xref: /openbmc/linux/drivers/acpi/pci_root.c (revision 27ab1c1c)
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 static DEFINE_MUTEX(osc_lock);
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 	int ret;
71 	struct acpi_device *device;
72 
73 	ret = acpi_bus_get_device(handle, &device);
74 	if (ret)
75 		return 0;
76 
77 	ret = acpi_match_device_ids(device, root_device_ids);
78 	if (ret)
79 		return 0;
80 	else
81 		return 1;
82 }
83 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
84 
85 static acpi_status
86 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
87 {
88 	struct resource *res = data;
89 	struct acpi_resource_address64 address;
90 	acpi_status status;
91 
92 	status = acpi_resource_to_address64(resource, &address);
93 	if (ACPI_FAILURE(status))
94 		return AE_OK;
95 
96 	if ((address.address.address_length > 0) &&
97 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
98 		res->start = address.address.minimum;
99 		res->end = address.address.minimum + address.address.address_length - 1;
100 	}
101 
102 	return AE_OK;
103 }
104 
105 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
106 					     struct resource *res)
107 {
108 	acpi_status status;
109 
110 	res->start = -1;
111 	status =
112 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
113 				get_root_bridge_busnr_callback, res);
114 	if (ACPI_FAILURE(status))
115 		return status;
116 	if (res->start == -1)
117 		return AE_ERROR;
118 	return AE_OK;
119 }
120 
121 struct pci_osc_bit_struct {
122 	u32 bit;
123 	char *desc;
124 };
125 
126 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
127 	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
128 	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
129 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
130 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
131 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
132 	{ OSC_PCI_EDR_SUPPORT, "EDR" },
133 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
134 };
135 
136 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
137 	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
138 	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
139 	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
140 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
141 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
142 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
143 	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
144 };
145 
146 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
147 			    struct pci_osc_bit_struct *table, int size)
148 {
149 	char buf[80];
150 	int i, len = 0;
151 	struct pci_osc_bit_struct *entry;
152 
153 	buf[0] = '\0';
154 	for (i = 0, entry = table; i < size; i++, entry++)
155 		if (word & entry->bit)
156 			len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
157 					len ? " " : "", entry->desc);
158 
159 	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
160 }
161 
162 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
163 {
164 	decode_osc_bits(root, msg, word, pci_osc_support_bit,
165 			ARRAY_SIZE(pci_osc_support_bit));
166 }
167 
168 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
169 {
170 	decode_osc_bits(root, msg, word, pci_osc_control_bit,
171 			ARRAY_SIZE(pci_osc_control_bit));
172 }
173 
174 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
175 
176 static acpi_status acpi_pci_run_osc(acpi_handle handle,
177 				    const u32 *capbuf, u32 *retval)
178 {
179 	struct acpi_osc_context context = {
180 		.uuid_str = pci_osc_uuid_str,
181 		.rev = 1,
182 		.cap.length = 12,
183 		.cap.pointer = (void *)capbuf,
184 	};
185 	acpi_status status;
186 
187 	status = acpi_run_osc(handle, &context);
188 	if (ACPI_SUCCESS(status)) {
189 		*retval = *((u32 *)(context.ret.pointer + 8));
190 		kfree(context.ret.pointer);
191 	}
192 	return status;
193 }
194 
195 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
196 					u32 support,
197 					u32 *control)
198 {
199 	acpi_status status;
200 	u32 result, capbuf[3];
201 
202 	support &= OSC_PCI_SUPPORT_MASKS;
203 	support |= root->osc_support_set;
204 
205 	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
206 	capbuf[OSC_SUPPORT_DWORD] = support;
207 	if (control) {
208 		*control &= OSC_PCI_CONTROL_MASKS;
209 		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
210 	} else {
211 		/* Run _OSC query only with existing controls. */
212 		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
213 	}
214 
215 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
216 	if (ACPI_SUCCESS(status)) {
217 		root->osc_support_set = support;
218 		if (control)
219 			*control = result;
220 	}
221 	return status;
222 }
223 
224 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
225 {
226 	acpi_status status;
227 
228 	mutex_lock(&osc_lock);
229 	status = acpi_pci_query_osc(root, flags, NULL);
230 	mutex_unlock(&osc_lock);
231 	return status;
232 }
233 
234 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
235 {
236 	struct acpi_pci_root *root;
237 	struct acpi_device *device;
238 
239 	if (acpi_bus_get_device(handle, &device) ||
240 	    acpi_match_device_ids(device, root_device_ids))
241 		return NULL;
242 
243 	root = acpi_driver_data(device);
244 
245 	return root;
246 }
247 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
248 
249 struct acpi_handle_node {
250 	struct list_head node;
251 	acpi_handle handle;
252 };
253 
254 /**
255  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
256  * @handle: the handle in question
257  *
258  * Given an ACPI CA handle, the desired PCI device is located in the
259  * list of PCI devices.
