xref: /linux/drivers/acpi/pci_root.c (revision 2634682fdffd9ba6e74b76be8aa91cf8b2e05c41)
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 _COMPONENT		ACPI_PCI_COMPONENT
28 ACPI_MODULE_NAME("pci_root");
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 static DEFINE_MUTEX(osc_lock);
62 
63 /**
64  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
65  * @handle - the ACPI CA node in question.
66  *
67  * Note: we could make this API take a struct acpi_device * instead, but
68  * for now, it's more convenient to operate on an acpi_handle.
69  */
70 int acpi_is_root_bridge(acpi_handle handle)
71 {
72 	int ret;
73 	struct acpi_device *device;
74 
75 	ret = acpi_bus_get_device(handle, &device);
76 	if (ret)
77 		return 0;
78 
79 	ret = acpi_match_device_ids(device, root_device_ids);
80 	if (ret)
81 		return 0;
82 	else
83 		return 1;
84 }
85 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
86 
87 static acpi_status
88 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
89 {
90 	struct resource *res = data;
91 	struct acpi_resource_address64 address;
92 	acpi_status status;
93 
94 	status = acpi_resource_to_address64(resource, &address);
95 	if (ACPI_FAILURE(status))
96 		return AE_OK;
97 
98 	if ((address.address.address_length > 0) &&
99 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
100 		res->start = address.address.minimum;
101 		res->end = address.address.minimum + address.address.address_length - 1;
102 	}
103 
104 	return AE_OK;
105 }
106 
107 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
108 					     struct resource *res)
109 {
110 	acpi_status status;
111 
112 	res->start = -1;
113 	status =
114 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
115 				get_root_bridge_busnr_callback, res);
116 	if (ACPI_FAILURE(status))
117 		return status;
118 	if (res->start == -1)
119 		return AE_ERROR;
120 	return AE_OK;
121 }
122 
123 struct pci_osc_bit_struct {
124 	u32 bit;
125 	char *desc;
126 };
127 
128 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
129 	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
130 	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
131 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
132 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
133 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
134 	{ OSC_PCI_EDR_SUPPORT, "EDR" },
135 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
136 };
137 
138 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
139 	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
140 	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
141 	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
142 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
143 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
144 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
145 	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
146 };
147 
148 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
149 			    struct pci_osc_bit_struct *table, int size)
150 {
151 	char buf[80];
152 	int i, len = 0;
153 	struct pci_osc_bit_struct *entry;
154 
155 	buf[0] = '\0';
156 	for (i = 0, entry = table; i < size; i++, entry++)
157 		if (word & entry->bit)
158 			len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
159 					len ? " " : "", entry->desc);
160 
161 	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
162 }
163 
164 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
165 {
166 	decode_osc_bits(root, msg, word, pci_osc_support_bit,
167 			ARRAY_SIZE(pci_osc_support_bit));
168 }
169 
170 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
171 {
172 	decode_osc_bits(root, msg, word, pci_osc_control_bit,
173 			ARRAY_SIZE(pci_osc_control_bit));
174 }
175 
176 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
177 
178 static acpi_status acpi_pci_run_osc(acpi_handle handle,
179 				    const u32 *capbuf, u32 *retval)
180 {
181 	struct acpi_osc_context context = {
182 		.uuid_str = pci_osc_uuid_str,
183 		.rev = 1,
184 		.cap.length = 12,
185 		.cap.pointer = (void *)capbuf,
186 	};
187 	acpi_status status;
188 
189 	status = acpi_run_osc(handle, &context);
190 	if (ACPI_SUCCESS(status)) {
191 		*retval = *((u32 *)(context.ret.pointer + 8));
192 		kfree(context.ret.pointer);
193 	}
194 	return status;
195 }
196 
197 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
198 					u32 support,
199 					u32 *control)
200 {
201 	acpi_status status;
202 	u32 result, capbuf[3];
203 
204 	support &= OSC_PCI_SUPPORT_MASKS;
205 	support |= root->osc_support_set;
206 
207 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
208 	capbuf[OSC_SUPPORT_DWORD] = support;
209 	if (control) {
210 		*control &= OSC_PCI_CONTROL_MASKS;
211 		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
212 	} else {
213 		/* Run _OSC query only with existing controls. */
214 		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
215 	}
216 
217 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
218 	if (ACPI_SUCCESS(status)) {
219 		root->osc_support_set = support;
220 		if (control)
221 			*control = result;
222 	}
223 	return status;
224 }
225 
226 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
227 {
228 	acpi_status status;
229 
230 	mutex_lock(&osc_lock);
231 	status = acpi_pci_query_osc(root, flags, NULL);
232 	mutex_unlock(&osc_lock);
233 	return status;
234 }
235 
236 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
237 {
238 	struct acpi_pci_root *root;
239 	struct acpi_device *device;
240 
241 	if (acpi_bus_get_device(handle, &device) ||
242 	    acpi_match_device_ids(device, root_device_ids))
243 		return NULL;
244 
245 	root = acpi_driver_data(device);
246 
247 	return root;
248 }
249 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
250 
251 struct acpi_handle_node {
252 	struct list_head node;
253 	acpi_handle handle;
254 };
255 
256 /**
257  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
258  * @handle: the handle in question
259  *
260  * Given an ACPI CA handle, the desired PCI device is located in the
261  * list of PCI devices.
