xref: /openbmc/linux/drivers/acpi/pci_root.c (revision 8bdc2a19)
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 "internal.h"
26 
27 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
28 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
29 static int acpi_pci_root_add(struct acpi_device *device,
30 			     const struct acpi_device_id *not_used);
31 static void acpi_pci_root_remove(struct acpi_device *device);
32 
33 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
34 {
35 	acpiphp_check_host_bridge(adev);
36 	return 0;
37 }
38 
39 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
40 				| OSC_PCI_ASPM_SUPPORT \
41 				| OSC_PCI_CLOCK_PM_SUPPORT \
42 				| OSC_PCI_MSI_SUPPORT)
43 
44 static const struct acpi_device_id root_device_ids[] = {
45 	{"PNP0A03", 0},
46 	{"", 0},
47 };
48 
49 static struct acpi_scan_handler pci_root_handler = {
50 	.ids = root_device_ids,
51 	.attach = acpi_pci_root_add,
52 	.detach = acpi_pci_root_remove,
53 	.hotplug = {
54 		.enabled = true,
55 		.scan_dependent = acpi_pci_root_scan_dependent,
56 	},
57 };
58 
59 /**
60  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
61  * @handle:  the ACPI CA node in question.
62  *
63  * Note: we could make this API take a struct acpi_device * instead, but
64  * for now, it's more convenient to operate on an acpi_handle.
65  */
66 int acpi_is_root_bridge(acpi_handle handle)
67 {
68 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
69 	int ret;
70 
71 	if (!device)
72 		return 0;
73 
74 	ret = acpi_match_device_ids(device, root_device_ids);
75 	if (ret)
76 		return 0;
77 	else
78 		return 1;
79 }
80 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
81 
82 static acpi_status
83 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
84 {
85 	struct resource *res = data;
86 	struct acpi_resource_address64 address;
87 	acpi_status status;
88 
89 	status = acpi_resource_to_address64(resource, &address);
90 	if (ACPI_FAILURE(status))
91 		return AE_OK;
92 
93 	if ((address.address.address_length > 0) &&
94 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
95 		res->start = address.address.minimum;
96 		res->end = address.address.minimum + address.address.address_length - 1;
97 	}
98 
99 	return AE_OK;
100 }
101 
102 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
103 					     struct resource *res)
104 {
105 	acpi_status status;
106 
107 	res->start = -1;
108 	status =
109 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
110 				get_root_bridge_busnr_callback, res);
111 	if (ACPI_FAILURE(status))
112 		return status;
113 	if (res->start == -1)
114 		return AE_ERROR;
115 	return AE_OK;
116 }
117 
118 struct pci_osc_bit_struct {
119 	u32 bit;
120 	char *desc;
121 };
122 
123 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
124 	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
125 	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
126 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
127 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
128 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
129 	{ OSC_PCI_EDR_SUPPORT, "EDR" },
130 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
131 };
132 
133 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
134 	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
135 	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
136 	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
137 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
138 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
139 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
140 	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
141 };
142 
143 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
144 			    struct pci_osc_bit_struct *table, int size)
145 {
146 	char buf[80];
147 	int i, len = 0;
148 	struct pci_osc_bit_struct *entry;
149 
150 	buf[0] = '\0';
151 	for (i = 0, entry = table; i < size; i++, entry++)
152 		if (word & entry->bit)
153 			len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
154 					len ? " " : "", entry->desc);
155 
156 	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
157 }
158 
159 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
160 {
161 	decode_osc_bits(root, msg, word, pci_osc_support_bit,
162 			ARRAY_SIZE(pci_osc_support_bit));
163 }
164 
165 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
166 {
167 	decode_osc_bits(root, msg, word, pci_osc_control_bit,
168 			ARRAY_SIZE(pci_osc_control_bit));
169 }
170 
171 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
172 
173 static acpi_status acpi_pci_run_osc(acpi_handle handle,
174 				    const u32 *capbuf, u32 *retval)
175 {
176 	struct acpi_osc_context context = {
177 		.uuid_str = pci_osc_uuid_str,
178 		.rev = 1,
179 		.cap.length = 12,
180 		.cap.pointer = (void *)capbuf,
181 	};
182 	acpi_status status;
183 
184 	status = acpi_run_osc(handle, &context);
185 	if (ACPI_SUCCESS(status)) {
186 		*retval = *((u32 *)(context.ret.pointer + 8));
187 		kfree(context.ret.pointer);
188 	}
189 	return status;
190 }
191 
192 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
193 					u32 support,
194 					u32 *control)
195 {
196 	acpi_status status;
197 	u32 result, capbuf[3];
198 
199 	support |= root->osc_support_set;
200 
201 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
202 	capbuf[OSC_SUPPORT_DWORD] = support;
203 	capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
204 
205 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
206 	if (ACPI_SUCCESS(status)) {
207 		root->osc_support_set = support;
208 		*control = result;
209 	}
210 	return status;
211 }
212 
213 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
214 {
215 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
216 	struct acpi_pci_root *root;
217 
218 	if (!device || acpi_match_device_ids(device, root_device_ids))
219 		return NULL;
220 
221 	root = acpi_driver_data(device);
222 
223 	return root;
224 }
225 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
226 
227 struct acpi_handle_node {
228 	struct list_head node;
229 	acpi_handle handle;
230 };
231 
232 /**
233  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
234  * @handle: the handle in question
235  *
236  * Given an ACPI CA handle, the desired PCI device is located in the
237  * list of PCI devices.
