, it may be
837		 * necessary to save its state.
838		 */
839		if (!pci_dev->state_saved)
840			pci_save_state(pci_dev);
841	} else if (!pci_dev->state_saved) {
842		pci_save_state(pci_dev);
843		if (pci_power_manageable(pci_dev))
844			pci_prepare_to_sleep(pci_dev);
845	}
846
847	pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
848		pci_power_name(pci_dev->current_state));
849
850	if (pci_dev->current_state == PCI_D0) {
851		pci_dev->skip_bus_pm = true;
852		/*
853		 * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
854		 * downstream device is in D0, so avoid changing the power state
855		 * of the parent bridge by setting the skip_bus_pm flag for it.
856		 */
857		if (pci_dev->bus->self)
858			pci_dev->bus->self->skip_bus_pm = true;
859	}
860
861	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
862		pci_dbg(pci_dev, "PCI PM: Skipped\n");
863		goto Fixup;
864	}
865
866	pci_pm_set_unknown_state(pci_dev);
867
868	/*
869	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
870	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
871	 * hasn't been quiesced and tries to turn it off.  If the controller
872	 * is already in D3, this can hang or cause memory corruption.
873	 *
874	 * Since the value of the COMMAND register doesn't matter once the
875	 * device has been suspended, we can safely set it to 0 here.
876	 */
877	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
878		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
879
880Fixup:
881	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
882
883	/*
884	 * If the target system sleep state is suspend-to-idle, it is sufficient
885	 * to check whether or not the device's wakeup settings are good for
886	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
887	 * pci_pm_complete() to take care of fixing up the device's state
888	 * anyway, if need be.
889	 */
890	if (device_can_wakeup(dev) && !device_may_wakeup(dev))
891		dev->power.may_skip_resume = false;
892
893	return 0;
894}
895
896static int pci_pm_resume_noirq(struct device *dev)
897{
898	struct pci_dev *pci_dev = to_pci_dev(dev);
899	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
900	pci_power_t prev_state = pci_dev->current_state;
901	bool skip_bus_pm = pci_dev->skip_bus_pm;
902
903	if (dev_pm_skip_resume(dev))
904		return 0;
905
906	/*
907	 * In the suspend-to-idle case, devices left in D0 during suspend will
908	 * stay in D0, so it is not necessary to restore or update their
909	 * configuration here and attempting to put them into D0 again is
910	 * pointless, so avoid doing that.
911	 */
912	if (!(skip_bus_pm && pm_suspend_no_platform()))
913		pci_pm_default_resume_early(pci_dev);
914
915	pci_fixup_device(pci_fixup_resume_early, pci_dev);
916	pcie_pme_root_status_cleanup(pci_dev);
917
918	if (!skip_bus_pm && prev_state == PCI_D3cold)
919		pci_bridge_wait_for_secondary_bus(pci_dev, "resume", PCI_RESET_WAIT);
920
921	if (pci_has_legacy_pm_support(pci_dev))
922		return 0;
923
924	if (pm && pm->resume_noirq)
925		return pm->resume_noirq(dev);
926
927	return 0;
928}
929
930static int pci_pm_resume_early(struct device *dev)
931{
932	if (dev_pm_skip_resume(dev))
933		return 0;
934
935	return pm_generic_resume_early(dev);
936}
937
938static int pci_pm_resume(struct device *dev)
939{
940	struct pci_dev *pci_dev = to_pci_dev(dev);
941	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
942
943	/*
944	 * This is necessary for the suspend error path in which resume is
945	 * called without restoring the standard config registers of the device.
946	 */
947	if (pci_dev->state_saved)
948		pci_restore_standard_config(pci_dev);
949
950	if (pci_has_legacy_pm_support(pci_dev))
951		return pci_legacy_resume(dev);
952
953	pci_pm_default_resume(pci_dev);
954
955	if (pm) {
956		if (pm->resume)
957			return pm->resume(dev);
958	} else {
959		pci_pm_reenable_device(pci_dev);
960	}
961
962	return 0;
963}
964
965#else /* !CONFIG_SUSPEND */
966
967#define pci_pm_suspend		NULL
968#define pci_pm_suspend_late	NULL
969#define pci_pm_suspend_noirq	NULL
970#define pci_pm_resume		NULL
971#define pci_pm_resume_early	NULL
972#define pci_pm_resume_noirq	NULL
973
974#endif /* !CONFIG_SUSPEND */
975
976#ifdef CONFIG_HIBERNATE_CALLBACKS
977
978static int pci_pm_freeze(struct device *dev)
979{
980	struct pci_dev *pci_dev = to_pci_dev(dev);
981	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
982
983	if (pci_has_legacy_pm_support(pci_dev))
984		return pci_legacy_suspend(dev, PMSG_FREEZE);
985
986	if (!pm) {
987		pci_pm_default_suspend(pci_dev);
988		return 0;
989	}
990
991	/*
992	 * Resume all runtime-suspended devices before creating a snapshot
993	 * image of system memory, because the restore kernel generally cannot
994	 * be expected to always handle them consistently and they need to be
995	 * put into the runtime-active metastate during system resume anyway,
996	 * so it is better to ensure that the state saved in the image will be
997	 * always consistent with that.
