xref: /linux/drivers/pci/pci-acpi.c (revision 69fb09f6ccdb2f070557fd1f4c56c4d646694c8e)
1 /*
2  * File:	pci-acpi.c
3  * Purpose:	Provide PCI support in ACPI
4  *
5  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7  * Copyright (C) 2004 Intel Corp.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/irqdomain.h>
13 #include <linux/pci.h>
14 #include <linux/msi.h>
15 #include <linux/pci_hotplug.h>
16 #include <linux/module.h>
17 #include <linux/pci-aspm.h>
18 #include <linux/pci-acpi.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/pm_qos.h>
21 #include "pci.h"
22 
23 /*
24  * The GUID is defined in the PCI Firmware Specification available here:
25  * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
26  */
27 const guid_t pci_acpi_dsm_guid =
28 	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
29 		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);
30 
31 #if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
32 static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
33 {
34 	struct device *dev = &adev->dev;
35 	struct resource_entry *entry;
36 	struct list_head list;
37 	unsigned long flags;
38 	int ret;
39 
40 	INIT_LIST_HEAD(&list);
41 	flags = IORESOURCE_MEM;
42 	ret = acpi_dev_get_resources(adev, &list,
43 				     acpi_dev_filter_resource_type_cb,
44 				     (void *) flags);
45 	if (ret < 0) {
46 		dev_err(dev, "failed to parse _CRS method, error code %d\n",
47 			ret);
48 		return ret;
49 	}
50 
51 	if (ret == 0) {
52 		dev_err(dev, "no IO and memory resources present in _CRS\n");
53 		return -EINVAL;
54 	}
55 
56 	entry = list_first_entry(&list, struct resource_entry, node);
57 	*res = *entry->res;
58 	acpi_dev_free_resource_list(&list);
59 	return 0;
60 }
61 
62 static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
63 				 void **retval)
64 {
65 	u16 *segment = context;
66 	unsigned long long uid;
67 	acpi_status status;
68 
69 	status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
70 	if (ACPI_FAILURE(status) || uid != *segment)
71 		return AE_CTRL_DEPTH;
72 
73 	*(acpi_handle *)retval = handle;
74 	return AE_CTRL_TERMINATE;
75 }
76 
77 int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
78 			  struct resource *res)
79 {
80 	struct acpi_device *adev;
81 	acpi_status status;
82 	acpi_handle handle;
83 	int ret;
84 
85 	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
86 	if (ACPI_FAILURE(status)) {
87 		dev_err(dev, "can't find _HID %s device to locate resources\n",
88 			hid);
89 		return -ENODEV;
90 	}
91 
92 	ret = acpi_bus_get_device(handle, &adev);
93 	if (ret)
94 		return ret;
95 
96 	ret = acpi_get_rc_addr(adev, res);
97 	if (ret) {
98 		dev_err(dev, "can't get resource from %s\n",
99 			dev_name(&adev->dev));
100 		return ret;
101 	}
102 
103 	return 0;
104 }
105 #endif
106 
107 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
108 {
109 	acpi_status status = AE_NOT_EXIST;
110 	unsigned long long mcfg_addr;
111 
112 	if (handle)
113 		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
114 					       NULL, &mcfg_addr);
115 	if (ACPI_FAILURE(status))
116 		return 0;
117 
118 	return (phys_addr_t)mcfg_addr;
119 }
120 
121 static acpi_status decode_type0_hpx_record(union acpi_object *record,
122 					   struct hotplug_params *hpx)
123 {
124 	int i;
125 	union acpi_object *fields = record->package.elements;
126 	u32 revision = fields[1].integer.value;
127 
128 	switch (revision) {
129 	case 1:
130 		if (record->package.count != 6)
