xref: /linux/drivers/acpi/pci_root.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
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 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/types.h>
13 #include <linux/mutex.h>
14 #include <linux/pm.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/pci.h>
17 #include <linux/pci-acpi.h>
18 #include <linux/dmar.h>
19 #include <linux/acpi.h>
20 #include <linux/slab.h>
21 #include <linux/dmi.h>
22 #include <linux/platform_data/x86/apple.h>
23 #include <acpi/apei.h>	/* for acpi_hest_init() */
24 
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 	int ret;
69 	struct acpi_device *device;
70 
71 	ret = acpi_bus_get_device(handle, &device);
72 	if (ret)
73 		return 0;
74 
75 	ret = acpi_match_device_ids(device, root_device_ids);
76 	if (ret)
77 		return 0;
78 	else
79 		return 1;
80 }
81 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
82 
83 static acpi_status
84 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
85 {
86 	struct resource *res = data;
87 	struct acpi_resource_address64 address;
88 	acpi_status status;
89 
90 	status = acpi_resource_to_address64(resource, &address);
91 	if (ACPI_FAILURE(status))
92 		return AE_OK;
93 
94 	if ((address.address.address_length > 0) &&
95 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
96 		res->start = address.address.minimum;
97 		res->end = address.address.minimum + address.address.address_length - 1;
98 	}
99 
100 	return AE_OK;
101 }
102 
103 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
104 					     struct resource *res)
105 {
106 	acpi_status status;
107 
108 	res->start = -1;
109 	status =
110 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
111 				get_root_bridge_busnr_callback, res);
112 	if (ACPI_FAILURE(status))
113 		return status;
114 	if (res->start == -1)
115 		return AE_ERROR;
116 	return AE_OK;
117 }
118 
119 struct pci_osc_bit_struct {
120 	u32 bit;
121 	char *desc;
122 };
123 
124 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
125 	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
126 	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
127 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
128 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
129 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
130 	{ OSC_PCI_EDR_SUPPORT, "EDR" },
131 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
132 };
133 
134 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
135 	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
136 	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
137 	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
138 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
139 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
140 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
141 	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
142 };
143 
144 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
145 			    struct pci_osc_bit_struct *table, int size)
146 {
147 	char buf[80];
148 	int i, len = 0;
149 	struct pci_osc_bit_struct *entry;
150 
151 	buf[0] = '\0';
152 	for (i = 0, entry = table; i < size; i++, entry++)
153 		if (word & entry->bit)
154 			len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
155 					len ? " " : "", entry->desc);
156 
157 	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
158 }
159 
160 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
161 {
162 	decode_osc_bits(root, msg, word, pci_osc_support_bit,
163 			ARRAY_SIZE(pci_osc_support_bit));
164 }
165 
166 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
167 {
168 	decode_osc_bits(root, msg, word, pci_osc_control_bit,
169 			ARRAY_SIZE(pci_osc_control_bit));
170 }
171 
172 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
173 
174 static acpi_status acpi_pci_run_osc(acpi_handle handle,
175 				    const u32 *capbuf, u32 *retval)
176 {
177 	struct acpi_osc_context context = {
178 		.uuid_str = pci_osc_uuid_str,
179 		.rev = 1,
180 		.cap.length = 12,
181 		.cap.pointer = (void *)capbuf,
182 	};
183 	acpi_status status;
184 
185 	status = acpi_run_osc(handle, &context);
186 	if (ACPI_SUCCESS(status)) {
187 		*retval = *((u32 *)(context.ret.pointer + 8));
188 		kfree(context.ret.pointer);
189 	}
190 	return status;
191 }
192 
193 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
194 					u32 support,
195 					u32 *control)
196 {
197 	acpi_status status;
198 	u32 result, capbuf[3];
199 
200 	support &= OSC_PCI_SUPPORT_MASKS;
201 	support |= root->osc_support_set;
202 
203 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
204 	capbuf[OSC_SUPPORT_DWORD] = support;
205 	if (control) {
206 		*control &= OSC_PCI_CONTROL_MASKS;
207 		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
208 	} else {
209 		/* Run _OSC query only with existing controls. */
210 		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
211 	}
212 
213 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
214 	if (ACPI_SUCCESS(status)) {
215 		root->osc_support_set = support;
216 		if (control)
217 			*control = result;
218 	}
219 	return status;
220 }
221 
222 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
223 {
224 	return acpi_pci_query_osc(root, flags, NULL);
225 }
226 
227 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
228 {
229 	struct acpi_pci_root *root;
230 	struct acpi_device *device;
231 
232 	if (acpi_bus_get_device(handle, &device) ||
233 	    acpi_match_device_ids(device, root_device_ids))
234 		return NULL;
235 
236 	root = acpi_driver_data(device);
237 
238 	return root;
239 }
240 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
241 
242 struct acpi_handle_node {
243 	struct list_head node;
244 	acpi_handle handle;
245 };
246 
247 /**
248  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
249  * @handle: the handle in question
250  *
251  * Given an ACPI CA handle, the desired PCI device is located in the
252  * list of PCI devices.
