xref: /openbmc/linux/drivers/acpi/pci_root.c (revision 5c816641)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  */
8 
9 #define pr_fmt(fmt) "ACPI: " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <linux/mutex.h>
16 #include <linux/pm.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/pci.h>
19 #include <linux/pci-acpi.h>
20 #include <linux/dmar.h>
21 #include <linux/acpi.h>
22 #include <linux/slab.h>
23 #include <linux/dmi.h>
24 #include <linux/platform_data/x86/apple.h>
25 #include <acpi/apei.h>	/* for acpi_hest_init() */
26 
27 #include "internal.h"
28 
29 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
30 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
31 static int acpi_pci_root_add(struct acpi_device *device,
32 			     const struct acpi_device_id *not_used);
33 static void acpi_pci_root_remove(struct acpi_device *device);
34 
35 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
36 {
37 	acpiphp_check_host_bridge(adev);
38 	return 0;
39 }
40 
41 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
42 				| OSC_PCI_ASPM_SUPPORT \
43 				| OSC_PCI_CLOCK_PM_SUPPORT \
44 				| OSC_PCI_MSI_SUPPORT)
45 
46 static const struct acpi_device_id root_device_ids[] = {
47 	{"PNP0A03", 0},
48 	{"", 0},
49 };
50 
51 static struct acpi_scan_handler pci_root_handler = {
52 	.ids = root_device_ids,
53 	.attach = acpi_pci_root_add,
54 	.detach = acpi_pci_root_remove,
55 	.hotplug = {
56 		.enabled = true,
57 		.scan_dependent = acpi_pci_root_scan_dependent,
58 	},
59 };
60 
61 /**
62  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
63  * @handle:  the ACPI CA node in question.
64  *
65  * Note: we could make this API take a struct acpi_device * instead, but
66  * for now, it's more convenient to operate on an acpi_handle.
67  */
68 int acpi_is_root_bridge(acpi_handle handle)
69 {
70 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
71 	int ret;
72 
73 	if (!device)
74 		return 0;
75 
76 	ret = acpi_match_device_ids(device, root_device_ids);
77 	if (ret)
78 		return 0;
79 	else
80 		return 1;
81 }
82 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
83 
84 static acpi_status
85 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
86 {
87 	struct resource *res = data;
88 	struct acpi_resource_address64 address;
89 	acpi_status status;
90 
91 	status = acpi_resource_to_address64(resource, &address);
92 	if (ACPI_FAILURE(status))
93 		return AE_OK;
94 
95 	if ((address.address.address_length > 0) &&
96 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
97 		res->start = address.address.minimum;
98 		res->end = address.address.minimum + address.address.address_length - 1;
99 	}
100 
101 	return AE_OK;
102 }
103 
104 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
105 					     struct resource *res)
106 {
107 	acpi_status status;
108 
109 	res->start = -1;
110 	status =
111 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
112 				get_root_bridge_busnr_callback, res);
113 	if (ACPI_FAILURE(status))
114 		return status;
115 	if (res->start == -1)
116 		return AE_ERROR;
117 	return AE_OK;
118 }
119 
120 struct pci_osc_bit_struct {
121 	u32 bit;
122 	char *desc;
123 };
124 
125 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
126 	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
127 	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
128 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
129 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
130 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
131 	{ OSC_PCI_EDR_SUPPORT, "EDR" },
132 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
133 };
134 
135 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
136 	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
137 	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
138 	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
139 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
140 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
141 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
142 	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
143 };
144 
145 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
146 			    struct pci_osc_bit_struct *table, int size)
147 {
148 	char buf[80];
149 	int i, len = 0;
150 	struct pci_osc_bit_struct *entry;
151 
152 	buf[0] = '\0';
153 	for (i = 0, entry = table; i < size; i++, entry++)
154 		if (word & entry->bit)