238  *
239  * If the device is found, its reference count is increased and this
240  * function returns a pointer to its data structure.  The caller must
241  * decrement the reference count by calling pci_dev_put().
242  * If no device is found, %NULL is returned.
243  */
244 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
245 {
246 	int dev, fn;
247 	unsigned long long adr;
248 	acpi_status status;
249 	acpi_handle phandle;
250 	struct pci_bus *pbus;
251 	struct pci_dev *pdev = NULL;
252 	struct acpi_handle_node *node, *tmp;
253 	struct acpi_pci_root *root;
254 	LIST_HEAD(device_list);
255 
256 	/*
257 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
258 	 */
259 	phandle = handle;
260 	while (!acpi_is_root_bridge(phandle)) {
261 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
262 		if (!node)
263 			goto out;
264 
265 		INIT_LIST_HEAD(&node->node);
266 		node->handle = phandle;
267 		list_add(&node->node, &device_list);
268 
269 		status = acpi_get_parent(phandle, &phandle);
270 		if (ACPI_FAILURE(status))
271 			goto out;
272 	}
273 
274 	root = acpi_pci_find_root(phandle);
275 	if (!root)
276 		goto out;
277 
278 	pbus = root->bus;
279 
280 	/*
281 	 * Now, walk back down the PCI device tree until we return to our
282 	 * original handle. Assumes that everything between the PCI root
283 	 * bridge and the device we're looking for must be a P2P bridge.
284 	 */
285 	list_for_each_entry(node, &device_list, node) {
286 		acpi_handle hnd = node->handle;
287 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
288 		if (ACPI_FAILURE(status))
289 			goto out;
290 		dev = (adr >> 16) & 0xffff;
291 		fn  = adr & 0xffff;
292 
293 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
294 		if (!pdev || hnd == handle)
295 			break;
296 
297 		pbus = pdev->subordinate;
298 		pci_dev_put(pdev);
299 
300 		/*
301 		 * This function may be called for a non-PCI device that has a
302 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
303 		 * case pdev->subordinate will be NULL for the parent.
304 		 */
305 		if (!pbus) {
306 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
307 			pdev = NULL;
308 			break;
309 		}
310 	}
311 out:
312 	list_for_each_entry_safe(node, tmp, &device_list, node)
313 		kfree(node);
314 
315 	return pdev;
316 }
317 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
318 
319 /**
320  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
321  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
322  * @mask: Mask of _OSC bits to request control of, place to store control mask.
323  * @support: _OSC supported capability.
324  *
325  * Run _OSC query for @mask and if that is successful, compare the returned
326  * mask of control bits with @req.  If all of the @req bits are set in the
327  * returned mask, run _OSC request for it.
328  *
329  * The variable at the @mask address may be modified regardless of whether or
330  * not the function returns success.  On success it will contain the mask of
331  * _OSC bits the BIOS has granted control of, but its contents are meaningless
332  * on failure.