253  *
254  * If the device is found, its reference count is increased and this
255  * function returns a pointer to its data structure.  The caller must
256  * decrement the reference count by calling pci_dev_put().
257  * If no device is found, %NULL is returned.
258  */
259 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
260 {
261 	int dev, fn;
262 	unsigned long long adr;
263 	acpi_status status;
264 	acpi_handle phandle;
265 	struct pci_bus *pbus;
266 	struct pci_dev *pdev = NULL;
267 	struct acpi_handle_node *node, *tmp;
268 	struct acpi_pci_root *root;
269 	LIST_HEAD(device_list);
270 
271 	/*
272 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
273 	 */
274 	phandle = handle;
275 	while (!acpi_is_root_bridge(phandle)) {
276 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
277 		if (!node)
278 			goto out;
279 
280 		INIT_LIST_HEAD(&node->node);
281 		node->handle = phandle;
282 		list_add(&node->node, &device_list);
283 
284 		status = acpi_get_parent(phandle, &phandle);
285 		if (ACPI_FAILURE(status))
286 			goto out;
287 	}
288 
289 	root = acpi_pci_find_root(phandle);
290 	if (!root)
291 		goto out;
292 
293 	pbus = root->bus;
294 
295 	/*
296 	 * Now, walk back down the PCI device tree until we return to our
297 	 * original handle. Assumes that everything between the PCI root
298 	 * bridge and the device we're looking for must be a P2P bridge.
299 	 */
300 	list_for_each_entry(node, &device_list, node) {
301 		acpi_handle hnd = node->handle;
302 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
303 		if (ACPI_FAILURE(status))
304 			goto out;
305 		dev = (adr >> 16) & 0xffff;
306 		fn  = adr & 0xffff;
307 
308 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
309 		if (!pdev || hnd == handle)
310 			break;
311 
312 		pbus = pdev->subordinate;
313 		pci_dev_put(pdev);
314 
315 		/*
316 		 * This function may be called for a non-PCI device that has a
317 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
318 		 * case pdev->subordinate will be NULL for the parent.
319 		 */
320 		if (!pbus) {
321 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
322 			pdev = NULL;
323 			break;
324 		}
325 	}
326 out:
327 	list_for_each_entry_safe(node, tmp, &device_list, node)
328 		kfree(node);
329 
330 	return pdev;
331 }
332 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
333 
334 /**
335  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
336  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
337  * @mask: Mask of _OSC bits to request control of, place to store control mask.
338  * @req: Mask of _OSC bits the control of is essential to the caller.
339  *
340  * Run _OSC query for @mask and if that is successful, compare the returned
341  * mask of control bits with @req.  If all of the @req bits are set in the
342  * returned mask, run _OSC request for it.
343  *
344  * The variable at the @mask address may be modified regardless of whether or
345  * not the function returns success.  On success it will contain the mask of
346  * _OSC bits the BIOS has granted control of, but its contents are meaningless
347  * on failure.