131 			return AE_ERROR;
132 		for (i = 2; i < 6; i++)
133 			if (fields[i].type != ACPI_TYPE_INTEGER)
134 				return AE_ERROR;
135 		hpx->t0 = &hpx->type0_data;
136 		hpx->t0->revision        = revision;
137 		hpx->t0->cache_line_size = fields[2].integer.value;
138 		hpx->t0->latency_timer   = fields[3].integer.value;
139 		hpx->t0->enable_serr     = fields[4].integer.value;
140 		hpx->t0->enable_perr     = fields[5].integer.value;
141 		break;
142 	default:
143 		printk(KERN_WARNING
144 		       "%s: Type 0 Revision %d record not supported\n",
145 		       __func__, revision);
146 		return AE_ERROR;
147 	}
148 	return AE_OK;
149 }
150 
151 static acpi_status decode_type1_hpx_record(union acpi_object *record,
152 					   struct hotplug_params *hpx)
153 {
154 	int i;
155 	union acpi_object *fields = record->package.elements;
156 	u32 revision = fields[1].integer.value;
157 
158 	switch (revision) {
159 	case 1:
160 		if (record->package.count != 5)
161 			return AE_ERROR;
162 		for (i = 2; i < 5; i++)
163 			if (fields[i].type != ACPI_TYPE_INTEGER)
164 				return AE_ERROR;
165 		hpx->t1 = &hpx->type1_data;
166 		hpx->t1->revision      = revision;
167 		hpx->t1->max_mem_read  = fields[2].integer.value;
168 		hpx->t1->avg_max_split = fields[3].integer.value;
169 		hpx->t1->tot_max_split = fields[4].integer.value;
170 		break;
171 	default:
172 		printk(KERN_WARNING
173 		       "%s: Type 1 Revision %d record not supported\n",
174 		       __func__, revision);
175 		return AE_ERROR;
176 	}
177 	return AE_OK;
178 }
179 
180 static acpi_status decode_type2_hpx_record(union acpi_object *record,
181 					   struct hotplug_params *hpx)
182 {
183 	int i;
184 	union acpi_object *fields = record->package.elements;
185 	u32 revision = fields[1].integer.value;
186 
187 	switch (revision) {
188 	case 1:
189 		if (record->package.count != 18)
190 			return AE_ERROR;
191 		for (i = 2; i < 18; i++)
192 			if (fields[i].type != ACPI_TYPE_INTEGER)
193 				return AE_ERROR;
194 		hpx->t2 = &hpx->type2_data;
195 		hpx->t2->revision      = revision;
196 		hpx->t2->unc_err_mask_and      = fields[2].integer.value;
197 		hpx->t2->unc_err_mask_or       = fields[3].integer.value;
198 		hpx->t2->unc_err_sever_and     = fields[4].integer.value;
199 		hpx->t2->unc_err_sever_or      = fields[5].integer.value;
200 		hpx->t2->cor_err_mask_and      = fields[6].integer.value;
201 		hpx->t2->cor_err_mask_or       = fields[7].integer.value;
202 		hpx->t2->adv_err_cap_and       = fields[8].integer.value;
203 		hpx->t2->adv_err_cap_or        = fields[9].integer.value;
204 		hpx->t2->pci_exp_devctl_and    = fields[10].integer.value;
205 		hpx->t2->pci_exp_devctl_or     = fields[11].integer.value;
206 		hpx->t2->pci_exp_lnkctl_and    = fields[12].integer.value;
207 		hpx->t2->pci_exp_lnkctl_or     = fields[13].integer.value;
208 		hpx->t2->sec_unc_err_sever_and = fields[14].integer.value;
209 		hpx->t2->sec_unc_err_sever_or  = fields[15].integer.value;
210 		hpx->t2->sec_unc_err_mask_and  = fields[16].integer.value;
211 		hpx->t2->sec_unc_err_mask_or   = fields[17].integer.value;
212 		break;
213 	default:
214 		printk(KERN_WARNING
215 		       "%s: Type 2 Revision %d record not supported\n",
216 		       __func__, revision);
217 		return AE_ERROR;
218 	}
219 	return AE_OK;
220 }
221 
222 static acpi_status acpi_run_hpx(acpi_handle handle, struct hotplug_params *hpx)
223 {
224 	acpi_status status;
225 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