262  *
263  * If the device is found, its reference count is increased and this
264  * function returns a pointer to its data structure.  The caller must
265  * decrement the reference count by calling pci_dev_put().
266  * If no device is found, %NULL is returned.
267  */
268 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
269 {
270 	int dev, fn;
271 	unsigned long long adr;
272 	acpi_status status;
273 	acpi_handle phandle;
274 	struct pci_bus *pbus;
275 	struct pci_dev *pdev = NULL;
276 	struct acpi_handle_node *node, *tmp;
277 	struct acpi_pci_root *root;
278 	LIST_HEAD(device_list);
279 
280 	/*
281 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
282 	 */
283 	phandle = handle;
284 	while (!acpi_is_root_bridge(phandle)) {
285 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
286 		if (!node)
287 			goto out;
288 
289 		INIT_LIST_HEAD(&node->node);
290 		node->handle = phandle;
291 		list_add(&node->node, &device_list);
292 
293 		status = acpi_get_parent(phandle, &phandle);
294 		if (ACPI_FAILURE(status))
295 			goto out;
296 	}
297 
298 	root = acpi_pci_find_root(phandle);
299 	if (!root)
300 		goto out;
301 
302 	pbus = root->bus;
303 
304 	/*
305 	 * Now, walk back down the PCI device tree until we return to our
306 	 * original handle. Assumes that everything between the PCI root
307 	 * bridge and the device we're looking for must be a P2P bridge.
308 	 */
309 	list_for_each_entry(node, &device_list, node) {
310 		acpi_handle hnd = node->handle;
311 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
312 		if (ACPI_FAILURE(status))
313 			goto out;
314 		dev = (adr >> 16) & 0xffff;
315 		fn  = adr & 0xffff;
316 
317 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
318 		if (!pdev || hnd == handle)
319 			break;
320 
321 		pbus = pdev->subordinate;
322 		pci_dev_put(pdev);
323 
324 		/*
325 		 * This function may be called for a non-PCI device that has a
326 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
327 		 * case pdev->subordinate will be NULL for the parent.
328 		 */
329 		if (!pbus) {
330 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
331 			pdev = NULL;
332 			break;
333 		}
334 	}
335 out:
336 	list_for_each_entry_safe(node, tmp, &device_list, node)
337 		kfree(node);
338 
339 	return pdev;
340 }
341 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
342 
343 /**
344  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
345  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
346  * @mask: Mask of _OSC bits to request control of, place to store control mask.
347  * @req: Mask of _OSC bits the control of is essential to the caller.
348  *
349  * Run _OSC query for @mask and if that is successful, compare the returned
350  * mask of control bits with @req.  If all of the @req bits are set in the
351  * returned mask, run _OSC request for it.
352  *
353  * The variable at the @mask address may be modified regardless of whether or
354  * not the function returns success.  On success it will contain the mask of
355  * _OSC bits the BIOS has granted control of, but its contents are meaningless
356  * on failure.