348  **/
349 static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
350 {
351 	struct acpi_pci_root *root;
352 	acpi_status status;
353 	u32 ctrl, capbuf[3];
354 
355 	if (!mask)
356 		return AE_BAD_PARAMETER;
357 
358 	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
359 	if ((ctrl & req) != req)
360 		return AE_TYPE;
361 
362 	root = acpi_pci_find_root(handle);
363 	if (!root)
364 		return AE_NOT_EXIST;
365 
366 	*mask = ctrl | root->osc_control_set;
367 	/* No need to evaluate _OSC if the control was already granted. */
368 	if ((root->osc_control_set & ctrl) == ctrl)
369 		return AE_OK;
370 
371 	/* Need to check the available controls bits before requesting them. */
372 	while (*mask) {
373 		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
374 		if (ACPI_FAILURE(status))
375 			return status;
376 		if (ctrl == *mask)
377 			break;
378 		decode_osc_control(root, "platform does not support",
379 				   ctrl & ~(*mask));
380 		ctrl = *mask;
381 	}
382 
383 	if ((ctrl & req) != req) {
384 		decode_osc_control(root, "not requesting control; platform does not support",
385 				   req & ~(ctrl));
386 		return AE_SUPPORT;
387 	}
388 
389 	capbuf[OSC_QUERY_DWORD] = 0;
390 	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
391 	capbuf[OSC_CONTROL_DWORD] = ctrl;
392 	status = acpi_pci_run_osc(handle, capbuf, mask);
393 	if (ACPI_FAILURE(status))
394 		return status;
395 
396 	root->osc_control_set = *mask;
397 	return AE_OK;
398 }
399 
400 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
401 				 bool is_pcie)
402 {
403 	u32 support, control, requested;
404 	acpi_status status;
405 	struct acpi_device *device = root->device;
406 	acpi_handle handle = device->handle;
407 
408 	/*
409 	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
410 	 * been called successfully. We know the feature set supported by the
411 	 * platform, so avoid calling _OSC at all
412 	 */
413 	if (x86_apple_machine) {
414 		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
415 		decode_osc_control(root, "OS assumes control of",
416 				   root->osc_control_set);
417 		return;
418 	}
419 
420 	/*
421 	 * All supported architectures that use ACPI have support for
422 	 * PCI domains, so we indicate this in _OSC support capabilities.
423 	 */
424 	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
425 	support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
426 	if (pci_ext_cfg_avail())
427 		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
428 	if (pcie_aspm_support_enabled())
429 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
430 	if (pci_msi_enabled())
431 		support |= OSC_PCI_MSI_SUPPORT;
432 	if (IS_ENABLED(CONFIG_PCIE_EDR))
433 		support |= OSC_PCI_EDR_SUPPORT;
434 
435 	decode_osc_support(root, "OS supports", support);
436 	status = acpi_pci_osc_support(root, support);
437 	if (ACPI_FAILURE(status)) {
438 		*no_aspm = 1;
439 
440 		/* _OSC is optional for PCI host bridges */
441 		if ((status == AE_NOT_FOUND) && !is_pcie)
442 			return;
443 
444 		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
445 			 acpi_format_exception(status));
446 		return;
447 	}
448 
449 	if (pcie_ports_disabled) {
450 		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
451 		return;
452 	}
453 
454 	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
455 		decode_osc_support(root, "not requesting OS control; OS requires",
456 				   ACPI_PCIE_REQ_SUPPORT);
457 		return;
458 	}
459 
460 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
461 		| OSC_PCI_EXPRESS_PME_CONTROL;
462 
463 	if (IS_ENABLED(CONFIG_PCIEASPM))
464 		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
465 
466 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
467 		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
468 
469 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
470 		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
471 
472 	if (pci_aer_available())
473 		control |= OSC_PCI_EXPRESS_AER_CONTROL;
474 
475 	/*
476 	 * Per the Downstream Port Containment Related Enhancements ECN to
477 	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
478 	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
479 	 * and EDR.
480 	 */
481 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
482 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
483 
484 	requested = control;
485 	status = acpi_pci_osc_control_set(handle, &control,
486 					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
487 	if (ACPI_SUCCESS(status)) {
488 		decode_osc_control(root, "OS now controls", control);
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 		decode_osc_control(root, "OS requested", requested);
500 		decode_osc_control(root, "platform willing to grant", control);
501 		dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
502 			acpi_format_exception(status));
503 
504 		/*
505 		 * We want to disable ASPM here, but aspm_disabled
506 		 * needs to remain in its state from boot so that we
507 		 * properly handle PCIe 1.1 devices.  So we set this
508 		 * flag here, to defer the action until after the ACPI
509 		 * root scan.
