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