357  **/
358 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
359 {
360 	struct acpi_pci_root *root;
361 	acpi_status status = AE_OK;
362 	u32 ctrl, capbuf[3];
363 
364 	if (!mask)
365 		return AE_BAD_PARAMETER;
366 
367 	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
368 	if ((ctrl & req) != req)
369 		return AE_TYPE;
370 
371 	root = acpi_pci_find_root(handle);
372 	if (!root)
373 		return AE_NOT_EXIST;
374 
375 	mutex_lock(&osc_lock);
376 
377 	*mask = ctrl | root->osc_control_set;
378 	/* No need to evaluate _OSC if the control was already granted. */
379 	if ((root->osc_control_set & ctrl) == ctrl)
380 		goto out;
381 
382 	/* Need to check the available controls bits before requesting them. */
383 	while (*mask) {
384 		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
385 		if (ACPI_FAILURE(status))
386 			goto out;
387 		if (ctrl == *mask)
388 			break;
389 		decode_osc_control(root, "platform does not support",
390 				   ctrl & ~(*mask));
391 		ctrl = *mask;
392 	}
393 
394 	if ((ctrl & req) != req) {
395 		decode_osc_control(root, "not requesting control; platform does not support",
396 				   req & ~(ctrl));
397 		status = AE_SUPPORT;
398 		goto out;
399 	}
400 
401 	capbuf[OSC_QUERY_DWORD] = 0;
402 	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
403 	capbuf[OSC_CONTROL_DWORD] = ctrl;
404 	status = acpi_pci_run_osc(handle, capbuf, mask);
405 	if (ACPI_SUCCESS(status))
406 		root->osc_control_set = *mask;
407 out:
408 	mutex_unlock(&osc_lock);
409 	return status;
410 }
411 EXPORT_SYMBOL(acpi_pci_osc_control_set);
412 
413 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
414 				 bool is_pcie)
415 {
416 	u32 support, control, requested;
417 	acpi_status status;
418 	struct acpi_device *device = root->device;
419 	acpi_handle handle = device->handle;
420 
421 	/*
422 	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
423 	 * been called successfully. We know the feature set supported by the
424 	 * platform, so avoid calling _OSC at all
425 	 */
426 	if (x86_apple_machine) {
427 		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
428 		decode_osc_control(root, "OS assumes control of",
429 				   root->osc_control_set);
430 		return;
431 	}
432 
433 	/*
434 	 * All supported architectures that use ACPI have support for
435 	 * PCI domains, so we indicate this in _OSC support capabilities.
436 	 */
437 	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
438 	support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
439 	if (pci_ext_cfg_avail())
440 		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
441 	if (pcie_aspm_support_enabled())
442 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
443 	if (pci_msi_enabled())
444 		support |= OSC_PCI_MSI_SUPPORT;
445 	if (IS_ENABLED(CONFIG_PCIE_EDR))
446 		support |= OSC_PCI_EDR_SUPPORT;
447 
448 	decode_osc_support(root, "OS supports", support);
449 	status = acpi_pci_osc_support(root, support);
450 	if (ACPI_FAILURE(status)) {
451 		*no_aspm = 1;
452 
453 		/* _OSC is optional for PCI host bridges */
454 		if ((status == AE_NOT_FOUND) && !is_pcie)
455 			return;
456 
457 		dev_info(&device->dev, "_OSC failed (%s)%s\n",
458 			 acpi_format_exception(status),
459 			 pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
460 		return;
461 	}
462 
463 	if (pcie_ports_disabled) {
464 		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
465 		return;
466 	}
467 
468 	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
469 		decode_osc_support(root, "not requesting OS control; OS requires",
470 				   ACPI_PCIE_REQ_SUPPORT);
471 		return;
472 	}
473 
474 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
475 		| OSC_PCI_EXPRESS_PME_CONTROL;
476 
477 	if (IS_ENABLED(CONFIG_PCIEASPM))
478 		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
479 
480 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
481 		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
482 
483 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
484 		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
485 
486 	if (pci_aer_available())
487 		control |= OSC_PCI_EXPRESS_AER_CONTROL;
488 
489 	/*
490 	 * Per the Downstream Port Containment Related Enhancements ECN to
491 	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
492 	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
493 	 * and EDR.
494 	 */
495 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
496 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
497 
498 	requested = control;
499 	status = acpi_pci_osc_control_set(handle, &control,
500 					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
501 	if (ACPI_SUCCESS(status)) {
502 		decode_osc_control(root, "OS now controls", control);
503 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
504 			/*
505 			 * We have ASPM control, but the FADT indicates that
506 			 * it's unsupported. Leave existing configuration
507 			 * intact and prevent the OS from touching it.
508 			 */
509 			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
510 			*no_aspm = 1;
511 		}
512 	} else {
513 		decode_osc_control(root, "OS requested", requested);
514 		decode_osc_control(root, "platform willing to grant", control);
515 		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
516 			acpi_format_exception(status));
517 
518 		/*
519 		 * We want to disable ASPM here, but aspm_disabled
520 		 * needs to remain in its state from boot so that we
521 		 * properly handle PCIe 1.1 devices.  So we set this
522 		 * flag here, to defer the action until after the ACPI
523 		 * root scan.