998	 */
999	pm_runtime_resume(dev);
1000	pci_dev->state_saved = false;
1001
1002	if (pm->freeze) {
1003		int error;
1004
1005		error = pm->freeze(dev);
1006		suspend_report_result(pm->freeze, error);
1007		if (error)
1008			return error;
1009	}
1010
1011	return 0;
1012}
1013
1014static int pci_pm_freeze_noirq(struct device *dev)
1015{
1016	struct pci_dev *pci_dev = to_pci_dev(dev);
1017	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1018
1019	if (pci_has_legacy_pm_support(pci_dev))
1020		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
1021
1022	if (pm && pm->freeze_noirq) {
1023		int error;
1024
1025		error = pm->freeze_noirq(dev);
1026		suspend_report_result(pm->freeze_noirq, error);
1027		if (error)
1028			return error;
1029	}
1030
1031	if (!pci_dev->state_saved)
1032		pci_save_state(pci_dev);
1033
1034	pci_pm_set_unknown_state(pci_dev);
1035
1036	return 0;
1037}
1038
1039static int pci_pm_thaw_noirq(struct device *dev)
1040{
1041	struct pci_dev *pci_dev = to_pci_dev(dev);
1042	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1043
1044	/*
1045	 * The pm->thaw_noirq() callback assumes the device has been
1046	 * returned to D0 and its config state has been restored.
1047	 *
1048	 * In addition, pci_restore_state() restores MSI-X state in MMIO
1049	 * space, which requires the device to be in D0, so return it to D0
1050	 * in case the driver's "freeze" callbacks put it into a low-power
1051	 * state.
1052	 */
1053	pci_set_power_state(pci_dev, PCI_D0);
1054	pci_restore_state(pci_dev);
1055
1056	if (pci_has_legacy_pm_support(pci_dev))
1057		return 0;
1058
1059	if (pm && pm->thaw_noirq)
1060		return pm->thaw_noirq(dev);
1061
1062	return 0;
1063}
1064
1065static int pci_pm_thaw(struct device *dev)
1066{
1067	struct pci_dev *pci_dev = to_pci_dev(dev);
1068	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1069	int error = 0;
1070
1071	if (pci_has_legacy_pm_support(pci_dev))
1072		return pci_legacy_resume(dev);
1073
1074	if (pm) {
1075		if (pm->thaw)
1076			error = pm->thaw(dev);
1077	} else {
1078		pci_pm_reenable_device(pci_dev);
1079	}
1080
1081	pci_dev->state_saved = false;
1082
1083	return error;
1084}
1085
1086static int pci_pm_poweroff(struct device *dev)
1087{
1088	struct pci_dev *pci_dev = to_pci_dev(dev);
1089	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1090
1091	if (pci_has_legacy_pm_support(pci_dev))
1092		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
1093
1094	if (!pm) {
1095		pci_pm_default_suspend(pci_dev);
1096		return 0;
1097	}
1098
1099	/* The reason to do that is the same as in pci_pm_suspend(). */
1100	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1101	    pci_dev_need_resume(pci_dev)) {
1102		pm_runtime_resume(dev);
1103		pci_dev->state_saved = false;
1104	} else {
1105		pci_dev_adjust_pme(pci_dev);
1106	}
1107
1108	if (pm->poweroff) {
1109		int error;
1110
1111		error = pm->poweroff(dev);
1112		suspend_report_result(pm->poweroff, error);
1113		if (error)
1114			return error;
1115	}
1116
1117	return 0;
1118}
1119
1120static int pci_pm_poweroff_late(struct device *dev)
1121{
1122	if (dev_pm_skip_suspend(dev))
1123		return 0;
1124
1125	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
1126
1127	return pm_generic_poweroff_late(dev);
1128}
1129
1130static int pci_pm_poweroff_noirq(struct device *dev)
1131{
1132	struct pci_dev *pci_dev = to_pci_dev(dev);
1133	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1134
1135	if (dev_pm_skip_suspend(dev))
1136		return 0;
1137
1138	if (pci_has_legacy_pm_support(pci_dev))
1139		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
1140
1141	if (!pm) {
1142		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1143		return 0;
1144	}
1145
1146	if (pm->poweroff_noirq) {
1147		int error;
1148
1149		error = pm->poweroff_noirq(dev);
1150		suspend_report_result(pm->poweroff_noirq, error);
1151		if (error)
1152			return error;
1153	}
1154
1155	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
1156		pci_prepare_to_sleep(pci_dev);
1157
1158	/*
1159	 * The reason for doing this here is the same as for the analogous code
1160	 * in pci_pm_suspend_noirq().