155 			len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
156 					len ? " " : "", entry->desc);
157 
158 	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
159 }
160 
161 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
162 {
163 	decode_osc_bits(root, msg, word, pci_osc_support_bit,
164 			ARRAY_SIZE(pci_osc_support_bit));
165 }
166 
167 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
168 {
169 	decode_osc_bits(root, msg, word, pci_osc_control_bit,
170 			ARRAY_SIZE(pci_osc_control_bit));
171 }
172 
173 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
174 
175 static acpi_status acpi_pci_run_osc(acpi_handle handle,
176 				    const u32 *capbuf, u32 *retval)
177 {
178 	struct acpi_osc_context context = {
179 		.uuid_str = pci_osc_uuid_str,
180 		.rev = 1,
181 		.cap.length = 12,
182 		.cap.pointer = (void *)capbuf,
183 	};
184 	acpi_status status;
185 
186 	status = acpi_run_osc(handle, &context);
187 	if (ACPI_SUCCESS(status)) {
188 		*retval = *((u32 *)(context.ret.pointer + 8));
189 		kfree(context.ret.pointer);
190 	}
191 	return status;
192 }
193 
194 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
195 					u32 support,
196 					u32 *control)
197 {
198 	acpi_status status;
199 	u32 result, capbuf[3];
200 
201 	support |= root->osc_support_set;
202 
203 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
204 	capbuf[OSC_SUPPORT_DWORD] = support;
205 	capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
206 
207 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
208 	if (ACPI_SUCCESS(status)) {
209 		root->osc_support_set = support;
210 		*control = result;
211 	}
212 	return status;
213 }
214 
215 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
216 {
217 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
218 	struct acpi_pci_root *root;
219 
220 	if (!device || acpi_match_device_ids(device, root_device_ids))
221 		return NULL;
222 
223 	root = acpi_driver_data(device);
224 
225 	return root;
226 }
227 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
228 
229 struct acpi_handle_node {
230 	struct list_head node;
231 	acpi_handle handle;
232 };
233 
234 /**
235  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
236  * @handle: the handle in question
237  *
238  * Given an ACPI CA handle, the desired PCI device is located in the
239  * list of PCI devices.
240  *
241  * If the device is found, its reference count is increased and this
242  * function returns a pointer to its data structure.  The caller must
243  * decrement the reference count by calling pci_dev_put().
244  * If no device is found, %NULL is returned.
245  */
246 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
247 {
248 	int dev, fn;
249 	unsigned long long adr;
250 	acpi_status status;
251 	acpi_handle phandle;
252 	struct pci_bus *pbus;
253 	struct pci_dev *pdev = NULL;
254 	struct acpi_handle_node *node, *tmp;
255 	struct acpi_pci_root *root;
256 	LIST_HEAD(device_list);
257 
258 	/*
259 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
260 	 */
261 	phandle = handle;
262 	while (!acpi_is_root_bridge(phandle)) {
263 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
264 		if (!node)
265 			goto out;
266 
267 		INIT_LIST_HEAD(&node->node);
268 		node->handle = phandle;
269 		list_add(&node->node, &device_list);
270 
271 		status = acpi_get_parent(phandle, &phandle);
272 		if (ACPI_FAILURE(status))
273 			goto out;
274 	}
275 
276 	root = acpi_pci_find_root(phandle);
277 	if (!root)
278 		goto out;
279 
280 	pbus = root->bus;
281 
282 	/*
283 	 * Now, walk back down the PCI device tree until we return to our
284 	 * original handle. Assumes that everything between the PCI root
285 	 * bridge and the device we're looking for must be a P2P bridge.
286 	 */
287 	list_for_each_entry(node, &device_list, node) {
288 		acpi_handle hnd = node->handle;
289 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
290 		if (ACPI_FAILURE(status))
291 			goto out;
292 		dev = (adr >> 16) & 0xffff;
293 		fn  = adr & 0xffff;
294 
295 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
296 		if (!pdev || hnd == handle)
297 			break;
298 
299 		pbus = pdev->subordinate;
300 		pci_dev_put(pdev);
301 
302 		/*
303 		 * This function may be called for a non-PCI device that has a
304 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
305 		 * case pdev->subordinate will be NULL for the parent.