524 		 */
525 		*no_aspm = 1;
526 	}
527 }
528 
529 static int acpi_pci_root_add(struct acpi_device *device,
530 			     const struct acpi_device_id *not_used)
531 {
532 	unsigned long long segment, bus;
533 	acpi_status status;
534 	int result;
535 	struct acpi_pci_root *root;
536 	acpi_handle handle = device->handle;
537 	int no_aspm = 0;
538 	bool hotadd = system_state == SYSTEM_RUNNING;
539 	bool is_pcie;
540 
541 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
542 	if (!root)
543 		return -ENOMEM;
544 
545 	segment = 0;
546 	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
547 				       &segment);
548 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
549 		dev_err(&device->dev,  "can't evaluate _SEG\n");
550 		result = -ENODEV;
551 		goto end;
552 	}
553 
554 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
555 	root->secondary.flags = IORESOURCE_BUS;
556 	status = try_get_root_bridge_busnr(handle, &root->secondary);
557 	if (ACPI_FAILURE(status)) {
558 		/*
559 		 * We need both the start and end of the downstream bus range
560 		 * to interpret _CBA (MMCONFIG base address), so it really is
561 		 * supposed to be in _CRS.  If we don't find it there, all we
562 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
563 		 */
564 		root->secondary.end = 0xFF;
565 		dev_warn(&device->dev,
566 			 FW_BUG "no secondary bus range in _CRS\n");
567 		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
568 					       NULL, &bus);
569 		if (ACPI_SUCCESS(status))
570 			root->secondary.start = bus;
571 		else if (status == AE_NOT_FOUND)
572 			root->secondary.start = 0;
573 		else {
574 			dev_err(&device->dev, "can't evaluate _BBN\n");
575 			result = -ENODEV;
576 			goto end;
577 		}
578 	}
579 
580 	root->device = device;
581 	root->segment = segment & 0xFFFF;
582 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
583 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
584 	device->driver_data = root;
585 
586 	if (hotadd && dmar_device_add(handle)) {
587 		result = -ENXIO;
588 		goto end;
589 	}
590 
591 	pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
592 	       acpi_device_name(device), acpi_device_bid(device),
593 	       root->segment, &root->secondary);
594 
595 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
596 
597 	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
598 	negotiate_os_control(root, &no_aspm, is_pcie);
599 
600 	/*
601 	 * TBD: Need PCI interface for enumeration/configuration of roots.
602 	 */
603 
604 	/*
605 	 * Scan the Root Bridge
606 	 * --------------------
607 	 * Must do this prior to any attempt to bind the root device, as the
608 	 * PCI namespace does not get created until this call is made (and
609 	 * thus the root bridge's pci_dev does not exist).
610 	 */
611 	root->bus = pci_acpi_scan_root(root);
612 	if (!root->bus) {
613 		dev_err(&device->dev,
614 			"Bus %04x:%02x not present in PCI namespace\n",
615 			root->segment, (unsigned int)root->secondary.start);
616 		device->driver_data = NULL;
617 		result = -ENODEV;
618 		goto remove_dmar;
619 	}
620 
621 	if (no_aspm)
622 		pcie_no_aspm();
623 
624 	pci_acpi_add_bus_pm_notifier(device);
625 	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
626 
627 	if (hotadd) {
628 		pcibios_resource_survey_bus(root->bus);
629 		pci_assign_unassigned_root_bus_resources(root->bus);
630 		/*
631 		 * This is only called for the hotadd case. For the boot-time
632 		 * case, we need to wait until after PCI initialization in
633 		 * order to deal with IOAPICs mapped in on a PCI BAR.
634 		 *
635 		 * This is currently x86-specific, because acpi_ioapic_add()
636 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
637 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
638 		 * (see drivers/acpi/Kconfig).