260  *
261  * If the device is found, its reference count is increased and this
262  * function returns a pointer to its data structure.  The caller must
263  * decrement the reference count by calling pci_dev_put().
264  * If no device is found, %NULL is returned.
265  */
266 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
267 {
268 	int dev, fn;
269 	unsigned long long adr;
270 	acpi_status status;
271 	acpi_handle phandle;
272 	struct pci_bus *pbus;
273 	struct pci_dev *pdev = NULL;
274 	struct acpi_handle_node *node, *tmp;
275 	struct acpi_pci_root *root;
276 	LIST_HEAD(device_list);
277 
278 	/*
279 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
280 	 */
281 	phandle = handle;
282 	while (!acpi_is_root_bridge(phandle)) {
283 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
284 		if (!node)
285 			goto out;
286 
287 		INIT_LIST_HEAD(&node->node);
288 		node->handle = phandle;
289 		list_add(&node->node, &device_list);
290 
291 		status = acpi_get_parent(phandle, &phandle);
292 		if (ACPI_FAILURE(status))
293 			goto out;
294 	}
295 
296 	root = acpi_pci_find_root(phandle);
297 	if (!root)
298 		goto out;
299 
300 	pbus = root->bus;
301 
302 	/*
303 	 * Now, walk back down the PCI device tree until we return to our
304 	 * original handle. Assumes that everything between the PCI root
305 	 * bridge and the device we're looking for must be a P2P bridge.
306 	 */
307 	list_for_each_entry(node, &device_list, node) {
308 		acpi_handle hnd = node->handle;
309 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
310 		if (ACPI_FAILURE(status))
311 			goto out;
312 		dev = (adr >> 16) & 0xffff;
313 		fn  = adr & 0xffff;
314 
315 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
316 		if (!pdev || hnd == handle)
317 			break;
318 
319 		pbus = pdev->subordinate;
320 		pci_dev_put(pdev);
321 
322 		/*
323 		 * This function may be called for a non-PCI device that has a
324 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
325 		 * case pdev->subordinate will be NULL for the parent.
326 		 */
327 		if (!pbus) {
328 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
329 			pdev = NULL;
330 			break;
331 		}
332 	}
333 out:
334 	list_for_each_entry_safe(node, tmp, &device_list, node)
335 		kfree(node);
336 
337 	return pdev;
338 }
339 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
340 
341 /**
342  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
343  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
344  * @mask: Mask of _OSC bits to request control of, place to store control mask.
345  * @req: Mask of _OSC bits the control of is essential to the caller.
346  *
347  * Run _OSC query for @mask and if that is successful, compare the returned
348  * mask of control bits with @req.  If all of the @req bits are set in the
349  * returned mask, run _OSC request for it.
350  *
351  * The variable at the @mask address may be modified regardless of whether or
352  * not the function returns success.  On success it will contain the mask of
353  * _OSC bits the BIOS has granted control of, but its contents are meaningless
354  * on failure.