226 	union acpi_object *package, *record, *fields;
227 	u32 type;
228 	int i;
229 
230 	/* Clear the return buffer with zeros */
231 	memset(hpx, 0, sizeof(struct hotplug_params));
232 
233 	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
234 	if (ACPI_FAILURE(status))
235 		return status;
236 
237 	package = (union acpi_object *)buffer.pointer;
238 	if (package->type != ACPI_TYPE_PACKAGE) {
239 		status = AE_ERROR;
240 		goto exit;
241 	}
242 
243 	for (i = 0; i < package->package.count; i++) {
244 		record = &package->package.elements[i];
245 		if (record->type != ACPI_TYPE_PACKAGE) {
246 			status = AE_ERROR;
247 			goto exit;
248 		}
249 
250 		fields = record->package.elements;
251 		if (fields[0].type != ACPI_TYPE_INTEGER ||
252 		    fields[1].type != ACPI_TYPE_INTEGER) {
253 			status = AE_ERROR;
254 			goto exit;
255 		}
256 
257 		type = fields[0].integer.value;
258 		switch (type) {
259 		case 0:
260 			status = decode_type0_hpx_record(record, hpx);
261 			if (ACPI_FAILURE(status))
262 				goto exit;
263 			break;
264 		case 1:
265 			status = decode_type1_hpx_record(record, hpx);
266 			if (ACPI_FAILURE(status))
267 				goto exit;
268 			break;
269 		case 2:
270 			status = decode_type2_hpx_record(record, hpx);
271 			if (ACPI_FAILURE(status))
272 				goto exit;
273 			break;
274 		default:
275 			printk(KERN_ERR "%s: Type %d record not supported\n",
276 			       __func__, type);
277 			status = AE_ERROR;
278 			goto exit;
279 		}
280 	}
281  exit:
282 	kfree(buffer.pointer);
283 	return status;
284 }
285 
286 static acpi_status acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
287 {
288 	acpi_status status;
289 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
290 	union acpi_object *package, *fields;
291 	int i;
292 
293 	memset(hpp, 0, sizeof(struct hotplug_params));
294 
295 	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
296 	if (ACPI_FAILURE(status))
297 		return status;
298 
299 	package = (union acpi_object *) buffer.pointer;
300 	if (package->type != ACPI_TYPE_PACKAGE ||
301 	    package->package.count != 4) {
302 		status = AE_ERROR;
303 		goto exit;
304 	}
305 
306 	fields = package->package.elements;
307 	for (i = 0; i < 4; i++) {
308 		if (fields[i].type != ACPI_TYPE_INTEGER) {
309 			status = AE_ERROR;
310 			goto exit;
311 		}
312 	}
313 
314 	hpp->t0 = &hpp->type0_data;
315 	hpp->t0->revision        = 1;
316 	hpp->t0->cache_line_size = fields[0].integer.value;
317 	hpp->t0->latency_timer   = fields[1].integer.value;
318 	hpp->t0->enable_serr     = fields[2].integer.value;
319 	hpp->t0->enable_perr     = fields[3].integer.value;
320 
321 exit:
322 	kfree(buffer.pointer);
323 	return status;
324 }
325 
326 /* pci_get_hp_params
327  *
328  * @dev - the pci_dev for which we want parameters
329  * @hpp - allocated by the caller
330  */
331 int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp)
332 {
333 	acpi_status status;
334 	acpi_handle handle, phandle;
335 	struct pci_bus *pbus;
336 
337 	if (acpi_pci_disabled)
338 		return -ENODEV;
339 
340 	handle = NULL;
341 	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
342 		handle = acpi_pci_get_bridge_handle(pbus);
343 		if (handle)
344 			break;
345 	}
346 
347 	/*
348 	 * _HPP settings apply to all child buses, until another _HPP is
349 	 * encountered. If we don't find an _HPP for the input pci dev,
350 	 * look for it in the parent device scope since that would apply to
351 	 * this pci dev.