1161	 */
1162	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
1163		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
1164
1165	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
1166
1167	return 0;
1168}
1169
1170static int pci_pm_restore_noirq(struct device *dev)
1171{
1172	struct pci_dev *pci_dev = to_pci_dev(dev);
1173	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1174
1175	pci_pm_default_resume_early(pci_dev);
1176	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1177
1178	if (pci_has_legacy_pm_support(pci_dev))
1179		return 0;
1180
1181	if (pm && pm->restore_noirq)
1182		return pm->restore_noirq(dev);
1183
1184	return 0;
1185}
1186
1187static int pci_pm_restore(struct device *dev)
1188{
1189	struct pci_dev *pci_dev = to_pci_dev(dev);
1190	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1191
1192	/*
1193	 * This is necessary for the hibernation error path in which restore is
1194	 * called without restoring the standard config registers of the device.
1195	 */
1196	if (pci_dev->state_saved)
1197		pci_restore_standard_config(pci_dev);
1198
1199	if (pci_has_legacy_pm_support(pci_dev))
1200		return pci_legacy_resume(dev);
1201
1202	pci_pm_default_resume(pci_dev);
1203
1204	if (pm) {
1205		if (pm->restore)
1206			return pm->restore(dev);
1207	} else {
1208		pci_pm_reenable_device(pci_dev);
1209	}
1210
1211	return 0;
1212}
1213
1214#else /* !CONFIG_HIBERNATE_CALLBACKS */
1215
1216#define pci_pm_freeze		NULL
1217#define pci_pm_freeze_noirq	NULL
1218#define pci_pm_thaw		NULL
1219#define pci_pm_thaw_noirq	NULL
1220#define pci_pm_poweroff		NULL
1221#define pci_pm_poweroff_late	NULL
1222#define pci_pm_poweroff_noirq	NULL
1223#define pci_pm_restore		NULL
1224#define pci_pm_restore_noirq	NULL
1225
1226#endif /* !CONFIG_HIBERNATE_CALLBACKS */
1227
1228#ifdef CONFIG_PM
1229
1230static int pci_pm_runtime_suspend(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	pci_power_t prev = pci_dev->current_state;
1235	int error;
1236
1237	/*
1238	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
1239	 * but it may go to D3cold when the bridge above it runtime suspends.
1240	 * Save its config space in case that happens.
1241	 */
1242	if (!pci_dev->driver) {
1243		pci_save_state(pci_dev);
1244		return 0;
1245	}
1246
1247	pci_dev->state_saved = false;
1248	if (pm && pm->runtime_suspend) {
1249		error = pm->runtime_suspend(dev);
1250		/*
1251		 * -EBUSY and -EAGAIN is used to request the runtime PM core
1252		 * to schedule a new suspend, so log the event only with debug
1253		 * log level.