333  **/
334 static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 support)
335 {
336 	u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;
337 	struct acpi_pci_root *root;
338 	acpi_status status;
339 	u32 ctrl, capbuf[3];
340 
341 	if (!mask)
342 		return AE_BAD_PARAMETER;
343 
344 	root = acpi_pci_find_root(handle);
345 	if (!root)
346 		return AE_NOT_EXIST;
347 
348 	ctrl   = *mask;
349 	*mask |= root->osc_control_set;
350 
351 	/* Need to check the available controls bits before requesting them. */
352 	do {
353 		status = acpi_pci_query_osc(root, support, mask);
354 		if (ACPI_FAILURE(status))
355 			return status;
356 		if (ctrl == *mask)
357 			break;
358 		decode_osc_control(root, "platform does not support",
359 				   ctrl & ~(*mask));
360 		ctrl = *mask;
361 	} while (*mask);
362 
363 	/* No need to request _OSC if the control was already granted. */
364 	if ((root->osc_control_set & ctrl) == ctrl)
365 		return AE_OK;
366 
367 	if ((ctrl & req) != req) {
368 		decode_osc_control(root, "not requesting control; platform does not support",
369 				   req & ~(ctrl));
370 		return AE_SUPPORT;
371 	}
372 
373 	capbuf[OSC_QUERY_DWORD] = 0;
374 	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
375 	capbuf[OSC_CONTROL_DWORD] = ctrl;
376 	status = acpi_pci_run_osc(handle, capbuf, mask);
377 	if (ACPI_FAILURE(status))
378 		return status;
379 
380 	root->osc_control_set = *mask;
381 	return AE_OK;
382 }
383 
384 static u32 calculate_support(void)
385 {
386 	u32 support;
387 
388 	/*
389 	 * All supported architectures that use ACPI have support for
390 	 * PCI domains, so we indicate this in _OSC support capabilities.
391 	 */
392 	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
393 	support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
394 	if (pci_ext_cfg_avail())
395 		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
396 	if (pcie_aspm_support_enabled())
397 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
398 	if (pci_msi_enabled())
399 		support |= OSC_PCI_MSI_SUPPORT;
400 	if (IS_ENABLED(CONFIG_PCIE_EDR))
401 		support |= OSC_PCI_EDR_SUPPORT;
402 
403 	return support;
404 }
405 
406 static u32 calculate_control(void)
407 {
408 	u32 control;
409 
410 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
411 		| OSC_PCI_EXPRESS_PME_CONTROL;
412 
413 	if (IS_ENABLED(CONFIG_PCIEASPM))
414 		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
415 
416 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
417 		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
418 
419 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
420 		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
421 
422 	if (pci_aer_available())
423 		control |= OSC_PCI_EXPRESS_AER_CONTROL;
424 
425 	/*
426 	 * Per the Downstream Port Containment Related Enhancements ECN to
427 	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
428 	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
429 	 * and EDR.
430 	 */
431 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
432 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
433 
434 	return control;
435 }
436 
437 static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)
438 {
439 	struct acpi_device *device = root->device;
440 
441 	if (pcie_ports_disabled) {
442 		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
443 		return false;
444 	}
445 
446 	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
447 		decode_osc_support(root, "not requesting OS control; OS requires",
448 				   ACPI_PCIE_REQ_SUPPORT);
449 		return false;
450 	}
451 
452 	return true;
453 }
454 
455 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
456 				 bool is_pcie)
457 {
458 	u32 support, control = 0, requested = 0;
459 	acpi_status status;
460 	struct acpi_device *device = root->device;
461 	acpi_handle handle = device->handle;
462 
463 	/*
464 	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
465 	 * been called successfully. We know the feature set supported by the
466 	 * platform, so avoid calling _OSC at all
467 	 */
468 	if (x86_apple_machine) {
469 		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
470 		decode_osc_control(root, "OS assumes control of",
471 				   root->osc_control_set);
472 		return;
473 	}
474 
475 	support = calculate_support();
476 
477 	decode_osc_support(root, "OS supports", support);
478 
479 	if (os_control_query_checks(root, support))
480 		requested = control = calculate_control();
481 
482 	status = acpi_pci_osc_control_set(handle, &control, support);
483 	if (ACPI_SUCCESS(status)) {
484 		if (control)
485 			decode_osc_control(root, "OS now controls", control);
486 
487 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
488 			/*
489 			 * We have ASPM control, but the FADT indicates that
490 			 * it's unsupported. Leave existing configuration
491 			 * intact and prevent the OS from touching it.
492 			 */
493 			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
494 			*no_aspm = 1;
495 		}
496 	} else {
497 		/*
498 		 * We want to disable ASPM here, but aspm_disabled
499 		 * needs to remain in its state from boot so that we
500 		 * properly handle PCIe 1.1 devices.  So we set this
501 		 * flag here, to defer the action until after the ACPI
502 		 * root scan.