306 		 */
307 		if (!pbus) {
308 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
309 			pdev = NULL;
310 			break;
311 		}
312 	}
313 out:
314 	list_for_each_entry_safe(node, tmp, &device_list, node)
315 		kfree(node);
316 
317 	return pdev;
318 }
319 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
320 
321 /**
322  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
323  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
324  * @mask: Mask of _OSC bits to request control of, place to store control mask.
325  * @support: _OSC supported capability.
326  *
327  * Run _OSC query for @mask and if that is successful, compare the returned
328  * mask of control bits with @req.  If all of the @req bits are set in the
329  * returned mask, run _OSC request for it.
330  *
331  * The variable at the @mask address may be modified regardless of whether or
332  * not the function returns success.  On success it will contain the mask of
333  * _OSC bits the BIOS has granted control of, but its contents are meaningless
334  * on failure.
335  **/
336 static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 support)
337 {
338 	u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;
339 	struct acpi_pci_root *root;
340 	acpi_status status;
341 	u32 ctrl, capbuf[3];
342 
343 	if (!mask)
344 		return AE_BAD_PARAMETER;
345 
346 	root = acpi_pci_find_root(handle);
347 	if (!root)
348 		return AE_NOT_EXIST;
349 
350 	ctrl   = *mask;
351 	*mask |= root->osc_control_set;
352 
353 	/* Need to check the available controls bits before requesting them. */
354 	do {
355 		status = acpi_pci_query_osc(root, support, mask);
356 		if (ACPI_FAILURE(status))
357 			return status;
358 		if (ctrl == *mask)
359 			break;
360 		decode_osc_control(root, "platform does not support",
361 				   ctrl & ~(*mask));
362 		ctrl = *mask;
363 	} while (*mask);
364 
365 	/* No need to request _OSC if the control was already granted. */
366 	if ((root->osc_control_set & ctrl) == ctrl)
367 		return AE_OK;
368 
369 	if ((ctrl & req) != req) {
370 		decode_osc_control(root, "not requesting control; platform does not support",
371 				   req & ~(ctrl));
372 		return AE_SUPPORT;
373 	}
374 
375 	capbuf[OSC_QUERY_DWORD] = 0;
376 	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
377 	capbuf[OSC_CONTROL_DWORD] = ctrl;
378 	status = acpi_pci_run_osc(handle, capbuf, mask);
379 	if (ACPI_FAILURE(status))
380 		return status;
381 
382 	root->osc_control_set = *mask;
383 	return AE_OK;
384 }
385 
386 static u32 calculate_support(void)
387 {
388 	u32 support;
389 
390 	/*
391 	 * All supported architectures that use ACPI have support for
392 	 * PCI domains, so we indicate this in _OSC support capabilities.
393 	 */
394 	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
395 	support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
396 	if (pci_ext_cfg_avail())
397 		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
398 	if (pcie_aspm_support_enabled())
399 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
400 	if (pci_msi_enabled())
401 		support |= OSC_PCI_MSI_SUPPORT;
402 	if (IS_ENABLED(CONFIG_PCIE_EDR))
403 		support |= OSC_PCI_EDR_SUPPORT;
404 
405 	return support;
406 }
407 
408 static u32 calculate_control(void)
409 {
410 	u32 control;
411 
412 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
413 		| OSC_PCI_EXPRESS_PME_CONTROL;
414 
415 	if (IS_ENABLED(CONFIG_PCIEASPM))
416 		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
417 
418 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
419 		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
420 
421 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
422 		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
423 
424 	if (pci_aer_available())
425 		control |= OSC_PCI_EXPRESS_AER_CONTROL;
426 
427 	/*
428 	 * Per the Downstream Port Containment Related Enhancements ECN to
429 	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
430 	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
431 	 * and EDR.