1254		 */
1255		if (error == -EBUSY || error == -EAGAIN) {
1256			pci_dbg(pci_dev, "can't suspend now (%ps returned %d)\n",
1257				pm->runtime_suspend, error);
1258			return error;
1259		} else if (error) {
1260			pci_err(pci_dev, "can't suspend (%ps returned %d)\n",
1261				pm->runtime_suspend, error);
1262			return error;
1263		}
1264	}
1265
1266	pci_fixup_device(pci_fixup_suspend, pci_dev);
1267
1268	if (pm && pm->runtime_suspend
1269	    && !pci_dev->state_saved && pci_dev->current_state != PCI_D0
1270	    && pci_dev->current_state != PCI_UNKNOWN) {
1271		pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
1272			      "PCI PM: State of device not saved by %pS\n",
1273			      pm->runtime_suspend);
1274		return 0;
1275	}
1276
1277	if (!pci_dev->state_saved) {
1278		pci_save_state(pci_dev);
1279		pci_finish_runtime_suspend(pci_dev);
1280	}
1281
1282	return 0;
1283}
1284
1285static int pci_pm_runtime_resume(struct device *dev)
1286{
1287	struct pci_dev *pci_dev = to_pci_dev(dev);
1288	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1289	pci_power_t prev_state = pci_dev->current_state;
1290	int error = 0;
1291
1292	/*
1293	 * Restoring config space is necessary even if the device is not bound
1294	 * to a driver because although we left it in D0, it may have gone to
1295	 * D3cold when the bridge above it runtime suspended.
1296	 */
1297	pci_restore_standard_config(pci_dev);
1298
1299	if (!pci_dev->driver)
1300		return 0;
1301
1302	pci_fixup_device(pci_fixup_resume_early, pci_dev);
1303	pci_pm_default_resume(pci_dev);
1304
1305	if (prev_state == PCI_D3cold)
1306		pci_bridge_wait_for_secondary_bus(pci_dev, "resume", PCI_RESET_WAIT);
1307
1308	if (pm && pm->runtime_resume)
1309		error = pm->runtime_resume(dev);
1310
1311	pci_dev->runtime_d3cold = false;
1312
1313	return error;
1314}
1315
1316static int pci_pm_runtime_idle(struct device *dev)
1317{
1318	struct pci_dev *pci_dev = to_pci_dev(dev);
1319	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
1320
1321	/*
1322	 * If pci_dev->driver is not set (unbound), the device should
1323	 * always remain in D0 regardless of the runtime PM status
1324	 */
1325	if (!pci_dev->driver)
1326		return 0;
1327
1328	if (!pm)
1329		return -ENOSYS;
1330
1331	if (pm->runtime_idle)
1332		return pm->runtime_idle(dev);
1333
1334	return 0;
1335}
1336
1337static const struct dev_pm_ops pci_dev_pm_ops = {
1338	.prepare = pci_pm_prepare,
1339	.complete = pci_pm_complete,
1340	.suspend = pci_pm_suspend,
1341	.suspend_late = pci_pm_suspend_late,
1342	.resume = pci_pm_resume,
1343	.resume_early = pci_pm_resume_early,
1344	.freeze = pci_pm_freeze,
1345	.thaw = pci_pm_thaw,
1346	.poweroff = pci_pm_poweroff,
1347	.poweroff_late = pci_pm_poweroff_late,
1348	.restore = pci_pm_restore,
1349	.suspend_noirq = pci_pm_suspend_noirq,
1350	.resume_noirq = pci_pm_resume_noirq,
1351	.freeze_noirq = pci_pm_freeze_noirq,
1352	.thaw_noirq = pci_pm_thaw_noirq,
1353	.poweroff_noirq = pci_pm_poweroff_noirq,
1354	.restore_noirq = pci_pm_restore_noirq,
1355	.runtime_suspend = pci_pm_runtime_suspend,
1356	.runtime_resume = pci_pm_runtime_resume,
1357	.runtime_idle = pci_pm_runtime_idle,
1358};
1359
1360#define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
1361
1362#else /* !CONFIG_PM */
1363
1364#define pci_pm_runtime_suspend	NULL
1365#define pci_pm_runtime_resume	NULL
1366#define pci_pm_runtime_idle	NULL
1367
1368#define PCI_PM_OPS_PTR	NULL
1369
1370#endif /* !CONFIG_PM */
1371
1372/**
1373 * __pci_register_driver - register a new pci driver
1374 * @drv: the driver structure to register
1375 * @owner: owner module of drv
1376 * @mod_name: module name string
1377 *
1378 * Adds the driver structure to the list of registered drivers.
1379 * Returns a negative value on error, otherwise 0.
1380 * If no error occurred, the driver remains registered even if
1381 * no device was claimed during registration.