503 		 */
504 		*no_aspm = 1;
505 
506 		/* _OSC is optional for PCI host bridges */
507 		if ((status == AE_NOT_FOUND) && !is_pcie)
508 			return;
509 
510 		if (control) {
511 			decode_osc_control(root, "OS requested", requested);
512 			decode_osc_control(root, "platform willing to grant", control);
513 		}
514 
515 		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
516 			 acpi_format_exception(status));
517 	}
518 }
519 
520 static int acpi_pci_root_add(struct acpi_device *device,
521 			     const struct acpi_device_id *not_used)
522 {
523 	unsigned long long segment, bus;
524 	acpi_status status;
525 	int result;
526 	struct acpi_pci_root *root;
527 	acpi_handle handle = device->handle;
528 	int no_aspm = 0;
529 	bool hotadd = system_state == SYSTEM_RUNNING;
530 	bool is_pcie;
531 
532 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
533 	if (!root)
534 		return -ENOMEM;
535 
536 	segment = 0;
537 	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
538 				       &segment);
539 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
540 		dev_err(&device->dev,  "can't evaluate _SEG\n");
541 		result = -ENODEV;
542 		goto end;
543 	}
544 
545 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
546 	root->secondary.flags = IORESOURCE_BUS;
547 	status = try_get_root_bridge_busnr(handle, &root->secondary);
548 	if (ACPI_FAILURE(status)) {
549 		/*
550 		 * We need both the start and end of the downstream bus range
551 		 * to interpret _CBA (MMCONFIG base address), so it really is
552 		 * supposed to be in _CRS.  If we don't find it there, all we
553 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
554 		 */
555 		root->secondary.end = 0xFF;
556 		dev_warn(&device->dev,
557 			 FW_BUG "no secondary bus range in _CRS\n");
558 		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
559 					       NULL, &bus);
560 		if (ACPI_SUCCESS(status))
561 			root->secondary.start = bus;
562 		else if (status == AE_NOT_FOUND)
563 			root->secondary.start = 0;
564 		else {
565 			dev_err(&device->dev, "can't evaluate _BBN\n");
566 			result = -ENODEV;
567 			goto end;
568 		}
569 	}
570 
571 	root->device = device;
572 	root->segment = segment & 0xFFFF;
573 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
574 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
575 	device->driver_data = root;
576 
577 	if (hotadd && dmar_device_add(handle)) {
578 		result = -ENXIO;
579 		goto end;
580 	}
581 
582 	pr_info("%s [%s] (domain %04x %pR)\n",
583 	       acpi_device_name(device), acpi_device_bid(device),
584 	       root->segment, &root->secondary);
585 
586 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
587 
588 	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
589 	negotiate_os_control(root, &no_aspm, is_pcie);
590 
591 	/*
592 	 * TBD: Need PCI interface for enumeration/configuration of roots.
593 	 */
594 
595 	/*
596 	 * Scan the Root Bridge
597 	 * --------------------
598 	 * Must do this prior to any attempt to bind the root device, as the
599 	 * PCI namespace does not get created until this call is made (and
600 	 * thus the root bridge's pci_dev does not exist).
601 	 */
602 	root->bus = pci_acpi_scan_root(root);
603 	if (!root->bus) {
604 		dev_err(&device->dev,
605 			"Bus %04x:%02x not present in PCI namespace\n",
606 			root->segment, (unsigned int)root->secondary.start);
607 		device->driver_data = NULL;
608 		result = -ENODEV;
609 		goto remove_dmar;
610 	}
611 
612 	if (no_aspm)
613 		pcie_no_aspm();
614 
615 	pci_acpi_add_bus_pm_notifier(device);
616 	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
617 
618 	if (hotadd) {
619 		pcibios_resource_survey_bus(root->bus);
620 		pci_assign_unassigned_root_bus_resources(root->bus);
621 		/*
622 		 * This is only called for the hotadd case. For the boot-time
623 		 * case, we need to wait until after PCI initialization in
624 		 * order to deal with IOAPICs mapped in on a PCI BAR.
625 		 *
626 		 * This is currently x86-specific, because acpi_ioapic_add()
627 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
628 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
629 		 * (see drivers/acpi/Kconfig).