355  **/
356 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
357 {
358 	struct acpi_pci_root *root;
359 	acpi_status status = AE_OK;
360 	u32 ctrl, capbuf[3];
361 
362 	if (!mask)
363 		return AE_BAD_PARAMETER;
364 
365 	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
366 	if ((ctrl & req) != req)
367 		return AE_TYPE;
368 
369 	root = acpi_pci_find_root(handle);
370 	if (!root)
371 		return AE_NOT_EXIST;
372 
373 	mutex_lock(&osc_lock);
374 
375 	*mask = ctrl | root->osc_control_set;
376 	/* No need to evaluate _OSC if the control was already granted. */
377 	if ((root->osc_control_set & ctrl) == ctrl)
378 		goto out;
379 
380 	/* Need to check the available controls bits before requesting them. */
381 	while (*mask) {
382 		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
383 		if (ACPI_FAILURE(status))
384 			goto out;
385 		if (ctrl == *mask)
386 			break;
387 		decode_osc_control(root, "platform does not support",
388 				   ctrl & ~(*mask));
389 		ctrl = *mask;
390 	}
391 
392 	if ((ctrl & req) != req) {
393 		decode_osc_control(root, "not requesting control; platform does not support",
394 				   req & ~(ctrl));
395 		status = AE_SUPPORT;
396 		goto out;
397 	}
398 
399 	capbuf[OSC_QUERY_DWORD] = 0;
400 	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
401 	capbuf[OSC_CONTROL_DWORD] = ctrl;
402 	status = acpi_pci_run_osc(handle, capbuf, mask);
403 	if (ACPI_SUCCESS(status))
404 		root->osc_control_set = *mask;
405 out:
406 	mutex_unlock(&osc_lock);
407 	return status;
408 }
409 EXPORT_SYMBOL(acpi_pci_osc_control_set);
410 
411 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
412 				 bool is_pcie)
413 {
414 	u32 support, control, requested;
415 	acpi_status status;
416 	struct acpi_device *device = root->device;
417 	acpi_handle handle = device->handle;
418 
419 	/*
420 	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
421 	 * been called successfully. We know the feature set supported by the
422 	 * platform, so avoid calling _OSC at all
423 	 */
424 	if (x86_apple_machine) {
425 		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
426 		decode_osc_control(root, "OS assumes control of",
427 				   root->osc_control_set);
428 		return;
429 	}
430 
431 	/*
432 	 * All supported architectures that use ACPI have support for
433 	 * PCI domains, so we indicate this in _OSC support capabilities.
434 	 */
435 	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
436 	support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
437 	if (pci_ext_cfg_avail())
438 		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
439 	if (pcie_aspm_support_enabled())
440 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
441 	if (pci_msi_enabled())
442 		support |= OSC_PCI_MSI_SUPPORT;
443 	if (IS_ENABLED(CONFIG_PCIE_EDR))
444 		support |= OSC_PCI_EDR_SUPPORT;
445 
446 	decode_osc_support(root, "OS supports", support);
447 	status = acpi_pci_osc_support(root, support);
448 	if (ACPI_FAILURE(status)) {
449 		*no_aspm = 1;
450 
451 		/* _OSC is optional for PCI host bridges */
452 		if ((status == AE_NOT_FOUND) && !is_pcie)
453 			return;
454 
455 		dev_info(&device->dev, "_OSC failed (%s)%s\n",
456 			 acpi_format_exception(status),
457 			 pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
458 		return;
459 	}
460 
461 	if (pcie_ports_disabled) {
462 		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
463 		return;
464 	}
465 
466 	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
467 		decode_osc_support(root, "not requesting OS control; OS requires",
468 				   ACPI_PCIE_REQ_SUPPORT);
469 		return;
470 	}
471 
472 	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
473 		| OSC_PCI_EXPRESS_PME_CONTROL;
474 
475 	if (IS_ENABLED(CONFIG_PCIEASPM))
476 		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
477 
478 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
479 		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
480 
481 	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
482 		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
483 
484 	if (pci_aer_available())
485 		control |= OSC_PCI_EXPRESS_AER_CONTROL;
486 
487 	/*
488 	 * Per the Downstream Port Containment Related Enhancements ECN to
489 	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
490 	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
491 	 * and EDR.
492 	 */
493 	if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
494 		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
495 
496 	requested = control;
497 	status = acpi_pci_osc_control_set(handle, &control,
498 					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
499 	if (ACPI_SUCCESS(status)) {
500 		decode_osc_control(root, "OS now controls", control);
501 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
502 			/*
503 			 * We have ASPM control, but the FADT indicates that
504 			 * it's unsupported. Leave existing configuration
505 			 * intact and prevent the OS from touching it.
506 			 */
507 			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
508 			*no_aspm = 1;
509 		}
510 	} else {
511 		decode_osc_control(root, "OS requested", requested);
512 		decode_osc_control(root, "platform willing to grant", control);
513 		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
514 			acpi_format_exception(status));
515 
516 		/*
517 		 * We want to disable ASPM here, but aspm_disabled
518 		 * needs to remain in its state from boot so that we
519 		 * properly handle PCIe 1.1 devices.  So we set this
520 		 * flag here, to defer the action until after the ACPI
521 		 * root scan.