432 	 */
433 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
434 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
435 
436 	return control;
437 }
438 
439 static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)
440 {
441 	struct acpi_device *device = root->device;
442 
443 	if (pcie_ports_disabled) {
444 		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
445 		return false;
446 	}
447 
448 	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
449 		decode_osc_support(root, "not requesting OS control; OS requires",
450 				   ACPI_PCIE_REQ_SUPPORT);
451 		return false;
452 	}
453 
454 	return true;
455 }
456 
457 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
458 				 bool is_pcie)
459 {
460 	u32 support, control = 0, requested = 0;
461 	acpi_status status;
462 	struct acpi_device *device = root->device;
463 	acpi_handle handle = device->handle;
464 
465 	/*
466 	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
467 	 * been called successfully. We know the feature set supported by the
468 	 * platform, so avoid calling _OSC at all
469 	 */
470 	if (x86_apple_machine) {
471 		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
472 		decode_osc_control(root, "OS assumes control of",
473 				   root->osc_control_set);
474 		return;
475 	}
476 
477 	support = calculate_support();
478 
479 	decode_osc_support(root, "OS supports", support);
480 
481 	if (os_control_query_checks(root, support))
482 		requested = control = calculate_control();
483 
484 	status = acpi_pci_osc_control_set(handle, &control, support);
485 	if (ACPI_SUCCESS(status)) {
486 		if (control)
487 			decode_osc_control(root, "OS now controls", control);
488 
489 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
490 			/*
491 			 * We have ASPM control, but the FADT indicates that
492 			 * it's unsupported. Leave existing configuration
493 			 * intact and prevent the OS from touching it.
494 			 */
495 			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
496 			*no_aspm = 1;
497 		}
498 	} else {
499 		/*
500 		 * We want to disable ASPM here, but aspm_disabled
501 		 * needs to remain in its state from boot so that we
502 		 * properly handle PCIe 1.1 devices.  So we set this
503 		 * flag here, to defer the action until after the ACPI
504 		 * root scan.
505 		 */
506 		*no_aspm = 1;
507 
508 		/* _OSC is optional for PCI host bridges */
509 		if ((status == AE_NOT_FOUND) && !is_pcie)
510 			return;
511 
512 		if (control) {
513 			decode_osc_control(root, "OS requested", requested);
514 			decode_osc_control(root, "platform willing to grant", control);
515 		}
516 
517 		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
518 			 acpi_format_exception(status));
519 	}
520 }
521 
522 static int acpi_pci_root_add(struct acpi_device *device,
523 			     const struct acpi_device_id *not_used)
524 {
525 	unsigned long long segment, bus;
526 	acpi_status status;
527 	int result;
528 	struct acpi_pci_root *root;
529 	acpi_handle handle = device->handle;
530 	int no_aspm = 0;
531 	bool hotadd = system_state == SYSTEM_RUNNING;
532 	bool is_pcie;
533 
534 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
535 	if (!root)
536 		return -ENOMEM;
537 
538 	segment = 0;
539 	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
540 				       &segment);
541 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
542 		dev_err(&device->dev,  "can't evaluate _SEG\n");
543 		result = -ENODEV;
544 		goto end;
545 	}
546 
547 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
548 	root->secondary.flags = IORESOURCE_BUS;
549 	status = try_get_root_bridge_busnr(handle, &root->secondary);
550 	if (ACPI_FAILURE(status)) {
551 		/*
552 		 * We need both the start and end of the downstream bus range
553 		 * to interpret _CBA (MMCONFIG base address), so it really is
554 		 * supposed to be in _CRS.  If we don't find it there, all we
555 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
556 		 */
557 		root->secondary.end = 0xFF;
558 		dev_warn(&device->dev,
559 			 FW_BUG "no secondary bus range in _CRS\n");
560 		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
561 					       NULL, &bus);
562 		if (ACPI_SUCCESS(status))
563 			root->secondary.start = bus;
564 		else if (status == AE_NOT_FOUND)
565 			root->secondary.start = 0;
566 		else {
567 			dev_err(&device->dev, "can't evaluate _BBN\n");
568 			result = -ENODEV;
569 			goto end;
570 		}
571 	}
572 
573 	root->device = device;
574 	root->segment = segment & 0xFFFF;
575 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
576 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
577 	device->driver_data = root;
578 
579 	if (hotadd && dmar_device_add(handle)) {
580 		result = -ENXIO;
581 		goto end;
582 	}
583 
584 	pr_info("%s [%s] (domain %04x %pR)\n",
585 	       acpi_device_name(device), acpi_device_bid(device),
586 	       root->segment, &root->secondary);
587 
588 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
589 
590 	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
591 	negotiate_os_control(root, &no_aspm, is_pcie);
592 
593 	/*
594 	 * TBD: Need PCI interface for enumeration/configuration of roots.