630 		 */
631 		acpi_ioapic_add(root->device->handle);
632 	}
633 
634 	pci_lock_rescan_remove();
635 	pci_bus_add_devices(root->bus);
636 	pci_unlock_rescan_remove();
637 	return 1;
638 
639 remove_dmar:
640 	if (hotadd)
641 		dmar_device_remove(handle);
642 end:
643 	kfree(root);
644 	return result;
645 }
646 
647 static void acpi_pci_root_remove(struct acpi_device *device)
648 {
649 	struct acpi_pci_root *root = acpi_driver_data(device);
650 
651 	pci_lock_rescan_remove();
652 
653 	pci_stop_root_bus(root->bus);
654 
655 	pci_ioapic_remove(root);
656 	device_set_wakeup_capable(root->bus->bridge, false);
657 	pci_acpi_remove_bus_pm_notifier(device);
658 
659 	pci_remove_root_bus(root->bus);
660 	WARN_ON(acpi_ioapic_remove(root));
661 
662 	dmar_device_remove(device->handle);
663 
664 	pci_unlock_rescan_remove();
665 
666 	kfree(root);
667 }
668 
669 /*
670  * Following code to support acpi_pci_root_create() is copied from
671  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
672  * and ARM64.
673  */
674 static void acpi_pci_root_validate_resources(struct device *dev,
675 					     struct list_head *resources,
676 					     unsigned long type)
677 {
678 	LIST_HEAD(list);
679 	struct resource *res1, *res2, *root = NULL;
680 	struct resource_entry *tmp, *entry, *entry2;
681 
682 	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
683 	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
684 
685 	list_splice_init(resources, &list);
686 	resource_list_for_each_entry_safe(entry, tmp, &list) {
687 		bool free = false;
688 		resource_size_t end;
689 
690 		res1 = entry->res;
691 		if (!(res1->flags & type))
692 			goto next;
693 
694 		/* Exclude non-addressable range or non-addressable portion */
695 		end = min(res1->end, root->end);
696 		if (end <= res1->start) {
697 			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
698 				 res1);
699 			free = true;
700 			goto next;
701 		} else if (res1->end != end) {
702 			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
703 				 res1, (unsigned long long)end + 1,
704 				 (unsigned long long)res1->end);
705 			res1->end = end;
706 		}
707 
708 		resource_list_for_each_entry(entry2, resources) {
709 			res2 = entry2->res;
710 			if (!(res2->flags & type))
711 				continue;
712 
713 			/*
714 			 * I don't like throwing away windows because then
715 			 * our resources no longer match the ACPI _CRS, but
716 			 * the kernel resource tree doesn't allow overlaps.
717 			 */
718 			if (resource_union(res1, res2, res2)) {
719 				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
720 					 res2, res1);
721 				free = true;
722 				goto next;
723 			}
724 		}
725 
726 next:
727 		resource_list_del(entry);
728 		if (free)
729 			resource_list_free_entry(entry);
730 		else
731 			resource_list_add_tail(entry, resources);
732 	}
733 }
734 
735 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
736 			struct resource_entry *entry)
737 {
738 #ifdef PCI_IOBASE
739 	struct resource *res = entry->res;
740 	resource_size_t cpu_addr = res->start;
741 	resource_size_t pci_addr = cpu_addr - entry->offset;
742 	resource_size_t length = resource_size(res);
743 	unsigned long port;
744 
745 	if (pci_register_io_range(fwnode, cpu_addr, length))
746 		goto err;
747 
748 	port = pci_address_to_pio(cpu_addr);
749 	if (port == (unsigned long)-1)
750 		goto err;
751 
752 	res->start = port;
753 	res->end = port + length - 1;
754 	entry->offset = port - pci_addr;
755 
756 	if (pci_remap_iospace(res, cpu_addr) < 0)
757 		goto err;
758 
759 	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
760 	return;
761 err:
762 	res->flags |= IORESOURCE_DISABLED;
763 #endif
764 }
765 
766 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
767 {
768 	int ret;
769 	struct list_head *list = &info->resources;
770 	struct acpi_device *device = info->bridge;
771 	struct resource_entry *entry, *tmp;
772 	unsigned long flags;
773 
774 	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
775 	ret = acpi_dev_get_resources(device, list,
776 				     acpi_dev_filter_resource_type_cb,
777 				     (void *)flags);
778 	if (ret < 0)
779 		dev_warn(&device->dev,
780 			 "failed to parse _CRS method, error code %d\n", ret);
781 	else if (ret == 0)
782 		dev_dbg(&device->dev,
783 			"no IO and memory resources present in _CRS\n");
784 	else {
785 		resource_list_for_each_entry_safe(entry, tmp, list) {
786 			if (entry->res->flags & IORESOURCE_IO)
787 				acpi_pci_root_remap_iospace(&device->fwnode,
788 						entry);
789 
790 			if (entry->res->flags & IORESOURCE_DISABLED)
791 				resource_list_destroy_entry(entry);
792 			else
793 				entry->res->name = info->name;
794 		}
795 		acpi_pci_root_validate_resources(&device->dev, list,
796 						 IORESOURCE_MEM);
797 		acpi_pci_root_validate_resources(&device->dev, list,
798 						 IORESOURCE_IO);
799 	}
800 
801 	return ret;
802 }
803 
804 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
805 {
806 	struct resource_entry *entry, *tmp;
807 	struct resource *res, *conflict, *root = NULL;
808 
809 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
810 		res = entry->res;
811 		if (res->flags & IORESOURCE_MEM)
812 			root = &iomem_resource;
813 		else if (res->flags & IORESOURCE_IO)
814 			root = &ioport_resource;
815 		else
816 			continue;
817 
818 		/*
819 		 * Some legacy x86 host bridge drivers use iomem_resource and
820 		 * ioport_resource as default resource pool, skip it.