639 		 */
640 		acpi_ioapic_add(root->device->handle);
641 	}
642 
643 	pci_lock_rescan_remove();
644 	pci_bus_add_devices(root->bus);
645 	pci_unlock_rescan_remove();
646 	return 1;
647 
648 remove_dmar:
649 	if (hotadd)
650 		dmar_device_remove(handle);
651 end:
652 	kfree(root);
653 	return result;
654 }
655 
656 static void acpi_pci_root_remove(struct acpi_device *device)
657 {
658 	struct acpi_pci_root *root = acpi_driver_data(device);
659 
660 	pci_lock_rescan_remove();
661 
662 	pci_stop_root_bus(root->bus);
663 
664 	pci_ioapic_remove(root);
665 	device_set_wakeup_capable(root->bus->bridge, false);
666 	pci_acpi_remove_bus_pm_notifier(device);
667 
668 	pci_remove_root_bus(root->bus);
669 	WARN_ON(acpi_ioapic_remove(root));
670 
671 	dmar_device_remove(device->handle);
672 
673 	pci_unlock_rescan_remove();
674 
675 	kfree(root);
676 }
677 
678 /*
679  * Following code to support acpi_pci_root_create() is copied from
680  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
681  * and ARM64.
682  */
683 static void acpi_pci_root_validate_resources(struct device *dev,
684 					     struct list_head *resources,
685 					     unsigned long type)
686 {
687 	LIST_HEAD(list);
688 	struct resource *res1, *res2, *root = NULL;
689 	struct resource_entry *tmp, *entry, *entry2;
690 
691 	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
692 	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
693 
694 	list_splice_init(resources, &list);
695 	resource_list_for_each_entry_safe(entry, tmp, &list) {
696 		bool free = false;
697 		resource_size_t end;
698 
699 		res1 = entry->res;
700 		if (!(res1->flags & type))
701 			goto next;
702 
703 		/* Exclude non-addressable range or non-addressable portion */
704 		end = min(res1->end, root->end);
705 		if (end <= res1->start) {
706 			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
707 				 res1);
708 			free = true;
709 			goto next;
710 		} else if (res1->end != end) {
711 			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
712 				 res1, (unsigned long long)end + 1,
713 				 (unsigned long long)res1->end);
714 			res1->end = end;
715 		}
716 
717 		resource_list_for_each_entry(entry2, resources) {
718 			res2 = entry2->res;
719 			if (!(res2->flags & type))
720 				continue;
721 
722 			/*
723 			 * I don't like throwing away windows because then
724 			 * our resources no longer match the ACPI _CRS, but
725 			 * the kernel resource tree doesn't allow overlaps.
726 			 */
727 			if (resource_overlaps(res1, res2)) {
728 				res2->start = min(res1->start, res2->start);
729 				res2->end = max(res1->end, res2->end);
730 				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
731 					 res2, res1);
732 				free = true;
733 				goto next;
734 			}
735 		}
736 
737 next:
738 		resource_list_del(entry);
739 		if (free)
740 			resource_list_free_entry(entry);
741 		else
742 			resource_list_add_tail(entry, resources);
743 	}
744 }
745 
746 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
747 			struct resource_entry *entry)
748 {
749 #ifdef PCI_IOBASE
750 	struct resource *res = entry->res;
751 	resource_size_t cpu_addr = res->start;
752 	resource_size_t pci_addr = cpu_addr - entry->offset;
753 	resource_size_t length = resource_size(res);
754 	unsigned long port;
755 
756 	if (pci_register_io_range(fwnode, cpu_addr, length))
757 		goto err;
758 
759 	port = pci_address_to_pio(cpu_addr);
760 	if (port == (unsigned long)-1)
761 		goto err;
762 
763 	res->start = port;
764 	res->end = port + length - 1;
765 	entry->offset = port - pci_addr;
766 
767 	if (pci_remap_iospace(res, cpu_addr) < 0)
768 		goto err;
769 
770 	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
771 	return;
772 err:
773 	res->flags |= IORESOURCE_DISABLED;
774 #endif
775 }
776 
777 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
778 {
779 	int ret;
780 	struct list_head *list = &info->resources;
781 	struct acpi_device *device = info->bridge;
782 	struct resource_entry *entry, *tmp;
783 	unsigned long flags;
784 
785 	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
786 	ret = acpi_dev_get_resources(device, list,
787 				     acpi_dev_filter_resource_type_cb,
788 				     (void *)flags);
789 	if (ret < 0)
790 		dev_warn(&device->dev,
791 			 "failed to parse _CRS method, error code %d\n", ret);
792 	else if (ret == 0)
793 		dev_dbg(&device->dev,
794 			"no IO and memory resources present in _CRS\n");
795 	else {
796 		resource_list_for_each_entry_safe(entry, tmp, list) {
797 			if (entry->res->flags & IORESOURCE_IO)
798 				acpi_pci_root_remap_iospace(&device->fwnode,
799 						entry);
800 
801 			if (entry->res->flags & IORESOURCE_DISABLED)
802 				resource_list_destroy_entry(entry);
803 			else
804 				entry->res->name = info->name;
805 		}
806 		acpi_pci_root_validate_resources(&device->dev, list,
807 						 IORESOURCE_MEM);
808 		acpi_pci_root_validate_resources(&device->dev, list,
809 						 IORESOURCE_IO);
810 	}
811 
812 	return ret;
813 }
814 
815 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
816 {
817 	struct resource_entry *entry, *tmp;
818 	struct resource *res, *conflict, *root = NULL;
819 
820 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
821 		res = entry->res;
822 		if (res->flags & IORESOURCE_MEM)
823 			root = &iomem_resource;
824 		else if (res->flags & IORESOURCE_IO)
825 			root = &ioport_resource;
826 		else
827 			continue;
828 
829 		/*
830 		 * Some legacy x86 host bridge drivers use iomem_resource and
831 		 * ioport_resource as default resource pool, skip it.