352 	 */
353 	while (handle) {
354 		status = acpi_run_hpx(handle, hpp);
355 		if (ACPI_SUCCESS(status))
356 			return 0;
357 		status = acpi_run_hpp(handle, hpp);
358 		if (ACPI_SUCCESS(status))
359 			return 0;
360 		if (acpi_is_root_bridge(handle))
361 			break;
362 		status = acpi_get_parent(handle, &phandle);
363 		if (ACPI_FAILURE(status))
364 			break;
365 		handle = phandle;
366 	}
367 	return -ENODEV;
368 }
369 EXPORT_SYMBOL_GPL(pci_get_hp_params);
370 
371 /**
372  * pciehp_is_native - Check whether a hotplug port is handled by the OS
373  * @pdev: Hotplug port to check
374  *
375  * Walk up from @pdev to the host bridge, obtain its cached _OSC Control Field
376  * and return the value of the "PCI Express Native Hot Plug control" bit.
377  * On failure to obtain the _OSC Control Field return %false.
378  */
379 bool pciehp_is_native(struct pci_dev *pdev)
380 {
381 	struct acpi_pci_root *root;
382 	acpi_handle handle;
383 
384 	handle = acpi_find_root_bridge_handle(pdev);
385 	if (!handle)
386 		return false;
387 
388 	root = acpi_pci_find_root(handle);
389 	if (!root)
390 		return false;
391 
392 	return root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
393 }
394 
395 /**
396  * pci_acpi_wake_bus - Root bus wakeup notification fork function.
397  * @work: Work item to handle.
398  */
399 static void pci_acpi_wake_bus(struct work_struct *work)
400 {
401 	struct acpi_device *adev;
402 	struct acpi_pci_root *root;
403 
404 	adev = container_of(work, struct acpi_device, wakeup.context.work);
405 	root = acpi_driver_data(adev);
406 	pci_pme_wakeup_bus(root->bus);
407 }
408 
409 /**
410  * pci_acpi_wake_dev - PCI device wakeup notification work function.
411  * @handle: ACPI handle of a device the notification is for.
412  * @work: Work item to handle.
413  */
414 static void pci_acpi_wake_dev(struct work_struct *work)
415 {
416 	struct acpi_device_wakeup_context *context;
417 	struct pci_dev *pci_dev;
418 
419 	context = container_of(work, struct acpi_device_wakeup_context, work);
420 	pci_dev = to_pci_dev(context->dev);
421 
422 	if (pci_dev->pme_poll)
423 		pci_dev->pme_poll = false;
424 
425 	if (pci_dev->current_state == PCI_D3cold) {
426 		pci_wakeup_event(pci_dev);
427 		pm_runtime_resume(&pci_dev->dev);
428 		return;
429 	}
430 
431 	/* Clear PME Status if set. */
432 	if (pci_dev->pme_support)
433 		pci_check_pme_status(pci_dev);
434 
435 	pci_wakeup_event(pci_dev);
436 	pm_runtime_resume(&pci_dev->dev);
437 
438 	pci_pme_wakeup_bus(pci_dev->subordinate);
439 }
440 
441 /**
442  * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
443  * @dev: PCI root bridge ACPI device.
444  */
445 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
446 {
447 	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
448 }
449 
450 /**
451  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
452  * @dev: ACPI device to add the notifier for.
453  * @pci_dev: PCI device to check for the PME status if an event is signaled.
454  */
455 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
456 				     struct pci_dev *pci_dev)
457 {
458 	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
459 }
460 
461 /*
462  * _SxD returns the D-state with the highest power
463  * (lowest D-state number) supported in the S-state "x".
464  *
465  * If the devices does not have a _PRW
466  * (Power Resources for Wake) supporting system wakeup from "x"
467  * then the OS is free to choose a lower power (higher number
468  * D-state) than the return value from _SxD.
469  *
470  * But if _PRW is enabled at S-state "x", the OS
471  * must not choose a power lower than _SxD --
472  * unless the device has an _SxW method specifying
473  * the lowest power (highest D-state number) the device
474  * may enter while still able to wake the system.