821 		 */
822 		if (res == root)
823 			continue;
824 
825 		conflict = insert_resource_conflict(root, res);
826 		if (conflict) {
827 			dev_info(&info->bridge->dev,
828 				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
829 				 res, conflict->name, conflict);
830 			resource_list_destroy_entry(entry);
831 		}
832 	}
833 }
834 
835 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
836 {
837 	struct resource *res;
838 	struct resource_entry *entry, *tmp;
839 
840 	if (!info)
841 		return;
842 
843 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
844 		res = entry->res;
845 		if (res->parent &&
846 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
847 			release_resource(res);
848 		resource_list_destroy_entry(entry);
849 	}
850 
851 	info->ops->release_info(info);
852 }
853 
854 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
855 {
856 	struct resource *res;
857 	struct resource_entry *entry;
858 
859 	resource_list_for_each_entry(entry, &bridge->windows) {
860 		res = entry->res;
861 		if (res->flags & IORESOURCE_IO)
862 			pci_unmap_iospace(res);
863 		if (res->parent &&
864 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
865 			release_resource(res);
866 	}
867 	__acpi_pci_root_release_info(bridge->release_data);
868 }
869 
870 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
871 				     struct acpi_pci_root_ops *ops,
872 				     struct acpi_pci_root_info *info,
873 				     void *sysdata)
874 {
875 	int ret, busnum = root->secondary.start;
876 	struct acpi_device *device = root->device;
877 	int node = acpi_get_node(device->handle);
878 	struct pci_bus *bus;
879 	struct pci_host_bridge *host_bridge;
880 	union acpi_object *obj;
881 
882 	info->root = root;
883 	info->bridge = device;
884 	info->ops = ops;
885 	INIT_LIST_HEAD(&info->resources);
886 	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
887 		 root->segment, busnum);
888 
889 	if (ops->init_info && ops->init_info(info))
890 		goto out_release_info;
891 	if (ops->prepare_resources)
892 		ret = ops->prepare_resources(info);
893 	else
894 		ret = acpi_pci_probe_root_resources(info);
895 	if (ret < 0)
896 		goto out_release_info;
897 
898 	pci_acpi_root_add_resources(info);
899 	pci_add_resource(&info->resources, &root->secondary);
900 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
901 				  sysdata, &info->resources);
902 	if (!bus)
903 		goto out_release_info;
904 
905 	host_bridge = to_pci_host_bridge(bus->bridge);
906 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
907 		host_bridge->native_pcie_hotplug = 0;
908 	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
909 		host_bridge->native_shpc_hotplug = 0;
910 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
911 		host_bridge->native_aer = 0;
912 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
913 		host_bridge->native_pme = 0;
914 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
915 		host_bridge->native_ltr = 0;
916 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
917 		host_bridge->native_dpc = 0;
918 
919 	/*
920 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
921 	 * exists and returns 0, we must preserve any PCI resource
922 	 * assignments made by firmware for this host bridge.
923 	 */
924 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
925 				DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
926 	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
927 		host_bridge->preserve_config = 1;
928 	ACPI_FREE(obj);
929 
930 	acpi_dev_power_up_children_with_adr(device);
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 	if (acpi_pci_disabled)
947 		return;
948 
949 	pci_acpi_crs_quirks();
950 	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
951 }
952