510 		 */
511 		*no_aspm = 1;
512 	}
513 }
514 
515 static int acpi_pci_root_add(struct acpi_device *device,
516 			     const struct acpi_device_id *not_used)
517 {
518 	unsigned long long segment, bus;
519 	acpi_status status;
520 	int result;
521 	struct acpi_pci_root *root;
522 	acpi_handle handle = device->handle;
523 	int no_aspm = 0;
524 	bool hotadd = system_state == SYSTEM_RUNNING;
525 	bool is_pcie;
526 
527 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
528 	if (!root)
529 		return -ENOMEM;
530 
531 	segment = 0;
532 	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
533 				       &segment);
534 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
535 		dev_err(&device->dev,  "can't evaluate _SEG\n");
536 		result = -ENODEV;
537 		goto end;
538 	}
539 
540 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
541 	root->secondary.flags = IORESOURCE_BUS;
542 	status = try_get_root_bridge_busnr(handle, &root->secondary);
543 	if (ACPI_FAILURE(status)) {
544 		/*
545 		 * We need both the start and end of the downstream bus range
546 		 * to interpret _CBA (MMCONFIG base address), so it really is
547 		 * supposed to be in _CRS.  If we don't find it there, all we
548 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
549 		 */
550 		root->secondary.end = 0xFF;
551 		dev_warn(&device->dev,
552 			 FW_BUG "no secondary bus range in _CRS\n");
553 		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
554 					       NULL, &bus);
555 		if (ACPI_SUCCESS(status))
556 			root->secondary.start = bus;
557 		else if (status == AE_NOT_FOUND)
558 			root->secondary.start = 0;
559 		else {
560 			dev_err(&device->dev, "can't evaluate _BBN\n");
561 			result = -ENODEV;
562 			goto end;
563 		}
564 	}
565 
566 	root->device = device;
567 	root->segment = segment & 0xFFFF;
568 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
569 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
570 	device->driver_data = root;
571 
572 	if (hotadd && dmar_device_add(handle)) {
573 		result = -ENXIO;
574 		goto end;
575 	}
576 
577 	pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
578 	       acpi_device_name(device), acpi_device_bid(device),
579 	       root->segment, &root->secondary);
580 
581 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
582 
583 	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
584 	negotiate_os_control(root, &no_aspm, is_pcie);
585 
586 	/*
587 	 * TBD: Need PCI interface for enumeration/configuration of roots.
588 	 */
589 
590 	/*
591 	 * Scan the Root Bridge
592 	 * --------------------
593 	 * Must do this prior to any attempt to bind the root device, as the
594 	 * PCI namespace does not get created until this call is made (and
595 	 * thus the root bridge's pci_dev does not exist).
596 	 */
597 	root->bus = pci_acpi_scan_root(root);
598 	if (!root->bus) {
599 		dev_err(&device->dev,
600 			"Bus %04x:%02x not present in PCI namespace\n",
601 			root->segment, (unsigned int)root->secondary.start);
602 		device->driver_data = NULL;
603 		result = -ENODEV;
604 		goto remove_dmar;
605 	}
606 
607 	if (no_aspm)
608 		pcie_no_aspm();
609 
610 	pci_acpi_add_bus_pm_notifier(device);
611 	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
612 
613 	if (hotadd) {
614 		pcibios_resource_survey_bus(root->bus);
615 		pci_assign_unassigned_root_bus_resources(root->bus);
616 		/*
617 		 * This is only called for the hotadd case. For the boot-time
618 		 * case, we need to wait until after PCI initialization in
619 		 * order to deal with IOAPICs mapped in on a PCI BAR.
620 		 *
621 		 * This is currently x86-specific, because acpi_ioapic_add()
622 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
623 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
624 		 * (see drivers/acpi/Kconfig).
625 		 */
626 		acpi_ioapic_add(root->device->handle);
627 	}
628 
629 	pci_lock_rescan_remove();
630 	pci_bus_add_devices(root->bus);
631 	pci_unlock_rescan_remove();
632 	return 1;
633 
634 remove_dmar:
635 	if (hotadd)
636 		dmar_device_remove(handle);
637 end:
638 	kfree(root);
639 	return result;
640 }
641 
642 static void acpi_pci_root_remove(struct acpi_device *device)
643 {
644 	struct acpi_pci_root *root = acpi_driver_data(device);
645 
646 	pci_lock_rescan_remove();
647 
648 	pci_stop_root_bus(root->bus);
649 
650 	pci_ioapic_remove(root);
651 	device_set_wakeup_capable(root->bus->bridge, false);
652 	pci_acpi_remove_bus_pm_notifier(device);
653 
654 	pci_remove_root_bus(root->bus);
655 	WARN_ON(acpi_ioapic_remove(root));
656 
657 	dmar_device_remove(device->handle);
658 
659 	pci_unlock_rescan_remove();
660 
661 	kfree(root);
662 }
663 
664 /*
665  * Following code to support acpi_pci_root_create() is copied from
666  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
667  * and ARM64.