1382 */
1383int __pci_register_driver(struct pci_driver *drv, struct module *owner,
1384			  const char *mod_name)
1385{
1386	/* initialize common driver fields */
1387	drv->driver.name = drv->name;
1388	drv->driver.bus = &pci_bus_type;
1389	drv->driver.owner = owner;
1390	drv->driver.mod_name = mod_name;
1391	drv->driver.groups = drv->groups;
1392
1393	spin_lock_init(&drv->dynids.lock);
1394	INIT_LIST_HEAD(&drv->dynids.list);
1395
1396	/* register with core */
1397	return driver_register(&drv->driver);
1398}
1399EXPORT_SYMBOL(__pci_register_driver);
1400
1401/**
1402 * pci_unregister_driver - unregister a pci driver
1403 * @drv: the driver structure to unregister
1404 *
1405 * Deletes the driver structure from the list of registered PCI drivers,
1406 * gives it a chance to clean up by calling its remove() function for
1407 * each device it was responsible for, and marks those devices as
1408 * driverless.
1409 */
1410
1411void pci_unregister_driver(struct pci_driver *drv)
1412{
1413	driver_unregister(&drv->driver);
1414	pci_free_dynids(drv);
1415}
1416EXPORT_SYMBOL(pci_unregister_driver);
1417
1418static struct pci_driver pci_compat_driver = {
1419	.name = "compat"
1420};
1421
1422/**
1423 * pci_dev_driver - get the pci_driver of a device
1424 * @dev: the device to query
1425 *
1426 * Returns the appropriate pci_driver structure or %NULL if there is no
1427 * registered driver for the device.
1428 */
1429struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
1430{
1431	if (dev->driver)
1432		return dev->driver;
1433	else {
1434		int i;
1435		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
1436			if (dev->resource[i].flags & IORESOURCE_BUSY)
1437				return &pci_compat_driver;
1438	}
1439	return NULL;
1440}
1441EXPORT_SYMBOL(pci_dev_driver);
1442
1443/**
1444 * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
1445 * @dev: the PCI device structure to match against
1446 * @drv: the device driver to search for matching PCI device id structures
1447 *
1448 * Used by a driver to check whether a PCI device present in the
1449 * system is in its list of supported devices. Returns the matching
1450 * pci_device_id structure or %NULL if there is no match.
1451 */
1452static int pci_bus_match(struct device *dev, struct device_driver *drv)
1453{
1454	struct pci_dev *pci_dev = to_pci_dev(dev);
1455	struct pci_driver *pci_drv;
1456	const struct pci_device_id *found_id;
1457
1458	if (!pci_dev->match_driver)
1459		return 0;
1460
1461	pci_drv = to_pci_driver(drv);
1462	found_id = pci_match_device(pci_drv, pci_dev);
1463	if (found_id)
1464		return 1;
1465
1466	return 0;
1467}
1468
1469/**
1470 * pci_dev_get - increments the reference count of the pci device structure
1471 * @dev: the device being referenced
1472 *
1473 * Each live reference to a device should be refcounted.
1474 *
1475 * Drivers for PCI devices should normally record such references in
1476 * their probe() methods, when they bind to a device, and release
1477 * them by calling pci_dev_put(), in their disconnect() methods.
1478 *
1479 * A pointer to the device with the incremented reference counter is returned.
1480 */
1481struct pci_dev *pci_dev_get(struct pci_dev *dev)
1482{
1483	if (dev)
1484		get_device(&dev->dev);
1485	return dev;
1486}
1487EXPORT_SYMBOL(pci_dev_get);
1488
1489/**
1490 * pci_dev_put - release a use of the pci device structure
1491 * @dev: device that's been disconnected
1492 *
1493 * Must be called when a user of a device is finished with it.  When the last
1494 * user of the device calls this function, the memory of the device is freed.