595 	 */
596 
597 	/*
598 	 * Scan the Root Bridge
599 	 * --------------------
600 	 * Must do this prior to any attempt to bind the root device, as the
601 	 * PCI namespace does not get created until this call is made (and
602 	 * thus the root bridge's pci_dev does not exist).
603 	 */
604 	root->bus = pci_acpi_scan_root(root);
605 	if (!root->bus) {
606 		dev_err(&device->dev,
607 			"Bus %04x:%02x not present in PCI namespace\n",
608 			root->segment, (unsigned int)root->secondary.start);
609 		device->driver_data = NULL;
610 		result = -ENODEV;
611 		goto remove_dmar;
612 	}
613 
614 	if (no_aspm)
615 		pcie_no_aspm();
616 
617 	pci_acpi_add_bus_pm_notifier(device);
618 	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
619 
620 	if (hotadd) {
621 		pcibios_resource_survey_bus(root->bus);
622 		pci_assign_unassigned_root_bus_resources(root->bus);
623 		/*
624 		 * This is only called for the hotadd case. For the boot-time
625 		 * case, we need to wait until after PCI initialization in
626 		 * order to deal with IOAPICs mapped in on a PCI BAR.
627 		 *
628 		 * This is currently x86-specific, because acpi_ioapic_add()
629 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
630 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
631 		 * (see drivers/acpi/Kconfig).
632 		 */
633 		acpi_ioapic_add(root->device->handle);
634 	}
635 
636 	pci_lock_rescan_remove();
637 	pci_bus_add_devices(root->bus);
638 	pci_unlock_rescan_remove();
639 	return 1;
640 
641 remove_dmar:
642 	if (hotadd)
643 		dmar_device_remove(handle);
644 end:
645 	kfree(root);
646 	return result;
647 }
648 
649 static void acpi_pci_root_remove(struct acpi_device *device)
650 {
651 	struct acpi_pci_root *root = acpi_driver_data(device);
652 
653 	pci_lock_rescan_remove();
654 
655 	pci_stop_root_bus(root->bus);
656 
657 	pci_ioapic_remove(root);
658 	device_set_wakeup_capable(root->bus->bridge, false);
659 	pci_acpi_remove_bus_pm_notifier(device);
660 
661 	pci_remove_root_bus(root->bus);
662 	WARN_ON(acpi_ioapic_remove(root));
663 
664 	dmar_device_remove(device->handle);
665 
666 	pci_unlock_rescan_remove();
667 
668 	kfree(root);
669 }
670 
671 /*
672  * Following code to support acpi_pci_root_create() is copied from
673  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
674  * and ARM64.