832 		 */
833 		if (res == root)
834 			continue;
835 
836 		conflict = insert_resource_conflict(root, res);
837 		if (conflict) {
838 			dev_info(&info->bridge->dev,
839 				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
840 				 res, conflict->name, conflict);
841 			resource_list_destroy_entry(entry);
842 		}
843 	}
844 }
845 
846 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
847 {
848 	struct resource *res;
849 	struct resource_entry *entry, *tmp;
850 
851 	if (!info)
852 		return;
853 
854 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
855 		res = entry->res;
856 		if (res->parent &&
857 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
858 			release_resource(res);
859 		resource_list_destroy_entry(entry);
860 	}
861 
862 	info->ops->release_info(info);
863 }
864 
865 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
866 {
867 	struct resource *res;
868 	struct resource_entry *entry;
869 
870 	resource_list_for_each_entry(entry, &bridge->windows) {
871 		res = entry->res;
872 		if (res->flags & IORESOURCE_IO)
873 			pci_unmap_iospace(res);
874 		if (res->parent &&
875 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
876 			release_resource(res);
877 	}
878 	__acpi_pci_root_release_info(bridge->release_data);
879 }
880 
881 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
882 				     struct acpi_pci_root_ops *ops,
883 				     struct acpi_pci_root_info *info,
884 				     void *sysdata)
885 {
886 	int ret, busnum = root->secondary.start;
887 	struct acpi_device *device = root->device;
888 	int node = acpi_get_node(device->handle);
889 	struct pci_bus *bus;
890 	struct pci_host_bridge *host_bridge;
891 	union acpi_object *obj;
892 
893 	info->root = root;
894 	info->bridge = device;
895 	info->ops = ops;
896 	INIT_LIST_HEAD(&info->resources);
897 	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
898 		 root->segment, busnum);
899 
900 	if (ops->init_info && ops->init_info(info))
901 		goto out_release_info;
902 	if (ops->prepare_resources)
903 		ret = ops->prepare_resources(info);
904 	else
905 		ret = acpi_pci_probe_root_resources(info);
906 	if (ret < 0)
907 		goto out_release_info;
908 
909 	pci_acpi_root_add_resources(info);
910 	pci_add_resource(&info->resources, &root->secondary);
911 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
912 				  sysdata, &info->resources);
913 	if (!bus)
914 		goto out_release_info;
915 
916 	host_bridge = to_pci_host_bridge(bus->bridge);
917 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
918 		host_bridge->native_pcie_hotplug = 0;
919 	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
920 		host_bridge->native_shpc_hotplug = 0;
921 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
922 		host_bridge->native_aer = 0;
923 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
924 		host_bridge->native_pme = 0;
925 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
926 		host_bridge->native_ltr = 0;
927 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
928 		host_bridge->native_dpc = 0;
929 
930 	/*
931 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
932 	 * exists and returns 0, we must preserve any PCI resource
933 	 * assignments made by firmware for this host bridge.
934 	 */
935 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
936 				DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
937 	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
938 		host_bridge->preserve_config = 1;
939 	ACPI_FREE(obj);
940 
941 	pci_scan_child_bus(bus);
942 	pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
943 				    info);
944 	if (node != NUMA_NO_NODE)
945 		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
946 	return bus;
947 
948 out_release_info:
949 	__acpi_pci_root_release_info(info);
950 	return NULL;
951 }
952 
953 void __init acpi_pci_root_init(void)
954 {
955 	acpi_hest_init();
956 	if (acpi_pci_disabled)
957 		return;
958 
959 	pci_acpi_crs_quirks();
960 	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
961 }
962