522 		 */
523 		*no_aspm = 1;
524 	}
525 }
526 
527 static int acpi_pci_root_add(struct acpi_device *device,
528 			     const struct acpi_device_id *not_used)
529 {
530 	unsigned long long segment, bus;
531 	acpi_status status;
532 	int result;
533 	struct acpi_pci_root *root;
534 	acpi_handle handle = device->handle;
535 	int no_aspm = 0;
536 	bool hotadd = system_state == SYSTEM_RUNNING;
537 	bool is_pcie;
538 
539 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
540 	if (!root)
541 		return -ENOMEM;
542 
543 	segment = 0;
544 	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
545 				       &segment);
546 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
547 		dev_err(&device->dev,  "can't evaluate _SEG\n");
548 		result = -ENODEV;
549 		goto end;
550 	}
551 
552 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
553 	root->secondary.flags = IORESOURCE_BUS;
554 	status = try_get_root_bridge_busnr(handle, &root->secondary);
555 	if (ACPI_FAILURE(status)) {
556 		/*
557 		 * We need both the start and end of the downstream bus range
558 		 * to interpret _CBA (MMCONFIG base address), so it really is
559 		 * supposed to be in _CRS.  If we don't find it there, all we
560 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
561 		 */
562 		root->secondary.end = 0xFF;
563 		dev_warn(&device->dev,
564 			 FW_BUG "no secondary bus range in _CRS\n");
565 		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
566 					       NULL, &bus);
567 		if (ACPI_SUCCESS(status))
568 			root->secondary.start = bus;
569 		else if (status == AE_NOT_FOUND)
570 			root->secondary.start = 0;
571 		else {
572 			dev_err(&device->dev, "can't evaluate _BBN\n");
573 			result = -ENODEV;
574 			goto end;
575 		}
576 	}
577 
578 	root->device = device;
579 	root->segment = segment & 0xFFFF;
580 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
581 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
582 	device->driver_data = root;
583 
584 	if (hotadd && dmar_device_add(handle)) {
585 		result = -ENXIO;
586 		goto end;
587 	}
588 
589 	pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
590 	       acpi_device_name(device), acpi_device_bid(device),
591 	       root->segment, &root->secondary);
592 
593 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
594 
595 	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
596 	negotiate_os_control(root, &no_aspm, is_pcie);
597 
598 	/*
599 	 * TBD: Need PCI interface for enumeration/configuration of roots.
600 	 */
601 
602 	/*
603 	 * Scan the Root Bridge
604 	 * --------------------
605 	 * Must do this prior to any attempt to bind the root device, as the
606 	 * PCI namespace does not get created until this call is made (and
607 	 * thus the root bridge's pci_dev does not exist).
608 	 */
609 	root->bus = pci_acpi_scan_root(root);
610 	if (!root->bus) {
611 		dev_err(&device->dev,
612 			"Bus %04x:%02x not present in PCI namespace\n",
613 			root->segment, (unsigned int)root->secondary.start);
614 		device->driver_data = NULL;
615 		result = -ENODEV;
616 		goto remove_dmar;
617 	}
618 
619 	if (no_aspm)
620 		pcie_no_aspm();
621 
622 	pci_acpi_add_bus_pm_notifier(device);
623 	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
624 
625 	if (hotadd) {
626 		pcibios_resource_survey_bus(root->bus);
627 		pci_assign_unassigned_root_bus_resources(root->bus);
628 		/*
629 		 * This is only called for the hotadd case. For the boot-time
630 		 * case, we need to wait until after PCI initialization in
631 		 * order to deal with IOAPICs mapped in on a PCI BAR.
632 		 *
633 		 * This is currently x86-specific, because acpi_ioapic_add()
634 		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
635 		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
636 		 * (see drivers/acpi/Kconfig).
637 		 */
638 		acpi_ioapic_add(root->device->handle);
639 	}
640 
641 	pci_lock_rescan_remove();
642 	pci_bus_add_devices(root->bus);
643 	pci_unlock_rescan_remove();
644 	return 1;
645 
646 remove_dmar:
647 	if (hotadd)
648 		dmar_device_remove(handle);
649 end:
650 	kfree(root);
651 	return result;
652 }
653 
654 static void acpi_pci_root_remove(struct acpi_device *device)
655 {
656 	struct acpi_pci_root *root = acpi_driver_data(device);
657 
658 	pci_lock_rescan_remove();
659 
660 	pci_stop_root_bus(root->bus);
661 
662 	pci_ioapic_remove(root);
663 	device_set_wakeup_capable(root->bus->bridge, false);
664 	pci_acpi_remove_bus_pm_notifier(device);
665 
666 	pci_remove_root_bus(root->bus);
667 	WARN_ON(acpi_ioapic_remove(root));
668 
669 	dmar_device_remove(device->handle);
670 
671 	pci_unlock_rescan_remove();
672 
673 	kfree(root);
674 }
675 
676 /*
677  * Following code to support acpi_pci_root_create() is copied from
678  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
679  * and ARM64.