675  */
676 static void acpi_pci_root_validate_resources(struct device *dev,
677 					     struct list_head *resources,
678 					     unsigned long type)
679 {
680 	LIST_HEAD(list);
681 	struct resource *res1, *res2, *root = NULL;
682 	struct resource_entry *tmp, *entry, *entry2;
683 
684 	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
685 	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
686 
687 	list_splice_init(resources, &list);
688 	resource_list_for_each_entry_safe(entry, tmp, &list) {
689 		bool free = false;
690 		resource_size_t end;
691 
692 		res1 = entry->res;
693 		if (!(res1->flags & type))
694 			goto next;
695 
696 		/* Exclude non-addressable range or non-addressable portion */
697 		end = min(res1->end, root->end);
698 		if (end <= res1->start) {
699 			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
700 				 res1);
701 			free = true;
702 			goto next;
703 		} else if (res1->end != end) {
704 			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
705 				 res1, (unsigned long long)end + 1,
706 				 (unsigned long long)res1->end);
707 			res1->end = end;
708 		}
709 
710 		resource_list_for_each_entry(entry2, resources) {
711 			res2 = entry2->res;
712 			if (!(res2->flags & type))
713 				continue;
714 
715 			/*
716 			 * I don't like throwing away windows because then
717 			 * our resources no longer match the ACPI _CRS, but
718 			 * the kernel resource tree doesn't allow overlaps.
719 			 */
720 			if (resource_union(res1, res2, res2)) {
721 				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
722 					 res2, res1);
723 				free = true;
724 				goto next;
725 			}
726 		}
727 
728 next:
729 		resource_list_del(entry);
730 		if (free)
731 			resource_list_free_entry(entry);
732 		else
733 			resource_list_add_tail(entry, resources);
734 	}
735 }
736 
737 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
738 			struct resource_entry *entry)
739 {
740 #ifdef PCI_IOBASE
741 	struct resource *res = entry->res;
742 	resource_size_t cpu_addr = res->start;
743 	resource_size_t pci_addr = cpu_addr - entry->offset;
744 	resource_size_t length = resource_size(res);
745 	unsigned long port;
746 
747 	if (pci_register_io_range(fwnode, cpu_addr, length))
748 		goto err;
749 
750 	port = pci_address_to_pio(cpu_addr);
751 	if (port == (unsigned long)-1)
752 		goto err;
753 
754 	res->start = port;
755 	res->end = port + length - 1;
756 	entry->offset = port - pci_addr;
757 
758 	if (pci_remap_iospace(res, cpu_addr) < 0)
759 		goto err;
760 
761 	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
762 	return;
763 err:
764 	res->flags |= IORESOURCE_DISABLED;
765 #endif
766 }
767 
768 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
769 {
770 	int ret;
771 	struct list_head *list = &info->resources;
772 	struct acpi_device *device = info->bridge;
773 	struct resource_entry *entry, *tmp;
774 	unsigned long flags;
775 
776 	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
777 	ret = acpi_dev_get_resources(device, list,
778 				     acpi_dev_filter_resource_type_cb,
779 				     (void *)flags);
780 	if (ret < 0)
781 		dev_warn(&device->dev,
782 			 "failed to parse _CRS method, error code %d\n", ret);
783 	else if (ret == 0)
784 		dev_dbg(&device->dev,
785 			"no IO and memory resources present in _CRS\n");
786 	else {
787 		resource_list_for_each_entry_safe(entry, tmp, list) {
788 			if (entry->res->flags & IORESOURCE_IO)
789 				acpi_pci_root_remap_iospace(&device->fwnode,
790 						entry);
791 
792 			if (entry->res->flags & IORESOURCE_DISABLED)
793 				resource_list_destroy_entry(entry);
794 			else
795 				entry->res->name = info->name;
796 		}
797 		acpi_pci_root_validate_resources(&device->dev, list,
798 						 IORESOURCE_MEM);
799 		acpi_pci_root_validate_resources(&device->dev, list,
800 						 IORESOURCE_IO);
801 	}
802 
803 	return ret;
804 }
805 
806 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
807 {
808 	struct resource_entry *entry, *tmp;
809 	struct resource *res, *conflict, *root = NULL;
810 
811 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
812 		res = entry->res;
813 		if (res->flags & IORESOURCE_MEM)
814 			root = &iomem_resource;
815 		else if (res->flags & IORESOURCE_IO)
816 			root = &ioport_resource;
817 		else
818 			continue;
819 
820 		/*
821 		 * Some legacy x86 host bridge drivers use iomem_resource and
822 		 * ioport_resource as default resource pool, skip it.