475  *
476  * ie. depending on global OS policy:
477  *
478  * if (_PRW at S-state x)
479  *	choose from highest power _SxD to lowest power _SxW
480  * else // no _PRW at S-state x
481  *	choose highest power _SxD or any lower power
482  */
483 
484 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
485 {
486 	int acpi_state, d_max;
487 
488 	if (pdev->no_d3cold)
489 		d_max = ACPI_STATE_D3_HOT;
490 	else
491 		d_max = ACPI_STATE_D3_COLD;
492 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
493 	if (acpi_state < 0)
494 		return PCI_POWER_ERROR;
495 
496 	switch (acpi_state) {
497 	case ACPI_STATE_D0:
498 		return PCI_D0;
499 	case ACPI_STATE_D1:
500 		return PCI_D1;
501 	case ACPI_STATE_D2:
502 		return PCI_D2;
503 	case ACPI_STATE_D3_HOT:
504 		return PCI_D3hot;
505 	case ACPI_STATE_D3_COLD:
506 		return PCI_D3cold;
507 	}
508 	return PCI_POWER_ERROR;
509 }
510 
511 static bool acpi_pci_power_manageable(struct pci_dev *dev)
512 {
513 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
514 	return adev ? acpi_device_power_manageable(adev) : false;
515 }
516 
517 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
518 {
519 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
520 	static const u8 state_conv[] = {
521 		[PCI_D0] = ACPI_STATE_D0,
522 		[PCI_D1] = ACPI_STATE_D1,
523 		[PCI_D2] = ACPI_STATE_D2,
524 		[PCI_D3hot] = ACPI_STATE_D3_HOT,
525 		[PCI_D3cold] = ACPI_STATE_D3_COLD,
526 	};
527 	int error = -EINVAL;
528 
529 	/* If the ACPI device has _EJ0, ignore the device */
530 	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
531 		return -ENODEV;
532 
533 	switch (state) {
534 	case PCI_D3cold:
535 		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
536 				PM_QOS_FLAGS_ALL) {
537 			error = -EBUSY;
538 			break;
539 		}
540 	case PCI_D0:
541 	case PCI_D1:
542 	case PCI_D2:
543 	case PCI_D3hot:
544 		error = acpi_device_set_power(adev, state_conv[state]);
545 	}
546 
547 	if (!error)
548 		dev_dbg(&dev->dev, "power state changed by ACPI to %s\n",
549 			 acpi_power_state_string(state_conv[state]));
550 
551 	return error;
552 }
553 
554 static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
555 {
556 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
557 	static const pci_power_t state_conv[] = {
558 		[ACPI_STATE_D0]      = PCI_D0,
559 		[ACPI_STATE_D1]      = PCI_D1,
560 		[ACPI_STATE_D2]      = PCI_D2,
561 		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
562 		[ACPI_STATE_D3_COLD] = PCI_D3cold,
563 	};
564 	int state;
565 
566 	if (!adev || !acpi_device_power_manageable(adev))
567 		return PCI_UNKNOWN;
568 
569 	if (acpi_device_get_power(adev, &state) || state == ACPI_STATE_UNKNOWN)
570 		return PCI_UNKNOWN;
571 
572 	return state_conv[state];
573 }
574 
575 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
576 {
577 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
578 	return adev ? acpi_device_can_wakeup(adev) : false;
579 }
580 
581 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
582 {
583 	while (bus->parent) {
584 		if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
585 			return;
586 		bus = bus->parent;
587 	}
588 
589 	/* We have reached the root bus. */
590 	if (bus->bridge)
591 		acpi_pm_device_sleep_wake(bus->bridge, enable);
592 }
593 
594 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
595 {
596 	if (acpi_pci_can_wakeup(dev))
597 		return acpi_pm_device_sleep_wake(&dev->dev, enable);
598 
599 	acpi_pci_propagate_wakeup_enable(dev->bus, enable);
600 	return 0;
601 }
602 
603 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
604 {
605 	while (bus->parent) {
606 		struct pci_dev *bridge = bus->self;
607 
608 		if (bridge->pme_interrupt)
609 			return;
610 		if (!acpi_pm_device_run_wake(&bridge->dev, enable))
611 			return;
612 		bus = bus->parent;
613 	}
614 