668  */
669 static void acpi_pci_root_validate_resources(struct device *dev,
670 					     struct list_head *resources,
671 					     unsigned long type)
672 {
673 	LIST_HEAD(list);
674 	struct resource *res1, *res2, *root = NULL;
675 	struct resource_entry *tmp, *entry, *entry2;
676 
677 	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
678 	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
679 
680 	list_splice_init(resources, &list);
681 	resource_list_for_each_entry_safe(entry, tmp, &list) {
682 		bool free = false;
683 		resource_size_t end;
684 
685 		res1 = entry->res;
686 		if (!(res1->flags & type))
687 			goto next;
688 
689 		/* Exclude non-addressable range or non-addressable portion */
690 		end = min(res1->end, root->end);
691 		if (end <= res1->start) {
692 			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
693 				 res1);
694 			free = true;
695 			goto next;
696 		} else if (res1->end != end) {
697 			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
698 				 res1, (unsigned long long)end + 1,
699 				 (unsigned long long)res1->end);
700 			res1->end = end;
701 		}
702 
703 		resource_list_for_each_entry(entry2, resources) {
704 			res2 = entry2->res;
705 			if (!(res2->flags & type))
706 				continue;
707 
708 			/*
709 			 * I don't like throwing away windows because then
710 			 * our resources no longer match the ACPI _CRS, but
711 			 * the kernel resource tree doesn't allow overlaps.
712 			 */
713 			if (resource_union(res1, res2, res2)) {
714 				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
715 					 res2, res1);
716 				free = true;
717 				goto next;
718 			}
719 		}
720 
721 next:
722 		resource_list_del(entry);
723 		if (free)
724 			resource_list_free_entry(entry);
725 		else
726 			resource_list_add_tail(entry, resources);
727 	}
728 }
729 
730 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
731 			struct resource_entry *entry)
732 {
733 #ifdef PCI_IOBASE
734 	struct resource *res = entry->res;
735 	resource_size_t cpu_addr = res->start;
736 	resource_size_t pci_addr = cpu_addr - entry->offset;
737 	resource_size_t length = resource_size(res);
738 	unsigned long port;
739 
740 	if (pci_register_io_range(fwnode, cpu_addr, length))
741 		goto err;
742 
743 	port = pci_address_to_pio(cpu_addr);
744 	if (port == (unsigned long)-1)
745 		goto err;
746 
747 	res->start = port;
748 	res->end = port + length - 1;
749 	entry->offset = port - pci_addr;
750 
751 	if (pci_remap_iospace(res, cpu_addr) < 0)
752 		goto err;
753 
754 	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
755 	return;
756 err:
757 	res->flags |= IORESOURCE_DISABLED;
758 #endif
759 }
760 
761 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
762 {
763 	int ret;
764 	struct list_head *list = &info->resources;
765 	struct acpi_device *device = info->bridge;
766 	struct resource_entry *entry, *tmp;
767 	unsigned long flags;
768 
769 	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
770 	ret = acpi_dev_get_resources(device, list,
771 				     acpi_dev_filter_resource_type_cb,
772 				     (void *)flags);
773 	if (ret < 0)
774 		dev_warn(&device->dev,
775 			 "failed to parse _CRS method, error code %d\n", ret);
776 	else if (ret == 0)
777 		dev_dbg(&device->dev,
778 			"no IO and memory resources present in _CRS\n");
779 	else {
780 		resource_list_for_each_entry_safe(entry, tmp, list) {
781 			if (entry->res->flags & IORESOURCE_IO)
782 				acpi_pci_root_remap_iospace(&device->fwnode,
783 						entry);
784 
785 			if (entry->res->flags & IORESOURCE_DISABLED)
786 				resource_list_destroy_entry(entry);
787 			else
788 				entry->res->name = info->name;
789 		}
790 		acpi_pci_root_validate_resources(&device->dev, list,
791 						 IORESOURCE_MEM);
792 		acpi_pci_root_validate_resources(&device->dev, list,
793 						 IORESOURCE_IO);
794 	}
795 
796 	return ret;
797 }
798 
799 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
800 {
801 	struct resource_entry *entry, *tmp;
802 	struct resource *res, *conflict, *root = NULL;
803 
804 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
805 		res = entry->res;
806 		if (res->flags & IORESOURCE_MEM)
807 			root = &iomem_resource;
808 		else if (res->flags & IORESOURCE_IO)
809 			root = &ioport_resource;
810 		else
811 			continue;
812 
813 		/*
814 		 * Some legacy x86 host bridge drivers use iomem_resource and
815 		 * ioport_resource as default resource pool, skip it.