823 		 */
824 		if (res == root)
825 			continue;
826 
827 		conflict = insert_resource_conflict(root, res);
828 		if (conflict) {
829 			dev_info(&info->bridge->dev,
830 				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
831 				 res, conflict->name, conflict);
832 			resource_list_destroy_entry(entry);
833 		}
834 	}
835 }
836 
837 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
838 {
839 	struct resource *res;
840 	struct resource_entry *entry, *tmp;
841 
842 	if (!info)
843 		return;
844 
845 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
846 		res = entry->res;
847 		if (res->parent &&
848 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
849 			release_resource(res);
850 		resource_list_destroy_entry(entry);
851 	}
852 
853 	info->ops->release_info(info);
854 }
855 
856 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
857 {
858 	struct resource *res;
859 	struct resource_entry *entry;
860 
861 	resource_list_for_each_entry(entry, &bridge->windows) {
862 		res = entry->res;
863 		if (res->flags & IORESOURCE_IO)
864 			pci_unmap_iospace(res);
865 		if (res->parent &&
866 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
867 			release_resource(res);
868 	}
869 	__acpi_pci_root_release_info(bridge->release_data);
870 }
871 
872 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
873 				     struct acpi_pci_root_ops *ops,
874 				     struct acpi_pci_root_info *info,
875 				     void *sysdata)
876 {
877 	int ret, busnum = root->secondary.start;
878 	struct acpi_device *device = root->device;
879 	int node = acpi_get_node(device->handle);
880 	struct pci_bus *bus;
881 	struct pci_host_bridge *host_bridge;
882 	union acpi_object *obj;
883 
884 	info->root = root;
885 	info->bridge = device;
886 	info->ops = ops;
887 	INIT_LIST_HEAD(&info->resources);
888 	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
889 		 root->segment, busnum);
890 
891 	if (ops->init_info && ops->init_info(info))
892 		goto out_release_info;
893 	if (ops->prepare_resources)
894 		ret = ops->prepare_resources(info);
895 	else
896 		ret = acpi_pci_probe_root_resources(info);
897 	if (ret < 0)
898 		goto out_release_info;
899 
900 	pci_acpi_root_add_resources(info);
901 	pci_add_resource(&info->resources, &root->secondary);
902 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
903 				  sysdata, &info->resources);
904 	if (!bus)
905 		goto out_release_info;
906 
907 	host_bridge = to_pci_host_bridge(bus->bridge);
908 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
909 		host_bridge->native_pcie_hotplug = 0;
910 	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
911 		host_bridge->native_shpc_hotplug = 0;
912 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
913 		host_bridge->native_aer = 0;
914 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
915 		host_bridge->native_pme = 0;
916 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
917 		host_bridge->native_ltr = 0;
918 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
919 		host_bridge->native_dpc = 0;
920 
921 	/*
922 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
923 	 * exists and returns 0, we must preserve any PCI resource
924 	 * assignments made by firmware for this host bridge.
925 	 */
926 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
927 				DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
928 	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
929 		host_bridge->preserve_config = 1;
930 	ACPI_FREE(obj);
931 
932 	pci_scan_child_bus(bus);
933 	pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
934 				    info);
935 	if (node != NUMA_NO_NODE)
936 		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
937 	return bus;
938 
939 out_release_info:
940 	__acpi_pci_root_release_info(info);
941 	return NULL;
942 }
943 
944 void __init acpi_pci_root_init(void)
945 {
946 	acpi_hest_init();
947 	if (acpi_pci_disabled)
948 		return;
949 
950 	pci_acpi_crs_quirks();
951 	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
952 }
953