680  */
681 static void acpi_pci_root_validate_resources(struct device *dev,
682 					     struct list_head *resources,
683 					     unsigned long type)
684 {
685 	LIST_HEAD(list);
686 	struct resource *res1, *res2, *root = NULL;
687 	struct resource_entry *tmp, *entry, *entry2;
688 
689 	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
690 	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
691 
692 	list_splice_init(resources, &list);
693 	resource_list_for_each_entry_safe(entry, tmp, &list) {
694 		bool free = false;
695 		resource_size_t end;
696 
697 		res1 = entry->res;
698 		if (!(res1->flags & type))
699 			goto next;
700 
701 		/* Exclude non-addressable range or non-addressable portion */
702 		end = min(res1->end, root->end);
703 		if (end <= res1->start) {
704 			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
705 				 res1);
706 			free = true;
707 			goto next;
708 		} else if (res1->end != end) {
709 			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
710 				 res1, (unsigned long long)end + 1,
711 				 (unsigned long long)res1->end);
712 			res1->end = end;
713 		}
714 
715 		resource_list_for_each_entry(entry2, resources) {
716 			res2 = entry2->res;
717 			if (!(res2->flags & type))
718 				continue;
719 
720 			/*
721 			 * I don't like throwing away windows because then
722 			 * our resources no longer match the ACPI _CRS, but
723 			 * the kernel resource tree doesn't allow overlaps.
724 			 */
725 			if (resource_union(res1, res2, res2)) {
726 				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
727 					 res2, res1);
728 				free = true;
729 				goto next;
730 			}
731 		}
732 
733 next:
734 		resource_list_del(entry);
735 		if (free)
736 			resource_list_free_entry(entry);
737 		else
738 			resource_list_add_tail(entry, resources);
739 	}
740 }
741 
742 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
743 			struct resource_entry *entry)
744 {
745 #ifdef PCI_IOBASE
746 	struct resource *res = entry->res;
747 	resource_size_t cpu_addr = res->start;
748 	resource_size_t pci_addr = cpu_addr - entry->offset;
749 	resource_size_t length = resource_size(res);
750 	unsigned long port;
751 
752 	if (pci_register_io_range(fwnode, cpu_addr, length))
753 		goto err;
754 
755 	port = pci_address_to_pio(cpu_addr);
756 	if (port == (unsigned long)-1)
757 		goto err;
758 
759 	res->start = port;
760 	res->end = port + length - 1;
761 	entry->offset = port - pci_addr;
762 
763 	if (pci_remap_iospace(res, cpu_addr) < 0)
764 		goto err;
765 
766 	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
767 	return;
768 err:
769 	res->flags |= IORESOURCE_DISABLED;
770 #endif
771 }
772 
773 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
774 {
775 	int ret;
776 	struct list_head *list = &info->resources;
777 	struct acpi_device *device = info->bridge;
778 	struct resource_entry *entry, *tmp;
779 	unsigned long flags;
780 
781 	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
782 	ret = acpi_dev_get_resources(device, list,
783 				     acpi_dev_filter_resource_type_cb,
784 				     (void *)flags);
785 	if (ret < 0)
786 		dev_warn(&device->dev,
787 			 "failed to parse _CRS method, error code %d\n", ret);
788 	else if (ret == 0)
789 		dev_dbg(&device->dev,
790 			"no IO and memory resources present in _CRS\n");
791 	else {
792 		resource_list_for_each_entry_safe(entry, tmp, list) {
793 			if (entry->res->flags & IORESOURCE_IO)
794 				acpi_pci_root_remap_iospace(&device->fwnode,
795 						entry);
796 
797 			if (entry->res->flags & IORESOURCE_DISABLED)
798 				resource_list_destroy_entry(entry);
799 			else
800 				entry->res->name = info->name;
801 		}
802 		acpi_pci_root_validate_resources(&device->dev, list,
803 						 IORESOURCE_MEM);
804 		acpi_pci_root_validate_resources(&device->dev, list,
805 						 IORESOURCE_IO);
806 	}
807 
808 	return ret;
809 }
810 
811 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
812 {
813 	struct resource_entry *entry, *tmp;
814 	struct resource *res, *conflict, *root = NULL;
815 
816 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
817 		res = entry->res;
818 		if (res->flags & IORESOURCE_MEM)
819 			root = &iomem_resource;
820 		else if (res->flags & IORESOURCE_IO)
821 			root = &ioport_resource;
822 		else
823 			continue;
824 
825 		/*
826 		 * Some legacy x86 host bridge drivers use iomem_resource and
827 		 * ioport_resource as default resource pool, skip it.