615 	/* We have reached the root bus. */
616 	if (bus->bridge)
617 		acpi_pm_device_run_wake(bus->bridge, enable);
618 }
619 
620 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
621 {
622 	/*
623 	 * Per PCI Express Base Specification Revision 2.0 section
624 	 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
625 	 * waking up to power on the main link even if there is PME
626 	 * support for D3cold
627 	 */
628 	if (dev->pme_interrupt && !dev->runtime_d3cold)
629 		return 0;
630 
631 	if (!acpi_pm_device_run_wake(&dev->dev, enable))
632 		return 0;
633 
634 	acpi_pci_propagate_run_wake(dev->bus, enable);
635 	return 0;
636 }
637 
638 static bool acpi_pci_need_resume(struct pci_dev *dev)
639 {
640 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
641 
642 	if (!adev || !acpi_device_power_manageable(adev))
643 		return false;
644 
645 	if (device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
646 		return true;
647 
648 	if (acpi_target_system_state() == ACPI_STATE_S0)
649 		return false;
650 
651 	return !!adev->power.flags.dsw_present;
652 }
653 
654 static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
655 	.is_manageable = acpi_pci_power_manageable,
656 	.set_state = acpi_pci_set_power_state,
657 	.get_state = acpi_pci_get_power_state,
658 	.choose_state = acpi_pci_choose_state,
659 	.sleep_wake = acpi_pci_sleep_wake,
660 	.run_wake = acpi_pci_run_wake,
661 	.need_resume = acpi_pci_need_resume,
662 };
663 
664 void acpi_pci_add_bus(struct pci_bus *bus)
665 {
666 	union acpi_object *obj;
667 	struct pci_host_bridge *bridge;
668 
669 	if (acpi_pci_disabled || !bus->bridge)
670 		return;
671 
672 	acpi_pci_slot_enumerate(bus);
673 	acpiphp_enumerate_slots(bus);
674 
675 	/*
676 	 * For a host bridge, check its _DSM for function 8 and if
677 	 * that is available, mark it in pci_host_bridge.
678 	 */
679 	if (!pci_is_root_bus(bus))
680 		return;
681 
682 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
683 				RESET_DELAY_DSM, NULL);
684 	if (!obj)
685 		return;
686 
687 	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
688 		bridge = pci_find_host_bridge(bus);
689 		bridge->ignore_reset_delay = 1;
690 	}
691 	ACPI_FREE(obj);
692 }
693 
694 void acpi_pci_remove_bus(struct pci_bus *bus)
695 {
696 	if (acpi_pci_disabled || !bus->bridge)
697 		return;
698 
699 	acpiphp_remove_slots(bus);
700 	acpi_pci_slot_remove(bus);
701 }
702 
703 /* ACPI bus type */
704 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
705 {
706 	struct pci_dev *pci_dev = to_pci_dev(dev);
707 	bool check_children;
708 	u64 addr;
709 
710 	check_children = pci_is_bridge(pci_dev);
711 	/* Please ref to ACPI spec for the syntax of _ADR */
712 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
713 	return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
714 				      check_children);
715 }
716 
717 /**
718  * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
719  * @pdev: the PCI device whose delay is to be updated
720  * @handle: ACPI handle of this device
721  *
722  * Update the d3_delay and d3cold_delay of a PCI device from the ACPI _DSM
723  * control method of either the device itself or the PCI host bridge.
724  *
725  * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
726  * host bridge.  If it returns one, the OS may assume that all devices in
727  * the hierarchy have already completed power-on reset delays.
728  *
729  * Function 9, "Device Readiness Durations," applies only to the object
730  * where it is located.  It returns delay durations required after various
731  * events if the device requires less time than the spec requires.  Delays
732  * from this function take precedence over the Reset Delay function.
733  *
734  * These _DSM functions are defined by the draft ECN of January 28, 2014,
735  * titled "ACPI additions for FW latency optimizations."