816 		 */
817 		if (res == root)
818 			continue;
819 
820 		conflict = insert_resource_conflict(root, res);
821 		if (conflict) {
822 			dev_info(&info->bridge->dev,
823 				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
824 				 res, conflict->name, conflict);
825 			resource_list_destroy_entry(entry);
826 		}
827 	}
828 }
829 
830 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
831 {
832 	struct resource *res;
833 	struct resource_entry *entry, *tmp;
834 
835 	if (!info)
836 		return;
837 
838 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
839 		res = entry->res;
840 		if (res->parent &&
841 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
842 			release_resource(res);
843 		resource_list_destroy_entry(entry);
844 	}
845 
846 	info->ops->release_info(info);
847 }
848 
849 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
850 {
851 	struct resource *res;
852 	struct resource_entry *entry;
853 
854 	resource_list_for_each_entry(entry, &bridge->windows) {
855 		res = entry->res;
856 		if (res->flags & IORESOURCE_IO)
857 			pci_unmap_iospace(res);
858 		if (res->parent &&
859 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
860 			release_resource(res);
861 	}
862 	__acpi_pci_root_release_info(bridge->release_data);
863 }
864 
865 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
866 				     struct acpi_pci_root_ops *ops,
867 				     struct acpi_pci_root_info *info,
868 				     void *sysdata)
869 {
870 	int ret, busnum = root->secondary.start;
871 	struct acpi_device *device = root->device;
872 	int node = acpi_get_node(device->handle);
873 	struct pci_bus *bus;
874 	struct pci_host_bridge *host_bridge;
875 	union acpi_object *obj;
876 
877 	info->root = root;
878 	info->bridge = device;
879 	info->ops = ops;
880 	INIT_LIST_HEAD(&info->resources);
881 	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
882 		 root->segment, busnum);
883 
884 	if (ops->init_info && ops->init_info(info))
885 		goto out_release_info;
886 	if (ops->prepare_resources)
887 		ret = ops->prepare_resources(info);
888 	else
889 		ret = acpi_pci_probe_root_resources(info);
890 	if (ret < 0)
891 		goto out_release_info;
892 
893 	pci_acpi_root_add_resources(info);
894 	pci_add_resource(&info->resources, &root->secondary);
895 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
896 				  sysdata, &info->resources);
897 	if (!bus)
898 		goto out_release_info;
899 
900 	host_bridge = to_pci_host_bridge(bus->bridge);
901 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
902 		host_bridge->native_pcie_hotplug = 0;
903 	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
904 		host_bridge->native_shpc_hotplug = 0;
905 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
906 		host_bridge->native_aer = 0;
907 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
908 		host_bridge->native_pme = 0;
909 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
910 		host_bridge->native_ltr = 0;
911 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
912 		host_bridge->native_dpc = 0;
913 
914 	/*
915 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
916 	 * exists and returns 0, we must preserve any PCI resource
917 	 * assignments made by firmware for this host bridge.
918 	 */
919 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
920 				DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
921 	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
922 		host_bridge->preserve_config = 1;
923 	ACPI_FREE(obj);
924 
925 	pci_scan_child_bus(bus);
926 	pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
927 				    info);
928 	if (node != NUMA_NO_NODE)
929 		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
930 	return bus;
931 
932 out_release_info:
933 	__acpi_pci_root_release_info(info);
934 	return NULL;
935 }
936 
937 void __init acpi_pci_root_init(void)
938 {
939 	acpi_hest_init();
940 	if (acpi_pci_disabled)
941 		return;
942 
943 	pci_acpi_crs_quirks();
944 	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
945 }
946