828 		 */
829 		if (res == root)
830 			continue;
831 
832 		conflict = insert_resource_conflict(root, res);
833 		if (conflict) {
834 			dev_info(&info->bridge->dev,
835 				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
836 				 res, conflict->name, conflict);
837 			resource_list_destroy_entry(entry);
838 		}
839 	}
840 }
841 
842 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
843 {
844 	struct resource *res;
845 	struct resource_entry *entry, *tmp;
846 
847 	if (!info)
848 		return;
849 
850 	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
851 		res = entry->res;
852 		if (res->parent &&
853 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
854 			release_resource(res);
855 		resource_list_destroy_entry(entry);
856 	}
857 
858 	info->ops->release_info(info);
859 }
860 
861 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
862 {
863 	struct resource *res;
864 	struct resource_entry *entry;
865 
866 	resource_list_for_each_entry(entry, &bridge->windows) {
867 		res = entry->res;
868 		if (res->flags & IORESOURCE_IO)
869 			pci_unmap_iospace(res);
870 		if (res->parent &&
871 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
872 			release_resource(res);
873 	}
874 	__acpi_pci_root_release_info(bridge->release_data);
875 }
876 
877 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
878 				     struct acpi_pci_root_ops *ops,
879 				     struct acpi_pci_root_info *info,
880 				     void *sysdata)
881 {
882 	int ret, busnum = root->secondary.start;
883 	struct acpi_device *device = root->device;
884 	int node = acpi_get_node(device->handle);
885 	struct pci_bus *bus;
886 	struct pci_host_bridge *host_bridge;
887 	union acpi_object *obj;
888 
889 	info->root = root;
890 	info->bridge = device;
891 	info->ops = ops;
892 	INIT_LIST_HEAD(&info->resources);
893 	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
894 		 root->segment, busnum);
895 
896 	if (ops->init_info && ops->init_info(info))
897 		goto out_release_info;
898 	if (ops->prepare_resources)
899 		ret = ops->prepare_resources(info);
900 	else
901 		ret = acpi_pci_probe_root_resources(info);
902 	if (ret < 0)
903 		goto out_release_info;
904 
905 	pci_acpi_root_add_resources(info);
906 	pci_add_resource(&info->resources, &root->secondary);
907 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
908 				  sysdata, &info->resources);
909 	if (!bus)
910 		goto out_release_info;
911 
912 	host_bridge = to_pci_host_bridge(bus->bridge);
913 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
914 		host_bridge->native_pcie_hotplug = 0;
915 	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
916 		host_bridge->native_shpc_hotplug = 0;
917 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
918 		host_bridge->native_aer = 0;
919 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
920 		host_bridge->native_pme = 0;
921 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
922 		host_bridge->native_ltr = 0;
923 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
924 		host_bridge->native_dpc = 0;
925 
926 	/*
927 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
928 	 * exists and returns 0, we must preserve any PCI resource
929 	 * assignments made by firmware for this host bridge.
930 	 */
931 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
932 				DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
933 	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
934 		host_bridge->preserve_config = 1;
935 	ACPI_FREE(obj);
936 
937 	pci_scan_child_bus(bus);
938 	pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
939 				    info);
940 	if (node != NUMA_NO_NODE)
941 		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
942 	return bus;
943 
944 out_release_info:
945 	__acpi_pci_root_release_info(info);
946 	return NULL;
947 }
948 
949 void __init acpi_pci_root_init(void)
950 {
951 	acpi_hest_init();
952 	if (acpi_pci_disabled)
953 		return;
954 
955 	pci_acpi_crs_quirks();
956 	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
957 }
958