736  */
737 static void pci_acpi_optimize_delay(struct pci_dev *pdev,
738 				    acpi_handle handle)
739 {
740 	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
741 	int value;
742 	union acpi_object *obj, *elements;
743 
744 	if (bridge->ignore_reset_delay)
745 		pdev->d3cold_delay = 0;
746 
747 	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
748 				FUNCTION_DELAY_DSM, NULL);
749 	if (!obj)
750 		return;
751 
752 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
753 		elements = obj->package.elements;
754 		if (elements[0].type == ACPI_TYPE_INTEGER) {
755 			value = (int)elements[0].integer.value / 1000;
756 			if (value < PCI_PM_D3COLD_WAIT)
757 				pdev->d3cold_delay = value;
758 		}
759 		if (elements[3].type == ACPI_TYPE_INTEGER) {
760 			value = (int)elements[3].integer.value / 1000;
761 			if (value < PCI_PM_D3_WAIT)
762 				pdev->d3_delay = value;
763 		}
764 	}
765 	ACPI_FREE(obj);
766 }
767 
768 static void pci_acpi_setup(struct device *dev)
769 {
770 	struct pci_dev *pci_dev = to_pci_dev(dev);
771 	struct acpi_device *adev = ACPI_COMPANION(dev);
772 
773 	if (!adev)
774 		return;
775 
776 	pci_acpi_optimize_delay(pci_dev, adev->handle);
777 
778 	pci_acpi_add_pm_notifier(adev, pci_dev);
779 	if (!adev->wakeup.flags.valid)
780 		return;
781 
782 	device_set_wakeup_capable(dev, true);
783 	acpi_pci_sleep_wake(pci_dev, false);
784 	if (adev->wakeup.flags.run_wake)
785 		device_set_run_wake(dev, true);
786 }
787 
788 static void pci_acpi_cleanup(struct device *dev)
789 {
790 	struct acpi_device *adev = ACPI_COMPANION(dev);
791 
792 	if (!adev)
793 		return;
794 
795 	pci_acpi_remove_pm_notifier(adev);
796 	if (adev->wakeup.flags.valid) {
797 		device_set_wakeup_capable(dev, false);
798 		device_set_run_wake(dev, false);
799 	}
800 }
801 
802 static bool pci_acpi_bus_match(struct device *dev)
803 {
804 	return dev_is_pci(dev);
805 }
806 
807 static struct acpi_bus_type acpi_pci_bus = {
808 	.name = "PCI",
809 	.match = pci_acpi_bus_match,
810 	.find_companion = acpi_pci_find_companion,
811 	.setup = pci_acpi_setup,
812 	.cleanup = pci_acpi_cleanup,
813 };
814 
815 
816 static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
817 
818 /**
819  * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
820  * @fn:       Callback matching a device to a fwnode that identifies a PCI
821  *            MSI domain.
822  *
823  * This should be called by irqchip driver, which is the parent of
824  * the MSI domain to provide callback interface to query fwnode.
825  */
826 void
827 pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
828 {
829 	pci_msi_get_fwnode_cb = fn;
830 }
831 
832 /**
833  * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
834  * @bus:      The PCI host bridge bus.
835  *
836  * This function uses the callback function registered by
837  * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
838  * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
839  * This returns NULL on error or when the domain is not found.
840  */
841 struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
842 {
843 	struct fwnode_handle *fwnode;
844 
845 	if (!pci_msi_get_fwnode_cb)
846 		return NULL;
847 
848 	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
849 	if (!fwnode)
850 		return NULL;
851 
852 	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
853 }
854 
855 static int __init acpi_pci_init(void)
856 {
857 	int ret;
858 
859 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
860 		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
861 		pci_no_msi();
862 	}
863 
864 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
865 		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
866 		pcie_no_aspm();
867 	}
868 
869 	ret = register_acpi_bus_type(&acpi_pci_bus);
870 	if (ret)
871 		return 0;
872 
873 	pci_set_platform_pm(&acpi_pci_platform_pm);
874 	acpi_pci_slot_init();
875 	acpiphp_init();
876 
877 	return 0;
878 }
879 arch_initcall(acpi_pci_init);
880