1495 */
1496void pci_dev_put(struct pci_dev *dev)
1497{
1498	if (dev)
1499		put_device(&dev->dev);
1500}
1501EXPORT_SYMBOL(pci_dev_put);
1502
1503static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
1504{
1505	struct pci_dev *pdev;
1506
1507	if (!dev)
1508		return -ENODEV;
1509
1510	pdev = to_pci_dev(dev);
1511
1512	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
1513		return -ENOMEM;
1514
1515	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
1516		return -ENOMEM;
1517
1518	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
1519			   pdev->subsystem_device))
1520		return -ENOMEM;
1521
1522	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
1523		return -ENOMEM;
1524
1525	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
1526			   pdev->vendor, pdev->device,
1527			   pdev->subsystem_vendor, pdev->subsystem_device,
1528			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
1529			   (u8)(pdev->class)))
1530		return -ENOMEM;
1531
1532	return 0;
1533}
1534
1535#if defined(CONFIG_PCIEPORTBUS) || defined(CONFIG_EEH)
1536/**
1537 * pci_uevent_ers - emit a uevent during recovery path of PCI device
1538 * @pdev: PCI device undergoing error recovery
1539 * @err_type: type of error event
1540 */
1541void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type)
1542{
1543	int idx = 0;
1544	char *envp[3];
1545
1546	switch (err_type) {
1547	case PCI_ERS_RESULT_NONE:
1548	case PCI_ERS_RESULT_CAN_RECOVER:
1549		envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
1550		envp[idx++] = "DEVICE_ONLINE=0";
1551		break;
1552	case PCI_ERS_RESULT_RECOVERED:
1553		envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
1554		envp[idx++] = "DEVICE_ONLINE=1";
1555		break;
1556	case PCI_ERS_RESULT_DISCONNECT:
1557		envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
1558		envp[idx++] = "DEVICE_ONLINE=0";
1559		break;
1560	default:
1561		break;
1562	}
1563
1564	if (idx > 0) {
1565		envp[idx++] = NULL;
1566		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
1567	}
1568}
1569#endif
1570
1571static int pci_bus_num_vf(struct device *dev)
1572{
1573	return pci_num_vf(to_pci_dev(dev));
1574}
1575
1576/**
1577 * pci_dma_configure - Setup DMA configuration
1578 * @dev: ptr to dev structure
1579 *
1580 * Function to update PCI devices's DMA configuration using the same
1581 * info from the OF node or ACPI node of host bridge's parent (if any).
1582 */
1583static int pci_dma_configure(struct device *dev)
1584{
1585	struct device *bridge;
1586	int ret = 0;
1587
1588	bridge = pci_get_host_bridge_device(to_pci_dev(dev));
1589
1590	if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
1591	    bridge->parent->of_node) {
1592		ret = of_dma_configure(dev, bridge->parent->of_node, true);
1593	} else if (has_acpi_companion(bridge)) {
1594		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
1595
1596		ret = acpi_dma_configure(dev, acpi_get_dma_attr(adev));
1597	}
1598
1599	pci_put_host_bridge_device(bridge);
1600	return ret;
1601}
1602
1603struct bus_type pci_bus_type = {
1604	.name		= "pci",
1605	.match		= pci_bus_match,
1606	.uevent		= pci_uevent,
1607	.probe		= pci_device_probe,
1608	.remove		= pci_device_remove,
1609	.shutdown	= pci_device_shutdown,
1610	.dev_groups	= pci_dev_groups,
1611	.bus_groups	= pci_bus_groups,
1612	.drv_groups	= pci_drv_groups,
1613	.pm		= PCI_PM_OPS_PTR,
1614	.num_vf		= pci_bus_num_vf,
1615	.dma_configure	= pci_dma_configure,
1616};
1617EXPORT_SYMBOL(pci_bus_type);
1618
1619#ifdef CONFIG_PCIEPORTBUS
1620static int pcie_port_bus_match(struct device *dev, struct device_driver *drv)
1621{
1622	struct pcie_device *pciedev;
1623	struct pcie_port_service_driver *driver;
1624
1625	if (drv->bus != &pcie_port_bus_type || dev->bus != &pcie_port_bus_type)
1626		return 0;
1627
1628	pciedev = to_pcie_device(dev);
1629	driver = to_service_driver(drv);
1630
1631	if (driver->service != pciedev->service)
1632		return 0;
1633
1634	if (driver->port_type != PCIE_ANY_PORT &&
1635	    driver->port_type != pci_pcie_type(pciedev->port))
1636		return 0;
1637
1638	return 1;
1639}
1640
1641struct bus_type pcie_port_bus_type = {
1642	.name		= "pci_express",
1643	.match		= pcie_port_bus_match,
1644};
1645EXPORT_SYMBOL_GPL(pcie_port_bus_type);
1646#endif
1647
1648static int __init pci_driver_init(void)
1649{
1650	int ret;
1651
1652	ret = bus_register(&pci_bus_type);
1653	if (ret)
1654		return ret;
1655
1656#ifdef CONFIG_PCIEPORTBUS
1657	ret = bus_register(&pcie_port_bus_type);
1658	if (ret)
1659		return ret;
1660#endif
1661	dma_debug_add_bus(&pci_bus_type);
1662	return 0;
1663}
1664postcore_initcall(pci_driver_init);
1665